The Lancet Global Health Commission on Global Eye Health: vision beyond 2020

Ferroptosis: underlying mechanisms and involvement in neurodegenerative diseases

Ferroptosis, a mode of cell death that was recently identified in 2012, is driven by iron-dependent lipid peroxidation and distinct from other mechanisms of cell death such as autophagy and apoptosis. Ferroptosis has the unique features of disruptions in iron equilibrium, iron-induced lipid peroxidation, and the accumulation of glutamate-induced cellular toxicity. The regulation of ferroptosis mainly involves the iron, lipid, and amino acid metabolic pathways, which are controlled by system Xc-, voltage-dependent anion channels, p53 and other pathways. Neurodegenerative diseases involve gradual neuronal loss predominantly within the central nervous system and are categorized into both sporadic and rare hereditary disorders. These diseases result in the progressive decline of specific neuron populations and their interconnections. Recent investigations have revealed a strong correlation between the manifestation and progression of neurodegenerative diseases and ferroptosis. The pharmacological modulation of ferroptosis, whether by induction or inhibition, exhibits promising prospects for therapeutic interventions for these diseases. This review aims to examine the literature on ferroptosis and its implications in various neurodegenerative diseases. We hope to offer novel insights into the potential therapies targeting ferroptosis in central nervous system neurodegenerative diseases. However, there are still limitations of this review. First, despite our efforts to maintain objectivity during our analysis, this review does not cover all the studies on ferroptosis and neurodegenerative diseases. Second, cell death in neurodegenerative diseases is not solely caused by ferroptosis. Future research should focus on the interplay of different cell death mechanisms to better elucidate the specific disease pathogenesis.

[Global ophthalmology : Update]

The aim of global ophthalmology is to maximize vision, ocular health and functional ability, thereby contributing to overall health and well-being, social inclusion and quality of life of every individual worldwide. Currently, an estimated 1.1 billion people live with visual impairment, 90% of which can be prevented or cured through largely cost-effective interventions. At the same time, 90% of people affected live in regions with insufficient eye health coverage. This challenge drove the World Health Organization (WHO) and a group of nongovernmental organizations to launch "VISION 2020: the Right to Sight", a global campaign which recently concluded after 20 years. The achievements, challenges and lessons learned were identified and incorporated into the current campaign "2030 IN SIGHT".

Magnitude and Determinants of Awareness Regarding Refractive Surgeries Among Saudi Adults

Objectives

This study aimed to present the magnitude and determinants of awareness about refractive surgery among the adult Saudi population and recommend knowledge improvement.

Methods

This web-based cross-sectional study was conducted between June 2020 and May 2021 across various regions of Saudi Arabia on the adult Saudi population. A total of 11 close-ended questions regarding indication, contraindication, preparation and surgery procedures were asked. The awareness scores were grouped as 'good' (≥6) or 'poor' (≤5). Demographic and ocular parameters were associated with the outcomes.

Results

Of the 6,746 participants, 6,580 (response rate = 97.5%) completed the survey. The participation of younger women and older men was greater than their proportions in the population, while older women participated less than their proportion. Good awareness about refractive surgery was noted in 1,165 (17.7%; 95% confidence interval: 16.2-18.0) participants. Women (P <0.001), the 18-29 age group (P <0.001), residents of the central region of Saudi Arabia (P <0.001), health professionals (P <0.001), health sector students (P = 0.0004), people with myopia (P <0.001) and history of refractive surgery (P <0.001) were associated with good awareness. Women (adjusted odds ratio [AOR] = 1.5; P <0.001), health sector students (AOR = 1.57; P <0.001), and residents in the central region (AOR = 1.27; P <0.001) were independent predictors of awareness. Knowledge about contraindications for surgery was good in more than one-third of the participants. Of the 535 participants who underwent surgery in the past, 452 (84.5%) were satisfied with their outcomes.

Conclusion

Awareness of refractive surgeries is low in the adult Saudi population. Targeted counseling is recommended to improve the knowledge and acceptance of refractive surgery.

Comparison of Schlemm's Canal Morphology Parameters Between Propensity Score-Matched Primary Open-Angle Glaucoma and Exfoliation Glaucoma

Purpose

This study aimed to histologically compare the status of Schlemm's canal (SC) and Schlemm's canal endothelial (SCE) cells between trabeculectomy specimens from patients with primary open-angle glaucoma (POAG) and exfoliation glaucoma (EXG).

Methods

A total of 182 eyes from 152 patients with POAG and 138 eyes from 116 patients with EXG underwent immunohistochemical staining for thrombomodulin. Equal numbers of cases were selected from both groups using propensity score matching. The following parameters were evaluated: total SC length, staining positive and negative SC length (PSC and NSC, respectively), opened and closed SC length, staining positive and opened SC length, staining positive and closed SC length, staining negative and opened SC length (NOSC), and staining negative and closed SC length.

Results

After matching for age and gender, 87 cases were selected in each group. The EXG group had significantly higher preoperative IOP and medication scores. PSC was significantly longer in the POAG group, while NSC and NOSC were longer in the EXG group. Multiple regression analysis of these 174 cases revealed that PSC was significantly shorter in the EXG group. After matching for age, gender, preoperative IOP, and medication score, 64 cases were selected in each group, and NOSC was significantly longer in the EXG group.

Conclusions

These findings suggest that in EXG, SCE loss occurs independently of background factors such as aging and medication use. The loss of SCE may have a more critical impact on IOP elevation in EXG compared to POAG.

Eye exercises for myopia prevention and control: a comprehensive systematic review and meta-analysis of controlled trials

OBJECTIVES

To evaluate the efficacy of eye exercises in preventing and controlling myopia.

METHODS

We searched studies on eye exercises from nine Chinese and English databases from their inception to December 15, 2022. Using random-effect models and sensitivity/subgroup analyses, we estimated the effects of eye exercises compared to control on changes in three measures: visual acuity, refractive error (both quantified using standardized mean differences, SMDs), and protective/mitigating effects (assessed through risk ratios, RRs).

RESULTS

Eleven studies were included in the meta-analysis, with 921 participants. Nine studies had some concerns of bias in at least two domains, and two studies had a high risk of bias in two domains. Seven studies used visual acuity to measure myopia; visual acuity declined after eye-exercise interventions (SMD = -0.67, 95% CI -1.28 to -0.07, Z = 2.17, P = 0.03) and the effect was not better than control (SMD = -0.50, 95% CI -1.16 to 0.16, Z = 1.49, P = 0.14). Two studies used refractive error to measure myopia; the effect of eye-exercise interventions did not differ from control (SMD = -1.74, 95% CI -6.27 to 2.79, Z = 0.75, P = 0.45). Seven studies reported on protective/mitigating effects; eye exercises exhibited a greater protective/mitigating effect than control (RR = 0.40, 95% CI 0.23-0.71, Z = 3.13, P < 0.01).

CONCLUSIONS

Overall, the results suggest that eye exercises have limited to no efficacy in preventing or controlling myopia progression. Until robust evidence supports their efficacy, available evidence suggests retiring the eye-exercise policy.

PRESENTATIONS AND FACTORS AFFECTING OUTCOME OF RHEGMATOGENOUS RETINAL DETACHMENT WITH CHOROIDAL DETACHMENT: An Indo-Taiwanese Study

PURPOSE

To report the clinical settings, management, and factors associated with outcomes of rhegmatogenous retinal detachment with concurrent choroidal detachment.

METHODS

Retrospective, consecutive, multicenter case series from January 2014 to January 2021 were included. Cases were from a tertiary eye care center in India and Taiwan.

RESULTS

Overall 303 eyes were included. Mean age was 43.72 ± 20.64 years (median 46). Best-corrected presenting visual acuity was 1.79 ± 0.92 logMAR (median 2.10) (Snellen 20/1,233). Forty-four patients (17.91%) received preoperative steroids. Final visual acuity was 1.33 ± 0.94 logMAR (median 1.10) (Snellen 20/427). Favorable anatomic outcome was seen in 200/303 (66%), whereas favorable functional outcome was seen in 128/303 (42.20%). Factors predicting favorable anatomic outcome were absence of phakic lens status (odds ratio [OR] 2.76), absence of proliferative vitreoretinopathy worse than Grade A (OR 7.69), use of preoperative steroids (OR 4.50), and use of an encircling band (3.85). Factors predicting favorable functional outcome were better presenting visual acuity (OR 3.03), absence of phakic lens status (OR 4.93), absence of proliferative vitreoretinopathy worse than Grade A (OR 10.41), and use of preoperative steroids (OR 7.24).

CONCLUSION

Administration of preoperative steroids, use of an encircling band during surgery, and pseudophakic status of the eye were found to have better outcomes in rhegmatogenous retinal detachment with concurrent choroidal detachment.

Outcomes of newly referred patients with suspected angle closure: do we need to redefine the clinical pathways?

BACKGROUND/OBJECTIVES

To investigate outcomes of referrals for suspected angle closure and explore whether anterior segment optical coherence tomography (AS-OCT) can be used to tighten triaging criteria in a glaucoma virtual clinic.

