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PURPOSE: Hyperreflective foci (HRF) are optical coherence tomography (OCT) biomarkers for progression of non-neovascular age-related macular degeneration (AMD) attributed to anteriorly migrated retinal pigment epithelial (RPE) cells. We examined associations between rod- and cone-mediated vision and HRF plus smaller hyperreflective specks (HRS); we sought a histologic candidate for HRS. DESIGN: cross-sectional study; histologic survey PARTICIPANTS: Patients with normal maculas (n=34), early AMD (N=26), and intermediate AMD (N=41) METHODS: AMD severity was determined via the 9-step Age-Related Eye Disease Study scale. In OCT scans HRF and HRS were manually counted. Vision tests probed cones (best corrected visual acuity (VA), contrast sensitivity), mixed cones and rods (low luminance VA, low luminance deficit, mesopic light sensitivity), or rods (scotopic light sensitivity, rod-mediated dark adaptation (RMDA)). An online AMD histopathology resource was reviewed. MAIN OUTCOME MEASURES: Vision in eyes assessed for HRF and HRS; candidate histology for HRS. RESULTS: In 101 eyes of 101 patients, HRF and HRS were identified in 25 and 95 eyes, respectively, with good intra- and inter-rater reliability. HRF were present but sparse in normal eyes, infrequent in early AMD eyes, and frequent but highly variable among intermediate AMD eyes (number per eye, 0.1±0.2, 0.2±0.5, 1.9 ± 3.4; normal, early, intermediate, respectively). HRS outnumbered HRF in all groups (4.5 ± 3.2; 6.3±5.8; 19.4 ± 22.4). Delayed RMDA was strongly associated with more HRF and HRS (both p

BackgroundTests of binocular vision (BVTs) and ocular motility are used in concussion assessment and management.PurposeTo determine the one-week test-retest reliability of 9 binocular vision tests (BVTs) and a test of saccades proposed for use in concussion management.Study DesignProspective test-retest.MethodsWe examined the one-week test-retest reliability of 9 BVTs in healthy participants: 3D vision (gross stereoscopic acuity), phoria at 30cm and 3m, ability of eyes to move/fixate in-sync (positive and negative fusional vergence at 30cm and 3m, near point of convergence and near point of convergence – break [i.e. double vision]) and 1 ocular motor test, saccades.ResultsWe tested 10 males and 10 females without concussion and a mean age of 25.5 (4.1) years. The intraclass correlations suggest good reliability for phoria 3m (0.88) and gross stereoscopic acuity (0.86), and moderate reliability for phoria 30cm (0.69), near point of convergence (0.54), positive fusional vergence (0.54) and negative fusional vergence (0.66) at 30cm, and near point of convergence - break (0.64). There was poor reliability for saccades (0.34), and both positive and negative fusional vergence (0.49 and 0.43, respectively) at 3m. Limits of agreement (LoA) were best for saccade (±34%) and worst for phoria 30 cm (±121%) and ranged from ±58% to ±70% for 7 of the 8 other tests. The LoA for phoria at 3m were uninformative because measurements for 18 of 20 participants were identical.ConclusionWe found test-retest reliability of the BVTs and saccades ranging from poor to good in healthy participants, with the majority being moderate.Clinical RelevanceFor these vision tests to be clinically useful, the effect of concussion must have a moderate to large effect on the scores of most of the tests.What is known about the subjectConcussions may affect some parts of visual function1-week test-retest reliability for most visual tests is under-studiedWhat this study adds to existing knowledgeWe provide intra-class coefficients and limits of agreement for 10 different visual function tests commonly conducted by clinicians in patients with concussion.

Significance Accommodation/convergence mismatch induced by 3D displays can cause discomfort symptoms such as those induced by accommodation/convergence mismatch in clinical vergence testing. We found that the limits of clear and single vision during vergence tests are very different between 3D and clinical tests. Clinical vergences should not be used as substitutes for measures of vergences in 3D displays. Purpose The purposes of this study were to determine whether the limits of clear and single binocular vision derived from phoropter prism vergence tests match the limits measured in a 3D display and to determine whether vergence mode, smooth versus jump, affected those limits in the 3D display. Methods We tested the phoropter prism vergence limits of clear and single vision at 40 cm in 47 binocular young adults. In separate sessions, we tested, in a 3D display, the analogous 40-cm vergence limits for smooth vergence and jump vergence. The 3D fixation target was a Maltese cross whose visual angle changed congruently with target disparity. Results Our mean phoropter vergence blur and break values were similar to those reported in previous studies. The mean smooth divergence limit was less in the 3D display (9.8Δ) than in the phoropter (12.8Δ). Most smooth convergence limits were much larger in the 3D display than in the phoropter, reaching the 35Δ limit of the 3D display without blur or diplopia in 24 subjects. Mean jump vergence limits were significantly smaller than smooth vergence limits in the 3D display. Conclusions The limits of clear and single binocular vision derived from phoropter vergence tests were not a good approximation of the analogous limits in our 3D display.

This report describes development of spherical equivalent refraction (SER) and axial length (AL) in two population-based cohorts of white, European children. Predictive factors for myopic growth were explored. Participants were aged 6–7- (n = 390) and 12–13-years (n = 657) at baseline. SER and AL were assessed at baseline and 3, 6 and 9 years prospectively. Between 6 and 16 years: latent growth mixture modelling identified four SER classes (Persistent Emmetropes-PEMM, Persistent Moderate Hyperopes-PMHYP, Persistent High Hyperopes-PHHYP and Emerging Myopes-EMYO) as optimal to characterise refractive progression and two classes to characterise AL. Between 12 and 22-years: five SER classes (PHHYP, PMHYP, PEMM, Low Progressing Myopes-LPMYO and High Progressing Myopes-HPMYO) and four AL classes were identified. EMYO had significantly longer baseline AL (≥ 23.19 mm) (OR 2.5, CI 1.05–5.97) and at least one myopic parent (OR 6.28, CI 1.01–38.93). More myopic SER at 6–7 years (≤ + 0.19D) signalled risk for earlier myopia onset by 10-years in comparison to baseline SER of those who became myopic by 13 or 16 years (p ≤ 0.02). SER and AL progressed more slowly in myopes aged 12–22-years (− 0.16D, 0.15 mm) compared to 6–16-years (− 0.41D, 0.30 mm). These growth trajectories and risk criteria allow prediction of abnormal myopigenic growth and constitute an important resource for developing and testing anti-myopia interventions.

Aims This study aims to quantify the diagnostic test-accuracy of three visual function self-monitoring tests for detection of active disease in patients with neovascular age-related macular degeneration (nAMD) when compared with usual care. An integrated qualitative study will investigate the acceptability of these home-based testing strategies. Methods All consenting participants are provided with an equipment pack containing an iPod touch with two vision test applications installed and a paper journal of reading tests. Participants self-monitor their vision at home each week with all three tests for 12–18 months. Usual care continues over this period. Key eligibility criteria are: age ≥50 years; at least one eye with AMD with ≥6–≤42 months since first AMD treatment; and vision not worse than Snellen 6/60, LogMAR 1.04 or 33 letters. The primary outcome, and reference standard, is diagnosis of active disease during usual care monitoring in the Hospital Eye Service. Secondary outcomes include duration of study participation, ability of participants to do the tests, adherence to weekly testing and acceptability of the tests to participants. Conclusions Recruitment is in progress at five NHS centres. Challenges in procuring equipment, setting up the devices and transporting devices containing lithium batteries to participating sites delayed the start of recruitment. The study will describe the performance of the tests self-administered at home in detecting active disease compared to usual care monitoring. It will also describe the feasibility of the NHS implementing patient-administered electronic tests or similar applications at home for monitoring health.

