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Background Lens opacities (LO) occur at an earlier age and have a higher prevalence in developing countries. In this pilot study, we assessed the feasibility and practical challenges of conducting a migration study, testing the hypothesis that migration from Bangladesh to the UK decreases the amount of LO on account of less exposure to adverse environmental factors. Methods The sample, which was selected from East London, UK and in Bangladesh, underwent detailed examination and lens grading by the same certified grader using Lens Opacification Classification System III. Data were analysed using univariate and multivariable logistic regression analyses. Results Considerable difficulties were encountered in recruiting the sample in both locations. 372 Bangladeshis aged 40-70 years were examined: 131 in London and 241 in Bangladesh. Having never migrated from Bangladesh was an independent risk factor for opacities (OR 7.6; 95% CI 3.6 to 15.9; p=0.001) as were age (OR 7.1; 95% CI 4.0 to 12.7; p=0.001) and diabetes (OR 2.5; 95% 1.0 to 6.0; p=0.04). The odds of LO were lower among those who had lived in the UK for a higher proportion of their life (OR 0.96; 95% CI 0.93 to 0.99; p=0.01), but this was not significant after adjusting for age and diabetes (OR 0.97; 95% CI 0.94 to 1.01; p=0.16). Discussion The study highlights the challenges of migration studies, and of studies involving ethnic minorities. Preliminary findings suggest that migration to the UK is protective for LO despite a significantly higher rate of diabetes in the UK. A larger study is warranted based on these preliminary findings. [ABSTRACT FROM AUTHOR]

Purpose To measure visual acuity (VA) outcomes, complication rates, and the social impact of cataract surgery in a cohort who underwent surgery as children in Bangladesh. Design Case series. Participants A total of 471 of 850 children from 6 Bangladeshi districts who had been identified as cataract blind using key informants (KIs) between 2004 and 2009 during the Bangladesh Childhood Cataract Campaign (BCCC) together with all those children not included in the BCCC database but in the Child Sight Foundation (CSF) database who had been identified as cataract blind. Methods The subjects and families were contacted again by KIs and transported to local examination centers, where parents and subjects were administered a questionnaire and subjects underwent full ocular examination. Where operative data were available (15%), they were analyzed in conjunction with questionnaire and examination findings. Statistical analysis was performed using SPSS Statistics (IBM, Armonk, NY). Main Outcome Measures Presenting and best-corrected visual acuities (BCVAs), cause(s) of poor outcome, postoperative refraction, and school attendance. Results A total of 407 of the participants had undergone bilateral surgery as children, with a mean follow-up of 8.8 years. The mean age at examination was 16 years (range, 5–28 years; standard deviation [SD], 4.6 years); 63% of those examined were male; 22% had a binocular presenting VA of >20/60; and 53% were severely visually impaired or blind (VA <20/200). After refraction, 33% had VA >20/60 in their better eye and 33% had VA <20/200. Factors that predicted poor VA in multivariate logistic regression analysis were nystagmus ( P < 0.001), longer delay in presentation ( P < 0.001), and magnitude of absolute spherical equivalent refractive error ( P < 0.001). Some 50% had nystagmus, and 69% of those currently aged ≤16 years were attending school. Better acuity was associated with school attendance ( P < 0.001), whereas gender was not. Conclusions Approximately one third of all participants had a BCVA of ≥20/60 in their better eye. Amblyopia and nystagmus limited visual outcome, indicating the need for earlier detection and treatment. This is the first study to show the link between pediatric cataract outcome and access to education, a millennium development goal. [ABSTRACT FROM AUTHOR]

Abstract: Supplementation with carotenoids is proposed to protect against age-related macular degeneration. There is, however, considerable variability in retinal macular pigment response, which may be due to underlying genetic variation. The purpose of this study was to determine whether genetic factors, which have been previously associated with cross-sectional macular pigment levels in the retina or serum lutein, also influence response to supplementation. To this end we conducted an association study in 310 subjects from the TwinsUK cohort between variants in 8 candidate genes and serum lutein and retinal macular pigment optical density (MPOD) levels before and after supplementation. Four variants were associated with MPOD response to supplementation (p < 0.05): rs11057841 (SCARB1), rs4926339 (RPE65), rs1929841 (ABCA1) and rs174534 (FADS1). We also confirmed previous associations between rs6564851 near BMCO1 (p < 0.001) and rs11057841 within SCARB1 (p = 0.01) and baseline measures of serum lutein; while the latter was also associated with MPOD response, none of the BMCO1 variants were. Finally, there was evidence for association between variants near RPE65 and ELOVL2 and changes in lutein concentration after supplementation. This study is the first to show association between genetic variants and response to carotenoids supplementation. Our findings suggest an important link between MP response and the biological processes of carotenoids transport and fatty acid metabolism. [Copyright &y& Elsevier]

Objective: We sought to describe the clinical presentation, effect on visual acuity, impact on school attendance, and access to appropriate eye care in children with vernal keratoconjunctivitis (VKC) in Rwanda (Central Africa). Design: Case-control study nested within a cross-sectional survey. Participants: We examined 3041 children; 121 had VKC. Methods: Primary schools were randomly selected and children were interviewed using a questionnaire on VKC-related symptoms. Data on health-seeking behavior and school attendance were recorded. Children received a full eye examination, including visual acuity using a LogMar E Chart. Main Outcome Measures: Description of the clinical findings, unaided visual acuity, prior attendance for medical eye care, and the impact of VKC on school attendance. Results: Of the 121 children with VKC, 119 (98.4%) had only limbal disease. Ocular itching (n = 101; 83.5%) was the predominant symptom and this was seasonal in 66 children (65.4%), constant but with variable intensity in 18 (17.8%), and constant with constant intensity in 17 children (16.8%). Children with VKC were >6 times more likely to have corneal astigmatism >2 diopters in their worse eye (odds ratio [OR], 6.31; 95% confidence interval [CI], 3.26–12.26; P<0.001) than controls. Eight affected eyes had astigmatism >4 diopters or irregular astigmatism incompatible with autokeratometry. Although 4 eyes (1.7%) had uncorrected low vision from VKC-induced corneal astigmatism or keratoconus, only 1 child was visually impaired in both eyes. School nonattendance for an ocular reason during the last 3 months was 5 times more likely in children with VKC (n = 44; 36.4%) than among those without (n = 297; 10.2%; OR, 5.04; 95% CI, 3.40–7.47; P < 0.001). Repeating a school year or having ever dropped out of school was not more common among children with VKC than those without. Medical eye care had been sought by 54 (44.6%) children with VKC. Conclusions: This survey of prevalence and treatment of VKC in an African community adds to the argument for better primary eye care, including a safe topical medication. Long-term follow-up of this cohort is required to ascertain the overall risk of sight-threatening complications. Financial Disclosure(s): The authors have no proprietary or commercial interest in any of the materials discussed in this article. [Copyright &y& Elsevier]