SUBJECTS/METHODS

Retrospectively collected data. The first audit (04/2018-03/2019) identified referrals for suspected angle closure without other glaucoma-related findings (primary angle closure suspect (PACS) referrals). All patients underwent gonioscopy. The second audit (04-08/2019) identified patients with suspected angle closure in a virtual clinic. Management outcomes were assessed, using gonioscopy as reference standard. The outcomes of the second audit were re-audited after changing the triaging criterion from angle width <10° to iridotrabecular contact (ITC) in ≥1 quadrants on AS-OCT.

RESULTS

Out of 1754 glaucoma referrals (first audit), 24.6% (431/1754) were PACS referrals. Of these, only 10.7% (42/393) had an occludable angle on gonioscopy, with 97.6% (41/42) being PACS. Of these, 78% (32/41) underwent laser peripheral iridotomy. Out of 137 referrals in the virtual clinic (second audit), 66.4% (91/137) were triaged to the face-to-face clinic. Of these, 31.9% (29/91) were discharged. AS-OCT had positive and negative predictive value of 74.3% (95% confidence intervals (CI) 57.8-86.0) and 82.1% (95% CI 70.0-90.2%), respectively, in detecting ITC in ≥1 quadrants. In the re-audit 45.9% (45/98) of those with suspected angle closure were triaged for gonioscopy, with 24.4% (11/45) of them being discharged.

CONCLUSION

PACS referrals represent a substantial burden to hospital-based services and their accuracy is low. ITC in ≥1 quadrants on AS-OCT can be useful in triaging those who need further evaluation with gonioscopy.

Insights Into Visual Rehabilitation: Pan-Retinal Photocoagulation for Proliferative Diabetic Retinopathy

This review comprehensively explores pan-retinal photocoagulation (PRP) as a pivotal intervention in visually rehabilitating individuals afflicted with proliferative diabetic retinopathy (PDR). The review begins by elucidating the significance of PDR within the spectrum of diabetic retinopathy (DR), emphasizing the progressive nature of the disease and the consequential impact on visual health. A detailed analysis of PRP follows, encompassing its definition, purpose, and historical development, shedding light on the procedural intricacies and mechanisms of action. The postoperative care and follow-up section underscores the necessity of vigilant monitoring for complications, visual recovery, and the importance of regular ophthalmic check-ups. The subsequent discussion delves into patient education and counseling, stressing the need to manage expectations, encourage lifestyle modifications, and highlight the significance of follow-up appointments. The review concludes with insights into future directions, including advancements in laser technology and emerging therapies, offering a glimpse into the evolving landscape of DR management. By addressing ongoing challenges and embracing innovative approaches, this review provides a comprehensive guide for clinicians, researchers, and healthcare practitioners who visually rehabilitate individuals struggling with PDR.

Sex Disparities in Ophthalmology From Training Through Practice: A Systematic Review

Importance

Sex-based research in medicine has revealed inequities against females on almost every metric at almost every career stage; ophthalmology is no exception.

Objective

To systematically review the experiences of females in ophthalmology (FiO) from training through practice in high-income countries (HICs).

Evidence Review

A systematic review of English-language studies, published between January 1990 and May 2022, relating to FiO in HICs was performed. PubMed, MEDLINE, and Embase electronic databases were searched, as well as the Journal of Academic Ophthalmology as it was not indexed in the searched databases. Studies were organized by theme at each career stage, starting in medical school when an interest in ophthalmology is expressed, and extending up to retirement.

Findings

A total of 91 studies, 87 cross-sectional and 4 cohort, were included. In medical school, mentorship and recruitment of female students into ophthalmology was influenced by sex bias, with fewer females identifying with ophthalmologist mentors and gender stereotypes perpetuated in reference letters written by both male and female referees. In residency, females had unequal learning opportunities, with lower surgical case volumes than male trainees and fewer females pursued fellowships in lucrative subspecialties. In practice, female ophthalmologists had lower incomes, less academic success, and poorer representation in leadership roles. Female ophthalmologists had a greater scholarly impact factor than their male counterparts, but this was only after approximately 30 years of publication experience. Pervasive throughout all stages of training and practice was the experience of greater sexual harassment among females from both patients and colleagues. Despite these disparities, some studies found that females reported equal overall career satisfaction rating with males in ophthalmology, whereas others suggested higher burnout rates.

Conclusions and Relevance

Ophthalmology is approaching sex parity, however, the increase in the proportion of females in ophthalmology had not translated to an increase in female representation in leadership positions. Sex disparities persisted across many domains including recruitment, training, practice patterns, academic productivity, and income. Interventions may improve sex equity in the field.

Urban greenspace and visual acuity in schoolchildren: a large prospective cohort study in China

BACKGROUND

Greenspace is known to have a positive impact on human health and well-being, but its potential effects on visual acuity have not been extensively studied.

OBJECTIVES

Our aim was to examine the relationship between long-term greenspace exposure and visual acuity in children, while also exploring the potential mechanisms in this association.

METHODS

We conducted this prospective cohort study based on the Children's growth environment, lifestyle, physical, and mental health development project (COHERENCE), which screened 286,801 schoolchildren in Guangzhou, China, starting in the 2016/17 academic year and followed them up for three academic years (2017/18-2019/20). Visual acuity was measured using a standardized logarithmic chart, and visual impairment was defined as visual acuity worse than 0.0 logarithm of the minimum angle of resolution (LogMAR) units in the better eye. We used the Normalized Difference Vegetation Index (NDVI), the Soil-Adjusted Vegetation Index (SAVI), and the Enhanced Vegetation Index (EVI) to assess the greenspace surrounding child's geocoded home and school at each visit.

RESULTS

Our analysis indicated that higher greenspace exposure was associated with greater visual acuity z-score at baseline and with slower decline in visual acuity z-score during the 3-year follow-up. An interquartile range increase in home-school-based NDVI 300m was associated with a 7% decrease [hazard ratios (HRs): 0.93, 95% confidence interval (CI): 0.92, 0.94] in the risk of visual impairment. We also found that air pollution, physical activity, outdoor time, and recreational screen time partially mediated the greenspace-visual acuity association.

CONCLUSION

Our findings suggest that increasing greenspace exposure could benefit children's visual acuity development and reduce the risk of visual impairment by reducing air pollution and recreational screen time while increasing physical activity and outdoor time. All results could have potential policy implications, given the individual and societal burdens associated with visual impairment.

Progress in the Application of Microneedles in Eye Disorders and the Proposal of the Upgraded Microneedle with Spinule

PURPOSE

In the local administration methods for treating eye diseases, the application of microneedles has great potential due to the shortcomings of low efficacy and significant side effects of local administration preparations. This article provides ideas for the research on the application of ophthalmic microneedle in the treatment of eye diseases.

RESULTS

This article analyzes the physiological structures of the eyes, ocular diseases and its existing ocular preparations in sequence. Finally, this article reviews the development and trends of ocular microneedles in recent years, and summarizes and discusses the drugs of ocular microneedles as well as the future directions of development. At the same time, according to the inspiration of previous work, the concept of "microneedle with spinule" is proposed for the first time, and its advantages and limitations are discussed in the article.

CONCLUSIONS

At present, the application of ocular microneedles still faces multiple challenges. The aspects of auxiliary devices, appearance, the properties of the matrix materials, and preparation technology of ophthalmic microneedle are crucial for their application in the treatment of eye diseases.

Ocular injuries sustained at home in five metropolitan cities: a review of 5008 cases

Background

In Iran, ocular injuries sustained at home are a growing public health issue, and few studies have explored their prevalence and the frequencies of different causes of these injuries. We investigated the features of ocular injuries at home among children and adolescents (aged < 18 years), adults (18 - 64 years), and the elderly ( ≥ 65 years) in five metropolitan cities.

Methods

In this cross-sectional study, we recruited individuals with ocular injuries sustained at home who presented to 12 public/teaching hospitals in five metropolitan cities during a 5-month period. Using clinical records within the emergency department archives, we collected the following data: age, sex, frequency of injuries requiring hospital admission or surgical intervention, and causes of eye injuries, documented as 1) cleaning products, 2) chemical products, 3) kitchen items, 4) cooking activities, 5) toys, 6) falls from height, 7) sports equipment, 8) penetrating or cutting, 9) abrasions, 10) foreign bodies, and 11) direct blows by other individuals.