To evaluate the diagnostic accuracy of rapid assessment of avoidable blindness (RAAB).Population-based diagnostic accuracy study.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 eye3/60 and6/60, respectively. Visual impairment (VI) was defined as VA6/18 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.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.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, PVA3/60); 89.5%, 98.7%, 0.940, 69.2, and 0.11, respectively, for detection of economic blindness (PVA6/60); and 90.3%, 97.7%, 0.940, 38.7, and 0.10, respectively, for detection of VI (PVA6/18). 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 (PVA6/18) owing to cataract and refractive error, respectively.The diagnostic performances of RAAB were high for detecting the prevalence of blindness, VI, and VI owing to cataract.

Video games have grown in popularity due to their entertainment factor and, more recently, the possibility of their use in health care. Specifically, this review examines video game potential to allow the implementation of a subjacent diagnosis system, in the context of a study case: The optometric LEA vision test. A first approach exposes and discusses the context in which video games were considered relevant through the management of the engagement factor (considered as a key point in game adoption and will to participate). Since the case study focuses on the underlying capability to perform the diagnosis with a significant level of confidence in the children’s visual acuity, a reflection on the necessary information support system, knowledge base and learning capacity is made. The technical aspects required for the game implementation are then exposed, followed by performance considerations (which certainly have an impact on the end-user experience, and therefore on engagement and concentration). Finally, a conclusion underlines the most relevant aspects in the context of the study case.

There is a paucity of data relating to refugee eye health in Australia. This study aimed at investigating the spectrum of vision impairment and other ocular conditions in refugees utilising the Victorian Eyecare Service operated by the Australian College of Optometry.A cross-sectional study of electronic clinical records of 518 individuals (adults and children) recognised as refugees by the Australian College of Optometry and treated between January 2013 and May 2014 were identified. Extracted data included presenting visual acuities, best-corrected visual acuities, and final refraction values (using spherical equivalents), for both eyes. Diagnoses of presenting ocular conditions were also extracted.Of all refugees examined, 129 (27.2 per cent) had some degree of vision impairment (≤ 6/9.5) based on presenting visual acuities in their better eye; five (1.0 per cent) being of a severe (≤ 6/60) or profound (≤ 6/120) nature. In contrast, 27 (6.3 per cent) refugees had some degree of vision impairment based on best-corrected visual acuities in their better eye; two (0.4 per cent) being of a severe or profound nature. The prevalence of myopia (≥ -0.50 D) in the better eye was 23.0 per cent (n = 114); 25 (5.0 per cent) being moderate (≥ -3.00 D) to high (≥ -6.00 D). The prevalence of hypermetropia (≥ +2.00 D) in the better eye was 3.2 per cent (n = 16); 12 (2.4 per cent) being moderate (≥ +2.25 D) to high (≥ +5.25 D). The most common ocular conditions diagnosed at initial presentation were refractive error (n = 104, 20.1 per cent) and dry eyes (n = 57, 11.0 per cent).Mild vision impairment and refractive error are significant issues for refugees attending the Australian College of Optometry, emphasising the need for optometry, particularly refractive, services in this population.

The visual system in the central nervous system processes diverse visual signals. Although the overall structure has been characterized from the retina through the lateral geniculate nucleus to the visual cortex, the system is complex. Cellular and molecular studies have been conducted to elucidate the mechanisms underpinning visual processing and, by extension, disease mechanisms. These studies may contribute to the development of artificial visual systems. To validate the results of these studies, behavioral vision testing is necessary. Here, we show that the looming stimulation experiment is a reliable mouse vision test that requires a relatively simple setup. The looming experiment was conducted in a large enclosure with a shelter in one corner and a computer monitor located on the ceiling. A CCD camera positioned next to the computer monitor served to observe mouse behavior. A mouse was placed in the enclosure for 10 minutes and allowed to acclimate to and explore the surroundings. Then, the monitor projected a program-derived looming stimulus 10 times. The mouse responded to the stimuli either by freezing or by fleeing to the hiding place. The mouse's behavior before and after the looming stimuli was recorded, and the video was analyzed using motion tracking software. The velocity of the mouse movement significantly changed after the looming stimuli. In contrast, no reaction was observed in blind mice. Our results demonstrate that the simple looming experiment is a reliable test of mouse vision.

PURPOSE: To analyze the efficacy, safety, predictability, and stability in hyperopic presbyopic laser in situ keratomileusis (LASIK) surgeries with the TENEO 317 algorithm (Bausch & Lomb Technolas, Munich, Germany). METHODS: Eighty eyes from 40 patients who underwent hyperopic and presbyopic LASIK in this retrospective, observational, and longitudinal study were included. All patients had a 24-month follow-up. Excimer laser treatment was performed with TECNOLAS Perfect Vision GmbH TENEO 317 software version 1.25 (Bausch & Lomb) with the PROSCAN platform for the distance dominant eye and the SUPRACOR mild platform for the near dominant eye. RESULTS: Mean age was 53.90 ± 4.84 years (range: 42 to 66 years). Postoperative uncorrected distance visual acuity (UDVA) was 0.00 ± 0.04 (20/19.97) for the dominant eye and 0.14 ± 0.05 (20/27.65) for the non-dominant eye. Postoperative uncorrected near visual acuity was 0.51 ± 0.17 (J9) for the dominant eye and 0.09 ± 0.06 (J1.5) for the non-dominant eye, whereas 2.5% of non-dominant eyes lost two lines of corrected distance visual acuity. Half of non-dominant eyes lost one line, and 2.5% of dominant and non-dominant eyes changed 0.50 D or more between 3 and 24 months. CONCLUSIONS: PROSCAN surgery in the dominant eye and SUPRACOR surgery in the non-dominant eye using the TENEO 317 algorithm demonstrated that the hyperopic presbyopic excimer laser surgery technique resulted in acceptable and stable outcomes after 24 months of follow-up. [ J Refract Surg. 2019;35(9):591–598.]

PURPOSE: To describe a patient with pellucid macular degeneration suffering from visual deterioration due to high irregular astigmatism and intolerant to contact lenses, who underwent a new surgical procedure that combined intrastromal lamellar keratoplasty and a 359° intracorneal ring segment implantation, enabling both ametropia and corneal thinning correction. METHODS: Case report. RESULTS: Refractive lenticule obtained during a myopic small incision lenticule extraction procedure was used as the donor lamellar graft. The technique described allowed for partial cylinder reduction and reinforcement of the thinned cornea. Uncorrected distance visual acuity improved from 0.02 to 0.5 (decimal) and corrected distance visual acuity improved from 0.4 to 0.7 with a decrease of 4.50 diopters in corneal astigmatism. CONCLUSIONS: Despite the lack of long-term observation, the new technique described in this case report was successful for this specific patient and therefore might be effective and safe in severe stages of disease. [ J Refract Surg. 2019;35(9):606–609.]

Background: Ocular discomfort resulting from accommodative anomalies can impair reading efficiency, school performance and possibly a person’s quality of life. Aim: The aim of this study is to determine the prevalence of accommodative anomalies in schoolchildren in Abia State, Nigeria, and to assess possible associations with sample demographics such as age, gender and school level. Setting: The study was conducted in primary and secondary schools in Abia State, Nigeria. Methods: Case history questionnaires and vision tests were administered to 537 (mean age 13.0 ± 2.0 years) children randomly selected from nine schools in Abia State. The following vision parameters were measured: visual acuity, non-cycloplegic refraction, cover test, near point of convergence, fusional vergences, accommodative functions and ocular health evaluation. All accommodative and binocular function tests were performed following the subjective refraction with compensating lenses in place, if prescribed. Anomalies of interest such as accommodative insufficiency, accommodative excess and accommodative infacility were classified using the findings of accommodative and vergence parameters. Results: A total of 90 (16.8%) children had accommodative anomalies. Prevalence estimates include accommodative insufficiency (3.9%), accommodative excess (2.8%) and accommodative infacility (10.1%). There was no significant difference in the distribution of various accommodative anomalies between age group, gender or school level. Conclusion: The significant proportion (16.8%) of children with accommodative anomalies in the present study is an important finding, considering that paediatric vision screening programmes that only focus on visual acuity are unlikely to detect these critical visual anomalies. The result of this study is expected to direct the development of a common and broad vision screening strategy.

