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Introduction: The purpose of our work was to study the characteristics of Headache associated with refractive errors (HARE) 1 , and to search for the correlation between headaches characteristics and some risk factors. We aimed also to assess the impact of these headaches on the quality of life of patients., Methods: A cross-sectional, retrospective, comparative study including 90 patients followed between August 2019 and January 2020. These patients were divided into two groups: Group 1 including patients presenting headaches due to uncorrected ametropia, and group 2 including control subjects. We studied HARE characteristics, the influence of certain risk factors (profession, triggers factors, characteristics of ametropia, and orthoptic abnormalities) on them, their evolution after one month of treatment, and their impact on patients' quality of life with the HIT-6 score., Results: Headaches due to ametropia were mainly chronic (20.9±15.76 months on average) progressive (100% of cases), daily (90% of cases) predominantly during the second half of the day (82% of cases). They were moderate (64% of cases), with a fronto-orbital topography in 52% of cases. Headaches were compression-type in 36% of cases (18 patients) and pressure-type in 64% (32 patients). The multivariate study retained prolonged screen working (P=0.013), combined ametropias (P=0.001), moderate hyperopia (P=0.01) and astigmatism (P=0.03) to be risk factors of HARE. Headaches induced a substantial to major impact on the quality of life in 68% (34 patients had a score greater than 55), the latter is significantly influenced by the presence of high myopia. After optical correction and orthoptic treatment, we noted an improvement in headache in 100% of cases. The multivariate analysis did not identify any independent factor that impact the evolution of headache at one month., Conclusion: HARE may influence life quality; it needs an appropriate treatment based on risk factor management. A healthy lifestyle in addition to adequate refractive error correction is essential in children and, sometimes in adults. Oculomotor abnormalities treatment leads to improve long term results., (Copyright © 2021 Elsevier Masson SAS. All rights reserved.)

Background: Few epidemiological data describe the prevalence of blindness and visual impairment in Senegal. Data from West African studies estimate blindness prevalence between 1.2 - 3.4% and that of visual impairment between 10.4 - 17.1%. IRIS Mundial (IM) is a non-governmental organization collaborating with l'Association St-Louisienne pour la Vue (ASV) to develop eye care in Senegal., Objective: Describe the relative importance of and causes of blindness and visual impairment in a population consulting for vision problems in the Senegalese region of St. Louis, to assist in planning of relevant eye care programs., Methods: Results from eye exams carried out by a team from IM in 2018 have been complied and analyzed., Results: In all, 1944 patients were examined (56.5% female). Some 25.7% of patients presented a visual impairment (22.5% moderate; 3.2% severe). Regarding refractive error, 15.3% of patients had myopia, 10.7% had hyperopia, 54.8% had astigmatism and 55.8% were presbyopic. Clinically significant cataracts is present in 17.4% of patients and glaucoma in 2.5%., Conclusion: Our data give a glimpse of the prevalence of visual impairment and ocular disease in St. Louis, Senegal. Uncorrected refractive error, cataracts and glaucoma are present in this population and may guide the planning of relevant eye care interventions., Competing Interests: Les auteurs ne déclarent aucun conflit d'intérêt., (Copyright © 2021 SFMTSI.)

Purpose: To estimate the prevalence, causes and risk factors of bilateral visual impairment in rural areas of Tianjin, China., Methods: A large population-based, cross-sectional study. A stratified random cluster sampling method was used to investigate 12 233 participants in all age groups living in rural Tianjin. Participants completed questionnaires and received professional ophthalmology examinations., Results: According to World Health Organization best-corrected visual acuity (BCVA) criteria, the crude prevalence of bilateral visual impairment (BCVA < 20/63), bilateral low vision (BCVA < 20/63 to ≥20/400) and bilateral blindness (BCVA < 20/400) was 2.53%, 2.40% and 0.14% (age- and gender-standardized prevalence was 1.86%, 1.76% and 0.11%). The prevalence increased with age and was higher in women than men. The most common causes of bilateral visual impairment in the total population were cataract (48.39%), refractive error/amblyopia (17.74%), age-related macular degeneration (AMD) (10.00%), diabetic retinopathy (5.81%) and glaucoma (3.87%). For participants younger than 50 years, refractive error/amblyopia was the leading cause of low vision and blindness, while cataract was the major cause in the participants over 50. Female gender, older age and self-reported diabetes were associated with increased risks of visual impairment., Conclusion: The age- and gender-standardized prevalence of low vision, especially in the older group (50+), was higher in this study compared with previous studies in China. Refractive error/amblyopia was the leading cause of bilateral visual impairment in younger group, while cataract was the primary cause in the older group. These findings will provide useful information for planning comprehensive eye healthcare programmes in China., (© 2020 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Purpose:  To summarize the association between diabetic retinopathy and refractory status as well as ocular biometric parameters; To review the theories of the protective effect of high myopia against diabetic retinopathy. Methods: A comprehensive literature search on MEDLINE, EMBASE, Web of Science and Scopus databases as well as reference list search, and systematic review of relevant publications.  Results: Myopia may delay the onset and progression of diabetic retinopathy. Increased axial length in myopia is associated with reduced risk of any diabetic retinopathy and vision-threatening diabetic retinopathy. The possible mechanisms for the protective effect of myopia against diabetic retinopathy may include posterior vitreous detachment, change in retinal blood flow and oxygen demand, choroidal thinning and altered cytokine profiles.  Conclusions: High myopia may be a protective factor against the onset and progression of diabetic retinopathy. Further studies about the mechanisms of how myopia, axial length and ocular biometrics influence the onset and progression of DR are needed.

Background: Many causes of vision impairment can be prevented or treated. With an ageing global population, the demands for eye health services are increasing. We estimated the prevalence and relative contribution of avoidable causes of blindness and vision impairment globally from 1990 to 2020. We aimed to compare the results with the World Health Assembly Global Action Plan (WHA GAP) target of a 25% global reduction from 2010 to 2019 in avoidable vision impairment, defined as cataract and undercorrected refractive error., Methods: We did a systematic review and meta-analysis of population-based surveys of eye disease from January, 1980, to October, 2018. We fitted hierarchical models to estimate prevalence (with 95% uncertainty intervals [UIs]) of moderate and severe vision impairment (MSVI; presenting visual acuity from <6/18 to 3/60) and blindness (<3/60 or less than 10° visual field around central fixation) by cause, age, region, and year. Because of data sparsity at younger ages, our analysis focused on adults aged 50 years and older., Findings: Global crude prevalence of avoidable vision impairment and blindness in adults aged 50 years and older did not change between 2010 and 2019 (percentage change -0·2% [95% UI -1·5 to 1·0]; 2019 prevalence 9·58 cases per 1000 people [95% IU 8·51 to 10·8], 2010 prevalence 96·0 cases per 1000 people [86·0 to 107·0]). Age-standardised prevalence of avoidable blindness decreased by -15·4% [-16·8 to -14·3], while avoidable MSVI showed no change (0·5% [-0·8 to 1·6]). However, the number of cases increased for both avoidable blindness (10·8% [8·9 to 12·4]) and MSVI (31·5% [30·0 to 33·1]). The leading global causes of blindness in those aged 50 years and older in 2020 were cataract (15·2 million cases [9% IU 12·7-18·0]), followed by glaucoma (3·6 million cases [2·8-4·4]), undercorrected refractive error (2·3 million cases [1·8-2·8]), age-related macular degeneration (1·8 million cases [1·3-2·4]), and diabetic retinopathy (0·86 million cases [0·59-1·23]). Leading causes of MSVI were undercorrected refractive error (86·1 million cases [74·2-101·0]) and cataract (78·8 million cases [67·2-91·4])., Interpretation: Results suggest eye care services contributed to the observed reduction of age-standardised rates of avoidable blindness but not of MSVI, and that the target in an ageing global population was not reached., Funding: Brien Holden Vision Institute, Fondation Théa, The Fred Hollows Foundation, Bill & Melinda Gates Foundation, Lions Clubs International Foundation, Sightsavers International, and University of Heidelberg., (Copyright © 2021 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Purpose: Refractive errors, particularly myopia, are common and a leading cause of blindness. This study aimed to explore associations between medications and refractive error in an aging adult cohort and to determine whether childhood-onset refractive errors predict future medication use to provide novel insights into disease mechanisms., Methods: The study compared the spherical equivalent values measured in 102,318 UK Biobank participants taking the 960 most commonly used medications. The strengths of associations were evaluated against the self-reported age of spectacle wear. The causality of refractive error changes was inferred using sensitivity and Mendelian randomization analyses., Results: Anti-glaucoma drugs were associated with 1 to 2 diopters greater myopic refraction, particularly in subjects who started wearing correction in the first two decades of life, potentially due to the association of higher intraocular pressure since early years with both myopia and, later in life, glaucoma. All classes of pain-control medications, including paracetamol, opiates, non-steroidal antiinflammatory drugs, and gabapentinoids, were associated with greater hyperopia (+0.68-1.15 diopters), after correction for deprivation, education, and polypharmacy and sensitivity analyses for common diagnoses. Oral hypoglycemics (metformin, gliburonide) were associated with myopia, as was allopurinol, and participants using bronchodilators (ipratropium and salbutamol) were more hyperopic., Conclusions: This study finds for the first time, to our knowledge, that medication use is associated with refractive error in adults. The novel finding that analgesics are associated with hyperopic refraction, and the possibility that multisite chronic pain predisposes to hyperopia, deserves further research. Some drugs, such as antihyperglycemic or bronchodilators, may directly alter refractive error. Intraocular pressure appears causative for myopia.