Results

Of 5008 participants from the five cities, 74% (n = 3711) were male and 26% (n = 1297) were female. The most frequent causes of injury among children and adolescents, adults, and the elderly were toys, kitchen items, and cooking activities, respectively. In children and adolescents, injuries were caused by kitchen items, toys, foreign bodies, and direct blows by other individuals more frequently than in adults or the elderly, and by cleaning products and abrasions more frequently than in the elderly (all P < 0.05). In adults, injuries were caused by cleaning products, cooking activities, falls from height, sports equipment, penetrating or cutting, and abrasions more frequently than in children and adolescents or the elderly (all P < 0.05), and by kitchen items, toys, and blows by other individuals more frequently than in the elderly (all P < 0.05). In the elderly, injuries were caused by chemical products more frequently than in children and adolescents or adults, and by cooking activities, falls from height, and sports equipment more frequently than in children and adolescents (all P < 0.05). In adults, the frequency of ocular injuries was significantly higher in Tehran and lower in Mashhad when comparing each with that of the other four cities (all P < 0.05). We found a significantly higher frequency of ocular injuries by cleaning and chemical products in Tehran, by toys in Shiraz, by falls from height in Isfahan, and by direct blows by other individuals in Ahvaz when comparing each to that of the other four cities (all P < 0.05). Regarding the prevalence of severe ocular injuries among the children/adolescent and adult age groups, conditions were relatively better in Shiraz and relatively unfavorable in Mashhad.

Conclusions

Ocular trauma was more common in male individuals and the younger age groups. Approximately half of the causes were kitchen items, toys, and foreign bodies, which are avoidable by enhancing public eye health awareness. The prevalence of severe ocular injuries in individuals aged < 18 years was high, highlighting the necessity of nationwide preventive strategies for pediatric ocular injuries.

What is the coverage of retina screening services for people with diabetes? Protocol for a systematic review and meta-analysis

INTRODUCTION

Diabetic retinopathy is a leading cause of vision impairment globally. Vision loss from diabetic retinopathy can generally be prevented by early detection and timely treatment. The WHO included a measure of service access for diabetic retinopathy as a core indicator in the Eye Care Indicator Menu launched in 2022: retina screening coverage for people with diabetes. The aim of this review is to provide a comprehensive global and regional summary of the available information on retina screening coverage for people with diabetes.

METHODS AND ANALYSIS

A search will be conducted in five databases without language restrictions for studies from any country reporting retina screening coverage for adults with any type of diabetes at the national or subnational level using data collected since 1 January 2000 until the search date. We will also seek reports and coverage statistics from government websites of all WHO member states. Two investigators will independently screen studies, extract relevant data and assess risk of bias of included studies. The results of the review will be reported using the Preferred Reporting Items for Systematic Review and Meta-Analysis guideline. We will summarise the range of coverage definitions reported across included studies and present the median retina screening coverage in WHO regions and by World Bank country income level. Depending on the availability of data, we will conduct meta-analysis to assess disparities in retina screening coverage for people with diabetes by factors in the PROGRESS framework (Place of residence, Race/ethnicity/culture/language, Occupation, Gender/sex, Religion, Education, Socioeconomic status and Social capital).

ETHICS AND DISSEMINATION

This review will only include published data thus no ethical approval will be sought. The findings of this review will be published in a peer-reviewed journal and presented at relevant conferences.

PROTOCOL REGISTRATION NUMBER

OSF registration 17/10/2023: https://osf.io/k5p69.

Persistence of severe global inequalities in the burden of blindness and vision loss from 1990 to 2019: findings from the Global Burden of Disease Study 2019

AIMS

To assess the global burden and economic inequalities in the distribution of blindness and vision loss between 1990 and 2019.

METHODS

A secondary analysis of the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019. Data for disability-adjusted life-years (DALYs) due to blindness and vision loss were extracted from the GBD 2019. Data for gross domestic product per capita were extracted from the World Bank database. Slope index of inequality (SII) and concentration index were computed to assess absolute and relative cross-national health inequality, respectively.

RESULTS

Countries with high, high-middle, middle, low-middle and low Socio-demographic Index (SDI) had decline of age-standardised DALY rate of 4.3%, 5.2%, 16.0%, 21.4% and 11.30% from 1990 to 2019, respectively. The poorest 50% of world citizens bore 59.0% and 66.2% of the burden of blindness and vision loss in 1990 and 2019, respectively. The absolute cross-national inequality (SII) fell from -303.5 (95% CI -370.8 to -236.2) in 1990 to -256.0 (95% CI -288.1 to -223.8) in 2019. The relative inequality (concentration index) for global blindness and vision loss remained essentially constant between 1991 (-0.197, 95% CI -0.234 to -0.160) and 2019 (-0.193, 95% CI -0.216 to -0.169).

CONCLUSION

Though countries with middle and low-middle SDI were the most successful in decreasing burden of blindness and vision loss, a high level of cross-national health inequality persisted over the past three decades. More attention must be paid to the elimination of avoidable blindness and vision loss in low-income and middle-income countries.

Artificial intelligence-supported diabetic retinopathy screening in Tanzania: rationale and design of a randomised controlled trial

INTRODUCTION

Globally, diabetic retinopathy (DR) is a major cause of blindness. Sub-Saharan Africa is projected to see the largest proportionate increase in the number of people living with diabetes over the next two decades. Screening for DR is recommended to prevent sight loss; however, in many low and middle-income countries, because of a lack of specialist eye care staff, current screening services for DR are not optimal. The use of artificial intelligence (AI) for DR screening, which automates the grading of retinal photographs and provides a point-of-screening result, offers an innovative potential solution to improve DR screening in Tanzania.

METHODS AND ANALYSIS

We will test the hypothesis that AI-supported DR screening increases the proportion of persons with true referable DR who attend the central ophthalmology clinic following referral after screening in a single-masked, parallel group, individually randomised controlled trial. Participants (2364) will be randomised (1:1 ratio) to either AI-supported or the standard of care DR screening pathway. Participants allocated to the AI-supported screening pathway will receive their result followed by point-of-screening counselling immediately after retinal image capture. Participants in the standard of care arm will receive their result and counselling by phone once the retinal images have been graded in the usual way (typically after 2-4 weeks). The primary outcome is the proportion of persons with true referable DR attending the central ophthalmology clinic within 8 weeks of screening. Secondary outcomes, by trial arm, include the proportion of persons attending the central ophthalmology clinic out of all those referred, sensitivity and specificity, number of false positive referrals, acceptability and fidelity of AI-supported screening.

ETHICS AND DISSEMINATION

The London School of Hygiene & Tropical Medicine, Kilimanjaro Christian Medical Centre and Tanzanian National Institute of Medical Research ethics committees have approved the trial. The results will be submitted to peer-reviewed journals for publication.

TRIAL REGISTRATION NUMBER

ISRCTN18317152.

Case Report: Vision-Threatening Fungal Keratitis in a Service Member Stationed at Guantanamo Bay

Fungal keratitis is a major cause of corneal blindness worldwide. Compared to other types of infectious keratitis, fungal keratitis has a relatively poor prognosis because of various factors such as delayed patient presentation and diagnosis. Although associated in earlier studies with poverty and low socioeconomic status, military personnel stationed in tropical and subtropical climates, in low-resource settings, are at risk. Here, we report a case of a 20-year-old active duty contact lens-wearing military service member stationed at Guantanamo Bay who developed a severe vision-threatening fungal keratitis in her left eye. Enhancing health and safety precautions in at-risk settings, maintaining vigilance, and leveraging new imaging modalities will be important to ensure early recognition and treatment.

Near vision data and near correction requirements from community eye health programmes in nine countries

BACKGROUND

Recent estimates of global prevalence of uncorrected presbyopia range from 510 to 826 million. There is a shortage of primary data regarding Near Visual Impairment (NVI) magnitude.

METHODS

Near visual acuity (NVA) and NVI data was collected from over 388,000 people aged 35 or over across 9 countries, within Community Eye Health programmes between January 2022 and June 2023. In Kenya (n = 34,328), dioptric power of required near correction was also recorded, and any association with age, gender or level of NVA was assessed via linear regression model.

RESULTS

146,801 of 388,939 people failed initial near vision screening (37.74%, 95% CI 37.59-37.89%), with significantly higher prevalence of NVI in Sub-Saharan Africa than South Asia. Of those with distance acuity 6/12 or better, 27.97% failed (95% CI 27.81-28.13%) with evidence of difference between genders (p < 0.001): 30.77% of women vs. 24.47% of men. The most commonly required dioptric powers of correction were +2.00D, +2.50D and +3.00D, and required power correlated with age and NVA.

CONCLUSIONS

NVI remains common among Community Eye Health programme participants aged 35 and over. Data from large scale programmes such as these provide an opportunity to contribute to more accurate epidemiological estimates, and to guide future research, resource planning and intervention, ideally with improved standardisation of testing in the future.

Individual-level socioeconomic status and cataract-induced visual disability among older adults in China: the overview and urban-rural difference

Objective

To investigate the prevalence of cataract-induced visual disability and its association with individual-level socioeconomic status (SES) among older adults in China.

Methods

Using the data of 354,743 older adults (60 years and older) from the Second China National Sample Survey on Disability in 2006. Cross-sectional study design was applied. The differences in visual disability prevalence of cataracts among sociodemographic subgroups were analyzed by the chi-square test, and the association between individual-level SES and cataract-induced visual disability was investigated by the multivariate logistic regression model.