SIGNIFICANCE Vertically yoked prisms have been used in treatment of binocular vision dysfunction despite minimal supporting evidence. In people with normal binocular vision, the impact on phorias has been assessed but not the impact on accommodation, accommodation vergence interactions, or the horopter. We found that vertically yoked prisms have minor effects during short-term wear in young adults. PURPOSE The purpose of this study was to determine effects of vertically yoked prisms on accommodative response and several binocular vision tasks. METHODS There were 45 participants aged 18 to 24 years. The 23 myopes wore distance-corrected soft contact lenses. In a random arrangement, each person wore spectacles containing planopower lenses with either 8 Δ base-up, 4 Δ base-up, zero, 4 Δ base-down, and 8 Δ base-down prisms. Before spectacle wear, baseline measurements of near heterophoria, accommodation response, negative and positive relative accommodations, fusional vergence, and Nonius-horopter spatial perception were taken. Measurements were repeated after a 40-minute wear, spectacles were removed, and tests were performed 20 minutes later. On a 22-participant subset, on a separate occasion, measurements of heterophoria, accommodation response, and relative accommodation were made immediately after spectacles were fitted. RESULTS Most changes relative to baseline were not significant. Where effects occurred, these were nearly all associated with prism presence rather than adaptation. There were significant effects on accommodation response, but these seem to be refraction effects produced by pantoscopic tilt-induced power changes rather than perceptual effects altering accommodation. There were statistically significant effects on negative relative accommodation (P < .01), with zero prism giving more negative relative accommodation than 8 Δ base-down prisms. Tendencies were noted for prisms to move horopter limits toward the observer. Effects were small and likely not of clinical relevance. CONCLUSIONS Vertically yoked prisms have minor effects on accommodation and binocular vision, at least during short-term wear in young adults with normal binocular vision.

Purpose: To test the validity of the ASTEROID stereotest as a clinical test of depth perception by comparing it to clinical and research standard tests. Methods: Thirty-nine subjects completed four stereotests twice: the ASTEROID test on an autostereo 3D tablet, a research standard on a VPixx PROPixx 3D projector, Randot Circles, and Randot Preschool. Within 14 days, subjects completed each test for a third time. Results: ASTEROID stereo thresholds correlated well with research standard thresholds (r = 0.87, P < 0.001), although ASTEROID underestimated standard threshold (mean difference = 11 arcsec). ASTEROID results correlated less strongly with Randot Circles (r = 0.54, P < 0.001) and Randot Preschool (r = 0.64, P < 0.001), due to the greater measurement range of ASTEROID (1–1000 arcsec) compared to Randot Circles or Randot Preschool. Stereo threshold variability was low for all three clinical stereotests (Bland–Altman 95% limits of agreement between test and retest: ASTEROID, ±0.37; Randot Circles, ±0.24; Randot Preschool, ±0.23). ASTEROID captured the largest range of stereo in a normal population with test–retest reliability comparable to research standards (immediate r = 0.86 for ASTEROID vs. 0.90 for PROPixx; follow-up r = 0.68 for ASTEROID vs. 0.88 for PROPixx). Conclusions: Compared to clinical and research standards for assessing depth perception, ASTEROID is highly accurate, has good test–retest reliability, and measures a wider range of stereo threshold. Translational Relevance: The ASTEROID stereotest is a better clinical tool for determining baseline stereopsis and tracking changes during treatment for amblyopia and strabismus compared to current clinical tests.

To characterize age- and sex-related changes in corneal refractive parameters in myopic and hyperopic patients undergoing refractive surgery.A retrospective cross-sectional study.Analysis of demographic and refractive parameters of myopic and hyperopic patients who underwent laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK) between January 2000 and December 2014 at the Care-Vision Laser Centers, Tel-Aviv, Israel.A total of 62,422 eyes of 31,211 patients were included. With advancing age, refractive surgery was performed for lower magnitudes of myopia and hyperopia. The magnitude of cylinder was higher in men than in women in both myopic and hyperopic patients. In comparison, women were significantly more myopic than men (spherical equivalent of -3.73 diopter [D] versus -4.07 D; P0.01). The myopic group sphere (r = 0.044; P0.001) had a positive correlation with age, whereas other parameters had a negative correlation with age: astigmatism (r = -0.09; P0.001), best-correct visual acuity (BCVA) (r = -0.04; P0.001), flat K (r = -0.09; P0.001), steep K (r = -0.06; P0.001), average K (r = -0.07; P0.001), and J0 (r = -0.05; P0.001). For hyperopic patients, astigmatism (r = 0.35; P0.001), BCVA (r = 0.11; P0.001), flat K (r = 0.30; P0.001), average K (0.14; P0.001), and central corneal thickness (r = 0.10; P0.001) correlated positively with age, whereas sphere (r = -0.23; P0.001), J0 (r = -0.31; P0.001), and overall blurring strength (r = -0.31; P0.001) had negative correlations with age.This large cohort study shows age- and sex-related refractive parameters among myopic and hyperopic patients seeking refractive surgery. These parameters can explain and predict trends in patients attending refractive surgery.

To assess the effects of sustained gazing on visual function of dry eye patients.Prospective, comparative before-and-after study.A total of 176 patients with dry eye and 33 control subjects ≥50 years old were included. Dry eye symptomatology along and clinical parameters were assessed. Out-loud reading speed was measured using the International Reading Speed Test (IReST) as words per minute (wpm). Reading speed was repeated using different IReST excerpts following 30-minute silent reading.At baseline, there were no differences between dry eye patients and control subjects with respect to reading speed (172 vs 180 wpm, respectively; P = 0.21) or the time to read the excerpt (33 vs 30 seconds, respectively; P = 0.17). After silent reading, the dry eye patients had decreased reading speed and increases in the length of time to read the passage compared to baseline (161 vs 172 wpm, respectively; P = 0.002; and 38 vs 33 seconds, respectively; P0.001). The control subjects did not show significant differences for either parameter. There were significant differences with respect to both parameters between the dry eye and control groups after sustained gazing (161 vs 188 wpm, respectively; P = 0.006; and 38 vs 31 seconds, respectively; P = 0.003). Each 1-point increase in baseline corneal staining score (0-6) led to a 5-wpm reduction in reading speed (95% confidence interval, -8 to -1; P = 0.01).Sustained gazing, such as in silent reading, has a measurable negative impact on visual performance of dry eye patients. Corneal staining represents a clinical parameter relevant to visual function.

Experimental visual acuity (VA) of eight subjects was measured using the Freiburg vision test in a custom-made adaptive optics system. Measurements were conducted under one control and five defocus-induced conditions. In the defocus-induced conditions, 1 diopter of myopic defocus was added to the system using the Badal stage, and defocus vibrations with five different levels of amplitude were generated by a deformable mirror at 50 Hz. Computational simulations of the visual Strehl ratio (VSOTF) were performed using average aberrations of each subject recorded in the control condition. For the first time, to the best of our knowledge, it has been shown experimentally that both the simulated VSOTF and experimentally measured VA improve when defocus vibrations are added to a defocused eye.