Purpose: To describe the clinical features of children with anophthalmos, microphthalmos, and typical coloboma (AMC). Design: Descriptive, observational, cross-sectional study of the United Kingdom. Participants: A total of 135 children with AMC newly diagnosed over an 18-month period beginning in October 2006. Methods: Cases were identified using active surveillance through an established ophthalmic surveillance system. Eligible cases were followed up 6 months after first notification. Main Outcome Measures: Phenotypic characteristics, both ocular and systemic, clinical investigations, causes, and interventions. Results: A total of 210 eyes (of 135 children) were affected by AMC, of which 153 had isolated coloboma or coloboma with microphthalmos. The most common colobomatous anomaly was a chorioretinal defect present in 109 eyes (71.2%). Some 44% of children were bilaterally visually impaired. Systemic abnormalities were present in 59.7% of children, with craniofacial anomalies being the most common. Children with bilateral disease had a 2.7 times higher odds (95% confidence interval, 1.3–5.5, P = 0.006) of having systemic involvement than unilaterally affected children. Neurologic imaging was the most frequent investigation (58.5%) performed. Less than one third (30.3%) of the children with microphthalmos had ocular axial lengths measured. Eight children had confirmed genetic mutations. Approximately half (49.2%) of the children required ocular intervention. Conclusions: Colobomatous defects were the most common phenotype within this spectrum of anomalies in the United Kingdom. The high frequency of posterior segment colobomatous involvement means that a dilated fundal examination should be made in all cases. The significant visual and systemic morbidity in affected children underlines the importance of a multidisciplinary approach to management. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. [ABSTRACT FROM AUTHOR]

Purpose: Eight million people have trachomatous trichiasis (TT). The World Health Organization (WHO) recommends entropion surgery for TT regardless of severity. However, epilation is widely practiced for treating minor TT (1–5 lashes touching the globe). We report the frequency and effectiveness of patient-initiated epilation and its relationship to corneal opacity. Design: Cross-sectional baseline data of individuals recruited to 2 randomized, clinical trials. Participants: We included 2556 individuals (4310 eyes) with previously unoperated TT in ≥1 eye. Methods: A single ophthalmologist examined all participants for signs of trachoma using WHO grading systems with additional assessment of entropion grading, location and number of trichiatic lashes, and evidence of epilation. A questionnaire enquired about epilation practices. Main Outcome Measures: The association between epilation and degree of corneal opacity. Epilation practices of TT patients. Results: Central corneal scarring was present in 1436 (33%) eyes. Entropion was absent/mild in 2328 (54%) eyes, moderate in 1259 (29.2%), and severe in 723 (16.8%). The median number of lashes touching the eye was 2 (interquartile range, 1–5; range, 0–133). There was clinical evidence of epilation in 3018 (70%) eyes, of which 738 (24%) were successfully epilated (no lashes touching globe). Epilation was performed frequently (at least monthly in 3311 [76.8%] eyes), by someone other than the patient (92.8%), and using locally made forceps (88.9%). Controlling for age and degree of entropion, successful epilation was associated with less corneal opacity (odds ratio [OR], 0.61; 95% confidence interval [CI]. 0.43–0.88; P = 0.007). The association was only significant in patients with severe entropion (OR, 0.07; 95% CI, 0.02–0.25; P<0.005). Conclusions: We found an association between successful epilation and less central corneal opacity. This indicates the importance of preventing eyelashes from touching the cornea, particularly in individuals with severe entropion. This is a cross-sectional study; therefore, a causative relationship cannot be concluded. However, the results suggest that among patients who decline or are unable to access surgery, and perhaps in minor TT where the management remains controversial, the provision of high-quality forceps and epilation training may be beneficial. Financial Disclosure(s): The authors have no proprietary or commercial interest in any of the materials discussed in this article. [ABSTRACT FROM AUTHOR]

Aims To assess associations of visual function (VF) and quality of life (QOL) by visual acuity (VA), causes of blindness and types of cataract procedures in Nigeria. Methods Multi-stage stratified cluster random sampling was used to identify a nationally representative sample of persons aged &ges;40 years. VF/QOL questionnaires were administered to participants with VA <6/60 in one or both eyes and/or Mehra-Minassian cataract grade 2B or 3 in one or both eyes and a random sample of those with bilateral VA &ges6/12. Results VF/QOL questionnaires were administered to 2076 participants. Spearman's rank correlation showed a strong correlation between decreasing VA and VF/QOL scores (p<0.0001) with greatest impact on social (p<0.0001) and mobility-related activities (p<0.0001). People who were blind due to glaucoma had lower VF and QOL scores than those who were blind due to cataract. Mean VF and QOL scores were lower after couching compared with conventional cataract surgery (mean VF score=51.0 vs 63.0 and mean QOL score=71.3 vs 79.3). Finally, VF and QOL scores were lower among populations with specific characteristics. Conclusions Populations with the following characteristics should be targeted to improve VF and QOL: people who are blind, older people, women, manual labourers, people living in rural areas, those living in the northern geopolitical zones, those practising Islamic and Traditionalism faith, those not currently married and those who have undergone couching [ABSTRACT FROM AUTHOR]

Summary Objectives The prevalence of visual loss and blindness from cataract remains high in India. Marginalized communities are frequently reached through outreach clinics. The aim of this study was to explore the hypothesis that regular outreach, held in the same location by the same provider, leads to greater acceptance of cataract surgery than outreach clinics that are irregular in terms of timing and location. Methods The study was integrated into outreach clinics run in two districts by Sankara Eye Centre, Coimbatore, Southern India. A semi-structured questionnaire was administered to patients who had attended outreach eye clinics and either accepted or not accepted the offer of cataract surgery. Results Overall acceptance of surgery was high (91.7%), being higher in the district with regular outreach (94.6% vs. 82.3%, P < 0.001). A total of 398 participants (240, 60% acceptors) were interviewed. Acceptors were more likely to live in smaller households and in supportive families than non-acceptors who lived in larger families which could not provide support and where transport and distance were also barriers ( P < 0.001). Attending regular outreach and having had first eye cataract surgery were independent predictors of acceptance in a logistic regression model. Conclusion The findings indicate the importance of providers building trust by organizing regular outreach in the same location. Previous eye surgery was also a strong predictor of accepting cataract surgery. To promote universal access to health care, marginalized rural communities will continue to need outreach for some time to come. [ABSTRACT FROM AUTHOR]

Background: Age-related cataracts are a major public health problem. The relative importance of genes and environment in the causation of nuclear cataracts, the most common form of age-related cataracts, is not known. Methods: We studied 506 pairs of female twins (226 monozygotic and 280 dizygotic) who were 50 to 79 years old (mean, 62). The amount of nuclear cataract in the right and left eyes was determined objectively by analysis of Scheimpflug lens photographs (yielding three measures) and subjectively with use of the Oxford Clinical Cataract Classification and Grading System (yielding one measure). All eight measures (four in each eye) were subsequently combined in one summary measure of nuclear cataract for each woman. A univariate maximum-likelihood model was used to estimate the variance of the genetic and environmental contributions to each of the measures. Results: The different measures of cataract formation were highly correlated (correlation coefficients, 0.71 to 0.94). The mean scores were similar for the right and left eyes and for monozygotic and dizygotic twins. Quantitative genetic modeling of each of the nuclear-cataract scores invariably resulted in a best-fitting model that involved additive genetic effects, unique environmental effects, and age. The common environmental and dominant genetic effects could be removed from the models without significant loss of fit. The overall heritability in the combined nuclear-cataract score (the proportion of the variance explained by genetic factors) was 48 percent (95 percent confidence interval, 42 to 54 percent); age accounted for 38 percent of the variance (95 percent confidence interval, 31 to 44 percent) and unique environmental effects for 14 percent (95 percent confidence interval, 12 to 18 percent). Conclusions: Genetic effects are important even in such a clearly age-related disease as nuclear cataract, explaining almost 50 percent of the variation in the severity of this disease. (N Engl J Med 2000;342:1786-90.) [ABSTRACT FROM AUTHOR]