Results

The weighted visual disability prevalence of cataracts was 4.84% in 2006. Older people with a higher household income per capita (OR = 0.83, 95% CI: 0.81-0.85), higher education level (primary school vs. illiteracy: OR = 0.80, 95% CI: 0.76-0.83; ≥undergraduate college vs. illiteracy: OR = 0.31, 95% CI: 0.25-0.39), and occupation (OR = 0.53, 95% CI: 0.50-0.56) were less likely to suffer from cataract-induced visual disability. Household income per capita and education level increase played a greater role in decreasing the risk of visual disability caused by cataracts in urban areas, while having occupation contributed more to reducing the risk of disability in rural areas.

Conclusion

The gap in individual-level SES is closely related to the visual health inequities among older Chinese people and there are two distinct mechanisms in rural and urban areas. Strategies to promote collaborative healthcare development regionally, strengthen safeguards for disadvantaged groups, and increase public awareness of visual disability prevention are warranted.

Time Savings Using a Digital Workflow versus a Conventional for Intraocular Lens Implantation in a Corporate Chain Hospital Setting

Purpose

To evaluate and compare the digital cataract workflow with the existing conventional workflow in terms of time savings for overall diagnostic procedures from preoperative measurements, data transfer, intraocular lens (IOL) power calculation, and axis marking for cataract surgery in a corporate hospital chain setting.

Patients and Methods

This prospective non-clinical study assessed the mean procedural times for preoperative assessments, calculation of IOL power, data transfer to operating devices, and total surgery for both digital and existing conventional workflows.

Results

Overall, 430 workflows (digital cataract workflow: 227; existing conventional workflow: 203) were included for time measurements. The digital cataract workflow resulted in shorter mean (± standard deviation [SD]) preoperative assessments with lesser variability among individual assessments than the existing workflow (14.15 ± 1.86 vs 21.41 ± 1.18 min, respectively); with a time saving of 35%. Similarly, the mean (± SD) time required for the subsequent assessment steps such as IOL calculation (2.19 ± 1.23 vs 3.17± 2.29 min; 30%), data transfer (0 vs 1.33 ± 0.25 min; 100%), IOL axis marking and alignment (0 vs 3.07 ± 0.53 min; 100%) were shorter with digital cataract workflow versus existing conventional cataract workflow. Briefly, the overall mean time from preoperative assessments to final surgery was 16.48 min with digital cataract workflow and 30.58 min with existing conventional workflow; resulting in a time saving of 46%.

Conclusion

The Zeiss digital cataract workflow demonstrated greater time savings at each step of the cataract surgery workflow compared to the existing conventional workflow. In addition, digitalization can lead to a more streamlined cataract surgery workflow that is more convenient and cost-effective than the existing conventional practices in a corporate chain hospital setting.

Evaluation of the LDN-0060609 PERK Inhibitor as a Selective Treatment for Primary Open-Angle Glaucoma: An In Vitro Study on Human Retinal Astrocytes

The term glaucoma encompasses various neurodegenerative eye disorders, among which the most common is primary open-angle glaucoma (POAG). Recently, the essential role of human retinal astrocytes (HRA) in glaucoma progression has been placed in the spotlight. It has been found that placing the endoplasmic reticulum (ER) under stress and activating PERK leads to apoptosis of HRA cells, which inhibits their neuroprotective effect in the course of glaucoma. Therefore, the aim of the present study was to evaluate the effectiveness of the small-molecule PERK inhibitor LDN-0060609 in countering ER stress conditions induced in HRA cells in vitro. The activity of LDN-0060609 was studied in terms of protein and mRNA expression, cytotoxicity, genotoxicity, caspase-3 level and cell cycle progression. LDN-0060609 at 25 μM proved to be a potent inhibitor of the major PERK substrate, p-eIF2α (49% inhibition). The compound markedly decreased the expression of pro-apoptotic ER stress-related genes (ATF4, DDIT3, BAX and Bcl-2). Treatment with LDN-0060609 significantly increased cell viability, decreased genotoxicity and caspase-3 levels, and restored cell cycle distribution in HRA cells with activated ER stress conditions. These findings indicate that the small-molecule PERK inhibitor LDN-0060609 can potentially be developed into a novel anti-glaucoma agent.

Barriers to uptake of cataract surgery among elderly patients in rural China: a cross-sectional study

OBJECTIVE

To investigate factors that differentiate elderly adults in rural China who accept free vision screening and cataract surgery from those who could benefit from vision care but refuse it when offered.

DESIGN

We conducted a population-based, cross-sectional study between October and December 2016. Logistic regression models were used to examine the predictors of accepting free vision screening and cataract surgery.

SETTING

Rural communities in Handan, China.

PARTICIPANTS

Adults aged 50 years or older, with presenting visual acuity ≤6/18 in the better seeing eye, suspected by examining ophthalmologist to be due to cataract.

RESULTS

Among 613 persons with cataract identified on a population basis, 596 (97.2%) completed the household survey (mean (SD) age, 71.5 (10.0) years; 79.8% female). A total of 214 persons (35.9%) refused participation, while 382 (64.1%) took part in the vision screening. A total of 193 (50.5%) participants were found eligible for surgery, while 189 (49.5%) were not. Among 99 randomly selected participants who were offered immediate free surgery, surgery was accepted by 77 participants (77.8%) and refused by 22 (22.2%). In the multivariate model, being engaged in income-generating activities (p<0.01), self-reported better physical capacity (p<0.001) and having had a recent physical examination (p=0.01) were significantly associated with acceptance of vision screening. The only variable significantly associated with acceptance of surgery was presenting visual acuity, with better vision inversely associated with acceptance of surgery (p<0.05) models.

CONCLUSION

Our results suggest that refusal of basic eye examinations may be at least as important a determinant of low surgical rates in rural China as lack of acceptance of surgery itself.

Spatial and network mapping of comorbidity with trachoma and visual-impairing NCDs in a pastoralist community in Kenya: implications for SDGs and UHC

BACKGROUND

We explore the spatial distribution of comorbidity with trachoma and potentially visual-impairing non-communicable diseases (NCDs) and their risk factors among Kenyan pastoralists.

METHODS

Using a cross-sectional study design, we recruited and clinically examined 262 study participants for NCDs (hypertension or diabetes) and trachoma using the World Health Organization grading system. Network models estimated interactions and risks linked with trachoma and NCDs while the Poisson point process determined their spatial distribution.

RESULTS

Of the 262 participants, 140 (53%) had trachoma, with >71% of these cases identified among females and those >60 y of age. A total of 36 trachoma cases co-occurred with hypertension (26%) and diabetes (0.01%). NCDs were frequent among those with recurring trachoma (21%) and trachomatous trichiasis (14.3%). Trachoma and NCDs clustered together in <1 km distances (R=0.18, p=0.02). In network analysis, age was strongly associated with trachoma and NCDs. Trachoma was linked with geographic location while diabetes was linked with water source distances. Education level became the central risk factor.

CONCLUSIONS

We demonstrate a twin trachoma-NCD burden that is higher among elderly pastoralists in southern Kenya. Attenuating adverse population-level visual impairment, including integrating the trachoma SAFE strategy with NCD comprehensive care, amplifies the benefits from economies of scale, accelerating realization of Sustainable Development Goal 3 and universal health coverage in hard-to-reach areas.

Artificial intelligence enhanced ophthalmological screening in children: insights from a cohort study in Lubelskie Voivodeship

This study aims to investigate the prevalence of visual impairments, such as myopia, hyperopia, and astigmatism, among school-age children (7-9 years) in Lubelskie Voivodeship (Republic of Poland) and apply artificial intelligence (AI) in the detection of severe ocular diseases. A total of 1049 participants (1.7% of the total child population in the region) were examined through a combination of standardized visual acuity tests, autorefraction, and assessment of fundus images by a convolutional neural network (CNN) model. The results from this artificial intelligence (AI) model were juxtaposed with assessments conducted by two experienced ophthalmologists to gauge the model's accuracy. The results demonstrated myopia, hyperopia, and astigmatism prevalences of 3.7%, 16.9%, and 7.8%, respectively, with myopia showing a significant age-related increase and hyperopia decreasing with age. The AI model performance was evaluated using the Dice coefficient, reaching 93.3%, indicating that the CNN model was highly accurate. The study underscores the utility of AI in the early detection and diagnosis of severe ocular diseases, providing a foundation for future research to improve paediatric ophthalmic screening and treatment outcomes.

Barriers and enablers to low vision care and rehabilitation in sub-Saharan Africa within a global context

Low vision is an uncorrectable form of visual impairment that affect millions of people worldwide. Low vision care and rehabilitation are essential to improving the independence of affected individuals. Even though sub-Saharan Africa has one of the highest burdens of low vision globally, there are inadequate care and rehabilitation services in most countries and in some cases they are non-existent This scoping review aimed to identify the barriers and enablers to low vision care and rehabilitation in sub-Saharan Africa and assess these within the global context. The review was conducted using the five-step Arksey and O'Malley framework. Search terms were formulated based on the research questions and a search strategy was designed to search for eligible research articles from electronic databases; Pubmed, Ovid, Medline, and Embase. The data was screened by two members of the research team in accordance with set inclusion and exclusion criteria. Twenty-five out of 260 articles satisfied the inclusion criteria for the study. Inadequate low vision care infrastructure and supplies, non-standardised training of low vision care providers, health system failure and poor awareness of low vision care were the main barriers noted by eye care practitioners. Patients living with low vision cited the cost and availability of low vision aids, societal stigma, and poor awareness of services as the main barriers. No direct enablers were identified in sub-Saharan Africa; however, practitioners suggested improved training in low vision as a potential enabler. The barriers to low vision care and rehabilitation services identified were not unique to sub-Saharan Africa when viewed within a global context. Adopting and adapting solutions from other countries may therefore assist in improving low vision care and rehabilitation in sub-Saharan Africa.