Head-mounted displays (HMDs) are expected to dominate the market of wearable electronics in the next 5 years. This foreseen proliferation of HMDs yields a plethora of design opportunities for revolutionizing everyday life via novel use cases, but also generates a considerable number of substantial safety implications. In this work, we systematically investigated the effect of a novel monocular laser-based HMD on the ability of our participants to see in low ambient light conditions in lab settings. We recruited a total of 19 participants in two studies and performed a series of established vision tests while using the newly available Focals by North HMD. We tested our participants' night vision after being exposed to different levels of laser luminous power and laser colors while using Focals, either with one or both eyes open. Our results showcase that the image perceived by the non-exposed eye compensates for the loss of contrast sensitivity observed in the image perceived by the laser-exposed eye. This indicates that monocular laser-based HMDs, such as Focals, permit dark adaptation to occur naturally for the non-exposed eye.

Background The purpose of this study was to test the sensitivity and specificity of eight undergraduate volunteer examiners conducting vision screening tests in a community setting, in order to determine if non-eye care professionals were able to be trained to an appropriate level of skill. Methods Eight undergraduate volunteer examiners were trained to conduct vision screening tests to address a gap in pediatric community eye care. Phase I of the study was implemented in the pediatric ophthalmology clinic, and phase II was conducted in nine local schools. Phase I consisted of 40 h of training for each volunteer regarding specific vision tests. Phase II consisted of screening children at nine local schools. Results A total of 690 children from nine local schools were screened by both the volunteer examiners and the optometrist during the course of this study. Volunteer examiners had a screening sensitivity of 0.80 (95%CI 0.66–0.90) and screening specificity of 0.75 (95%CI 0.71–0.78) when compared to the study optometrist. The overall accuracy of volunteer examiners was 75%. The resulting positive likelihood ratio was 3.24 (95%CI 2.6–3.9), indicating that a child with vision impairment was 3.2 times more likely to fail the vision test performed by the volunteer examiners compared to a child with no vision impairment. Conclusions Non-healthcare professionals can be trained to an acceptable degree of accuracy to perform vision screening tests on children, which may assist in mitigating existing gaps in paediatric eye care.

PurposeTo investigate longitudinal changes in risk factors for amblyopia in children treated with congenital nasolacrimal duct obstruction (CNLDO).MethodsRetrospective observational case control study. A total of 446 children under 4 years of age who underwent probing and/or intubation for CNLDO between January 2004 and January 2018, and 446 age-matched controls were included. Cycloplegic refraction and ocular alignment were investigated at the time of treatment and after at least one year of symptom improvement. Children were classified as having amblyopia risk factors on the basis of the American Association for Pediatric Ophthalmology and Strabismus guideline in 2013.Main outcome measuresThe prevalence of amblyogenic refractive errors, and determinants associated with the presence of amblyogenic refractive errors in CNLDO patients.ResultsThe prevalence of amblyogenic refractive errors in CNLDO patients (5.4%) was similar to that of the control group (6.5%) (P = 0.571). After one year of symptom improvement in CNLDO patients, the prevalence of amblyogenic refractive errors was 4.7%. There was no difference in the prevalence of amblyogenic refractive errors between unilateral and bilateral CNLDO patients. Multivariate analysis revealed that manifest strabismus was the only risk factor related with the presence of amblyogenic refractive errors (odds ratio = 6.383, confidence interval = 1.205-33.826, P = 0.029).ConclusionsThis study found no evidence to suggest that the prevalence of amblyopia risk factors is higher in CNLDO patients compared with normal controls. Manifest strabismus was the only determinant associated with the presence of amblyogenic refractive errors.

This study investigates the influence of the household registration system on rural&ndash, urban disparity in healthcare access (including healthcare quality, blood pressure check, blood test, vision test, dental examination, and breast exam), using data from a large-scale nationwide life history survey that covered 150 counties across 28 provinces and municipalities in China. In contrast to the findings of many previous studies that emphasize the disparity in the residence place as the cause of rural&ndash, urban disparity in healthcare access, this study finds that the residence place just has a very limited influence on healthcare access in China, and what really matters is the household registration type. Our empirical results show that people with a non-rural household registration type generally have better healthcare access than those with a rural one. For rural residents, changing the registration type of their household (from rural to non-rural) can improve their healthcare access, whereas changing the residence place or migrating from rural to urban areas have no effect. Therefore, mere rural-to-urban migration may not be a valid measure to eliminate the rural&ndash, urban disparity in healthcare access, unless the institution of healthcare resource allocation is reformed.

To investigate the prevalence and associations of visual impairment and spectacle use in university students in central China.Cross-sectional study.This study included students aged 16-26 years in China. Study subjects from 2 universities underwent distance visual acuity (VA) assessment in both eyes with a logarithm of the minimum angle of resolution chart and their refractions were measured by cycloplegic autorefraction. Blindness was defined as presenting VA less than three-sixtieth in the better eye (World Health Organization definition), and visual impairment was defined as presenting VA less than six-twelfths.Overall, 9710 undergraduates were enumerated, 7704 (79.3%) subjects were included in this study. The prevalence of uncorrected VA less than six-twelfths and less than three-sixtieth in the better eye were 69.9% and 0.9%, respectively. Only 77.0% (4148/5388) of subjects with uncorrected VA in the better eye of less than six-twelfths wore glasses. For presenting VA, the prevalence of mild (VA6/12 to 6/18), moderate (VA6/18 to 6/60), and severe (VA6/60 to 3/60) visual impairment was 6.3%, 11.2%, and 0.7%, respectively. Overall, 71.7% (4300/6001) of students with myopia (spherical equivalent ≤-0.5 diopters) wore spectacles. In multiple logistic regression analysis, visual impairment was associated with female sex (P.001) and lower year level of education (P = .006) when presenting with VA.This study has documented a relatively high prevalence of visual impairment and relatively low spectacle coverage in Chinese university students. Given the potential impact of visual impairment, target education and accessible refraction services are highly important to solve the problem.

Background: To determine the prevalence of diabetic retinopathy maculopathy and cataract amongst diabetics and the prevalence of visual impairment amongst diabetics attending the Komfo Anokye Teaching Hospital eye unit. There are no current data in the study area on the prevalence of visual impairment and blindness amongst diabetics. This data is required in planning for screening and prevention of blindness due to diabetics. Methods: This was a hospital based cross sectional study. Subjects were diabetic patients attending the diabetic clinic. Simple random sampling was used. Demographic was taken. Visual acuity and refraction was done. Slit lamp examination was used to identify cataract. Maculopathy and retinopathy was determined using a 90D Volk lens and an indirect ophthalmoscope. Results: Non -insulin dependent diabetics constituted 97.1% whilst 2.9% were insulin dependent diabetics. The prevalence of the outcomes measures was: Cataract (23.7%) mild and moderate retinopathy (13.7%) severe proliferative retinopathy (1.8%) maculopathy (6.8%). Prevalence of low vision and blindness was 18.4%. Amongst diabetics 59.1% had no previous eye evaluation. Impaired vision due to cataract was 24.0 % representing a 40% decline in a decade. Conclusion: The prevalence of visual impairment was high at 18.4%. The reduction in impaired vision due to cataract over a decade is suggestive of either an improved cataract surgical rate or improved diabetic care or both. Majority of the diabetic patients 59.1% had not received prior ocular evaluation. There is an urgent need to have a screening program in this area Funding: None Keywords: Diabetics, retinopathy, maculopathy, visual impairment, blindness

Purpose: Preschool myopia generally indicated a high risk of progression to high myopia. However, no previous study has reported its longitudinal evolution. This study aimed to investigate the longitudinal changes in preschool myopia and explore the associated key determinants. Methods: Medical records of patients seeking refractions at Zhongshan Ophthalmic Center between 2009 and 2017 were retrospectively reviewed. Mean rates of change in spherical equivalent (SE) refractive errors were evaluated in patients with preschool myopia. Association between the rate of change in SE and patient characteristics at the initial visit were examined using linear mixed-effect regression models. Results: A total of 495 cases (median initial age: 5.12 years, interquartile range [IQR], 4.12-5.76 years) were assessed with at least 2-year follow-up. The initial median SE was -3.00 D (IQR, -5.25 to -1.75 D) and the median duration of follow-up was 3.69 years (IQR, 2.89-4.99 years). On average, myopia progressed by -0.59 ± 0.47 D/year. A total of 312 (63.0%) children demonstrated myopia progression (mean rate of change in SE ≤ -0.50 D/year in either eye) and 177 (35.8%) children demonstrated refraction stability (mean rate of change < ±0.50 D/year in both eyes). Older age (β = -0.06, P = 0.003), female sex (β = -0.09, P = 0.035), and initial lower myopic SE (β = -0.07, P < 0.001) were associated with faster myopia progression. Conclusions: Preschool myopia on average progresses, although considerable proportion of subjects demonstrates longitudinal refraction stability. The rate of myopia progression is associated with initial patient characteristics.