Objective: This study aims to examine the reduction and subsequent recovery of routine digital screening (RDS) uptake in England from 2018 to 2022, exploring national, regional and individual Diabetic Eye Screening Programme (DESP) levels. The COVID-19 lockdown in most areas of England was from 26 March 2020 to 23 June 2020 (first national lockdown), 5 November 2020 to 2 December 2020 (second national lockdown) and 6 January 2021 to 8 March 2021 (third national lockdown)., Design: Retrospective data analysis., Setting: DESPs of England., Participants: Individuals with diabetes who were invited to take part in the DESP programmes., Methods: Publicly available data from Public Health England (2018-2019) and National Health Service England (2019-2022) were examined to identify the rate of uptake (proportion of those who attended the DESPs to those who were invited) of RDS at national and regional levels and by each DESP in England., Primary Outcome Measures: Rate of uptake of RDS., Results: The national uptake of RDS decreased from 82% (2019-2020) to 68% (2020-2021) and then increased to 78% (2021-2022). At the regional level, the sharpest drop was in the Midlands which decreased from 79% (2019-2020) to 53% (2020-2021), increasing to 73% (2021-2022) but did not reach pre-COVID-19 levels. At individual DESP levels across England, the greatest drop in attendance (2020-2021) was recorded in Derbyshire (79% to 45%), Barnsley and Rotherham (78% to 45%) and Arden, Herefordshire and Worcestershire (78% to 46%). Although these DESPs showed an increase in 2021-2022 of 33%, 21% and 31%, they did not reach prepandemic (2018-2019) rates of 81%, 85% and 82%, respectively. Data suggest that West Sussex, East Sussex and East and North Hertfordshire DESPs maintained relatively higher uptake rates (86%-89%) in 2020-2021., Conclusion: COVID-19 had an impact on England's diabetic eye screening attendance, with notable variations across regions and DESPs. Different regions and DESPs showed variable post-COVID-19 recovery. More importantly, what was not evident is the increased uptake that should have occurred after the COVID-19 lockdown to compensate for the low uptake during the lockdown. In some areas, addressing some of the barriers that affect retinal screening uptake may improve future attendance., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ Group.)

Background: As more preterm infants survive, complications of preterm birth, including retinopathy of prematurity (ROP), become more prevalent. ROP rates and blindness from ROP are higher in low-income and middle-income countries, where exposure to risk factors can be higher and where detection and treatment of ROP are under-resourced or non-existent. Access to low-cost imaging devices would improve remote screening capabilities for ROP., Methods: Target product profiles (TPPs) are developed early in the medical device development process to define the setting, target user and range of product requirements. A Delphi-like process, consisting of an online survey and consensus meeting, was used to develop a TPP for an ROP imaging device, collecting feedback on a proposed set of 64 product requirements., Results: Thirty-six stakeholders from 17 countries provided feedback: clinicians (72%), product developers (14%), technicians (6%) and other (8%). Thirty-six per cent reported not currently screening for ROP, with cited barriers including cost (44%), no training (17%) and poor image quality (16%). Among those screening (n=23), 48% use more than one device, with the most common being an indirect ophthalmoscope (87%), followed by RetCam (26%) and smartphone with image capture (26%). Consensus was reached on 53 (83%) product requirements. The 11 remaining were discussed at the consensus meeting, and all but two achieved consensus., Conclusions: This TPP process was novel in that it successfully brought together diverse stakeholders to reach consensus on the product requirements for an ROP imaging devices. The resulting TPP provides a framework from which innovators can develop prototypes., Competing Interests: Competing interests: RPK has provided consulting services to Minute Molecular and Schmidt Futures in the past. KMP was co-founder, treasurer and secretary of Minute Molecular Diagnostics. This does not alter our adherence to BMJ Open Ophthalmology policies on sharing data and materials., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY. Published by BMJ.)

Vision loss from cataract is unequally distributed, and there is very little evidence on how to overcome this inequity. This project aimed to engage multiple stakeholder groups to identify and prioritise (1) delivery strategies that improve access to cataract services for under-served groups and (2) population groups to target with these strategies across world regions. We recruited panellists knowledgeable about cataract services from eight world regions to complete a two-round online modified Delphi process. In Round 1, panellists answered open-ended questions about strategies to improve access to screening and surgery for cataract, and which population groups to target with these strategies. In Round 2, panellists ranked the strategies and groups to arrive at the final lists regionally and globally. 183 people completed both rounds (46% women). In total, 22 distinct population groups were identified. At the global level the priority groups for improving access to cataract services were people in rural/remote areas, with low socioeconomic status and low social support. South Asia and Sub-Saharan Africa were the only regions in which panellists ranked women in the top 5 priority groups. Panellists identified 16 and 19 discreet strategies to improve access to screening and surgical services, respectively. These mostly addressed health system/supply side factors, including policy, human resources, financing and service delivery. We believe these results can serve eye health decision-makers, researchers and funders as a starting point for coordinated action to improve access to cataract services, particularly among population groups who have historically been left behind., Competing Interests: The authors declare that no competing interests exist., (Copyright: © 2023 Ramke et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Objective: The aim of the study was to establish the technical capacities needed to deliver the WHO African Region's primary eye care package in primary healthcare facilities., Design: A two-round Delphi exercise was used to obtain expert consensus on the technical complexity of each component of the package and the technical capacities needed to deliver them using Gericke's framework of technical feasibility. The panel comprised nine eyecare experts in primary eyecare in sub-Saharan Africa. In each round panel members used a 4-point Likert scale to indicate their level of agreement. Consensus was predefined as ≥70% agreement on each statement. For round 1, statements on technical complexity were identified through a literature search of primary eyecare in sub-Saharan Africa from January 1980 to April 2018. Statements for which consensus was achieved were included in round 2, and the technical capacities were agreed., Results: Technical complexity statements were classified into four broad categories: intervention characteristics, delivery characteristics, government capacity requirements and usage characteristics. 34 of the 38 (89%) statements on health promotion and 40 of the 43 (93%) statements on facility case management were considered necessary technical capacities for implementation., Conclusion: This study establishes the technical capacities needed to implement the WHO Africa Office primary eye care package, which may be generalisable to countries in sub-Saharan Africa., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Recent reports have suggested a significant change in the causes of blindness in children in low-income countries cataract becoming the leading cause. We aimed to investigate the presentations and surgical outcomes in children with cataract operated at different ages in Tanzania., Methods: We conducted a prospective study of 228 children aged ≤192 months at three tertiary centres, 177 with bilateral cataracts and prospectively followed them for 1-year postsurgery. We collected demographic, surgical, preoperative and postoperative clinical characteristics using the standard childhood cataract surgical assessment questionnaire. Families were encouraged to return for follow-up by phone with travel reimbursement where necessary., Results: Preoperatively, 76% bilateral children were blind in the better eye. 86% of children were followed up at 1 year and 54% bilateral children achieved visual acuity of 0.48 logMAR or better in the better eye and 5% were blind. 33% of unilateral children achieved visual acuity of 0.48 logMAR or better and 17% were blind. Preoperative blindness (adjusted OR (AOR) 14.65; 95% CI 2.21 to 97.20), preoperative nystagmus/strabismus (AOR 9.22; 95% CI 2.66 to 31.97) and aphakia (AOR, 5.32; 95% CI 1.05 to 26.97) predicted poor visual outcome in bilateral cases. 9% of 342 refracted eyes had initial postoperative cylinder of 1.5 D or more, as did a similar proportion (11%) of 315 eyes refracted 1 year after surgery. Acute fibrinous uveitis occurred in 41 (12%) eyes., Conclusion: Three-quarters of children were blind preoperatively whereas over half had good vision 1-year postoperatively. Preoperative blindness, nystagmus/strabismus and aphakia predicted poor visual outcome, suggesting that cataract density determines density of amblyopia., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY. Published by BMJ.)