Purpose: This study describes the prevalence of visual impairment caused by uncorrected distance refractive error and the spectacle coverage in a large cohort of German children and adolescents. Furthermore, we determined the prevalence of amblyopia and amblyopia treatment., Methods: Optometrists carried out visual acuity (VA) testing, non-cycloplegic autorefraction, VA retesting with the refractive correction obtained by autorefraction, and if necessary subjective refraction and cover-test in 1,874 subjects (901 girls/973 boys), aged 3 to 16 years. Additionally, a questionnaire on the history of previous eye care was completed., Results: Distance visual impairment (VI) with VA worse than 6/18 Snellen in the better eye was present in 0.5% (95% confidence interval [95% CI]: 0.2% to 0.9%) of children. Logistic regression showed a significant positive association between VI and older age (OR = 1.21, P = 0.03). Gender differences were not found (P = 0.77). The spectacle coverage of all participants was 74.8% (95% CI: 65.2% to 82.8%). Amblyopia was found in 29 participants (1.5%; 95% CI: 1.0% to 2.2%) with no age or sex differences. The causes of unilateral amblyopia (27 cases, 93.1%) were anisometropia in 55.6% of children, strabismus in 25.9% and the combination of these factors in 18.5%. All children with bilateral amblyopia (2 cases, 6.9%) showed bilateral high ametropia. We observed 15 children with current amblyopia, who had been treated with occlusion therapy in the past (62.2%; 95% CI: 42.7% to 83.6%)., Conclusions: The prevalence of impaired VA caused by uncorrected refractive error and amblyopia is comparable with previous studies conducted in urban areas worldwide. Adding the measurement of refractive error to existing medical check-ups, possibly using autorefraction, would be desirable., (© 2020 The Authors. Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists.)

Background: Vision loss is an important public health issue in China, but a detailed understanding of national and regional trends in its prevalence and causes, which could inform health policy, has not been available. This study aimed to assess the prevalence, causes, and regional distribution of vision impairment and blindness in China in 1990 and 2019., Methods: Data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 were used to estimate the prevalence of moderate and severe vision impairment and blindness in China and compare with other Group of 20 (G20) countries. We used GBD methodology to systematically analyse all available demographic and epidemiological data at the provincial level in China. We compared the age-standardised prevalences across provinces, and the changes in proportion of vision loss attributable to various eye diseases in 1990 and 2019. We used two different counterfactual scenarios with respect to population structure and age-specific prevalence to assess the contribution of population growth and ageing to trends in vision loss., Findings: In 2019, the age-standardised prevalence was 2·57% (uncertainty interval [UI] 2·28-2·86) for moderate vision impairment, 0·25% (0·22-0·29) for severe vision impairment, and 0·48% (0·43-0·54) for blindness in China, which were all below the global average, but the prevalence of moderate and severe vision impairment had increased more rapidly than in other G20 countries from 1990 to 2019. The prevalence of vision loss increased with age, and the main causes of vision loss varied across age groups. The leading causes of vision impairment in China were uncorrected refractive error, cataract, and macular degeneration in both 1990 and 2019 in the overall population. From 1990 to 2019, the number of people with moderate vision impairment increased by 133·67% (from 19·65 to 45·92 million), those with severe vision impairment increased by 147·14% (from 1·89 to 4·67 million), and those with blindness increased by 64·35% (from 5·29 to 8·69 million); in each case, 20·16% of the increase could be explained by population growth. The contributions to these changes by population ageing were 87·22% for moderate vision impairment, 116·06% for severe vision impairment, and 99·22% for blindness, and the contributions by age-specific prevalence were 26·29% for moderate vision impairment, 10·91% for severe vision impairment, and -55·04% for blindness. The prevalence and specific causes of vision loss differed across provinces., Interpretation: Although a comprehensive national policy to prevent blindness is in place, public awareness of visual health needs improving, and reducing the prevalence of moderate and severe vision impairment should be prioritised in future work., Funding: China National Key Research and Development Programme and Beijing Municipal Special Funds for Medical Research on Public Welfare Development and Reform., (Copyright © 2020 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Background: This study aimed to assess the prevalence and causes of vision loss in sub-Saharan Africa (SSA) in 2015, compared with prior years, and to estimate expected values for 2020., Methods: A systematic review and meta-analysis assessed the prevalence of blindness (presenting distance visual acuity <3/60 in the better eye), moderate and severe vision impairment (MSVI; presenting distance visual acuity <6/18 but ≥3/60) and mild vision impairment (MVI; presenting distance visual acuity <6/12 and ≥6/18), and also near vision impairment (

Background: Visual impairment is the partial or complete loss of vision in which the presenting visual acuity lie between 6/18-no perceptions of light. In Kenya, little attention has been directed towards children vision and causes of visual impairment. Therefore, this study was designed to investigate the prevalence and causes of visual impairment in the children population of Kenya., Methods: This cross-sectional population-based study included 3400 (1800, 52.9% female) randomly selected children with a mean age of 12 ± 2 years (range 5-16 years). Visual acuity was taken using Snellens chart at 6 m. Anterior and posterior segment was assessed using slit lamp and indirect ophthalmoscope. The World Health Organization definition formed the baseline for calculating the mean prevalence of visual impairment., Results: Visual acuity measurements were available for 3240 (95.3%) participants. The mean prevalence of visual impairment based on pin-hole value was 1.7 ± 0.3% using World Health Organization definition. The prevalence of visual impairment based on presenting visual acuity value was 2.4 ± 0.7% using the World Health Organization definition. Multivariate analysis demonstrated that the presence of visual impairment on pin-hole increased significantly with increasing age (odds ratio 1.230, P = .021) and uncorrected refractive error (odds ratio 0.834, P = .032) according to World Health Organization definition. Cases of uncorrected refractive error remained the major cause for presenting visual impairment. Causes of visual impairment due to presenting visual acuity were nystagmus (14%), amblyopia (24%) and uncorrected refractive error (62%)., Conclusion: The prevalence of visual impairment in Kenya is associated with age. Uncorrected refractive error remains the major causes of visual impairment.

Purpose: To report the prevalence and causes of vision impairment (VI) in a population aged ≥40 years from a state-wide survey conducted in the northeastern state of Tripura, India., Methods: A population-based cross-sectional study was undertaken where a sample of 4500 people was selected using cluster random sampling methodology. A team comprising of an optometrist and field workers visited the households and conducted the eye examination that included visual acuity assessment, anterior segment examination including lens and fundus examination. VI was defined as presenting visual acuity <6/18 in the better eye and it included moderate VI (<6/18 to 6/60), severe VI (<6/60 to 3/60) and blindness (<3/60)., Results: In all, 4109/4500 (91.3%) subjects were examined from 90 clusters. Among those examined, 49.1% were men and 39.6% had no education. The age and gender-adjusted prevalence of VI was 8.7% (95% CI: 7.8-9.6). The prevalence of moderate VI was 6.2% (95% CI: 5.5-7.0), Severe VI was 1.0 (95% CI: 0.7-1.3) and blindness was 1.5% (95% CI: 1.1-1.9). On applying multiple regression analysis, the odds of having VI were higher in older age groups and among women. Overall, cataract was the leading cause of VI (54.5%) followed by uncorrected refractive errors (39.6%)., Conclusions: VI is common affecting nine out of every hundred people aged ≥40 years in the state of Tripura. Over 90% of which is due to avoidable causes such as cataract and uncorrected refractive errors. Provision of cataract surgery and spectacles may result in a substantial reduction in VI in Tripura.

Importance: There is substantial socioeconomic and individual burden from uncorrected refractive error (URE) and chronic ocular disease. Understanding the association of visual acuity (VA) reduction with URE and the adults most likely to benefit from refraction may help support clinical decision-making in ophthalmologic care and maximize patient outcomes., Objectives: To assess the magnitude of VA improvement associated with URE among adults under ophthalmic care who obtain low vision rehabilitation (LVR) services and identify the characteristics of the patients who are most likely to experience improvement., Design, Setting, and Participants: This retrospective case series assessed patients 20 years or older who were new to the LVR clinics from August 1, 2013, to December 31, 2015, and who had habitual VA between 20/40 and counting fingers (not including) and underwent refraction. Data analysis was performed from April 4, 2018, to December 20, 2019., Exposures: Patient demographics and clinical data, including habitual and refraction VA, refraction, and disease diagnosis. Habitual VA was categorized as mild (VA worse than 20/40 and at least 20/60), moderate (VA worse than 20/60 and better than 20/200), severe (VA 20/200 or worse and better than 20/500), and profound (VA 20/500 or worse) vision impairment (VI)., Main Outcomes and Measures: At least 2-line VA improvement and any VA improvement (≥1-line) by refraction., Results: Among the 2923 patients new to LVR clinics, 1773 (mean [SD] age, 70 [18.2] years; 1069 [60.3%] female) were included in these analyses. The mean habitual VA was 20/100 (mean [SD], 0.67 [0.36] logMAR). At least 2-line improvement was observed in 493 patients (27.8%), and any VA improvement was seen in 1023 patients (57.7%). At least 2-line improvement was observed in 54 patients (34.8%) with corneal disorders and was more likely seen among patients aged 40 to <65 years compared with those aged 20 to <40 years (odds ratio [OR], 1.57; 95% CI, 1.02-2.41), African American patients compared with white patients (OR, 1.41; 95% CI, 1.08-1.85), or patients with moderate VI compared with mild VI (OR, 1.36; 95% CI, 1.07-1.72)., Conclusions and Relevance: The findings suggest that URE is prevalent among patients with ocular disease and accessing LVR and that refractive evaluation should be considered for patients with ocular disease and reduced VA, especially working-age adults aged 40 to <65 years, African American patients, and those with moderate VI.