OBJECTIVE: Two strategies were compared for managing moderate hyperopia without manifest strabismus among 1- and 2-year-old children: 1) immediate prescription of glasses vs 2) observation without glasses unless reduced distance visual acuity (VA), reduced stereoacuity, or manifest strabismus. DESIGN: Prospective randomized clinical trial PARTICIPANTS: 130 children 1 to 2 years old with hyperopia between +3.00 diopters (D) and +6.00D spherical equivalent (SE) in at least one eye, anisometropia ≤1.50D SE and astigmatism ≤1.50D based on cycloplegic refraction, and no manifest strabismus. METHODS: Participants were randomly assigned to glasses (1.00D less than full cycloplegic hyperopia) versus observation and followed every 6 months for 3 years. Glasses were prescribed to those assigned to observation if they met pre-specified deterioration criteria of distance VA or near stereoacuity below age norms, or development of manifest strabismus. MAIN OUTCOME MEASURE: At the 3-year primary outcome examination, participants were classified as failing the randomized management regimen if distance VA or stereoacuity were below age norms, or manifest strabismus was observed (each with and without correction in trial frames, confirmed by masked retest, irrespective of whether deterioration had occurred previously), or if strabismus surgery had been performed. RESULTS: Of the 106 (82%) participants completing the 3-year primary outcome examination, failure occurred in 11 (21%) of 53 in the glasses group and 18 (34%) of 53 in the observation group (difference = −13%; 95% CI = −31% to 4%; p=0.14). The reasons for failure in the glasses and observation groups were reduced stereoacuity in 6 (11%) and 16 (30%) respectively, reduced VA in 3 (6%) and 4 (8%), and manifest strabismus in 5 (9%) in each group. Fifty-eight percent (95% CI = 46% to 70%) in the observation group, and 33% (95% CI = 22% to 46%) in the glasses group met deterioration criteria (requiring glasses if not wearing). CONCLUSION: For 1- and 2-year-olds with uncorrected moderate hyperopia (+3.00D to +6.00D SE), our estimates of failure, after 3 years of 6-monthly follow-up, are inconclusive, and consistent with either a small to moderate benefit or no benefit of immediate prescription of glasses compared with careful observation (with glasses only if deteriorated).

To evaluate stereopsis before and after intravitreal ranibizumab (IVR) injections in patients with branch retinal vein occlusion (BRVO) and investigate the relationship between stereopsis and retinal microstructure.Prospective, observational, controlled study.Thirty-two eyes of 32 patients undergoing IVR treatment for BRVO and 28 eyes of age-matched healthy control participants.Stereopsis was measured using the Titmus stereo test (TST) and TNO stereo test before and 1, 2, 3, 4, 5, and 6 months after treatment.Stereopsis, best-corrected visual acuity (BCVA), duration of disease, central retinal thickness, status of the external limiting membrane, ellipsoid zone, and external limiting membrane, and serous retinal detachment (SRD) after treatment.Treatment with IVR significantly improved the TST (P0.001) and TNO stereo test (P0.05) scores as well as BCVA (P0.001) and central retinal thickness (P0.005). Stereopsis after IVR injection in eyes with BRVO was significantly worse than that in healthy control participants (TST, P0.001; TNO stereo test, P0.001). The TST and TNO stereo test scores were correlated significantly with BCVA and the presence of SRD at baseline. After 6 months of treatment, an association of TST and TNO stereo test scores with BCVA and status of the external limiting membrane and ellipsoid zone was observed. Stereopsis after treatment showed a significant relationship with BCVA and presence of SRD at baseline.Administration of IVR for BRVO improved early stereopsis, albeit not to a normal level. Presence of SRD and visual acuity were predictors of stereopsis after treatment in patients with BRVO.

PurposeTo evaluate whether treatment with Citicoline in oral solution (OS-Citicoline) would increase visual function, retinal ganglion cells (RGCs) function, and neural conduction along visual pathways (neuroenhancement), and/or induce preservation of RGCs fibers' loss (neuroprotection) in non-arteritic ischemic optic neuropathy (NAION), a human model of neurodegeneration.MethodsThirty-six patients with NAION and 20 age-matched controls were enrolled. Nineteen NAION patients received 500 mg/day of OS-Citicoline for a 6-month period followed by 3-month of wash-out (NC Group); 17 NAION patients were not treated (NN Group) from baseline to 9 months. In all subjects at baseline, and in NC and NN eyes at 6 and 9 months of follow-up, we assessed Visual Acuity (VA), Pattern Electroretinogram (PERG), Visual Evoked Potentials (VEP), retinal nerve fiber layer thickness (RNFL-T), and Humphrey 24-2 visual field mean deviation (HFA MD). Mean differences were statistically evaluated with ANOVA between Groups, and linear correlations were analysed with Pearson's test.ResultsAt 6 months, significant differences between groups for all parameters were observed (ANOVA, pConclusionsOS-Citicoline treatment induced neuroenhancement (improvement in RGCs function and neural conduction along visual pathways related to improvement of visual field defects) and neuroprotection (unmodified or improved RNFL morphological condition) in a human model of NAION involving fast RGCs degeneration.Trial registrationClinicalTrials.gov NCT03758118.

Background: The visual span (i.e., an estimate of the number of letters that can be recognized reliably on a single glance) is widely considered to impose an important sensory limitation on reading speed. With the present research, we investigated adult age differences in the visual span for alphabetic stimuli (i.e., Latin alphabetic letters), as aging effects on span size may make an important contribution to slower reading speeds in older adulthood.\ud \ud Method: A trigram task, in which sets of three letters were displayed randomly at specified locations to the right and left of a central fixation point, was used to estimate the size of the visual span for young (18-30 years) and older (65+ years) adults while an eye tracker was used to ensure accurate central fixation during stimulus presentation. Participants also completed tests of visual acuity and visual crowding.\ud \ud Results: There were clear age differences in the size of the visual span. The older adults produced visual spans which were on average 1.2 letters smaller than the spans of young adults. However, both young and older adults produced spans smaller than those previously reported. In addition, span size correlated with measures of both visual acuity and measures of visual crowding.\ud \ud Conclusion: The findings show that the size of the visual span is smaller for older compared to young adults. The age-related reduction in span size is relatively small but may make a significant contribution to reduced parafoveal processing during natural reading so may play a role in the greater difficulty experienced by older adult readers. Moreover, these results highlight the importance of carefully controlling fixation location in visual span experiments.