Retinopathy of prematurity (ROP) is a largely avoidable cause of blindness in children worldwide, requiring high-quality neonatal care, early detection and treatment. In middle-income countries throughout Latin America, Eastern Europe and South Asia, there has been a rise in ROP blindness due to a combination of increased survival of preterm infants, resource-scarce medical environments and lack of policies, training and human resources. However, Argentina is an example of country where rates of ROP blindness have declined and ROP programmes have been successfully and effectively embedded within the health and legal system. The purpose of this study is to describe the activities and stakeholders, including Ministry of Health (MoH) and UNICEF, involved in the process, from recognition of an epidemic of ROP blindness to the development of national guidelines, policies and legislation for control. Using a retrospective mixed methods case study design, data on rates of severe ROP was collected from 13 neonatal intensive care units from 1999 to 2012, and on the proportion of children blind from ROP in nine blind schools in seven provinces. Legislative document review, focus group discussions and key informant interviews were conducted with neonatologists, ophthalmologists, neonatal nurses, parents, MoH officials, clinical societies, legislators and UNICEF officials in seven provinces. Results are presented combining the stages heuristic policy framework and Shiffman including: agenda setting, policy formulation, implementation and evaluation. By 2012, ROP had declined as a cause of blindness in children in schools for the blind as had rates of severe ROP needing treatment in the NICUs visited. Multiple factors played a role in reducing blindness from ROP in Argentina and successfully coordinating its control including national advocacy, leadership, legislation and international collaboration. Lessons learned in Argentina can potentially be scaled to other LMICs in Latin America and beyond with further context-specific research.

Background: To ascertain which countries in the world have retinopathy of prematurity (ROP) screening programmes and guidelines and how these were developed., Methods: An email database was created and requests were sent to ophthalmologists in 141 nations to complete an online survey on ROP screening in their country., Results: Representatives from 92/141 (65%) countries responded. 78/92 (85%) have existing ROP screening programmes, and 68/78 (88%) have defined screening criteria. Some countries have limited screening and those areas which have no screening or for which there is inadequate knowledge are mainly Southeast Asia, Africa and some former Soviet states., Discussion: With the increasing survival of premature babies in lower-middle-income and low-income countries, it is important to ensure that adequate ROP screening and treatment is in place. This information will help organisations focus their resources on those areas most in need., Competing Interests: Competing interests: None declared., (© 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.)

Objective: Inequalities in cataract blindness are well known, but data are rarely disaggregated to explore the combined effects of a range of axes describing social disadvantage. We examined inequalities in cataract blindness and services at the intersection of three social axes., Methods: Three dichotomous social variables (sex (male/female); place of residence (urban/rural); literacy (literate/illiterate)) from cross-sectional national blindness surveys in Pakistan (2001-2004; n=16 507) and Nigeria (2005-2007; n=13 591) were used to construct eight subgroups, with disadvantaged subgroups selected a priori (ie, women, rural dwellers, illiterate). In each data set, the social distribution of cataract blindness, cataract surgical coverage (CSC) and effective cataract surgical coverage (eCSC) were examined. Inequalities were assessed comparing the best-off and worst-off subgroups using rate differences and rate ratios (RRs). Logistic regression was used to assess cumulative effects of multiple disadvantage., Results: Disadvantaged subgroups experienced higher prevalence of cataract blindness, lower CSC and lower eCSC in both countries. A social gradient was present for CSC and eCSC, with coverage increasing as social position improved. Relative inequality in eCSC was approximately twice as high as CSC (Pakistan: eCSC RR 2.7 vs CSC RR 1.3; Nigeria: eCSC RR 8.7 vs CSC RR 4.1). Cumulative disadvantage was observed for all outcomes, deteriorating further with each additional axis along which disadvantage was experienced., Conclusions: Each outcome tended to be worse with the addition of each layer of social disadvantage. Illiterate, rural women fared worst in both settings. Moving beyond unidimensional analyses of social position identified subgroups in most need; this permits a more nuanced response to addressing the inequitable distribution of cataract blindness., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Purpose: We explored the risk factors for glaucoma blindness among adults aged 40 years and above with primary glaucoma in Nigeria., Participants and Methods: A total of 13,591 participants aged 40 years and above were examined in the Nigeria Blindness Survey; 682 (5.02%; 95 CI, 4.60%-5.47%) had glaucoma by ISGEO's criteria. This was a case-control study (n=890 eyes of 629 persons): glaucoma blind persons were cases and glaucoma not-blind were controls. Education and occupation were used to determine socioeconomic status scores, which were divided into 3 tertiles (affluent, medium, deprived). We assessed sociodemographic, biophysical, and ocular factors by logistic regression analysis for association with glaucoma blindness. Multinomial regression analysis was also performed with nonglaucoma as the reference category., Results: A total of 119/629 (18.9%; 95% CI, 15.9%-22.4%) persons were blind in both eyes; 510 were controls. There was interethnic variation in odds of blindness; age, male sex, socioeconomic status, prior diagnosis of glaucoma, hypertension, intraocular pressure, and lens opacity were associated with glaucoma blindness. Axial length, mean ocular perfusion pressure, and angle-closure glaucoma were associated with blind glaucoma eyes. In multivariate analysis, Igbo ethnicity (OR=2.79; 95% CI, 1.03-7.57) had higher risk as was being male (OR=4.59; 95% CI, 1.73-12.16) and unmarried (OR=2.50; 95% CI, 1.03-6.07). Deprivation (OR=3.57; 95% CI, 1.46-8.72), prior glaucoma diagnosis (OR=5.89; 95% CI, 1.79-19.40), and intraocular pressure (OR=1.07; 95% CI, 1.04-1.09) were also independent risk factors for glaucoma blindness., Conclusion: Approximately 1 in 5 people with primary glaucoma were blind. Male sex, ethnicity and deprivation were strongly associated with blindness. Services for glaucoma need to improve in Nigeria, focusing on poor communities and men.

Background: The glaucoma-specific blindness prevalence in Nigeria (0.7 %, 95 % CI 0.6-0.9 %) among those aged ≥40 years is one of the highest ever reported. This study determined the risk factors for open-angle glaucoma (OAG) in adults examined in the Nigeria National Blindness and Visual Impairment Survey., Methods: A nationally representative sample of 13,591 people aged ≥40 years in 305 clusters in Nigeria were examined (response rate 90.4 %) between January 2005 to June 2007. Everyone had logMAR visual acuity measurement, Frequency Doubling Technology (FDT) visual field testing, autorefraction, A-scan biometry and optic disc assessment. Full ocular examination (n = 6397), included Goldmann applanation tonometry. Values for defining glaucoma using International Society of Geographical and Epidemiological Ophthalmology criteria were derived from the study population. Disc images were graded by Moorfields Eye Hospital Reading Centre. Socio-demographic factors (age, gender, ethnicity, literacy and place of residence), ocular parameters (intraocular pressure [IOP], axial length and mean ocular perfusion pressure [MOPP]) and systemic parameters (blood pressure, blood glucose and body mass index [BMI]) were assessed for association with OAG., Results: Thirteen thousand eighty-one (96 %) of 13,591 participants had vertical cup:disc ratio measured in at least one eye. 682 eyes of 462 participants were classified as OAG, with 12,738 controls. In univariate analyses the following were associated with OAG: increasing age, male gender, Igbo and Yoruba ethnic groups, illiteracy, longer axial length, higher IOP, lower MOPP, greater severity of hypertension and low BMI (underweight). In multivariate analysis, increasing age (odds ratio [OR] 1.04, 95 % CI 1.03-1.05), higher IOP (OR 1.22, 95 % CI 1.18-1.25) and Igbo ethnicity (OR 1.73, 95 % CI 1.18-2.56) were independent risk factors for OAG., Conclusion: Case detection strategies for OAG should be improved for those aged ≥40 years and for ethnic groups most at risk as a public health intervention.