Objectives: To evaluate the diagnostic accuracy of rapid assessment of avoidable blindness (RAAB)., Design: Population-based diagnostic accuracy study., Methods: A total of 2145 (95.3%, 2145/2250) subjects aged 50 years and older who participated in the RAAB survey were included. All the recruited participants underwent ophthalmic examination according to the RAAB protocol and then were reexamined with instruments in a mobile eye clinic set up in a village center on the same day. Examination in the mobile clinic included standardized visual acuity (VA) tests using logMAR charts, refraction, slit-lamp biomicroscopy, and dilated fundal examination with a binocular indirect ophthalmoscope. Blindness and economic blindness were defined as VA in the better-seeing eye <3/60 and <6/60, respectively. Visual impairment (VI) was defined as VA <6/18 in the better eye. The primary cause of blindness and VI was defined according to the cause of VI in the participant's better eye., Main Outcome Measures: The sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and area under the curve (AUC) of receiver operating characteristics of RAAB for detection of blindness and the principal causes of VI., Results: A total of 1816 subjects (84.7%), including 686 men (37.8%) and 1130 women (62.2%), underwent ophthalmic examination in the mobile eye clinic. The mean (±standard deviation) age was 64.4 ± 9.6 years. The sensitivities, specificities, AUC, PLR, and NLR of RAAB were 90.3%, 99.3%, 0.948, 124.0, and 0.10, respectively, for detection of blindness (presenting visual acuity, PVA <3/60); 89.5%, 98.7%, 0.940, 69.2, and 0.11, respectively, for detection of economic blindness (PVA <6/60); and 90.3%, 97.7%, 0.940, 38.7, and 0.10, respectively, for detection of VI (PVA <6/18). The sensitivities, specificities, AUC, PLR, and NLR were 90.5%, 98.1%, 0.943, 48.1, and 0.10; and 60.4%, 98.7%, 0.796, 46.4, and 0.40 for detection of VI (PVA <6/18) owing to cataract and refractive error, respectively., Conclusion: The diagnostic performances of RAAB were high for detecting the prevalence of blindness, VI, and VI owing to cataract., (Copyright © 2019. Published by Elsevier Inc.)

Purpose : Recent global, regional and country-level prevalence estimates for blindness and vision impairment will be important when designing future public health policies. The aim of this paper is to contribute to this discussion by estimating the productivity impact of known effective interventions to treat all preventable cases of vision impairment at the global, regional and country-level up to 2050. We also provide estimates of potential reduction in the number of people with vision impairment, as well as averted vision-impaired years up to 2050. Methods : We combined recent estimates of the prevalence of blindness, distance and near vision impairment with the World Bank's World Development Indicators (WDI) and estimated the global, regional and country-level productivity gains up to 2030, 2040 and 2050 from known effective interventions, primarily cataract surgery and treated uncorrected refractive errors. The magnitude of productivity gains relative to baseline depended on population size, estimated current and future prevalence of vision impairment, level of economic development, long-term wage growth, and long-term real interest rates. Results : Globally, we estimate that the number of people affected by blindness could be reduced from the estimated 114.6 million by 2050 to 58.3 million. This would be associated with over one billion blind life-years averted and US$ 984 billion in global productivity gains. These numbers are dwarfed by the impact of interventions to reduce the prevalence of Moderate and Severe Vision Impairment (MSVI) [Presenting Acuity <20/60 to 20/400 in the better-seeing eye]. We estimate that the number of people affected by MSVI could be reduced by 435.8 million people to 147.9 million by 2050. This reduction would translate to over 9 billion MSVI -life-years avoided and US$ 17 trillion in productivity gains by 2050. While other causes of VI would not be possible to eliminate completely based on current known effective treatments, low-cost interventions to eliminate VI from uncorrected presbyopia would avert 1.2 billion presbyopia life-years and achieve US$ 1.05 trillion in productivity gains by 2050. In total, the global productivity gains for all three categories are estimated to be US$ 19 trillion by 2050. East Asia makes up the greatest share of productivity gains due to the high number of people affected by VI and the region's continuing economic growth. Conclusion : Implementation of currently known and effective treatments of avoidable blindness, MSVI and presbyopia would be expected to contribute significant productivity gains to the global economy at a fraction of the estimated costs to deliver them.

Objectives: To evaluate stereoacuity, fusional vergence amplitudes, and refractive errors in patients with attention-deficit hyperactivity disorder (ADHD)., Materials and Methods: Twenty-three patients who were newly diagnosed as having ADHD and had not started medication, and 48 children without ADHD were included. Retrospective data analysis of comprehensive eye examination, stereoacuity, and fusional vergence amplitudes of the patients were performed., Results: The mean age at ADHD diagnosis was 10.68±2.34 (7-16) years in the ADHD group (14 male, 9 female) and 12.23±2.16 (7-15) years in the control group (25 male, 23 female) patients (p=0.605). The mean stereoacuity was 142.14±152.65 (15-480) sec/arc in patients with ADHD and 46.3±44.11 (15-240) sec/arc in the control group (p<0.001). For ADHD patients, the mean convergence and divergence amplitudes at distance were 19.87±8.40 (6 to 38) prism diopter (PD) and -9.09±-4.34 (-4 to -25) PD, and 37.30±12.81 (14 to 70) PD and -13.13±-3.45 (-4 to -20) PD at near, respectively. The mean cycloplegic spherical equivalent was 1.06±1.13 (-1 to 4.63) diopter in ADHD patients, with 6 patients having significant refractive errors (hyperopia in 4 patients, astigmatism in 2 patients). There were no significant differences between groups in terms of spherical equivalents (p=0.358) or convergence and divergence amplitudes at distance (p=0.289 and p=0.492, respectively) or near (p=0.452 and p=0.127, respectively)., Conclusion: Fusional vergence amplitudes did not present significant difference, while the mean value of stereoacuity was significantly lower in newly diagnosed ADHD patients prior to treatment.

Background: Uncorrected refractive error (URE) is a major cause of vision impairment among children that impacts negatively on their lives including distresses. We aim to understand the disability-related distress among vision-impaired children due to URE in rural and semi-rural South Africa using qualitative techniques., Methods: Structured focus groups of children (aged 5-12 years old) with normal vision and vision impairment due to URE from four schools in Pinetown, KwaZulu Natal, South Africa, were performed (four mixed-gender group discussions and eight single gender group discussions). We recruited the study participants after the children underwent standardised vision screening. Criterion sampling was used when selecting study participants. The interviews were transcribed to identify meaning units and broken down to condensed meaning units, which were then grouped into megathemes. Themes were then generated., Results: Thirteen children with normal vision and 63 children with vision impairment due to URE participated in the twelve focus group discussions with 36 boys (47%) and 40 girls (53%). Twelve themes were generated. The megathemes were Loss of Self Confidence (number of themes (n) = 3), Loss of self-worth (n = 3), Loss of interconnection/ interaction with community (n = 2), Humiliation (n = 2) and Discrimination (n = 2)., Conclusions: We found that vision impairment due to URE can cause distress in different domains in children's life and further grouped them into different themes. The themes will be used for the development of a tool to assess disability-related distress among children with vision impairment due to URE. We also recommend that distresses caused by URE should be taken into consideration when designing eye care programmes for children., Competing Interests: The authors have declared that no competing interests exist.

Purpose: To provide a state-level prediction of the future burden of visual impairment and its causes in adults in the state of Georgia through 2050, accounting for age and race demographics., Design: A population prevalence projection study., Methods: Population data were obtained from the Georgia Governor's Office of Planning and Budget, stratified by age and race and applied to the Prevent Blindness America eye disease prevalence values. Prevalence of overall vision impairment and of blindness were calculated, in addition to the most common diseases., Results: In Georgia in 2050, there will be an estimated 226,000 visually impaired persons, and nearly 100,000 will be blind. Of those who are visually impaired or blind, 65% will be age 80 or older. There will be a greater than 350% projected increase in visual impairment in those 80 and older by 2050. A projected 1.7 million cases of cataract, 2.3 million of refractive error, over 250,000 cases of glaucoma, and 117,000 cases of macular degeneration will be present. The total caseload of diabetic retinopathy in adults age 40 and older is expected to increase by 150% between 2015 and 2040., Conclusion: The aging population and racial demographics impact projections for future eye disease burden, causing state-level projections to vary from national levels. As the demand for eye services increases, states must have individualized projections to evaluate the unique challenges they will face and prepare for enhanced service delivery, educational campaigns, and advocacy that match the need for their state., (Crown Copyright © 2019. Published by Elsevier Inc. All rights reserved.)

Purpose : To determine the magnitude and causes of blindness and low vision in children in Kinshasa. Methods : A study was conducted to carry out a survey in 96 health areas in Kinshasa city. Children aged less than 16 years old with supposed visual problems (Visual acuity < 6/18) were identified by volunteers and surveyors in households and were thereafter examined by two ophthalmologists. Prevalence and causes of blindness and low vision were determined. For each child, anatomic sites of abnormality, etiologic factors and avoidable causes responsible for visual impairment were considered. Results : Thirty-six children with bilateral visual impairment were identified, including 10 cases of blindness and 26 cases of low vision. The prevalence of blindness and low vision was, respectively, 0.08% [95% CI 0.04-0.14] and 0.19% [95% CI 0.13-0.28].Optic nerve and whole globe were the main anatomical sites responsible for blindness in, respectively, in 30% and 20%. Optic nerve atrophy and glaucoma were the leading causes of childhood blindness. The globe apparently normal (50%), uvea (12%) and cornea (12%) were the most common anatomic site responsible for low vision with refractive errors (42%) and uveitis (12%) as the main causes. Childhood and hereditary factors accounted for, respectively, 16.7% and 13.9% of low vision cases. Visual impairment was due to avoidable causes in 69.4% of children. Conclusion : Damage to the optic nerve and refractive errors were respectively the maincauses of blindness and low vision among children in Kinshasa.