Chart-based visual acuity measurements are used by billions of people to diagnose and guide treatment of vision impairment. However, the ubiquitous eye exam has no mechanism for reasoning about uncertainty and as such, suffers from a well-documented reproducibility problem. In this paper we make two core contributions. First, we uncover a new parametric probabilistic model of visual acuity response based on detailed measurements of patients with eye disease. Then, we present an adaptive, digital eye exam using modern artificial intelligence techniques which substantially reduces acuity exam error over existing approaches, while also introducing the novel ability to model its own uncertainty and incorporate prior beliefs. Using standard evaluation metrics, we estimate a 74% reduction in prediction error compared to the ubiquitous chart-based eye exam and up to 67% reduction compared to the previous best digital exam. For patients with eye disease, the novel ability to finely measure acuity from home could be a crucial part in early diagnosis. We provide a web implementation of our algorithm for anyone in the world to use. The insights in this paper also provide interesting implications for the field of psychometric Item Response Theory., Comment: Proceedings of the 34th AAAI Conference on Artificial Intelligence, New York, USA. 2020

Vergence prism adaptability was evaluated in subjects with high symptomatic and asymptomatic heterophoria and compared to individuals with a heterophoria within normal range (the control group). A computer haploscope was used to measure phoria values and changes in the eye position after introducing 6 prism diopters base out in front of the right eye. Phoria values were measured with a nonius paradigm every minute for a period of 10 minutes during adaptation. The results showed that subjects with symptomatic heterophoria are characterized by a lower rate of prism adaptation and adapted to a smaller extent with respect to the control group. The group with high but asymptomatic heterophoria showed prolonged adaptation time but after several minutes of binocular viewing the subjects were able to adapt to the prism to a level similar to the control group. These findings suggest that an impairment in the slow vergence control system may be responsible for the inability to fully reduce vergence effort, which results in poor vergence ranges and asthenopic symptoms during prolonged viewing.

Nominally plano prisms can have appreciable refractive errors that exceed the usual prescribing step of 0.25 D, particularly when an eye rotates to view off-axis objects.The purpose of this study was to determine theoretically the refractive power effects of nominally plano-refracting power prisms.Plano prisms with zero refraction were designed for the as-worn condition. A basic method was developed to determine refractive effects in the presence of pantoscopic tilt. A refined method was developed that considers the eye rotating behind the lens, and this and the basic method were compared with accurate raytracing.Plano prisms of 4 and 8 Δ were designed with astigmatic back surfaces to compensate for oblique incidence, and tangential and sagittal image vergence errors were investigated for base-up (BU) and base-down (BD) directions, 0 and -3.33 D object vergences, and pantoscopic tilts up to 10°. Basic and refined results did not differ from accurate results by more than 0.04 and 0.08 D, respectively. Errors for 8 Δ prisms were approximately twice those for 4 Δ prisms. Errors were approximately proportional to tilt. With 10° tilt, the errors ranged between -0.65 D/-0.23 D (8 Δ BD, -3.33 D object vergence) and +0.36 D/+0.15 D (8 Δ BU, 0 D object vergence). Sagittal errors were generally about one third of corresponding tangential errors. In the presence of tilt, BU prisms had positive errors, and BD prisms had similar, but negative, errors for distance objects. At -3.33 D object vergence with tilt, negative errors for BD were greater than positive errors for BU. When the eye rotates to look at objects at different positions, errors can increase beyond those occurring on-axis.When designed for nontilted conditions, but then subjected to tilt or to viewing off-axis objects, plano prisms can have errors exceeding the usual prescribing step of 0.25 D.

Purpose: To determine the prevalence of ptosis and nystagmus in the general rural population in Iran. Methods: Two villages were selected from the north and southwest of Iran using a multi-stage cluster sampling approach. After selection of the participants and inviting them to a complete eye exam, they all had vision tests and an ophthalmic examination. Vision tests included measurement of visual acuity, refraction, and the cover test. Then the slit-lamp exam was performed, and the diagnosis of ptosis and nystagmus was determined by an ophthalmologist. Results: Of the 3851 invitees, 3314 people participated in the study. The prevalence of ptosis in this study was 2.23% [95% confidence interval (CI): 1.73-2.74], and 45.3% of the cases were bilateral ptosis. The prevalence of ptosis was lowest in the 21-30 year (0.2%) and the under 5 year (0.8%) age groups, and the highest prevalence was observed in people over 70 years of age (6.7%) (P < 0.001). The prevalence of ptosis was higher in illiterate people than those with an academic education level (P = 0.012). The prevalence of astigmatism was 62.8% in those with ptosis and 34.2% in those without ptosis (P < 0.001). The prevalence of nystagmus was 0.39% (13 cases). Conclusions: This study found that the prevalence of ptosis is relatively high in the general rural population in Iran, and the prevalence increases with age. Astigmatism is significantly high among cases with ptosis, and its prevalence has an inverse relation with the level of education. Nystagmus also had a high prevalence in this population.

Background: Three-rods test is required as depth perception vision test to obtain motor vehicle license to drive taxies, buses, and trucks in Japan. Functional visual acuity is measured automatically by successive visual target presentation in a fixed period of time. This study examined three-rods test from the viewpoint of reproducibility, eye deviation, and functional visual acuity to assess the feasibility for drivers' license vision test. Methods: At three-rods test, a central rod was moved at the speed of 50 mm/sec forward and backward automatically against two fixed rods on both sides inside an illuminated box. An examinee at the distance of 2.5 m observed the rods inside the box from a small window and pushed a button to stop the central rod in alignment with the fixed rods. Erred distance of the central rod from the fixed rods as a mean of 4 measurements was used. At functional visual acuity test, an examinee moved a joystick to the same direction as Landolt-C opening as a visual target which was sequentially presented every 2 seconds for 30 times in 1 minute. Results: The mean erred distance of three-rods test was reproducible between two tests done on separate occasions (n = 44, ρ = 0.679, P < 0.0001, Spearman rank correlation). Exophoria induced by wearing 4-prism-diopter base-out prism did not significantly influence the mean erred distance while vertical diplopia induced by wearing 4-prism-diopter base-up prism disrupted the measurement (n = 9). The mean erred distance of three-rods test was better correlated with functional visual acuity tested with both eyes open than with conventional visual acuity with both eyes open (n = 17, ρ = 0.2 versus ρ = 0.179). Conclusion: In the context of the small sample size in the present study, the three-rods test was reproducible, and testable in the presence of phoria, but not testable in diplopia, indicating the feasibility as a depth perception vision test.

The Reading Accessibility Index (ACC) has been proposed as a single-value reading parameter that can capture information on both reading speed and print sizes that can be read. It is defined as the average reading speed across a relevant range of print sizes (1.3-0.4logMAR), normalised by typical young-adult reading speed of 200wpm, and with values typically in the range of 0-1. This study determines the impact of low vision aids (LVAs) on reading by evaluating ACC values for visually impaired observers reading both without and with an optical LVA. A secondary analysis of previously published data obtained from 100 visually impaired observers attending low vision assessments was undertaken. Observers had mixed causes of visual impairment but predominantly macular degeneration (n=55). All used an LVA for reading, with 88% using it ‘often’ or ‘very often’. MNREAD reading parameters, including ACC, were determined both for reading without an LVA (clinical function) and with the LVA habitually used for reading (aided function). There was a significant (p

Background Mouth-nose masks have been requested to prevent the transmission of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). The aim of the present study was to investigate, if wearing a mouth-nose mask impairs the visual field function in normals. Methods Thirty eyes of 30 subjects were recruited for the present study. White-on-white perimetry (OCTOPUS 900; 90°) was done and sensitivity was analysed in 14 defined test points (P1-P14, inferior visual field) under 3 different test conditions while the subjects were wearing a mouth-nose mask: (I) 1.5 cm under the lower eyelid, nose clip not used (position1.5cm_no_clip); (II) 1.5 cm under the lower eyelid, nose clip correctly positioned (position1.5cm_with_clip); (III) 0.5 cm under the lower eyelid, nose clip correctly positioned (position0.5cm_with_clip). All data were compared to sensitivity without wearing a mouth-nose mask (reference). Mean Δ was calculated, being the difference between the results of each test condition and reference, respectively. Results Sensitivity was significantly different between position1.5cm_no_clip and reference at 10 test points (p1.5cm_with_clip and position0.5cm_with_clip compared to reference (p1.5cm_with_clip (-8.3 dB ± 7.3 dB) < position0.5cm_with_clip (-11.3 dB ± 9.5 dB) < position1.5cm_no_clip (-20.1 dB ± 7.6 dB). Conclusion Visual field function was observed to be significantly impaired in the inferior-nasal sector while persons were wearing a mouth-nose mask, especially when the nose clip was not correctly used.