Purpose: Cataract is a common cause of avoidable blindness in children globally. Gender differences in service access among children are reported for several conditions, but not for surgery for bilateral cataract. In this review we compared the proportion of children undergoing surgery for bilateral, nontraumatic cataract who were girls, using data from high-income, gender-neutral countries as the reference., Design: Systematic review., Methods: A systematic review of MEDLINE was undertaken in November 2014. Studies published only from 2000 onward were included because techniques and services have improved over time. A wide range of study designs was included such as: population-based data, registers, studies of surgical techniques, clinical trials, and so forth. All articles with 20 or fewer cases were excluded or were of long-term follow-up only, because this may reflect gender differences during follow-up. A meta-analysis was not planned., Results: Thirty-eight studies (6854 children) were included from 1342 titles, 10 from high-income countries. Many did not present data disaggregated by gender. Overall, 36.5% of children were girls. In gender-neutral countries, 47.5% of children (777/1636) were girls, being similar in the Middle East, North Africa, and Central Asia (48.6%; 87/179) and in Latin America and the Caribbean (43.7%; 188/430). Proportions were significantly lower in sub-Saharan Africa (41.1%; 225/547), East Asia and the Pacific (36.0%; 237/658), and South Asia (29.1%; 991/3404)., Conclusions: Access to surgery by girls with bilateral cataract is lower in some regions than by boys. Barriers to access specific to girls need to be identified, particularly in Asia, to assess interventions to improve uptake., (Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Background: Glaucoma is the leading cause of irreversible blindness worldwide. There tends to be a lower reporting of glaucoma in Africa compared to other blinding conditions in global burden data. Research findings of glaucoma in Nigeria will significantly increase our understanding of glaucoma in Nigeria, in people of the West African diaspora and similar population groups. We determined the prevalence and types of glaucoma in Nigeria from the Nigeria National Blindness and Visual Impairment cross-sectional Survey of adults aged ≥40 years., Methods: Multistage stratified cluster random sampling with probability-proportional-to-size procedures were used to select a nationally representative sample of 15,027 persons aged ≥40 years. Participants had logMAR visual acuity measurement, FDT visual function testing, autorefraction, A-scan biometry and optic disc assessment. Participants with visual acuity of worse than 6/12 or suspicious optic discs had detailed examination including Goldmann applanation tonometry, gonioscopy and fundus photography. Disc images were graded by Moorfields Eye Hospital Reading Centre. Glaucoma was defined using International Society of Geographical and Epidemiological Ophthalmology criteria; and classified into primary open-angle or primary angle-closure or secondary glaucoma. Diagnosis of glaucoma was based on ISGEO classification. The type of glaucoma was determined by gonioscopy., Results: A total of 13,591 participants in 305 clusters were examined (response rate 90.4 %). Optic disc grading was available for 25,289 (93 %) eyes of 13,081 (96 %) participants. There were 682 participants with glaucoma; a prevalence of 5.02 % (95 % CI 4.60-5.47). Among those with definite primary glaucoma that had gonioscopy (n = 243), open-angle glaucoma was more common (86 %) than angle-closure glaucoma (14 %). 8 % of glaucoma was secondary with the commonest causes being couching (38 %), trauma (21 %) and uveitis (19 %). Only 5.6 % (38/682) of participants with glaucoma knew they had the condition. One in every 5 persons with glaucoma (136;20 %) was blind i.e., visual acuity worse than 3/60., Conclusion: Nigeria has a high prevalence of glaucoma which is largely open-angle glaucoma. A high proportion of those affected are blind. Secondary glaucoma was mostly as a consequence of procedures for cataract. Public health control strategies and high quality glaucoma care service will be required to reduce morbidity and blindness from glaucoma.

To describe the characteristics of infants with bilateral Stage 4b or 5 ROP (i.e. with subtotal or total retinal detachment) who presented to eye departments in two major cities in Mexico, to identify reasons why they may have become blind in order to recommend how programs could be improved. A large case-series of infants with Stage 4b or 5 ROP in both eyes confirmed by ultrasound who attended the ROP Clinic, Hospital Civil de Guadalajara from September 2010 to November 2012, and the Department of Ophthalmology, Hospital Infantil de Mexico Federico Gomez from December 2011 to December 2012 were identified from the diagnostic databases of each hospital. Mothers of infants in Guadalajara had a telephone interview. 89/94 eligible infants were included in the study, 48 in Guadalajara and 41 in Mexico City. Cases came from 22 of the 32 states in Mexico. Half of the infants attending Guadalajara 24/48 (50 %) had been cared for in NICUs without ROP screening programs and were not examined. Among the 24 infants cared for in NICUs with ROP programs, 7/24 (29.1 %) mothers reported that their infant had not been examined while in the NICU, and a further 9/24 (37.5 %) were either not referred for screening after discharge or they did not attend. Two infants had failed laser treatment. Strategies and resources to prevent end stage ROP have not been firmly established in Mexico. There is an urgent need to expand the coverage and quality of ROP programs, to ensure that existing screening guidelines are better adhered to, and to improve communication with parents.

Objectives: Little is known about the impact of HIV infection on biological ageing in sub-Saharan Africa. The study aimed to assess biological ageing in South African HIV-infected adults and HIV-seronegative individuals using two validated biomarkers, telomere length and CDKN2A expression (a mediator of cellular senescence)., Design: A case-control study., Methods: Two hundred and thirty-six HIV-infected adults aged at least 30 years and 250 age and sex frequency matched HIV-seronegative individuals were recruited from clinics in township communities in Cape Town. Biological ageing was evaluated by measurement of telomere length and CDKN2A expression in peripheral blood leukocytes., Results: The median ages of the HIV-infected and HIV-seronegative participants were 39 and 40 years, respectively. Among HIV-infected participants, 87.1% were receiving antiretroviral therapy (ART), their median CD4⁺ cell count was 468 cells/μl and 84.3% had undetectable viral load. Both biomarkers were validated against chronological age in HIV-seronegative individuals. Telomere length was significantly shorter in HIV-infected individuals than in HIV-seronegative individuals (mean relative T/S ratio ±SE:0.91 ± 0.007 vs. 1.07 ± 0.008, P < 0.0001). CD2NKA expression was higher in HIV-infected participants than in HIV-seronegative individuals (mean expression: 0.45 ± 0.02 vs. 0.36 ± 0.03, P = 0.003). Socioeconomic factors were not associated with biological ageing in HIV-infected participants. However, in participants on ART with undetectable viral load, biomarker levels indicated greater biological ageing in those with lower current CD4⁺ cell counts., Conclusion: Telomere length and CDKN2A expression were both consistent with increased biological ageing in HIV-infected individuals. Prospective studies of the impact of HIV on biological ageing in sub-Saharan Africa are warranted., (© 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins)

HIV-infected individuals have an increased risk of age-related morbidity despite antiretroviral treatment (ART). Several anatomic and functional ophthalmological parameters are associated with increasing chronological age. These may, therefore, potentially serve as biomarkers of ageing. We investigated associations between ocular parameters (lens density, retinal vessel calibre, corneal endothelium and retinal nerve fibre layer thickness) and two 'cellular' biomarkers of ageing (leukocyte telomere length and CDKN2A expression) and with frailty in a cross-sectional study of 216 HIV-infected individuals. All ocular parameters, telomere length and frailty were associated with chronological age, whereas CDKN2A expression was not. Retinal venular calibre and lens density were associated with shorter telomere length (p-trend=0.04, and 0.08, respectively), whereas CDKN2A expression and frailty status were not associated with ocular parameters. Longitudinal studies are warranted to assess the integration of retinal vascular calibre and lens density with systemic markers to develop an overall index of biological ageing in HIV infection., (Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.)