Tracing the barriers to decarbonising ophthalmology: A review

As climate change demands increasingly urgent mitigation of greenhouse gas emissions, the health sector needs to do its part to decarbonise. Ophthalmologists share concerns about climate change and seek opportunities to reduce their environmental impact. When measuring the footprint of ophthalmology, major contributions are from patient travel to clinics, and from the large amounts of single-use disposable materials that are consumed during surgeries and sterile procedures. Ophthalmic services in India have already demonstrated systems that consume far fewer of these products through efficient throughput of patients and the safe reuse of many items, while maintaining equivalent safety and quality outcomes. Choosing these low-cost low-emission options would seem obvious, but many ophthalmologists experience barriers that prevent them operating as Indian surgeons do. Understanding these barriers to change is a crucial step in the decarbonisation of ophthalmology and the health sector more broadly.

Global, Regional, and National Epidemiology of Visual Impairment in Working-Age Individuals, 1990-2019

Importance

Visual impairment in working-age individuals can affect their general health and employment prospects, leading to decreased social and economic productivity and increased poverty rates. Nonetheless, investigations in this population appear to be limited.

Objective

To investigate the trends of visual impairment prevalence and disability-adjusted life-years (DALYs) in working-age individuals from 1990 to 2019.

Design, Setting, and Participants

This cross-sectional, population-based study used data for individuals of working age (15-64 years) from 204 countries and territories obtained from the Global Burden of Disease 2019 study. The data analysis was performed between May 1 and 10, 2023.

Exposure

Visual impairment, defined as visual acuity of less than 6/18 (20/60) or near visual acuity of less than 6/12 (20/40) distance equivalent as determined by Snellen chart.

Main Outcomes and Measures

Trends of visual impairment prevalence, DALYs, and corresponding estimated annual percent changes (EAPCs) from 1990 to 2019 were stratified according to region, nation, and sociodemographic index (SDI).

Results

There were 437 539 484 (95% uncertainty interval [UI], 325 463 851-575 573 588) prevalent cases of visual impairment globally (53.12% female and 46.88% male) in 2019, representing an increase of 91.46% from 1990 (prevalent cases, 228 530 964; 95% UI, 172 515 833-297 118 596). Over 3 decades, visual impairment-associated DALYs increased from 7 601 852 (95% UI, 5 047 030-11 107 897) to 12 563 276 (95% UI, 8 278 866-18 961 723). Among the 5 SDI groups, the low-SDI group had the largest increase in DALYs (898 167 [95% UI, 597 161-1 301 931] in 1990 to 1 634 122 [95% UI, 1 079 102-2 444 381] in 2019). Regionally, the greatest increase in prevalence was observed in Eastern Europe (EAPC, 0.10; 95% CI, 0.02-0.19). Among all countries and territories, Nepal had the highest national prevalence of visual impairment per 100 000 population in 2019 (26 008.45; 95% UI, 19 987.35-32 482.09), while South Sudan had the highest DALY rate per 100 000 population (480.59; 95% UI, 316.06-697.06).

Conclusions and Relevance

Despite the mild decrease in visual impairment prevalence rates in less-developed countries, these findings suggest that the number of prevalent cases globally has increased substantially, with discernible unfavorable patterns in developed regions. The findings support the notion that visual impairment in working-age individuals is a growing global health challenge. A better understanding of its epidemiology may facilitate the development of appropriate measures for prevention and treatment from both medical and social perspectives.

Deep Transfer Learning for Ethnically Distinct Populations: Prediction of Refractive Error Using Optical Coherence Tomography

INTRODUCTION

The mismatch between training and testing data distribution causes significant degradation in the deep learning model performance in multi-ethnic scenarios. To reduce the performance differences between ethnic groups and image domains, we built a deep transfer learning model with adaptation training to predict uncorrected refractive errors using posterior segment optical coherence tomography (OCT) images of the macula and optic nerve.

METHODS

Observational, cross-sectional, multicenter study design. We pre-trained a deep learning model on OCT images from the B&VIIT Eye Center (Seoul, South Korea) (N = 2602 eyes of 1301 patients). OCT images from Poona Eye Care (Pune, India) were chronologically sorted into adaptation training data (N = 60 eyes of 30 patients) for transfer learning and test data (N = 142 eyes of 71 patients) for validation. Deep learning models were trained to predict spherical equivalent (SE) and mean keratometry (K) values via transfer learning for domain adaptation.

RESULTS

Both adaptation models for SE and K were significantly better than those without adaptation (P < 0.001). In myopia/hyperopia classification, the model trained on circular optic disc OCT images yielded the best performance (accuracy = 74.7%). It also performed best in estimating SE with the lowest mean absolute error (MAE) of 1.58 D. For classifying the degree of corneal curvature, the optic nerve vertical algorithm performed best (accuracy = 65.7%). The optic nerve horizontal model achieved the lowest MAE (1.85 D) when predicting the K value. Saliency maps frequently highlighted the retinal nerve fiber layers.

CONCLUSIONS

Adaptation training via transfer learning is an effective technique for estimating refractive errors and K values using macular and optic nerve OCT images from ethnically heterogeneous populations. Further studies with larger sample sizes and various data sources are needed to confirm the feasibility of the proposed algorithm.

Gender Disparities in the Global Burden of Refractive Disorders in Children: An Analysis From the Global Burden of Disease Study 2019

PURPOSE

To investigate gender disparities in the global burden of refractive disorders in children younger than 15 years by year, age, and national developmental status using disability-adjusted life years (DALYs).

METHODS

Global, regional, and national gender-specific DALY numbers and rates of refractive disorders in children were obtained by year (from 1990 to 2019) and age group (0 to 4, 5 to 9, and 10 to 14 years) from the Global Burden of Disease Study 2019. Data from the Inequality-adjusted Human Development Index in 2019 as an indicator of national developmental status were extracted from the Human Development Report. Pearson correlation and linear regression analyses were performed to explore the association between female-to-male DALY rate ratios and national developmental status.

RESULTS

Gender disparities in DALY numbers and rates of refractive disorders in children have persisted and shown little improvement from 1990 to 2019. Girls had a higher burden than boys of the same age, and gender disparities increased with age (1.120 in preschool children aged 0 to 4 years, 1.124 in younger school-aged children aged 5 to 9 years, and 1.135 in older school-aged children aged 10 to 14 years). Female-to-male DALY rate ratios were negatively related to Inequality-adjusted Human Development Index values (standardized b = -0.189, P < .05).

CONCLUSIONS

Gender disparities in the global burden of refractive disorders in children have persisted for decades, with girls who are older and from lower-income countries having a higher burden than boys. Gender-specific health policies should be made to manage refractive disorders in children. [J Pediatr Ophthalmol Strabismus. 2024;61(1):51-58.].

Quality of life and depression among patients with high myopia in Nigeria: a cross sectional study

AIM

To evaluate the quality of life (QOL) and level of depression among participants with high myopia in Nigeria and the demographic factors associated with these outcomes.

METHODS

This cross-sectional study was conducted on 100 adult participants with high myopia (defined as refractive error ≤-5.00 D or worse, and uncorrected visual acuity worse than 6/18 in the better seeing eye) attending ophthalmology centres in Nigeria from 2 October 2021 to 30 August 2022. The means and standard deviations were calculated for each of the four domains of World Health Organization Quality of life scale (WHOQOL-BREF) using the transformed scores. The Beck Depression Inventory (BDI) scale was used to assess the level of depression.

RESULTS

The highest and the lowest mean scores of WHOQOL-BREF domains were found for the psychological and physical health domains (mean percentage scores were 67.0 [95% confidence intervals (CI) 64.1-68.9] and 55.3 (95%CI 51.8-58.8, P<0.001), respectively. One-way analysis of variance (ANOVA) revealed significant differences in physical health with educational status (higher among those with tertiary education: mean difference 0.9, 95%CI -0.2-2.1; P=0.049), differences in psychological health with working status (higher among those who were working 1.2, 95%CI 0.3-2.1; P=0.012). Also, the result showed a statistically significant association between environmental health and marital status (higher among non-married: 1.7, 95%CI -0.9-2.3; P=0.012) while overall health was associated with place of residence (higher in urban areas: 2.3, 95%CI 1.2-3.5; P=0.024). For depression, one in every nine participants reported major depressive symptom, mostly younger people (aged 16-29 vs 30-49y: 17.0% vs 0, P=0.019), and slightly more women than men (14.3% vs 0, P=0.064). There were significant negative correlations between the depression scores and psychological health (r=-0.48, P<0.001), physical health (r=-0.29, P=0.002), social and relationship (r=-0.49, P<0.001), environmental (r=-0.48, P<0.001) and overall health (r=-0.49, P<0.001).