Aim: To estimate the prevalence, causes and risk factors for presenting distance and near vision impairment (VI) in Trinidad and Tobago., Methods: This is a national, population-based survey using multistage, cluster random sampling in 120 clusters with probability-proportionate-to-size methods. Stage 1 included standardised, community-based measurement of visual acuity. Stage 2 invited all 4263 people aged ≥40 years for comprehensive clinic-based assessment. The Moorfields Eye Hospital Reading Centre graded fundus photographs and optical coherence tomography images independently., Results: The response rates were 84.2% (n=3589) (stage 1) and 65.4% (n=2790) (stage 2), including 97.1% with VI. The mean age was 57.2 (SD 11.9) years, 54.5% were female, 42.6% were of African descent and 39.0% were of South Asian descent. 11.88% (95% CI 10.88 to 12.97, n=468) had distance VI (logarithm of the minimum angle of resolution [logMAR] >0.30), including blindness (logMAR >1.30) in 0.73% (95% CI 0.48 to 0.97, n=31), after adjustment for study design, non-response, age, sex and municipality. The leading causes of blindness included glaucoma (31.7%, 95% CI 18.7 to 44.8), cataract (28.8%, 95% CI 12.6 to 45.1) and diabetic retinopathy (19.1%, 95% CI 4.2 to 34.0). The leading cause of distance VI was uncorrected refractive error (47.4%, 95% CI 43.4 to 51.3). Potentially avoidable VI accounted for 86.1% (95% CI 82.88 to 88.81), an estimated 176 323 cases in the national population aged ≥40 years. 22.3% (95% CI 20.7 to 23.8, n=695) had uncorrected near VI (logMAR >0.30 at 40 cm with distance acuity <0.30). Significant independent associations with distance VI included increasing age, diagnosed diabetes and unemployment. Significant independent associations with near VI included male sex, no health insurance and unemployment., Conclusions: Trinidad and Tobago's burden of avoidable VI exceeds that of other high-income countries. Population and health system priorities are identified to help close the gap., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

The Rapid Assessment of Avoidable Blindness, or RAAB, is a relatively simple and low-cost survey methodology to provide data on the prevalence and causes of visual loss. The aim of this article is to reflect on the achievements and challenges of RAAB, and to describe the future developments that are needed to ensure that it remains a relevant and widely used tool. To date, at least 331 RAABs have been undertaken in 79 countries, and these surveys provide an important source of information on visual loss at both the local and global level. A RAAB repository has been developed which includes the site and date of RAABs undertaken, and, where authors have agreed, the core indicators, reports or even raw data from the survey. This dataset has already been used for meta-analyses, and there are further opportunities for its use. Despite these achievements, there are core areas in which RAAB needs to be strengthened so that the full benefits of undertaking the survey can be reaped. Key developments of RAAB are underway, and will include greater use of mobile technologies using a cloud-based platform to enable both digital data collection, real-time survey reviews, reporting and analysis, and a greater emphasis on using the data for planning., Competing Interests: Competing interests: The Peek Vision Foundation (09919543) is a registered charity in England and Wales (1165960), with a wholly owned trading subsidiary, Peek Vision Ltd (09937174). MJB is a trustee of the Peek Vision Foundation and AB is the Chief Executive Officer of the Peek Vision Foundation and Peek Vision Ltd., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To test the hypothesis that refractive errors such as myopia and hyperopia cause an increased risk of age-related macular degeneration (AMD) and to quantify the degree of risk., Design: Two-sample Mendelian randomization analysis of data from a genome-wide association study., Participants: As instrumental variables for refractive error, 126 genome-wide significant genetic variants identified by the Consortium for Refractive Error and Myopia and 23andMe Inc. were chosen. The association with refractive error for the 126 variants was obtained from a published study for a sample of 95,505 European ancestry participants from UK Biobank. Association with AMD for the 126 genetic variants was determined from a genome-wide association study (GWAS) published by the International Age-related Macular Degeneration Genomics consortium of 33,526 (16,144 cases and 17,832 controls) European ancestry participants., Methods: Two-sample Mendelian randomization (MR) analysis was used to assess the causal role of refractive error on AMD risk, using the 126 genetic variants associated with refractive error as instrumental variables, under the assumption that the relationship between refractive error and AMD risk is linear., Main Outcome Measurement: the risk AMD was caused by a 1-diopter (D) change in refractive error., Results: MR analysis suggested that refractive error had very limited influence on the risk of AMD. Specifically, 1 D more hyperopic refractive error was associated with an odds ratio (OR) of 1.080 (95% confidence interval [CI], 1.021-1.142; P = 0.007) increased risk of AMD. MR-Egger, MR pleiotropy residual sum and outlier, weighted median, and Phenoscanner-based sensitivity analyses detected minimal evidence to suggest that this result was biased by horizontal pleiotropy., Conclusions: Under the assumption of a linear relationship between refractive error and the risk of AMD, myopia and hyperopia only minimally influence the causal risk for AMD. Thus, inconsistently reported strong associations between refractive error and AMD are likely to be the result of noncausal factors such as stochastic variation, confounding, or selection bias., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: This study sought to determine the quality of life (QOL) of patients with visual impairment in Federal Medical Centre, Owerri, Imo State, with a view to making recommendations for comprehensive management of patients., Materials and Methods: This was a hospital-based, cross-sectional study carried out at the Eye Clinic of Federal Medical Centre, Owerri, Imo State, Southeast Nigeria. New patients aged 18 years and older were consecutively recruited. Data were obtained using a semi-structured questionnaire and a World Health Organization's QOL Scale-Short Form (WHO-QOL-BREF). Participants had comprehensive eye examinations, and data were analyzed using the Statistical Package for the Social Sciences version 22., Results: One hundred and eight (53.7%) females and 93 (46.3%) males with a mean age of 55.92 ± 16.94 years participated in the study. The major causes of visual impairment were uncorrected refractive error, glaucoma, and cataract. Glaucoma (6.5%) was the leading cause of blindness. The overall QOL score was 61.10 ± 19.75, with the lowest mean score in the environmental domain. With increasing visual impairment, there was a 19.1% reduction in QOL. QOL was also affected by age, duration of visual impairment, and history of poor near vision., Conclusion: The leading causes of visual impairment and blindness in this study are avoidable and treatable. Health education, appropriate intervention, and support groups should be encouraged. This may serve to reduce the burden of visual impairment and improve the QOL of patients., Competing Interests: There are no conflicts of interest., (Copyright: © 2019 Middle East African Journal of Ophthalmology.)

Purpose: Albinism degrades visual function due to developmental disorders of the eye and visual pathways, larger refractive errors, absent binocularity and poor fixation control. Reading spectacles is commonly prescribed in our clinic and well tolerated. The purpose was to evaluate whether the accommodative response is typical or affected in comparison to a reference group., Methods: Twenty-two children with albinism (median: 13.5 years) and 12 controls (median: 13 years) underwent a full optometric examination and an objective accommodation measurement (WAM-5500 @ 6 Hz; Grand Seiko) in response to minus-lens-blur (-1, -2 and -3 D) and to a prolonged near viewing task (20 cm) for 5 min., Results: Children with albinism displayed less accommodation to minus lens-blur and during sustained near viewing (p < 0.001) compared to the reference group. Higher visual acuity correlates with a better accommodative response (r ≥ 0.5; p ≤ 0.04). The subjective and objective measures of accommodation did not correlate. The habitual reading distance was always closer than the point towards which the subjects with albinism seemed to accommodate according to the measurements at 20 cm., Conclusion: Children with albinism benefits from reading spectacles due to a combination of close habitual reading distance and a poor accommodation. Objective recording of accommodation is not critical for a correct judgement of near visual function. Children already wearing reading spectacles were those with least accommodative response., (© 2019 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Background: This study was undertaken to ascertain the current magnitude and causes of blindness and visual impairment in persons aged 50 years and over and to assess the impact of a 10-year eye care program in Sokoto State, Nigeria., Methods: A rapid assessment of avoidable blindness (RAAB) survey (in persons 50 years and over) was conducted in 2016. Participants were selected in Wurno health zone using a two-stage cluster randomized sampling with probability proportional to size. Operational definitions were based on RAAB and World Health Organization eye examination record definitions. Eye care program documents were reviewed and data from a baseline survey undertaken in 2005 were reanalyzed., Results: A response of 89.1% (2405 of 2700 participants) was obtained in the 2016 survey. With available correction, the unadjusted prevalence of blindness was 7.7% (95% confidence interval [CI]: 6.4, 8.9). The odds of blindness were 1.8 times higher in females than males (95% CI: 1.3, 2.4; P < 0.001). Major causes of blindness were cataract (48.9%) corneal disease (20.1%), glaucoma (10.3%), and uncorrected refractive error/aphakia (8.7%). The age- and sex-adjusted prevalence of blindness has declined from 11.6% (95% CI: 7.4, 17.0) in 2005 to 6.8% (95% CI: 5.6, 8.0%) in 2016., Conclusion: The blindness prevalence is high, and the major causes are avoidable in the health zone. The findings suggest that investments in the program over the last 10 years might have led to almost a halving in the prevalence of blindness in th e population. However, the small sample size of persons 50+ years from Wurno zone in the 2005 survey necessitate caution when comparing the 2005 and the 2016 surveys., Competing Interests: There are no conflicts of interest.

Purpose: The purpose is to study the clinical profile of amblyopia by age at diagnosis., Subjects and Methods: A retrospective chart review of 327 amblyopic patients over 7 years (September 2009-December 2016) was performed, divided by age at diagnosis into four groups: <3, 3-7, 8-15, and >15 years. Demographics, eye conditions and eye examination parameters including visual acuity (VA), refractive errors, and motility measurements were collected., Results: Mean age at diagnosis and follow-up time was 6.2 ± 6.1 years standard deviation (SD) and 12.4 months ± 20.6 SD, respectively. The most common overall cause of amblyopia was strabismus (37%) followed by anisometropia (36%). The main causes by age at diagnosis were: strabismus at <3 years, anisometropia at 3-7 years, anisometropia at 8-15 years, and mixed at >15 years. Significant improvement in VA with treatment was noted with age between 3 and 15 years (3-7 years, P = 0.001 and 8-15 years, P = 0.03)., Conclusions: Strabismus was the main cause of amblyopia at <3 years of age; anisometropia was more prevalent in older children (3-15 years). The fact that more than a quarter of our amblyopic patients were detected late (after the age of 8 years) underscores the need for expanded vision screening measures in young children., Competing Interests: There are no conflicts of interest.