Certain anatomic and functional parameters of the eye change with increasing chronological age. They may, therefore, serve as potential biomarkers of ageing. We investigated associations between four such ocular parameters (lens density, retinal vessel calibre, corneal endothelial cells and retinal nerve fibre layer thickness) and two 'cellular' biomarkers of ageing (leukocyte telomere length and CDKN2A expression), with frailty (a clinical correlate of biological ageing) in a population of South African adults. All ocular parameters revealed an association with either telomere length or CDKN2A expression. However, lens density was most strongly correlated with age, increased CDKN2A expression, and with frailty (p=0.05 and 0.03, respectively). Narrow retinal arteriolar diameter, associated with increased chronological age, was also associated with increased CDK2NA expression (0.42 vs. 0.31, p=0.02) but not with frailty. Ocular parameters may aid in determining biological age, warranting investigation in longitudinal studies., (Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.)

Retinopathy of prematurity (ROP) programs require collaboration between neonatologists, ophthalmologists, nurses, and allied health personnel, together with parents. The concept of a ROP program will vary according to the setting. However, in every situation there should be 2 main aspects: primary prevention of ROP through better overall care, and secondary prevention through case detection (often called screening), treatment, and follow-up. ROP programs will have different content and emphasis according to whether the setting is in an economically advanced or developing country., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Purpose: Antioxidant supplements may reduce age-related macular degeneration (AMD) progression. The macular carotenoids are of particular interest because of their biochemical, optical, and anatomic properties. This classic twin study was designed to determine the heritability of macular pigment (MP) augmentation in response to supplemental lutein (L) and zeaxanthin (Z)., Methods: A total of 322 healthy female twin volunteers, aged 16-50 years (mean 40 ± 8.7) was enrolled in a prospective, nonrandomized supplement study. Macular pigment optical density (MPOD) measurements using two techniques (2-wavelength fundus autofluorescence [AF] and heterochromatic flicker photometry [HFP]), and serum concentrations of L and Z, were recorded at baseline, and at 3 and 6 months following daily supplementation with 18 mg L and 2.4 mg Z for a study period of 6 months., Results: At baseline, mean MPOD was 0.44 density units (SD 0.21, range 0.04-1.25) using HFP, and 0.41 density units (SD 0.15) using AF. Serum L and Z levels were raised significantly from baseline following 3 months' supplementation (mean increase 223% and 633%, respectively, P < 0.0001 for both), with no MPOD increase. After 6 months' supplementation, a small increase in MPOD was seen (mean increase 0.025 ± 0.16, P = 0.02, using HFP). Subdivision of baseline MPOD into quartiles revealed that baseline levels made no difference to the treatment effect. Genetic factors explained 27% (95% confidence interval [CI] 7-45) of the variation in MPOD response. Distribution profiles of macular pigment did not change in response to supplementation., Conclusions: MPOD response to supplemental L and Z for a period of 6 months was small (an increase over baseline of 5.7% and 3.7%, measured using HFP and AF, respectively), and was moderately heritable. Further study is indicated to investigate the functional and clinical impact of supplementation with the macular carotenoids.

Objective: To describe the preoperative surgical case mix among patients undergoing cataract extraction and explore associations between case mix, country level of development (as measured by the Human Development Index, HDI) and cataract surgery rates (CSRs)., Methods: Ophthalmologists in 50 countries were invited to join the newly-established International Eye Research Network and asked to complete a web-based questionnaire about their eye hospitals. Those who complied received a data collection form for recording demographic and clinical data on 100 consecutive patients about to undergo cataract surgery. Countries were ranked into five HDI categories and multivariable regression was used to explore associations., Findings: Ophthalmologists at 112 eye hospitals (54% of them nongovernmental) in 50 countries provided data on 11,048 cataract procedures over 9 months in 2008. Patients whose visual acuity (VA) before surgery was < 6/60 in the better eye comprised 47% of the total case mix in poorly developed countries and 1% in developed countries (P < 0.001). Overall, 72% of the eyes undergoing surgery had a VA < 6/60. Very low VA before cataract surgery was strongly associated with poor development at the country level and inversely associated with national CSR., Conclusion: The proportion of patients with very poor preoperative VA is a simple indicator that can be easily measured periodically to monitor progress in ophthalmological services. Additionally, the internet can be an effective tool for developing and supporting an ophthalmological research network capable of providing a global snapshot of service activity, particularly in developing countries.

Purpose: To estimate prevalence and describe causes of functional low vision (FLV) among a nationally representative sample of Nigerian adults, assess socioeconomic risk factors, and estimate the number of adults in Nigeria who might benefit from low vision assessment or rehabilitation services., Methods: Multistage, stratified, cluster random sampling with probability proportional to size procedures were used to identify a nationally representative sample of 15,027 persons aged 40 years or older. Distance vision was measured using a reduced logMAR tumbling E-chart. All participants with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause. FLV was defined as best corrected vision <6/18 in the better eye, after excluding those with no light perception in both eyes and those with treatable causes. Analysis took account of the clustered design., Results: In all, 13,591 individuals were examined in 305 clusters (response rate, 89.9%). The crude prevalence of FLV was 3.5% (95% confidence interval, 3.1-3.9%). This was lower than the prevalence of blindness, which was 4.2%. Glaucoma was the most common cause and age the most important risk factor. There are estimated to be approximately 5000 adults with FLV per million population and 340 who are totally blind. Only 9.3% of those with FLV were of working age and literate., Conclusions: These are the first data on the prevalence, causes, and risk factors for FLV from Africa. Results support studies from Asia that the prevalence of FLV is lower than previously thought. Because the majority of adults with FLV in Nigeria live in rural areas and are elderly and not literate, further research is required to assess the nature of the interventions required and who might best deliver them.

Purpose: To provide data on prevalence and types of refractive error and the spectacle-wearing rate among adults in Nigeria and the degree to which the need for distance correction could be met by off-the-shelf spectacles., Methods: Multistage, stratified, cluster random sampling with probability proportional to size was used to identify a nationally representative sample of 15,027 persons aged ≥40 years. Distance vision was measured using a reduced logMAR tumbling-E chart. All participants underwent autorefraction, and those with presenting acuity of <6/12 in one or both eyes had their corrected acuity measured and underwent detailed clinical examination to determine the cause., Results: Included in the survey were 13,599 (89.9%) of the 15,122 persons aged ≥40 years who were enumerated. Uncorrected refractive error was responsible for 77.9% of mild visual impairment (<6/12-6/18), 57.1% of moderate visual impairment (<6/18-6/60), 11.3% of severe visual impairment (<6/60-3/60), and 1.4% of blindness (<3/60). The crude prevalence of myopia (≤0.5 D) and high myopia (≤5.0 D) were 16.2% and 2.1%, respectively. Spectacles could improve the vision of 1279 (9.4%) and 882 (6.5%) participants at the 6/12 and 6/18 level, respectively, but only 3.4% and 4.4% of these individuals wore spectacles to the examination site. Approximately 2,140,000 adults in Nigeria would benefit from spectacles that improved their vision from <6/12 to ≥6/12. More than a third of the need could be met by low-cost, off-the-shelf spectacles., Conclusions: Uncorrected refractive errors are an important cause of visual impairment in Nigeria, and services must be dramatically improved to meet the need.