CONCLUSION

People with high myopia have a relatively moderate QOL, but poor physical health, particularly the younger age group, and women who are more likely to experience clinically relevant depression. Eye care professionals should consider possible referrals for counselling for people with high myopia.

[Depression, anxiety, stress, and social support: a cross-sectional study with caregivers of visually impaired children in Rio de Janeiro, Brazil - Views-QoL Study]

We aimed to identify the reports of symptoms of depression, anxiety, and stress among caregivers of children without visual impairment, with low vision, and with blindness and their relationship with the degree of social, emotional, material, and affective support. This cross-sectional and multicenter study was conducted in the municipality of Rio de Janeiro, Brazil, from 2019 to 2020. A questionnaire was applied to obtain caregivers' sociodemographic and economic data. The Medical Outcomes Study Social Support Scale (MOS-SSS) and The Depression, Anxiety, and Stress Scale (DASS-21) were used. Tests were used for multiple comparisons of these scales. The prevalence ratio of symptoms of depression, anxiety, and stress was estimated. Of all caregivers (N = 355), more than 90% were women-mothers. Caregivers of children with visual impairment show the highest proportion of no schooling, incomplete elementary education, or lower average monthly income. Most caregivers of children with blindness reported symptoms of depression, anxiety, and stress (66.7%, 73.3%, and 80%, respectively) as did those of children with low vision. The evaluation of the relationship between MOS-SSS and DASS-21 results shows greater support and lower scores of reports of depression, anxiety, and stress for caregivers of children without disabilities or with less visual impairment. For caregivers of blind children, the highest prevalence of such reports was independent of the received support. Results indicate the need for a care policy with mechanisms to protect the mental health of caregivers of visually impaired children.

Shifts in ophthalmic care utilization during the COVID-19 pandemic in the US

BACKGROUND

Healthcare restrictions during the COVID-19 pandemic, particularly in ophthalmology, led to a differential underutilization of care. An analytic approach is needed to characterize pandemic health services usage across many conditions.

METHODS

A common analytical framework identified pandemic care utilization patterns across 261 ophthalmic diagnoses. Using a United States eye care registry, predictions of utilization expected without the pandemic were established for each diagnosis via models trained on pre-pandemic data. Pandemic effects on utilization were estimated by calculating deviations between observed and expected patient volumes from January 2020 to December 2021, with two sub-periods of focus: the hiatus (March-May 2020) and post-hiatus (June 2020-December 2021). Deviation patterns were analyzed using cluster analyses, data visualizations, and hypothesis testing.

RESULTS

Records from 44.62 million patients and 2455 practices show lasting reductions in ophthalmic care utilization, including visits for leading causes of visual impairment (age-related macular degeneration, diabetic retinopathy, cataract, glaucoma). Mean deviations among all diagnoses are 67% below expectation during the hiatus peak, and 13% post-hiatus. Less severe conditions experience greater utilization reductions, with heterogeneities across diagnosis categories and pandemic phases. Intense post-hiatus reductions occur among non-vision-threatening conditions or asymptomatic precursors of vision-threatening diseases. Many conditions with above-average post-hiatus utilization pose a risk for irreversible morbidity, such as emergent pediatric, retinal, or uveitic diseases.

CONCLUSIONS

We derive high-resolution insights on pandemic care utilization in the US from high-dimensional data using an analytical framework that can be applied to study healthcare disruptions in other settings and inform efforts to pinpoint unmet clinical needs.

Changing Trends in the Global Burden of Cataract Over the Past 30 Years: Retrospective Data Analysis of the Global Burden of Disease Study 2019

BACKGROUND

Cataracts now account for the largest proportion of the global burden of blindness and vision loss. Understanding the changing trends in the global burden of cataracts over the past 30 years and the next 15 years is of clear significance for the prevention and control of cataracts in key populations. As far as we know, research on the future burden of cataracts is lacking.

OBJECTIVE

This study aims to assess the global burden of cataracts over the past 30 years by using age-period-cohort modeling and to estimate trends in the next 15 years.

METHODS

Data were obtained from the Global Burden of Disease Study 2019, the United Nations Development Programme, and the WHO (World Health Organization) Global Health Observatory data repository. The assessment of trends and disparities in the number and rate of disability-adjusted life years (DALYs) for cataracts from 1990 to 2019 was conducted. The association between the age-standardized DALY rate (ASDR) and the socio-demographic index (SDI), human development index (HDI), national levels of particulate matter <2.5 μm in diameter (PM2.5), and ambient ultraviolet radiation (UVR) was determined using linear regression analysis. Additionally, we used the Nordpred (Harald Fekjær and Bjørn Møller) age-period-cohort model to predict the cataract burden from 2020 to 2034.

RESULTS

Globally, the number of DALYs due to cataract increased from 3,492,604 (95% uncertainty interval [UI] 2,481,846-4,719,629) in 1990 to 6,676,281 (95% UI 4,761,210-9,006,193) in 2019. The ASDRs due to cataract decreased from 93.17 (95% UI 66.14-125.32) in 1990 to 82.94 (95% UI 59.06-111.75) in 2019, with an average annual percentage change of -0.37 (95% CI -0.44 to -0.3; P<.001). Age, female sex, air pollution, smoking, high fasting plasma glucose levels, and a high body mass index were risk factors for the burden of cataracts. SDI and HDI were negatively correlated with ASDRs of cataracts, while PM2.5 and UVR were positively associated with them. Higher DALY rates were also associated with lower SDI (R2=0.1939; P<.001), lower HDI (R2=0.2828; P<.001), national PM2.5 concentration (R2=0.1874; P<.001), and ambient UVR levels (R2=0.2354; P<.001). The prediction model suggested that the number of DALYs due to cataract will continue to rise globally, while the cataract DALY rate will continue to decrease.

CONCLUSIONS

While the ASDR of cataracts has decreased, there has been a notable increase in the number of DALYs over the past 30 years. Projections suggest that the global burden of cataracts will continue to rise over the next 15 years. To address this challenge, appropriate prevention and treatment policies must be implemented.

Prevalence of trachoma in the non-indigenous Baixo Jaguaribe micro-region, Ceará State, Northeast Brazil

BACKGROUND

The aim of the current study was to estimate the population prevalence of trachoma in non-indigenous populations in the Baixo Jaguaribe micro-region, in the state of Ceará, northeast region of Brazil, 2021-2022.

METHODS

A population-based prevalence survey focusing on detecting cases of trachomatous inflammation-follicular (TF) in children aged 1-9 y and trachomatous trichiasis (TT) 'unknown to the health system' in people aged ≥15 y, was conducted in rural areas of the Baixo Jaguaribe micro-region in the state of Ceará. Indigenous populations will be further researched.

RESULTS

There was no detection of cases of TF and TT. In 900 households, 2234 people were examined. In the Baixo Jaguaribe micro-region, females (54.6%; 1219/2234) and the mixed/Pardo-Brazilian ethnicity (68.1%; 1521/2234) predominated. The most commonly reported educational level was elementary and middle school (41.8%; 702/1679). In 56.2% (506/900) of households, there was a source of water within the household. The monthly income range of 50%-100% of the minimum wage predominated in the families of the Baixo Jaguaribe micro-region (43.1%; 388/900).

CONCLUSIONS

Although no cases of TF and TT were detected in the Baixo Jaguaribe micro-region in the state of Ceará during the study period, considering the historical endemicity, we emphasise the need for monitoring and sustainability of surveillance actions in areas at risk for trachoma, common contexts for neglected populations.

The case for investment in eye health: systematic review and economic modelling analysis

Objective

To assess how the returns on investment from correcting refractive errors and cataracts in low- and middle-income countries compare with the returns from other global development interventions.

Methods

We adopted two complementary approaches to estimate benefit-cost ratios from eye health investment. First, we systematically searched PubMed® and Web of Science™ on 14 August 2023 for studies conducted in low-and-middle-income countries, which have measured welfare impacts associated with correcting refractive errors and cataracts. Using benefit-cost analysis, we compared these impacts to costs. Second, we employed an economic modelling analysis to estimate benefit-cost ratios from eye health investments in India. We compared the returns from eye health to returns in other domains across global health and development.

Findings

We identified 21 studies from 10 countries. Thirteen outcomes highlighted impacts from refractive error correction for school students. From the systematic review, we used 17 out of 33 outcomes for benefit-cost analyses, with the median benefit-cost ratio being 36. The economic modelling approach for India generated benefit-cost ratios ranging from 28 for vision centres to 42 for school eye screening, with an aggregate ratio of 31. Comparing our findings to the typical investment in global development shows that eye health investment returns six times more benefits (median benefit-cost ratio: 36 vs 6).

Conclusion

Eye health investments provide economic benefits with varying degrees based on the intervention type and location. Our findings underline the importance of incorporating eye health initiatives into broader development strategies for substantial societal returns.