Background/objectives: To analyze the surgical and sensory outcomes of intermittent exotropia according to refractive errors and the factors associated with surgical success., Subjects/methods: A total of 326 children were divided into three groups according to preoperative refractive error; hyperopic eyes with SE ≥+2D (hyperopic group), eyes with SE between -1D and +2D (emmetropic group), and myopic eyes with SE ≤-1D (myopic group). The surgical outcomes and the sensory outcomes measured by near and distant stereoacuity were compared among the three groups., Results: The surgical success rate in hyperopic group was significantly lower compared to myopic group at last follow-up (P = 0.012). Preoperative near stereopsis was not different among three groups, however, the distance stereopsis was significantly deteriorated in the hyperopic group compared to the other two groups (Titmus; P = 0.168, FD2; P < 0.001, DR; P = 0.048). There was postoperative improvement in both near and distant stereopsis in all three groups (Titmus; P = 0.009, FD2; P = 0.021, DR; P = 0.036) and no significant difference was found in the postoperative distant stereopsis among the three groups., Conclusions: Preoperative refractive error is a prognostic factor of surgical success in patients with intermittent exotropia. Patients with hyperopia achieved less favorable surgical outcome compared to myopic patients. The preoperative distant stereoacuity was decreased in hyperopic patients compared to myopic patients, which eventually improved after surgery and showed no significant difference at postoperative measurements.

Purpose: To study the prevalence of keratoconus (KC) and the topographical characteristics of the affected corneas in patients with refractive errors who were seeking refractive surgery in the Egyptian delta., Methods: A retrospective study covering four and half years (Jan 2012-June 2016) where the topographical data of 8124 participants were obtained from the records of a refractive center in the Nile delta region, Egypt. The diagnosis of KC was based on the Holladay criteria in one or both eyes, using the Pentacam scans, whereas grading of KC was based on the Amsler-Krumeich classification., Results: The prevalence of KC was 1.12% (91/8124 participants) with 95% confidence interval 0.91-1.3. Of all the affected cases, 5 cases (5.5%) had unilateral, and the other 86 cases (94.5%) had bilateral KC. The affected and unaffected subjects did not show any significant difference regarding gender. Sixty-eight (38.4%) eyes had stage 1 KC, 53 eyes (29.9%) had stage 2, 27 eyes (15.3%) had stage 3, and 29 eyes (16.4%) had stage 4 KC. It was most prevalent (1.2%) among cases with astigmatism (P < 0.001)., Conclusion: Keratoconus was found in 1.12% of patients seeking refractive surgery, with no gender preference. Most cases had bilateral affection. Astigmatism was the most common refractive error to be associated with keratoconus.

Precis: Glaucoma suspect was the most prevalent category in this study followed by glaucoma associated with acquired ocular anomaly and juvenile open-angle glaucoma. Primary congenital glaucoma was diagnosed in only 3% of the population studied., Purpose: To describe the prevalence and clinical characteristics of childhood glaucoma diagnosed over a 10-year period among patients aged 18 years or below who were seen at a tertiary care children's hospital using the new Childhood Glaucoma Research Network classification system., Methods: Medical records of all patients aged 18 years or below (n=108) who were diagnosed with glaucoma between January 1, 2008 through September 30, 2018 were reviewed. Data collected included demographics (age at diagnosis, sex, and family history of glaucoma), intraocular pressure, disc-to-cup ratio, retinal nerve fiber layer thickness, and refractive errors. Clinical characteristics of each patient were evaluated according to the criteria established by Childhood Glaucoma Research Network. Categorical distributional equivalence comparisons were performed using the Pearson χ test. A P-value <0.05 was defined as statistically significant., Results: A total of 108 patients with a diagnosis of childhood glaucoma or glaucoma suspect were included in this study. Sixty-four percent of these patients were males (P<0.0001). The mean age at the time of diagnosis was 7.07±5.4 years. "Glaucoma suspect" was the most prevalent category (46%, P=0.0002), followed by glaucoma associated with the acquired ocular anomaly (20%) and juvenile open-angle glaucoma (16%). Primary congenital glaucoma represented 3% and all these patients were males. Sixty-nine percent of the patients had bilateral involvement (P=0.0073). The highest intraocular pressure recorded in the study was 57 mm Hg, the largest cup-to-disc ratio was 0.96, and the lowest retinal nerve fiber layer measurement was 39 μm. Ninety-two percent of the patients had refractive errors and 85% of them had astigmatism., Conclusions: Establishing a pattern and the associated clinical characteristics of childhood glaucoma at tertiary care children's hospitals will help in developing collaborative research efforts and effective treatment/management strategies for children with these rare groups of disorders.

Purpose: To document the development of disc torsion., Methods: Consecutive disc photographs obtained at an interval of at least 1 year were reviewed retrospectively in 173 eyes of 173 Korean children. The angle of the vertical disc axis (AVDA) was measured in each fundus photograph with the fovea-disc center axis set at 0°. The associated change in the morphology of the optic disc was assessed by measuring the ratio of the horizontal to vertical disc diameters and the ratio of the maximum parapapillary atrophy width to vertical disc diameter. Eyes were divided into two groups with respect to the development of disc torsion: torsion and non-torsion group. Progressive torsion was defined as a change in AVDA between baseline and follow-up photographs beyond the coefficient of intraobserver repeatab ility. Factors associated with optic disc torsion were evaluated using logistic regression analysis., Results: Mean subject age and refractive error at the time of baseline fundus examination were 6.8 ± 1.7 (range, 2 to 11) years and 0.2 ± 2.6 (range, -6.0 to +5.5) diopters, respectively. Mean follow-up period was 44.8 ± 21.1 (range, 12 to 103) months. Forty-two eyes (24%) were classified as torsion group who showed changes in AVDA that were greater than the intraobserver measurement variability (4.5°) during the follow-up period. The development of optic disc torsion was associated with greater myopic shift, a decrease in horizontal to vertical disc diameters, and an increase in parapapillary atrophy width to vertical disc diameter., Conclusions: Progressive optic disc torsion was a common phenomenon in the children included in this study. Torsion occurred as the result of optic disc tilt in an oblique axis in most cases. The findings provide a framework for understanding torsion-related glaucomatous optic nerve damage., Competing Interests: No potential conflict of interest relevant to this article was reported., (© 2019 The Korean Ophthalmological Society.)

Chromatic pupillometry is an emerging modality in the assessment of retinal and optic nerve disorders. Herein, we evaluate the effect of low and moderate refractive errors on pupillary responses to blue- and red-light stimuli in a healthy older population. This study included 139 participants (≥50 years) grouped by refractive error: moderate myopes (>-6.0D and ≤-3.0D, n = 24), low myopes (>-3.0D and <-0.5D, n = 30), emmetropes (≥-0.5D and ≤0.5D, n = 31) and hyperopes (>0.5D and <6.0D, n = 54). Participants were exposed to logarithmically ramping-up blue (462 nm) and red (638 nm) light stimuli, designed to sequentially activate rods, cones and intrinsically-photosensitive retinal ganglion cells. Pupil size was assessed monocularly using infra-red pupillography. Baseline pupil diameter correlated inversely with spherical equivalent (R = -0.26, P < 0.01), and positively with axial length (R = 0.37, P < 0.01) and anterior chamber depth (R = 0.43, P < 0.01). Baseline-adjusted pupillary constriction amplitudes to blue light did not differ between groups (P = 0.45), while constriction amplitudes to red light were greater in hyperopes compared to emmetropes (P = 0.04) at moderate to bright light intensities (12.25-14.0 Log photons/cm²/s). Our results demonstrate that low and moderate myopia do not alter pupillary responses to ramping-up blue- and red-light stimuli in healthy older individuals. Conversely, pupillary responses to red light should be interpreted cautiously in hyperopic eyes.

Purpose: To investigate the primary causes of visual impairment and blindness in rural China., Design: Population-based, cross-sectional study., Methods: Geographic cluster sampling was used in randomly selecting residents from a rural county/district within 9 provinces in the East Coast, Inland Middle, and West regions of mainland China. Persons aged 50 years or older were enumerated through household visits and invited to examination sites for visual acuity testing and ocular examination. Causes of vision impairment and blindness in 2014 were compared with data from an earlier 2006 survey., Results: Mild visual impairment (20.4% prevalence) was caused by uncorrected refractive error in two thirds of cases and by cataract in nearly another one fourth; moderate-to-severe visual impairment (10.3% prevalence) was caused by cataract in over onec half of cases and by uncorrected refractive error in another one fifth; blindness (1.66% prevalence) was caused by cataract in approximately one half of cases and in another one fourth by retinal disease. Primary causes of visual impairment and blindness in cataract-operated eyes were uncorrected refractive error, posterior capsule opacity, and retinal disease. From 2006 to 2014, the proportion of visual impairment caused by uncorrected refractive error increased, but rates for unoperated cataract were reduced., Conclusions: Uncorrected refractive error and unoperated cataract are the 2 primary causes of mild, moderate, and severe visual impairment in rural China, with unoperated cataract and retinal diseases primary causes for blindness. An effective public health strategy to increase service delivery for these causes would lead to substantial reduction in vision impairment and blindness., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objectives: To compare the effect of toric versus spherical soft contact lenses on objective measures of visual performance using visual acuity and electromyography of the orbicularis oculi muscle., Methods: Current soft contact lens wearers with -0.75 to -1.75 D astigmatism in each eye were binocularly fitted with toric (1-Day ACUVUE MOIST for astigmatism) and spherical (1-Day ACUVUE MOIST) contact lenses in random order. After each fitting and at 1-week follow-up, high- and low-contrast visual acuities were measured. Electromyography was used to objectively evaluate eyestrain. Linear mixed models were used to assess differences between toric and spherical contact lenses., Results: The mean age (±SD) of the 60 participants was 27.5±5.0 years, spherical refractive error was -3.68±2.01 D, and cylinder was -1.28±0.36 D. High- and low-contrast visual acuities with toric lenses were better than with spherical lenses at both fitting (toric high-contrast: -0.065±0.078 and low-contrast: 0.133±0.103 vs. spherical high-contrast: 0.001±0.104 and low-contrast: 0.224±0.107) and follow-up (toric high-contrast: -0.083±0.087 and low-contrast: 0.108±0.107 vs. spherical high-contrast: -0.015±0.095 and low-contrast: 0.211±0.104) (all P<0.0001). Electromyography-measured eyestrain was less with toric versus spherical contact lenses at fitting (least-square ratio of toric over spherical=0.72; P=0.0019) but not at follow-up (ratio=0.86; P=0.11)., Conclusion: These results suggest that toric contact lenses provided improved objective measures of vision in a low-to-moderate astigmatic population.