IMPORTANCE: The coronavirus disease 2019 pandemic illustrates the increasingly important role of telemedicine as a method of clinician-patient interaction. However, electronic applications (apps) for the testing of ophthalmology vital signs, such as visual acuity, can be published and used without any verification of accuracy, validity, or reliability. OBJECTIVE: To reassess the accuracy of visual acuity–testing apps and assess their viability for telehealth. DESIGN, SETTING, AND PARTICIPANTS: The US Apple App Store was queried for apps for visual acuity testing. Anticipated optotype size for various visual acuity lines were calculated and compared against the actual measured optotype size on 4 different Apple hardware devices. No human participants were part of this study. MAIN OUTCOMES AND MEASURES: Mean (SD) errors were calculated per device and across multiple devices. RESULTS: On iPhones, 10 apps met inclusion criteria, with mean errors ranging from 0.2% to 109.9%. On the iPads, 9 apps met inclusion criteria, with mean errors ranging from 0.2% to 398.1%. Six apps met criteria and worked on both iPhone and iPad, with mean errors from 0.2% to 249.5%. Of the 6 apps that worked across devices, the top 3 most accurate apps were Visual Acuity Charts (mean [SD] error, 0.2% [0.0%]), Kay iSight Test Professional (mean [SD] error, 3.5% [0.7%]), and Smart Optometry (mean [SD] error, 15.9% [4.3%]). None of the apps tested were ideal for telemedicine, because some apps displayed accurate optotype size, while others displayed the same letters on separate devices; no apps exhibited both characteristics. CONCLUSIONS AND RELEVANCE: Both Visual Acuity Charts and Kay iSight Test Professional had low mean (SD) errors and functionality across all tested devices, but no apps were suitable for telemedicine. This suggests that new and/or improved visual acuity–testing apps are necessary for optimal telemedicine use.

Visual dysfunction in MS can be quantified using a variety of tests. Many vision tests have not been formally evaluated among MS patients with existing visual dysfunction.Evaluate several versions of visual acuity and contrast sensitivity tests, measures of central and peripheral vision, retina structure, electrophysiologic function, and quality of life among MS patients with moderate/severe visual dysfunction.Cross-sectional study of 46 patients with stable, incompletely recovered optic neuritis. Testing included Snellen eye charts, several Sloan low contrast charts, Pelli Robson (PR) contrast sensitivity charts, optical coherence tomography, visual fields, Farnsworth Munsell 100-hue test, visual evoked potentials (VEP), and visual function quality of life (VFQ-25) testing.98% of eyes could read two lines of the PR chart, while only 43% read the 2.5% contrast chart. Low contrast tests correlated strongly with each other and with retinal nerve fiber layer (RNFL) thickness, visual fields, and color vision but not with VEPs. For patients with RNFL75µm, VFQ-25 scores dropped by approximately 2 points for every 1µm decrease in RNFL.Among MS patients with visual impairment due to optic neuritis, PR contrast sensitivity could be utilized as a single chart. Visual quality of life was associated with RNFL thinning below 75µm.

Introduction Although there are numerous studies that demonstrate that color vision deficient (CVD) individuals perform less well than color vision normal (CVN) individuals in tasks that require discrimination or identification of colored stimuli, there remains a need to quantify the relationship between the type and severity of CVD and performance on operationally relevant tasks. Methods Participants were classified as CVN (N = 45) or CVD (N = 49) using the Rabin cone contrast test, which is the standard color vision screening test used by the United States Air Force. In the color condition, test images that were representative of the size, shape, and color of symbols and lines used on fifth-generation fighter aircraft displays were used to measure operational performance. In the achromatic condition, all symbols and lines had the same chromaticity but differed in luminance. Subjects were asked to locate and discriminate between friend vs. foe symbols (red vs. green, or brighter vs. dimmer) while speed and accuracy were recorded. Results Increasing color deficiency was associated with decreasing speed and accuracy for the color condition (R2 > 0.2), but not for the achromatic condition. Mean differences between CVN and CVD individuals showed the same pattern. Discussion Although lower CCT scores are clearly associated with lower performance in color related tasks, the magnitude of the performance loss was relatively small and there were multiple examples of high-performing CVD individuals who had higher operational scores than low-performing CVN individuals. Gaska JP, Wright ST, Winterbottom MD, Hadley SC. Color vision and performance on color-coded cockpit displays. Aerosp Med Hum Perform. 2016; 87(11):921-927.

Human contrast vision and its quantitative assessment are gaining more attention. Publications on this topic can be confusing due to the overabundance of differing definitions and quantification of contrast vision. As a case in point, in Germany, contrast ratios as required for certain driving licenses and the DIN-defined contrast ratio are reciprocal. In this article, the five most important definitions of luminance contrast and contrast vision (Michelson, Weber, contrast ratios, logCS) are presented. We detail the specific domains for them, give formulae to convert between all of them and provide a table with equivalent values. We recommend the unit logCS wherever possible.

Hofstetter's equations are based on studies of Amplitude of Accommodation (AA) with methodological limitations, particularly in the case of children younger than 10 years of age. The aim of this study is to evaluate AA by age, gender, economic status, and time of day as well as accommodative insufficiency prevalence.A cross-sectional study was conducted with 867 schoolchildren aged 6-16 years attending two public schools in the urban area of the South Brazilian city of Pelotas. Subjective refraction was performed using a monocular fogging method to standard end point of maximum plus for best visual acuity (20/25). AA was assessed using the push-up method.The median AA value was 14.3D (P25 13.3-P75 16.7) among children aged 6-16 years, being 15.5D (P25 14.3D-P75 16.7) among children aged 6-10 years, 14.2D (P25 12.5D-P75 15.4) among 11-13-year-olds, 13.3D (P25 12.5D-P75 15.4) among children aged 14-15 and 12.9D (P25 11.1D-P75 14.3) among those aged 16. AA variability was 2.4D in those aged 6-8, 3.4D in children aged 9-12, and 2.9D in those aged 13-16. There was no significant difference in median AA according to gender, time of examination, or economic status; 2.8% of children showed AA of less than 2D lower than Hofstetter's minimum reference value.This study reports AA in a large sample of children and therefore may contribute to current knowledge on AA norms. In order to avoid the impact of outliers, it proposes the use of the median and percentiles to define AA standards by specific age. A set of studies using precise AA measurement and large sample size are needed to determine clinical standards for AA.

PURPOSE: To report on the utility of a computer tablet-based method for automated testing of visual acuity in children based on the principles of game design. We describe the testing procedure and present repeatability as well as agreement of the score with accepted visual acuity measures.DESIGN: Reliability and validity study.METHODS: Setting: Manchester Royal Eye Hospital Pediatric Ophthalmology Outpatients Department.PATIENT POPULATION: Total of 112 sequentially recruited patients.INTERVENTION: For each patient 1 eye was tested with the Mobile Assessment of Vision by intERactIve Computer for Children (MAVERIC-C) system, consisting of a software application running on a computer tablet, housed in a bespoke viewing chamber. The application elicited touch screen responses using a game design to encourage compliance and automatically acquire visual acuity scores of participating patients. Acuity was then assessed by an examiner with a standard chart-based near ETDRS acuity test before the MAVERIC-C assessment was repeated.MAIN OUTCOME MEASURE: Reliability of MAVERIC-C near visual acuity score and agreement of MAVERIC-C score with near ETDRS chart for visual acuity.RESULTS: Altogether, 106 children (95%) completed the MAVERIC-C system without assistance. The vision scores demonstrated satisfactory reliability, with test-retest VA scores having a mean difference of 0.001 (SD ±0.136) and limits of agreement of 2 SD (LOA) of ±0.267. Comparison with the near EDTRS chart showed agreement with a mean difference of -0.0879 (±0.106) with LOA of ±0.208.CONCLUSIONS: This study demonstrates promising utility for software using a game design to enable automated testing of acuity in children with ophthalmic disease in an objective and accurate manner.