Objective: To describe presenting and corrected visual acuities after cataract surgery in a nationally representative sample of adults. Another objective was to describe refractive errors in operated eyes and to determine the optimal range of intraocular lens (IOL) powers for this population., Design: Cross-sectional, population-based survey., Participants: Adults aged 40 years and more were selected using multistage stratified sampling and proportional to size procedures. A sample size of 15027 was calculated, and clusters were selected from all states., Methods: Individuals who had undergone cataract surgery were identified from interview and examination. All had their presenting visual acuity (VA) measured using a reduced logarithm of the minimum angle of resolution chart and underwent autorefraction. Corrected VAs were assessed using the autorefraction results in a trial set. An ophthalmologist conducted all examinations, including slit-lamp and dilated fundus examination. Causes of visual loss were determined for all eyes with a presenting VA <6/12 using the World Health Organization recommendations. Biometry data were derived from 20449 phakic eyes using the SRK-T formula after excluding those with poor VA or corneal opacities., Main Outcome Measures: Presenting and corrected visual acuities in pseudo/aphakic individuals and autorefraction findings; biometry profile of Nigerian adults., Results: Data from 288 eyes of 217 participants were analyzed. Only 39.5% of eyes had undergone IOL implantation at surgery. Only 29.9% of eyes had a good outcome (i.e., ≥6/18) at presentation, increasing to 55.9% with correction. Use of an IOL was the only factor associated with a good outcome at presentation (odds ratio 9.0; 95% confidence interval, 4.3-18.9; P=0.001). Eyes undergoing cataract surgery had a higher prevalence and degree of astigmatism than phakic eyes. Biometry data reveal that posterior chamber IOL powers of 20, 21, and 22 diopters (D) (A constant 118.0) will give a postoperative refraction range of -2.0 D to emmetropia in 71.4% of eyes, which increases to 82.6% if 19 D is also included., Conclusions: Postoperative astigmatism needs to be reduced through better surgical techniques and training, and use of biometry should be standard of care., (Copyright © 2011 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Aims: To determine if screening with an ultrasound A-scan and prophylactic treatment of primary angle closure (PAC) with laser peripheral iridotomy (LPI) can reduce the incidence of primary angle closure glaucoma (PACG) in Mongolia., Methods: A single-masked randomised controlled trial was initiated in 1999. 4725 volunteer Mongolian participants ≥ 50 years old from the capital Ulaanbaatar or the rural province of Bayankhongor were recruited, of which 128 were excluded with glaucoma. 4597 were randomly allocated to the control, no-screening arm or screening with ultrasound central anterior chamber depth (cACD), with the cut-off set at < 2.53 mm. 685 screen-positive participants were examined and angle closure was identified by gonioscopy in 160, of which 156 were treated with prophylactic LPI. Primary outcome of incident PACG was determined using both structural and functional evidence from objective grading of paired disc photographs from baseline and follow-up, objective grading of follow-up visual fields and clinical examination., Results: Six years later, 801 (17.42%) participants were known to have died, and a further 2047 (53.92%) were traced and underwent full ophthalmic examination. In an intention to treat analysis using available data, PACG was diagnosed in 33 participants (1.61%, 95% CI 1.11% to 2.25%), of which 19 were in the screened group and 14 in the non-screened group (OR 1.29, 95% CI 0.65 to 2.60, p = 0.47), indicating no difference between groups., Conclusions: We were not able to identify a reduction in the 6 year incidence of PACG after screening with cACD < 2.53 mm and prophylactic treatment of PAC.

Purpose: Couching is an ancient treatment for cataract which is still practiced in some of the poorer developing countries, particularly in sub-Saharan Africa. The purpose of this study is to describe risk factors for couching and visual acuity outcomes in a nationally representative sample of adults aged 40 years and above in Nigeria., Methods: Probability in proportion size methods were used to identify a representative sample. Of the 15,375 adults enumerated, 13,582 were interviewed and examined. Examination included logMar acuities, slit lamp examination and dilated fundoscopy with digital fundus imaging., Results: Almost half of the 583 eyes undergoing a procedure for cataract had been couched (249 eyes, 42.7%). Individuals living in rural areas (P = 0.033) and in the two underserved northern administrative zones (P = 0.33; P = 0.002) were more likely to have been couched. Visual outcomes were poor according to World Health Organization categories, with 55.8% of people and 73.1% of eyes having a presenting visual acuity of less than 3/60 and only 9.7% and 2.4% of people and eyes respectively having a good outcome (6/18 or better). None were wearing an aphakic correction, and with correction acuities improved but 42.6% of eyes were still blind (< 3/60)., Conclusions: Couching is still widely practiced in Nigeria and visual outcomes are very poor. The population needs to be made aware of the risks associated with the procedure, and services for high quality, affordable cataract surgery need to be expanded, particularly in rural areas and in the north of the country.

Purpose: To determine the prevalence and causes of functional low vision (FLV) and total blindness and to estimate the assessment needs for low-vision services in Pakistan., Methods: Multistage, cluster random sampling was used to select a nationally representative sample of adults (age, > or =30 years). Participants underwent visual acuity measurement and detailed ophthalmic examination. Functional low vision was defined as a corrected visual acuity in the better eye of less than 6/18 to more than no perception of light (NPL) in individuals with untreatable causes of visual loss. Total blindness was defined as NPL in both eyes. Needs assessments were categorized into three groups: optical services, nonoptical/environmental interventions, and rehabilitation., Results: A sample of 16,507 adults (95.3% response rate) was examined. The standardized prevalence of FLV and total blindness were 1.7% (95% CI: 1.5%-1.9%) and 0.2% (95% CI: 0.1%-0.2%), respectively. More than 90% of those with FLV were illiterate and 35.3% were of working age (i.e., <60 years). An estimated 727,000 (586,000-891,000) adults in Pakistan had FLV. Retinal conditions were the commonest cause in urban populations (39.8% vs. 26.5% rural) compared with corneal opacity in rural areas (38.0% vs. 25.5% urban). It was estimated that 565,000 adults require assessment for optical services, 735,000 for nonoptical interventions, and 424,000 for rehabilitation., Conclusions: As VISION 2020 enters its second 5-year phase, the provision of low-vision services and their integration into national eyecare programs is a priority. In Pakistan, planning must take account of the magnitude along with the demographic and educational characteristics of those affected.

Purpose: Data on the prevalence and causes of functional low vision (FLV) in adults and children are lacking but are important for planning low-vision services. This study was conducted to determine the prevalence and causes of FLV among children recruited in eight population-based prevalence surveys of visual impairment and refractive error from six countries (India [2 locations]; China [2 locations]; Malaysia, Chile, Nepal, and South Africa)., Methods: Using the same protocol, 4082 to 6527 children aged 5 (or 7) to 15 years were examined at each site. Uncorrected and presenting visual acuities were successfully measured with retroilluminated logMAR tumbling-E charts in 3997 to 5949 children; cycloplegic autorefraction was performed and best corrected acuities assessed. All children were examined by an ophthalmologist and a cause of visual loss assigned to eyes with uncorrected acuity < or =6/12. The prevalence of FLV was determined overall and by site; associations with gender, age, parental education and urban/rural location were assessed with logistic regression., Results: The prevalence of FLV ranged from 0.65 to 2.75 in 1000 children, with wide confidence intervals. The overall prevalence was 1.52 in 1000 children (95% CI 1.16-1.95). FLV was significantly associated with age (odds ratio [OR] 1.13 for each year, P = 0.01), and parental education was protective (OR 0.75 for each of five levels of education, P = 0.017). Retinal lesions and amblyopia were the commonest causes., Conclusions: More studies are needed to determine the prevalence and causes of FLV in children so that services can be planned that promote independence, improve quality of life, and increase access to education.