Introduction: Among the 1.4 million blind children in the world, 300,000 live in Africa. The causes of blindness vary from one country to another. The purpose of our study was to report the causes of childhood blindness and visual impairment in children attending the only school for the blind in Mali (National Institute for the Blind in Mali, INAM)., Materials and Methods: All children attending the INAM were examined. Blindness was defined as visual acuity less than 3/60 (20/400 or 0.05). Visual impairment was moderate when the visual acuity was less than 6/18 (20/70 or 0.30), but greater than or equal to 6/60 (20/200 or 0.1), and severe when visual acuity was less than 6/60 (20/200 or 0.1), but greater than or equal to 3/60 (20/400 or 0.05)., Results: The study included a total of 104 children. The average age of our patients was 12 years with a M/F sex-ratio of 1.12. In all, 85.6 % of the children were blind and 14.4 % visually impaired. The main causes of blindness were corneal opacities (26 %), and whole globe lesions and conditions (19.2 %). Ametropia accounted for 60 % of visual impairment., Discussion: According to WHO, corneal and retinal damage are the leading cause of blindness (50.6 %) in children. In our series, corneal diseases were the leading cause, following by damage to the whole globe., Conclusion: The results of our study indicate that avoidable and treatable causes of childhood blindness are the leading causes of blindness of children at INAM.

Purpose: A nationwide rapid assessment of avoidable blindness survey was undertaken in the Maldives among people aged 50 years or more to assess the prevalence and causes of blindness and visual impairment, cataract surgical coverage, cataract surgery outcome, and barriers to uptake of cataract surgical services., Design: Prospective population-based study., Methods: In the cluster sampling probability proportionate to size method, 3100 participants in 62 clusters across all 20 atolls were enrolled through house-to-house visits. They were examined in clusters by an ophthalmologist-led team. Data was recorded in mRAAB version 1.25 software on a smartphone., Results: The age-sex standardized prevalence of blindness was 2.0% [95% confidence interval (CI), 1.5-2.6]. Cataract was the leading cause of blindness (51.4%) and uncorrected refractive error was the leading cause of visual impairment (50.9%). Blindness was more prevalent in higher age groups and women (16.3%). Cataract surgical coverage was 86% in cataract blind eyes and 93.5% in cataract blind persons. Good visual outcome in cataract operated eyes was 67.9% (presenting) and 76.6% (best corrected visual acuity). In this study, 48.1% of people had received cataract surgery in neighboring countries. Important barriers for not using the services were "did not feel the need" (29.7%) and "treatment deferred" (33.3%)., Conclusions: Cataract surgical coverage is good, though nearly half the people received surgery outside the Maldives. Cataract surgery outcomes are below World Health Organization standards. Some barriers could be overcome with additional human resources and training to improve cataract surgical outcomes, which could encourage greater uptake of services within the country., (Copyright 2018 Asia-Pacific Academy of Ophthalmology.)

Purpose: The International Agency for Prevention of Blindness (IAPB) South East Asia region (SEAR) that consists of 11 countries contains 26% of the world's population (1,761,000,000). In this region 12 million are blind and 78.5 million are visually impaired. This amounts to 30% of global blindness and 32% of global visual impairment., Design: Rapid assessment of avoidable blindness (RAAB) survey analysis., Methods: RAAB, either a repeat or a first time survey, was completed in 8 countries in this decade (2010 onwards). These include Bangladesh, Bhutan, India, Indonesia, Maldives, Sri Lanka, Thailand, and Timor Leste., Results: Cataract is the principal cause of blindness and severe visual impairment in all countries. Refractive error is the principal cause of moderate visual impairment in 4 countries: Bangladesh, India, Maldives, and Sri Lanka; cataract continues to be the principal cause of moderate visual impairment in 4 other countries: Bhutan, Indonesia, Thailand, and Timor Leste. Outcome of cataract surgery is suboptimal in the Maldives and Timor Leste., Conclusions: Rigorous focus is necessary to improve cataract surgery outcomes and correction of refractive error without neglecting the quality of care. At the same time allowances must be made for care of the emerging causes of visual impairment and blindness such as glaucoma and posterior segment disorders, particularly diabetic retinopathy., (Copyright 2018 Asia-Pacific Academy of Ophthalmology.)

Background: Within a surveillance of the prevalence and causes of vision impairment in high-income regions and Central/Eastern Europe, we update figures through 2015 and forecast expected values in 2020., Methods: Based on a systematic review of medical literature, prevalence of blindness, moderate and severe vision impairment (MSVI), mild vision impairment and presbyopia was estimated for 1990, 2010, 2015, and 2020., Results: Age-standardised prevalence of blindness and MSVI for all ages decreased from 1990 to 2015 from 0.26% (0.10-0.46) to 0.15% (0.06-0.26) and from 1.74% (0.76-2.94) to 1.27% (0.55-2.17), respectively. In 2015, the number of individuals affected by blindness, MSVI and mild vision impairment ranged from 70 000, 630 000 and 610 000, respectively, in Australasia to 980 000, 7.46 million and 7.25 million, respectively, in North America and 1.16 million, 9.61 million and 9.47 million, respectively, in Western Europe. In 2015, cataract was the most common cause for blindness, followed by age-related macular degeneration (AMD), glaucoma, uncorrected refractive error, diabetic retinopathy and cornea-related disorders, with declining burden from cataract and AMD over time. Uncorrected refractive error was the leading cause of MSVI., Conclusions: While continuing to advance control of cataract and AMD as the leading causes of blindness remains a high priority, overcoming barriers to uptake of refractive error services would address approximately half of the MSVI burden. New data on burden of presbyopia identify this entity as an important public health problem in this population. Additional research on better treatments, better implementation with existing tools and ongoing surveillance of the problem is needed., Competing Interests: Competing interests: JBJ: consultant for Mundipharma (Cambridge, UK), patent holder with Biocompatibles UK (Farnham, Surrey, UK) (Title: Treatment of eye diseases using encapsulated cells encoding and secreting neuroprotective factor and/or anti-angiogenic factor; patent no 20120263794) and patent application with University of Heidelberg (Heidelberg, Germany) (Title: Agents for use in the therapeutic or prophylactic treatment of myopia or hyperopia; Europäische Patentanmeldung 15 000 771.4). AMB: consultant for Allergan, Bausch + Lomb, Carl Zeiss Meditec, Théa and VISUfarma. Research grants from Horus. JHK: consultant for Gilead and Santen. SR: consultant for Brien Holden Vision Institute., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Background: To report the prevalence and causes of visual impairment in seven-year-old children in Iran and its relationship with socio-economic conditions., Methods: In a cross-sectional population-based study, first-grade students in the primary schools of eight cities in the country were randomly selected from different geographic locations using multistage cluster sampling. The examinations included visual acuity measurement, ocular motility evaluation, and cycloplegic and non-cycloplegic refraction. Using the definitions of the World Health Organization (presenting visual acuity less than or equal to 6/18 in the better eye) to estimate the prevalence of vision impairment, the present study reported presenting visual impairment in seven-year-old children., Results: Of 4,614 selected students, 4,106 students participated in the study (response rate 89 per cent), of whom 2,127 (51.8 per cent) were male. The prevalence of visual impairment according to a visual acuity of 6/18 was 0.341 per cent (95 per cent confidence interval 0.187-0.571); 1.34 per cent (95 per cent confidence interval 1.011-1.74) of children had visual impairment according to a visual acuity of 6/18 in at least one eye. Sixty-six (1.6 per cent) and 23 (0.24 per cent) children had visual impairment according to a visual acuity of 6/12 in the worse and better eye, respectively. The most common causes of visual impairment were refractive errors (81.8 per cent) and amblyopia (14.5 per cent). Among different types of refractive errors, astigmatism was the main refractive error leading to visual impairment. According to the concentration index, the distribution of visual impairment in children from low-income families was higher., Conclusion: This study revealed a high prevalence of visual impairment in a representative sample of seven-year-old Iranian children. Astigmatism and amblyopia were the most common causes of visual impairment. The distribution of visual impairment was higher in children from low-income families. Cost-effective strategies are needed to address these easily treatable causes of visual impairment., (© 2017 Optometry Australia.)