PURPOSE To establish the repeatability and reproducibility of a virtual refraction process using simulated retinal images. METHODS With simulation software, aberrated images corresponding with each step of the refraction process were calculated following the typical protocol of conventional subjective refraction. Fifty external examiners judged simulated retinal images until the best sphero-cylindrical refraction and the best visual acuity were achieved starting from the aberrometry data of three patients. Data analyses were performed to assess repeatability and reproducibility of the virtual refraction as a function of pupil size and aberrometric profile of different patients. RESULTS SD values achieved in three components of refraction (M, J0, and J45) are lower than 0.25D in repeatability analysis. Regarding reproducibility, we found SD values lower than 0.25D in the most cases. When the results of virtual refraction with different pupil diameters (4 and 6 mm) were compared, the mean of differences (MoD) obtained were not clinically significant (less than 0.25D). Only one of the aberrometry profiles with high uncorrected astigmatism shows poor results for the M component in reproducibility and pupil size dependence analysis. In all cases, vision achieved was better than 0 logMAR. A comparison between the compensation obtained with virtual and conventional subjective refraction was made as an example of this application, showing good quality retinal images in both processes. CONCLUSIONS The present study shows that virtual refraction has similar levels of precision as conventional subjective refraction. Moreover, virtual refraction has also shown that when high low order astigmatism is present, the refraction result is less precise and highly dependent on pupil size.

PURPOSE To evaluate whether an induced astigmatism influences the subjective depth of focus. METHODS Fifty-one participants aged 18 to 35 years and with a mean spherical equivalent refractive error of -0.51 ± 2.35 DS participated in the study. The accommodation was blocked with three drops of 1% cyclopentolate. Refractive errors were corrected after subjective refraction with a 4-mm artificial pupil. To evaluate the depth of focus (DoF), defocus curves with a spherical range of ±1.5 DS were assessed. The DoF was calculated as the horizontal distance at a threshold level of +0.1 logMAR from the maximum visual acuity (VA). Defocus curves were estimated binocularly during distance (500 cm) and a near vision (40 cm) for two induced axis (ATR in 0° and WTR in 90°) and for a fixed amount of astigmatic defocus of -0.5 DC. RESULTS The mean natural DoF was 0.885 ± 0.316 D for far vision and 0.940 ± 0.400 D for near vision. With induced astigmatism, the DoF for far vision was significantly increased to 1.095 ± 0.421 D (p = 0.006, ANOVA) for the WTR astigmatism but not for the ATR astigmatism (1.030 ± 0.395 D; p = 0.164, ANOVA). The induced WTR astigmatism enhanced the DoF for near vision significantly to 1.144 ± 0.338 D (p = 0.04, ANOVA), and DoF with induced ATR astigmatism (0.953 ± 0.318 D) was not significantly different (p = 1.00, ANOVA). ATR-astigmatism reduced VA by +0.08 ± 0.08 logMAR (p < 0.01, t-test). CONCLUSIONS With an induced WTR astigmatism of -0.5 DC, the DoF can be enhanced in the near viewing distance with a marginal loss in binocular VA. The approach of using induced WTR astigmatism can lead to novel optical treatments for presbyopia.

Purpose To compare the optical performance of 3 trifocal intraocular lenses (IOLs): the Acrysof IQ Panoptix (+2.17 diopter [D]/+3.25 D IOL), AT LISA Tri 839MP (+1.66 D/+3.33 D IOL), and Finevision Micro F (+1.75 D/+3.50 D IOL). Setting Alcon Research Ltd., Fort Worth, Texas, USA. Design Experimental study. Methods The 3 trifocal IOLs were compared using optical performance tests. To measure image quality, through-focus modulation transfer function (MTF) curves were generated for a model eye. To assess resolution, through-focus Badal images of an Early Treatment Diabetic Retinopathy Study chart simulating viewing distances of infinity to 40 cm were recorded. To measure photic phenomena, simulated headlight images with a 50 μm pinhole target and a 5.0 mm pupil were obtained. Results The MTF measurements showed similar near and distance peaks for the IOLs, but the optimum intermediate peak for the +2.17 D/+3.25 D IOL was 60 cm versus 80 cm for the other 2 trifocal IOLs. Similarly, in bench Badal image testing, the optimum intermediate image was at 60 cm for the +2.17 D/+3.25 D IOL and 80 cm for the other 2 IOLs. Overall, halos surrounding simulated headlight images were equivalent for the 3 IOLs. Conclusions In bench studies, the new +2.17 D/+3.25 D trifocal IOL showed equivalent or better performance in image quality, resolution, and photic phenomena compared with the +1.66 D/+3.33 D and +1.75 D/+3.50 D trifocal IOLs. The new IOL is expected to provide better intermediate vision at 60 cm, which is preferred for real-life tasks such as computer work, over the 80 cm intermediate distance offered by the other 2 trifocal IOLs. Financial Disclosure All authors are employees of Alcon Research, Ltd.

PURPOSE: To evaluate functional results and reading performance using the Salzburg Reading Desk after implantation of a sector-shaped near-embedded, rotational asymmetrical multifocal intraocular lens (IOL) and a multifocal toric IOL with a +3.00 diopter (D) near addition. METHODS: In a prospective study, the LentisMplus and Mplus toric IOLs (Oculentis GmbH, Berlin, Germany) were implanted in 34 eyes of 18 patients at the University Eye Hospital of Heidelberg. Uncorrected and corrected distance visual acuity (UDVA, CDVA) and uncorrected and corrected near visual acuity (UNVA, CNVA) were evaluated using standardized visual acuity charts (ETDRS). The Salzburg Reading Desk was used to analyze unilateral and bilateral uncorrected and corrected reading acuity, reading distance, reading speed, and the smallest log-scaled print size that could be read effectively at a set (40 cm/80 cm) and subjective chosen near and intermediate distance. RESULTS: Postoperatively, the median UDVA was 0.08 logMAR (20/25 Snellen) and the median CDVA was 0.01 logMAR (20/20 Snellen). The median UNVA was 0.12 logMAR (20/25 Snellen) and the median CNVA was 0.03 logMAR (20/20 Snellen). The median uncorrected reading acuity measured with the Salzburg Reading Desk for near distance at 40 cm was 0.18 logMAR (20/32 Snellen). The subjectively preferred near distance was 39 cm and revealed similar visual acuity results. The best reading acuity for intermediate distance with a median of 0.22 logMAR (20/32 Snellen) was achieved at a median distance of 62 cm. CONCLUSIONS: Reading performance of the multifocal IOL corresponded for near standardized and individual distance, whereas reading function was better at the patient's preferred intermediate distance. [ J Refract Surg . 2016;32(8):526–532.]

To investigate the influence of daily activities on myopic refractive change and myopic onset in Chinese urban students. The Beijing Myopia Progression Study was a 3-year cohort study. Cycloplegic refraction and a daily activity questionnaire were assessed at baseline and at follow-up examinations. Refractive change was defined as the difference in cycloplegic spherical equivalent (SE) between the final follow-up and baseline. 386 students were initially enrolled in the baseline study. At the final follow-up, 222 students (57.5 %) with completed refractive error and daily activity data were analyzed. These students spent 0.32 ± 2.33 h/day more on near work (p = 0.04), and 0.21 ± 1.31 h/day less on outdoor leisure (p = 0.02), than they did at baseline. In the multivariate analysis, the younger among the secondary students (β = 0.06, p