Epidemiology and trends in the uptake of refractive error services in Harare, Zimbabwe: a hospital-based retrospective study

Aim

The study aimed to determine the epidemiology and evaluate the trends in the uptake of refractive error services in Harare.

Methods

A clinic-based retrospective study at the Greenwood Park Eye Centre and its three subsidiaries was conducted from January 1, 2015 to December 31, 2020.

Results

12,216 patients' records were retrieved, out of which 1074 (8.79%) had refractive error cases. The prevalence of visual impairment at presentation was 5.80% [95% CI: 5.39 - 6.23]. Among those with refractive error, the sample prevalence of visual impairment before correction was 41.30% [CI: 38.3 - 44.3, 95%], and 2.20% [95% CI: 1.4 - 3.3] after correction. There was inconsistency in the percentage utilization of refractive error services, with the highest being 42.60% in 2015. Refractive error types were related to age, employment position, and type of visual impairment prior to refractive error treatment.

Conclusion

There was a low percentage of refractive error services uptake in urban Zimbabwe.

Smartphone ophthalmoscope as a tool in teaching direct ophthalmoscopy: a crossover randomized controlled trial

To evaluate the effectiveness of smartphone ophthalmoscope (SO) in teaching ophthalmoscopy, compared with direct ophthalmoscope (DO). In this cross-over study, 45 final-year medical students attending sessions at a single institution were randomly allocated to two groups (A and B). Both groups attended two training sessions. In the first session, Group A students were taught ophthalmoscopy using DO and Group B students using SO. In the second session, the training sessions were crossed over. A series of eye models with 10 letters placed on the inner surface were designed to assess the students' skill on ophthalmoscopy. Students performed ophthalmoscopy on the eye models, recorded their findings, and completed a questionnaire of feedback on DO and SO. The main outcome measure was the score of ophthalmoscopy, assessed by the student correctly recording each letter (score 1 for each letter). For Group A, the mean score of ophthalmoscopy on the eye model using DO and SO was 3.9±2.4 and 8.2±2.2, respectively. For Group B, the mean score of ophthalmoscopy on the eye model using SO and DO 8.7±1.8 and 5.7±3.5 . Students scored significantly higher in ophthalmoscopy when using SO than DO (P<0.001). They expressed better visualization of the fundus using SO than DO (4.49±0.65 vs 4.13±0.81, P=0.004). Students' performance of ophthalmoscopy was better when SO was used compared with DO. The use of SO as an adjunctive tool is recommended to improve the effectiveness of teaching ophthalmoscopy.

Parapapillary βBM and γ Zones Played Different Roles in Axial Elongation Among Young Adolescents Using Optical Coherence Tomography

Purpose

To evaluate the influencing factors of parapapillary βBM and γ zones incidence in young adolescents and to explore their associations with axial length progression.

Methods

In this prospective cohort study, 976 seventh-grade students from nine secondary schools in Beijing, China, were enrolled and followed up 1 year later. Parapapillary βBM zone was defined as retinal pigment epithelium loss while Bruch's membrane was present. Parapapillary γ zone was defined as the absence of retinal pigment epithelium and Bruch's membrane. Logistic regression model was used to analyze the influencing factors of βBM and γ zone incidence. A linear mixed model was used to analyze the associations between parapapillary zones and axial elongation.

Results

Of the 976 participants, 139 (14.2%) had only βBM zone, 398 (40.8%) had only γ zone, and 171 (17.5%) had both. At follow-up, the incidence of βBM zone was 11.5% (76/659), and the incidence of γ zone was 9.7% (39/404). Optic disc tilt, thinner subfoveal choroid, and longer axial length at baseline showed a higher risk of γ zone incidence. The absence of γ zone at baseline showed a faster axial length progression. When the baseline axial length was 25 mm or longer, the βBM zone was also related to the axial elongation.

Conclusions

The γ zone was associated with axial length progression, and the βBM zone was also associated with the axial length progression when the axial length exceeded 25 mm, which was consistent with the notion that excessive axial length growth not only is the extension of the eyeball but also has its own pathologic changes.

Development and Validation of the Low Vision Severely Constricted Peripheral Eyesight (LV-SCOPE) Questionnaire

PURPOSE

To develop and validate a novel patient-reported outcome (PRO) measure to assess vision-related functioning in individuals with severe peripheral field loss (PFL).

DESIGN

Prospective outcome measure development/validation study.

METHODS

A 127-item questionnaire was developed based on a prior qualitative interview study. A total of 116 participants with severe PFL due to retinitis pigmentosa (RP) or glaucoma were recruited at the Kellogg Eye Center and completed the Likert-scaled telephone-administered questionnaire. Included participants had a horizontal extent of their visual field <20 degrees (RP) or a mixed or generalized stage 4 to 5 defect using the Enhanced Glaucoma Staging System (glaucoma) in the better seeing eye (or in 1 eye if the fellow eye visual acuity was <20/200). Response data were analyzed using exploratory factor analysis and Rasch modeling. Poorly functioning items were eliminated, confirmatory factor analysis was used to ensure scale unidimensionality, and the model was refit to produce the final instrument.

RESULTS

The final Low Vision Severely Constricted Peripheral Eyesight (LV-SCOPE) Questionnaire contains 53 items across 6 domains: mobility, object localization, object recognition, reading, social functioning, and technology. There were 74 items removed because of high missingness, poor factor loadings, low internal consistency, high local dependency, low item information, item redundancy, or differential item functioning. Using Rasch item calibrations, person ability scores could be calculated for each of the 6 unidimensional LV-SCOPE domains with good test-retest stability.

CONCLUSIONS

The LV-SCOPE Questionnaire provides a valid and reliable measure of vision-related functioning across 6 key domains relevant to individuals with severe PFL. Findings support the clinical utility of this psychometrically valid instrument.

CLAHE-CapsNet: Efficient retina optical coherence tomography classification using capsule networks with contrast limited adaptive histogram equalization

Manual detection of eye diseases using retina Optical Coherence Tomography (OCT) images by Ophthalmologists is time consuming, prone to errors and tedious. Previous researchers have developed a computer aided system using deep learning-based convolutional neural networks (CNNs) to aid in faster detection of the retina diseases. However, these methods find it difficult to achieve better classification performance due to noise in the OCT image. Moreover, the pooling operations in CNN reduce resolution of the image that limits the performance of the model. The contributions of the paper are in two folds. Firstly, this paper makes a comprehensive literature review to establish current-state-of-act methods successfully implemented in retina OCT image classifications. Additionally, this paper proposes a capsule network coupled with contrast limited adaptive histogram equalization (CLAHE-CapsNet) for retina OCT image classification. The CLAHE was implemented as layers to minimize the noise in the retina image for better performance of the model. A three-layer convolutional capsule network was designed with carefully chosen hyperparameters. The dataset used for this study was presented by University of California San Diego (UCSD). The dataset consists of 84,495 X-Ray images (JPEG) and 4 categories (NORMAL, CNV, DME, and DRUSEN). The images went through a grading system consisting of multiple layers of trained graders of expertise for verification and correction of image labels. Evaluation experiments were conducted and comparison of results was done with state-of-the-art models to find out the best performing model. The evaluation metrics; accuracy, sensitivity, precision, specificity, and AUC are used to determine the performance of the models. The evaluation results show that the proposed model achieves the best performing model of accuracies of 97.7%, 99.5%, and 99.3% on overall accuracy (OA), overall sensitivity (OS), and overall precision (OP), respectively. The results obtained indicate that the proposed model can be adopted and implemented to help ophthalmologists in detecting retina OCT diseases.

Comparison of the accuracy of 9 intraocular lens power calculation formulas after SMILE in Chinese myopic eyes

As of 2021, over 2.8 million small-incision lenticule extraction (SMILE) procedures have been performed in China. However, knowledge regarding the selection of intraocular lens (IOL) power calculation formula for post-SMILE cataract patients remains limited. This study included 52 eyes of 26 myopic patients from northern China who underwent SMILE at Tianjin Eye Hospital from September 2022 to February 2023 to investigate the suitability of multiple IOL calculation formulas in post-SMILE patients using a theoretical surgical model. We compared the postoperative results obtained from three artificial intelligence (AI)-based formulas and six conventional formulas provided by the American Society of Cataract and Refractive Surgery (ASCRS). These formulas were applied to calculate IOL power using both total keratometry (TK) and keratometry (K) values, and the results were compared to the preoperative results obtained from the Barrett Universal II (BUII) formula for the SMILE patients. Among the evaluated formulas, the results obtained from the Emmetropia Verifying Optical 2.0 Formula with TK (EVO-TK) (0.40 ± 0.29 D, range 0-1.23 D), Barrett True K with K formula (BTK-K, 0.41 ± 0.26 D, range 0.01-1.19 D), and Masket with K formula (Masket-K, 0.44 ± 0.33 D, range 0.02-1.39 D) demonstrated the closest proximity to BUII. Notably, the highest proportion of prediction errors within 0.5 D was observed with the BTK-K (71.15%), EVO-TK (69.23%), and Masket-K (67.31%), with the BTK-K showing a significantly higher proportion than the Masket-K (p < 0.001). Our research indicates that in post-SMILE patients, the EVO-TK, BTK-K, and Masket-K may yield more accurate calculation results. At their current stage in development, AI-based formulas do not demonstrate significant advantages over conventional formulas. However, the application of historical data can enhance the performance of these formulas.