Aim: This study aims to report the outcomes of new-generation hybrid contact lenses for visual rehabilitation of postkeratoplasty patients., Materials and Methods: Twenty eyes of twenty postkeratoplasty patients were fitted with hybrid lenses. Each patient's keratometric values, ocular surface irregularity indices, central corneal thickness (CCT), uncorrected visual acuity (UCVA), spectacle-corrected visual acuity, contact lens-corrected visual acuity, contact lens fitting data, and contact lens daily wearing time were recorded. Follow-up examinations were performed at 1 st week, 1 st month, and 3 rd month visit after successful fitting of the lenses., Results: The mean age of the patients was 38.42 ± 4.89 years. The mean spherical component of refractive error was -4.46 ± 2.1 D, and the mean astigmatism was -5.31 ± 1.55 D. The median UCVA was 1.00 logarithm of the minimum angle of resolution (logMAR) which improved to 0.40 logMAR after spectacle correction. The median visual acuity with hybrid contact lenses was 0.05 logMAR. The median CCT was 544.4 μm and increased to 549.2 μm at 3 months after contact lens wear. The difference was not statistically significant (P = 0.38). The mean follow-up of patients was 4.32 ± 0.45 months. Eighteen of twenty patients reported a mean of 8.37 ± 1.95 h comfortable wearing time per day during this period. Two patients discontinued contact lens wearing due to conjunctival hyperemia. No graft-related complications such as decompensation, rejection, and infection were documented during the follow-up period., Conclusion: The new-generation hybrid contact lenses can be considered helpful in the visual management of postcorneal graft patients, particularly who are unable to achieve an adequate visual outcome with spectacles., Competing Interests: There are no conflicts of interest

Background Uncorrected refractive error is one of the most important causes of visual impairment worldwide. Objective To ascertain the pattern and prevalence of refractive error and secondary visual impairment in subjects attending Ophthalmology department. Method A prospective hospital-based study was designed where presenting visual acuity, age of presentation, refractive status, best corrected visual acuity and status of visual impairment were assessed in participants, ages ranging from 3-39 years presenting to the Ophthalmology department of Dhulikhel Hospital, Kathmandu University Hospital. History of use of spectacle was noted and participants were categorized into different visual impairment categories as per their presenting visual acuity. Result Out of a total of 4500 total clients examined during the study period, 388 (8.62%) had refractive error where 219 (56.44%) were females and 169 (43.56%) were males. Mean age at presentation was 22.70±7.69 years (range, 3-39 years). Astigmatism was the most common subtype seen in 373 eyes (48.06%), followed by myopia (366 eyes, 47.16%) and hypermetropia (31 eyes, 4.0%). Only 40.50% subjects who required refractive correction were using spectacle. 62.37% (242 clients) had some of visual impairment during their presentation. There was statistically significant improvement in visual acuity after refractive correction (p=0.00). Conclusion Uncorrected refractive error is one of the most important causes of visual impairment. Lack of awareness, infrequent ocular examination and lack of community or preschool vision screening were the main causes for the late presentation and significant visual impairment associated with the condition. Social stigma, economical limitation and negative counseling and attitudes about spectacle wear were primary factors behind the unsatisfactory spectacle use.

Background and objective: Amblyopia is the leading cause of visual impairment in children and adults and is very common during childhood. The aim of this study was to identify the prevalence and the risk factors of amblyopia in a pediatric population with refractive errors from an Eastern European country. Materials and methods: A total of 1231 children aged 5⁻16 years, who had refractive errors and were examined from January to August 2017, were enrolled in a cross-sectional population-based study. Every child underwent a complete ophthalmological exam. Amblyopia was defined as a visual acuity (VA) of less than 0.63. The study respected the Multi-Ethnic Pediatric Eye Disease Study (MEPEDS) criteria for defining amblyopia (MEPEDS, 2008). Parents participated in a face-to-face interview. The questionnaire contained details about their family history of amblyopia; the child's maternal nutritional status in the preconception period; their history of maternal smoking or work in a toxic environment; the child's birth, and the child's history of congenital naso-lacrimal duct obstruction (CNLDO). Results: Amblyopia was identified in 2.8% of the participants. The ocular conditions hyperopia ( p = 0.0079), astigmatism ( p = 0.046), anisometropia ( p < 0.001), esotropia ( p < 0.001), exotropia ( p = 0.0195), and CNLDO ( p < 0.001), as well as a family history of amblyopia ( p < 0.001), were associated with amblyopia. The non-ocular risk factors for amblyopia that were found in the study included low birth weight ( p < 0.0009), prematurity ( p < 0.001), an Apgar score under 7 ( p = 0.0008), maternal age, maternal smoking history or work in toxic environment ( p < 0.001), and maternal body mass index in the preconception period ( p < 0.003). Conclusions: Some of the risk factors we identified for amblyopia are modifiable factors. This is an important observation as an adequate health education program can provide the relevant information for future mothers that will allow for a better management of the condition. We also wanted to highlight the need for amblyopia screening starting from the age of 3 years in case of significant parental refractive errors, strabismus, prematurity, and maternal risk factors., Competing Interests: The authors declare no conflict of interest.

Ricco's area (the largest area of visual space in which stimulus area and intensity are inversely proportional at threshold) has previously been hypothesised to be a result of centre/surround antagonism in retinal ganglion cell receptive fields, but recent evidence suggests a sizeable cortical contribution. Here, Ricco's area was measured in amblyopia, a condition in which retinal receptive fields are normal, to better understand its physiological basis. Spatial summation functions were determined at 12 visual field locations in both eyes of 14 amblyopic adults and 15 normal-sighted controls. Ricco's area was significantly larger in amblyopic eyes than in fellow non-amblyopic eyes. Compared to the size of Ricco's area in control eyes, Ricco's area measured significantly larger in amblyopic eyes. Additionally, Ricco's area in the fellow, non-amblyopic eye of amblyopic participants measured significantly smaller than in control eyes. Compared to controls, Ricco's area was larger in amblyopic eyes and smaller in fellow non-amblyopic eyes. Amblyopia type, binocularity, and inter-ocular difference in visual acuity were significantly associated with inter-ocular differences in Ricco's area in amblyopes. The physiological basis for Ricco's area is unlikely to be confined to the retina, but more likely representative of spatial summation at multiple sites along the visual pathway.

Purpose: To investigate the refractive characteristics of Japanese children with Down syndrome., Study Design: Retrospective study., Methods: The clinical records of refractive errors and ocular manifestations in children with Down syndrome who visited the Aichi Children's Health and Medical Center between November 2001 and January 2016 were retrospectively reviewed. The children were divided into the 3 following groups depending on their age: group 1 (≤ 6 years), group 2 (7-12 years), and group 3 (13-19 years). The collection of refractive error data was performed only for the right eyes and only once for each child, when the children were last examined with their pupils dilated., Results: The study included 416 children (224 boys, 192 girls; average age, 6.1 ± 4.1 years). Group 3 had significantly stronger myopia than did groups 1 and 2. The mean cylindrical power in all the children was - 2.1 ± 1.2 diopters (D), and cylindrical power ≤ - 1.0 D (stronger than - 1.0 D) was seen in 366 eyes (88%). No significant difference in cylindrical power was found among the 3 groups., Conclusions: The spherical equivalent refraction showed an age-dependent myopic shift. Given that the amount of astigmatism did not show age-dependent differences, the age-dependent myopic shift could be due mainly to the change in spherical power.

Background: Although the benefits of vision screening seem intuitive, the value of such programmes in junior and senior schools has been questioned. In addition there exists a lack of clarity regarding the optimum age for screening and frequency at which to carry out screening., Objectives: To evaluate the effectiveness of vision screening programmes carried out in schools to reduce the prevalence of correctable visual acuity deficits due to refractive error in school-age children., Search Methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 4); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the ICTRP. The date of the search was 3 May 2017., Selection Criteria: We included randomised controlled trials (RCTs), including cluster-randomised trials, that compared vision screening with no vision screening, or compared interventions to improve uptake of spectacles or efficiency of vision screening., Data Collection and Analysis: Two review authors independently screened search results and extracted data. Our pre-specified primary outcome was uncorrected, or suboptimally corrected, visual acuity deficit due to refractive error six months after screening. Pre-specified secondary outcomes included visual acuity deficit due to refractive error more than six months after screening, visual acuity deficit due to causes other than refractive error, spectacle wearing, quality of life, costs, and adverse effects. We graded the certainty of the evidence using GRADE., Main Results: We identified seven relevant studies. Five of these studies were conducted in China with one study in India and one in Tanzania. A total of 9858 children aged between 10 and 18 years were randomised in these studies, 8240 of whom (84%) were followed up between one and eight months after screening. Overall we judged the studies to be at low risk of bias. None of these studies compared vision screening for correctable visual acuity deficits with not screening.Two studies compared vision screening with the provision of free spectacles versus vision screening with no provision of free spectacles (prescription only). These studies provide high-certainty evidence that vision screening with provision of free spectacles results in a higher proportion of children wearing spectacles than if vision screening is accompanied by provision of a prescription only (risk ratio (RR) 1.60, 95% confidence interval (CI) 1.34 to 1.90; 1092 participants). The studies suggest that if approximately 250 per 1000 children given vision screening plus prescription only are wearing spectacles at follow-up (three to six months) then 400 per 1000 (335 to 475) children would be wearing spectacles after vision screening and provision of free spectacles. Low-certainty evidence suggested better educational attainment in children in the free spectacles group (adjusted difference 0.11 in standardised mathematics score, 95% CI 0.01 to 0.21, 1 study, 2289 participants). Costs were reported in one study in Tanzania in 2008 and indicated a relatively low cost of screening and spectacle provision (low-certainty evidence). There was no evidence of any important effect of provision of free spectacles on uncorrected visual acuity (mean difference -0.02 logMAR (95% CI adjusted for clustering -0.04 to 0.01) between the groups at follow-up (moderate-certainty evidence). Other pre-specified outcomes of this review were not reported.Two studies explored the effect of an educational intervention in addition to vision screening on spectacle wear. There was moderate-certainty evidence of little apparent effect of the education interventions investigated in these studies in addition to vision screening, compared to vision screening alone for spectacle wearing (RR 1.11, 95% CI 0.95 to 1.31, 1 study, 3177 participants) or related outcome spectacle purchase (odds ratio (OR) 0.84, 95% CI 0.55 to 1.31, 1 study, 4448 participants). Other pre-specified outcomes of this review were not reported.Three studies compared vision screening with ready-made spectacles versus vision screening with custom-made spectacles. These studies provide moderate-certainty evidence of no clinically meaningful differences between the two types of spectacles. In one study, mean logMAR acuity in better and worse eye was similar between groups: mean difference (MD) better eye 0.03 logMAR, 95% CI 0.01 to 0.05; 414 participants; MD worse eye 0.06 logMAR, 95% CI 0.04 to 0.08; 414 participants). There was high-certainty evidence of no important difference in spectacle wearing (RR 0.98, 95% CI 0.91 to 1.05; 1203 participants) between the two groups and moderate-certainty evidence of no important difference in quality of life between the two groups (the mean quality-of-life score measured using the National Eye Institute Refractive Error Quality of Life scale 42 was 1.42 better (1.04 worse to 3.90 better) in children with ready-made spectacles (1 study of 188 participants). Although none of the studies reported on costs directly, ready-made spectacles are cheaper and may represent considerable cost-savings for vision screening programmes in lower income settings. There was low-certainty evidence of no important difference in adverse effects between the two groups. Adverse effects were reported in one study and were similar between groups. These included blurred vision, distorted vision, headache, disorientation, dizziness, eyestrain and nausea., Authors' Conclusions: Vision screening plus provision of free spectacles improves the number of children who have and wear the spectacles they need compared with providing a prescription only. This may lead to better educational outcomes. Health education interventions, as currently devised and tested, do not appear to improve spectacle wearing in children. In lower-income settings, ready-made spectacles may provide a useful alternative to expensive custom-made spectacles.