Objective: To explore the association between blindness and deprivation in a nationally representative sample of adults in Pakistan., Design: Cross sectional population based survey., Setting: 221 rural and urban clusters selected randomly throughout Pakistan., Participants: Nationally representative sample of 16 507 adults aged 30 or above (95.3% response rate)., Main Outcome Measures: Associations between visual impairment and poverty assessed by a cluster level deprivation index and a household level poverty indicator; prevalence and causes of blindness; measures of the rate of uptake and quality of eye care services., Results: 561 blind participants (<3/60 in the better eye) were identified during the survey. Clusters in urban Sindh province were the most affluent, whereas rural areas in Balochistan were the poorest. The prevalence of blindness in adults living in affluent clusters was 2.2%, compared with 3.7% in medium clusters and 3.9% in poor clusters (P<0.001 for affluent v poor). The highest prevalence of blindness was found in rural Balochistan (5.2%). The prevalence of total blindness (bilateral no light perception) was more than three times higher in poor clusters than in affluent clusters (0.24% v 0.07%, P<0.001). The prevalences of blindness caused by cataract, glaucoma, and corneal opacity were lower in affluent clusters and households. Reflecting access to eye care services, cataract surgical coverage was higher in affluent clusters (80.6%) than in medium (76.8%) and poor areas (75.1%). Intraocular lens implantation rates were significantly lower in participants from poorer households. 10.2% of adults living in affluent clusters presented to the examination station wearing spectacles, compared with 6.7% in medium clusters and 4.4% in poor cluster areas. Spectacle coverage in affluent areas was more than double that in poor clusters (23.5% v 11.1%, P<0.001)., Conclusion: Blindness is associated with poverty in Pakistan; lower access to eye care services was one contributory factor. To reduce blindness, strategies targeting poor people will be needed. These interventions may have an impact on deprivation in Pakistan.

Aims: To examine the relative roles of genetic and environmental factors in central retinal thickness, by performing a classical twin study., Methods: 310 subjects were recruited from the TwinsUK adult registry at St Thomas' Hospital. Optical coherence tomography (Zeiss, stratus OCT3) was used to measure the average retinal thickness in the central 1 mm diameter area. The covariance of central retinal thickness (CRT), within MZ and DZ twin pairs, was compared and genetic modelling techniques were used to determine the relative contributions of genes and environment to the variation in CRT observed in this population., Main Outcome Measure: CRT (average retinal thickness in the central 1 mm diameter area, centred on the fovea)., Results: The mean CRT of all subjects was 212.1 microm (range 165-277). CRT was statistically related to refractive error, with increasing myopia associated with a thinner CRT. CRT was more highly correlated within MZ twin pairs (r = 0.88) than with DZ twin pairs (r = 0.58), suggesting a genetic role. A model combining additive genetic and unique environmental factors provided the best fitting model and gave a heritability estimate of 0.90., Conclusion: Genetic factors appear to play an important role in CRT, with a heritability estimate of 0.90.

Purpose: To estimate the relative importance of genes and environment in peripapillary atrophy type beta (beta-PPA) in a classic twin study., Methods: Female twin pairs (n = 506) aged 49 to 79 years were recruited from the St. Thomas' UK Adult Twin Registry. Peripapillary atrophy was identified from masked grading of stereoscopic optic disc photographs. Structural equation modeling was performed using Mx with polychoric correlations of beta-PPA and refractive error (divided into deciles)., Results: Beta-PPA prevalence was 25.1% and did not vary with zygosity. Case-wise concordance for right eyes was 0.76 (95% CI, 0.57-0.88) for monozygotic (MZ) and 0.37 (95% CI, 0.15-0.56) for dizygotic (DZ) pairs. Multivariate modeling suggested additive genetic effects and individual environment, with no shared environment or dominant genetic effect. Beta-PPA heritability was 0.70 (95% CI, 0.54-0.83), and spherical equivalent 0.88 (95% CI, 0.85-0.91); age had no significant effect on variance. The genetic correlation between beta-PPA and spherical equivalent was -0.21. However, only 3% of the genetic variance of beta-PPA was explained by genetic factors in common with refractive error, with 67% explained by specific genetic factors for beta-PPA. Of the 30% of variance explained by unique environmental factors, only 3% was explained by these factors in common with environmental factors involved in refractive error., Conclusions: The presence of beta-PPA, a frequent ocular finding known to be associated with open-angle glaucoma, appears to be under strong genetic control, with only a small amount of this genetic effect shared with genes involved in myopia.

Macular pigment (MP) has been suggested to have a protective role in age-related macular degeneration by reducing the amount of oxidative stress on the retina. MP levels peak at the foveal center, where it is found predominantly in the receptor axon and inner plexiform layers of the retina. The purpose of this study was to investigate the relationship between central retinal thickness and macular pigment optical density in a group of healthy subjects. We report that macular pigment optical density (MPOD) has a significant and positive relationship with central retinal thickness as measured by optical coherence tomography. The strength of the observed relationship (r approximately 0.30) was independent of the technique used to measure MPOD, whether heterochromatic flicker photometry (HFP) or 2-wavelength autofluorescence (AF). Of note, there was no statistically demonstrable relationship between MPOD at an eccentricity of 1- or 2-degrees and central retinal thickness. This finding has important implications for future studies investigating MPOD, and its response to dietary modification/supplementation.

Purpose: A classic twin study was performed to determine the heritability of central corneal thickness (CCT), an important parameter in glaucoma assessment., Methods: The concordance of CCT between monozygotic (MZ) and dizygotic (DZ) twins was compared. A total of 256 twin pairs (131 MZ and 125 DZ) were recruited from three centers: the Twin Eye Study in Tasmania, the Brisbane Adolescent Twin Study, and the Twins U.K. Adult Registry held at St. Thomas' Hospital in London. As part of an extensive ophthalmic evaluation, CCT was measured by ultrasound pachymetry. Structural equation modeling with the Mx program (Department of Psychiatry, Medical College of Virginia, Richmond, VA) was used to determine the heritability of CCT., Results: The mean age of subjects was 38 years (range, 8-81). The mean CCT of all eyes examined was 544.5 +/- 37.3 mum (SD). The CCT measurements correlated more highly in MZ twins than in DZ twins, with intraclass correlation coefficients of 0.95 and 0.52, respectively, suggesting a strong genetic influence. A model of additive genetic and unique environmental effects provided the best fit, yielding a heritability of 0.95 (95% confidence interval [CI], 0.93-0.96) with the remaining variation being attributable to unique environmental factors., Conclusions: In this study of Australian and U.K. twins, genetic factors were shown to be of major importance in CCT, with a heritability of 0.95.

Congenital malformations of the eye can cause blindness in children. They occur throughout the world and in most cases the aetiology is unknown. Linkage studies have largely been unsuccessful and the risk to siblings is generally low. Epidemiological and laboratory evidence support a hypothesis that there may be genetic (recessive) predisposition to the teratogenetic effects of mild to moderate maternal vitamin A deficiency (VAD) during pregnancy. This may explain the higher prevalence of congenital eye anomalies in a part of Asian countries, where maternal VAD is common and consanguineous marriages are popular. Other congenital malformations commonly found in association with ocular coloboma (e.g. oesophageal fistulae and heart defects in CHARGE association) may also be VAD related. Mutations in a gene involved in the cellular access to vitamin A that normally protects the tissue or embryo from natural variation in dietary vitamin A intake, could render that individual intolerant of conditions of VAD. An interaction of this kind could also explain a proportion of "sporadic" cases in locations where VAD is uncommon. If this interaction is shown to be true, there are public health implications for the prevention of blindness due to congenital eye malformations. The hypotheses proposed above are reminiscent of the research leading to the discovery that folic acid supplementation could prevent neural tube defects. However, this form of intervention would be much more difficult with vitamin A, which is itself a powerful teratogen if present in excess.