Purpose: To investigate the frequency of choroidal microvasculature dropout (CMvD) in healthy myopic eyes in comparison with that of myopic open-angle glaucoma (OAG) eyes and determine whether myopia is independently associated with CMvD., Patients and Methods: Choroidal layer microvasculature images were obtained using optical coherence tomography angiography in 89 myopic OAG patients and 89 age-matched and refractive error-matched healthy myopic eyes. CMvD was defined as a complete loss of the microvasculature network on the choroidal layer vessel density (VD) map. The frequency of CMvD was compared between myopic OAG and healthy myopic eyes. Hemispheric comparisons of various parameters were performed between CMvD-affected and CMvD-unaffected hemiretina. The association of myopia with the presence and angular circumference of CMvD was evaluated using logistic and linear regression analyses., Results: CMvD was identified in 40 eyes (47.6%) with myopic OAG, whereas no CMvD was found in healthy myopic eyes. Mean hemispheric visual field sensitivity (294.9±321.1 vs. 610.5±387.5, P=0.006), retinal nerve fiber layer thickness (68.9±11.5 vs. 82.5±20.6 μm, P=0.001), and circumpapillary VD (50.5%±7.3% vs. 53.9%±8.8%, P=0.048) were significantly worse in the CMvD-affected hemiretina than in the CMvD-unaffected hemiretina. The presence and angular circumference of CMvD was significantly associated with parameters (visual field mean deviation, retinal nerve fiber layer thickness, and circumpapillary VD; P<0.05) representing glaucoma severity rather than parameters (refractive error and axial length; P>0.05) representing myopic change., Conclusions: CMvD was observed only in glaucomatous eyes and associated with severity of glaucomatous damage in myopic OAG subjects. The angular circumference of CMvD was significantly related to glaucoma severity.

Background: To evaluate the effect of different adjustments of the refractive outcome of the first eye according to corneal power (K) in order to improve the intraocular lens (IOL) power calculation of the second eye in the SRK/T formula., Methods: One hundred thirty-four patients who underwent uncomplicated bilateral, sequential phacoemulsification with AcrySof IQ implantation were enrolled. The optimal partial adjustment of the refractive outcome of the first eye according to K was retrospectively analyzed using a regression formula., Results: In all patients, the optimal partial adjustment of the refractive outcome of the first eye was calculated as 56%. For K values between 42.8 D and 44.6 D, the optimal partial adjustment was calculated as 30%; however, this adjustment of the first eye did not significantly improve the refractive outcome in the second eye of the subgroup with K values between 42.8 D and 44.6 D. For K values greater than 44.6 D or less than 42.8 D, the optimal partial adjustments were calculated as 69% and 81%, respectively. According to these results, the adjustment of the first eye significantly improved the refractive outcome in the second eye from 0.36 to 0.26 D (P < 0.001) in the entire data set. This result was significantly lower than that using a single partial adjustment (56%) (0.28 D; P = 0.027)., Conclusions: For K values greater than 44.6 D or less than 42.8 D, an approximately 70-80% adjustment of the first eye error should be considered. In contrast, for K values between 42.8 D and 44.6 D, a 30% or less adjustment should be considered in the SRK/T formula.

Purpose: To assess prevalence and associated factors of myopia and high myopia in schoolchildren in Greater Beijing., Methods: The school-based, cross-sectional Greater Beijing School Children Myopia study was carried out in the year 2016 in 54 schools randomly selected from 15 districts in Beijing. Non-cycloplegic auto-refractometry of the right eyes was performed., Results: The study included 35,745 (99.4%) out of 35,968 eligible pupils with a mean age of 12.6±3.4 years (range 6-18 years). Prevalence of myopia defined as myopic refractive error of ≥-0.50 diopters (D),≥-1D,≥-6D,≥-8D and ≥-10D was 70.9%(95% confidence intervals (CI):70.5,71.4), 60.9% (95%CI:60.4,61.4), 8.6%(95%CI:8.4,8.9), 2.2%(95%CI:2.0,2.4), and 0.3% (95%CI:0.3,0.4), respectively. The frequency of high myopia (≥-6D, ≥-8D, ≥-10D) increased from 1.5% (95%CI:1.0,2.0), 0.4% (95%CI:0.1,0.6) and 0.1% (95%CI:0.00,0.02), respectively in 10-year-olds to 19.4% (95%CI:17.3,21.6), 5.2% (95%CI:4.0,6.4) and 0.9% (95%CI:0.4,1.5), respectively, in 18-year-olds. Mean refractive error in the 18-year-olds was -3.74±2.56D (median:-3.63D;range:-19.6D to + 6.25D). Higher prevalence of high myopia (≥-6D and ≥-8D) was correlated (all P<0.001) with older age (OR:1.18, and 1.15, respectively), female gender (OR: 1.44 and 1.40, respectively), higher body mass index (OR: 1.02 and 1.03, respectively), taller body height (OR: 1.03 and 1.02, respectively), urban region of habitation (OR: 1.26 and 1.33, respectively) and higher school type (OR:1.57 and 2.22, respectively). Prevalence of severe high myopia (≥-10D) was associated only with older age (P<0.001; OR: 1.44; 95%CI: 1.31, 1.59) but not with any education-related parameter such as higher school type (P = 0.48), urban region of habitation (P = 0.07) or female gender (P = 0.37)., Conclusion: In this most recent survey, prevalence of high myopia (≥-6D:19.4%;≥-8D:5.2%;≥-10D:0.9%) in 18-year-old school children was higher than in previous surveys from mainland China. In contrast to minor high myopia and moderate high myopia (defined as myopic refractive error of <-10D), severe high myopia (myopic refractive error ≥-10D) was not strongly correlated with educational parameters.

Aim/background: Associations between axial length (AL) to corneal radius of curvature (CR) ratio and refractive status in a healthy Nigerian adult population were studied., Materials and Methods: Healthy students and members of staff of Obafemi Awolowo Teaching Hospitals Complex, Ile-Ife, South West Nigeria, free of obvious ocular diseases except possible refractive errors were recruited. Consecutive consenting volunteers were recruited by simple random sampling and a proportionate sample of each population based on its representative fraction in the hospital community was recruited. The study was conducted between June and August 2011. Noncycloplegic objective refraction was done and spherical equivalent refraction (SER) of the right eyes was used for calculation. The AL, CR, and keratometric readings were measured with the IOL Master. The AL/CR ratio was calculated. The data were analyzed with statistical software package STATA 13., Results: Three hundred and fifty volunteers aged 18-60 years were studied. The mean ± standard deviation of AL/CR and SER were 3.04 ± 0.10 and -0.38 ± 1.42D, respectively. AL in myopia was significantly higher than in emmetropia and hypermetropia. There were no significant differences between CR in the refraction groups. Myopes had significantly higher AL/CR than nonmyopes. On controlling for age and gender, 1 mm increase in AL increased SER by -0.77D (95% confidence interval [CI] -0.91--0.64D) while a unit increase in AL/CR increased SER by -8.89D (95% CI -10.00--7.78D). Whereas AL accounts for 39% of variability in SER (P < 0.001), AL/CR accounts for 51% of the variability observed in SER (P < 0.001)., Conclusion: This study has further confirmed that the AL remains a strong determinant of refraction, but a derived factor AL/CR accounts for more variation in final refractive status than AL in isolation.

The purpose of this study was to study the etiologies and operative outcomes of pediatric retinal detachment at a tertiary eye referral center in Hong Kong over a 10-year period. A retrospective study of patients (below 18 years of age) who received primary retinal detachment repair operations at a University Teaching Hospital between 2005 and 2015 was conducted. The study comprised 37 patients with 39 eyes affected who received primary retinal detachment (RD) surgery. Two patients had bilateral RD. 69.2 % were male. The mean follow-up period was 40.6 ± 28.6 months. Their mean age at presentation was 13.4 ± 5.5 years. There were contributing factors for RD identified in 33 eyes (84.6 %), of which congenital/developmental anomalies (23.1 %), high myopia with refractive error greater than -6 diopters (17.9 %), and trauma (15.4 %) ranked the top 3 causes for RD. The retina was reattached after one surgical procedure in 69.2 %. Final anatomical success rate was 82.1 %. Postoperatively, 68.8 % of eyes had improved or stable vision. Functional visual loss with visual acuity less than 5/200 was found to be 30.6 % of eyes which were mostly from younger patients and those with congenital anomalies. Pediatric retinal detachment is often associated with predisposing factors. The presence of congenital/developmental ocular anomalies causing retinal detachment is more frequent in younger children and with worse functional and visual outcomes. Continuing efforts to improve treatment strategies for this group of patients are needed.