Modelling ready-made spectacle coverage for children and adults using a large global database

BACKGROUND/AIMS

To model the suitability of conventional ready-made spectacles (RMS) and interchangeable-lens ready-made spectacles (IRMS) with reference to prescribing guidelines among children and adults using a large, global database and to introduce a web-based application for exploring the database with user-defined eligibility criteria.

METHODS

Using refractive power and interpupillary distance data for near and distance spectacles prescribed to children and adults during OneSight clinics in 27 countries, from 2 January 2016 to 19 November 2019, we modelled the expected suitability of RMS and IRMS spectacle designs, compared with custom-made spectacles, according to published prescribing guidelines.

RESULTS

Records of 18 782 presbyopic adult prescriptions, 70 619 distance adult prescriptions and 40 862 paediatric prescriptions were included. Globally, 58.7%-63.9% of adults could be corrected at distance with RMS, depending on the prescribing cut-off. For presbyopic adult prescriptions, coverage was 44.1%-60.9%. Among children, 51.8% were eligible for conventional RMS. Coverage for all groups was similar to the above for IRMS. The most common reason for ineligibility for RMS in all service groups was astigmatism, responsible for 27.2% of all ineligible adult distance prescriptions using the strictest cut-off, 31.4% of children's prescriptions and 28.0% of all adults near prescriptions globally.

CONCLUSION

Despite their advantages in cost and convenience, coverage delivered by RMS is limited under current prescribing guidelines, particularly for children and presbyopic adults. Interchangeable designs do little to remediate this, despite extending coverage for anisometropia. Our free application allows users to estimate RMS coverage in specific target populations.

The alterations in ocular biometric parameters following short-term discontinuation of long-term orthokeratology and prior to subsequent lens fitting: a preliminary study

PURPOSE

To investigate the alterations in biometric parameters among Chinese adolescents over an extended period of wearing orthokeratology lenses, as well as the subsequent changes after a one-month cessation of lens usage prior to the secondary lens fitting.

METHODS

Twenty-four myopic patients aged 7-14 were enrolled in this 37-month prospective observational study. Ocular biometric parameters were measured in the study. Ocular biometric parameters were assessed, and the utilization of Generalized Estimating Equations (GEE) was employed in the analysis to address the correlation between the two eyes of each participant.

RESULTS

The axial length (AL) increased by 0.55 mm after 36 months of lens wearing and further increased to 0.62 mm at the 37-month follow-up compared to the initial measurement. The differences in AL elongation per month between the 37-month time point and the 12-, 24-, and 36-month marks of lens wearing were found to be statistically significant (p12-month = 0.001; p24-month = 0.003; p36-month = 0.001). Following the cessation of lens wear for 1 month, there was no significant complete recovery observed in the flat and steep keratometry values. However, the intraocular pressure and anterior chamber depth returned to their baseline levels.

CONCLUSIONS

The AL elongation undergoes alterations during temporary discontinuation of lenses, with the flat and steep keratometry measurements remaining significantly flatter compared to the baseline. However, the intraocular pressure and anterior chamber depth return to their initial levels after one month of lens cessation.

Comparison of visual performance with iTrace analyzer following femtosecond laser-assisted cataract surgery with bilateral implantation of two different trifocal intraocular lenses

AIM

To compare the postoperative binocular visual performance with an iTrace analyzer following femtosecond laser-assisted cataract surgery (FLACS) combined with bilateral implantation of two different types of diffractive trifocal intraocular lenses (IOL).

METHODS

During this retrospective observational study, patients who received bilateral FLACS combined with implantation of two different types of diffractive trifocal IOLs were evaluated. According to the IOLs' different types and design, the patients were divided into AT LISA tri839MP group (tri839 group) and AcrySof PanOptix TFNT00 group (TFNT group). Study parameters included preoperative and postoperative uncorrected distance visual acuity (UDVA) at 5 m, uncorrected near visual acuity (UNVA) at 30 cm and 40 cm, uncorrected intermediate visual acuity (UIVA) at 60 cm and 80 cm, postoperative refractive status, objective visual qualities and total high order aberrations (HOAs) postoperatively. The postoperative complications were also recorded.

RESULTS

Totally 56 eyes of 28 patients (tri839 group, n=26; TFNT group, n=30) were included. Preoperative baseline characteristics between groups were not statistically significantly different. UDVA was not significantly different between groups except for 1wk follow-up due to the postoperative corneal edema. TFNT group showed statistically significant better UNIA at 60 cm than tri839 group at the 1wk (0.05±0.19 vs 0.15±0.10 logMAR, P=0.013), 1mo (0.05±0.12 vs 0.15±0.09 logMAR, P=0.001) and 3mo (0.04±0.12 vs 0.15±0.11 logMAR, P=0.001) follow-up, while tri839 group showed statistically significant better UNIA at 80 cm than TFNT group at the 1d (0.14±0.15 vs 0.20±0.14 logMAR, P=0.041) and 1mo (0.09±0.07 vs 0.14±0.10 logMAR, P=0.042) follow-up. Postoperative refractive status showed stable at every visit. Modulated transfer function (MTF) values and strehl ratio (SR) values were improved and HOAs were lower significantly after surgery.

CONCLUSION

FLACS with bilateral implantations of both tri839 and TFNT00 can achieve satisfactory natural whole-course vision, high postoperative refractive stability and good visual quality but without significantly difference. iTrace aberration instrument can accurately evaluate the visual quality under different status.

Sociodemographic characteristics of community eye screening participants: protocol for cross-sectional equity analyses in Botswana, India, Kenya, and Nepal

Background

Attendance rates for eye clinics are low across low- and middle-income countries (LMICs) and exhibit marked sociodemographic inequalities. We aimed to quantify the association between a range of sociodemographic domains and attendance rates from vision screening in programmes launching in Botswana, India, Kenya and Nepal.

Methods

We performed a literature review of international guidance on sociodemographic data collection. Once we had identified 13 core candidate domains (age, gender, place of residence, language, ethnicity/tribe/caste, religion, marital status, parent/guardian status, place of birth, education, occupation, income, wealth) we held workshops with researchers, academics, programme implementers, and programme designers in each country to tailor the domains and response options to the national context, basing our survey development on the USAID Demographic and Health Survey model questionnaire and the RAAB7 eye health survey methodology. The draft surveys were reviewed by health economists and piloted with laypeople before being finalised, translated, and back-translated for use in Botswana, Kenya, India, and Nepal. These surveys will be used to assess the distribution of eye disease among different sociodemographic groups, and to track attendance rates between groups in four major eye screening programmes. We gather data from 3,850 people in each country and use logistic regression to identify the groups that experience the worst access to community-based eye care services in each setting. We will use a secure, password protected android-based app to gather sociodemographic information. These data will be stored using state-of-the art security measures, complying with each country's data management legislation and UK law.

Discussion

This low-risk, embedded, pragmatic, observational data collection will enable eye screening programme managers to accurately identify which sociodemographic groups are facing the highest systematic barriers to accessing care at any point in time. This information will be used to inform the development of service improvements to improve equity.

Applications and Recent Developments of Hydrogels in Ophthalmology

Hydrogels are a type of functional polymer material with a three-dimensional network structure composed of physically or chemically cross-linked polymers. All hydrogels have two common features: first, their structure contains a large number of hydrophilic groups; therefore, they have a high water content and can swell in water. Second, they have good regulation, and the physical and chemical properties of their cross-linked network can be changed by environmental factors and deliberate modification methods. In recent years, the application of hydrogels in ophthalmology has gradually attracted attention. By selecting an appropriate composition and cross-linking mode, hydrogels can be used in different fields for various applications, such as gel eye drops, in situ gel preparation, intravitreal injection, and corneal contact lenses. This Review provides a detailed introduction to the classification of hydrogels and their applications in glaucoma, vitreous substitutes, fundus diseases, corneal contact lenses, corneal diseases, and cataract surgery.

Fellow-Eye Comparison between Phaco-Tanito Microhook Trabeculotomy and Phaco-iStent Inject W

This study aims to compare the surgical efficacy and safety of the Tanito microhook trabeculotomy (TMH-CE) and iStent inject W (Inject-CE) when performed in combination with cataract surgery on the eyes of glaucoma patients. A total of 78 glaucomatous eyes from 39 participants were retrospectively analyzed. Intraocular pressure (IOP), the number of antiglaucoma medications, best-corrected visual acuity (BCVA), anterior chamber flare (ACF), and corneal endothelial cell density (CECD) were all evaluated preoperatively and at multiple postoperative time points. The preoperative IOP was significantly higher in the TMH-CE (19.6 ± 6.7 mmHg) than in the Inject-CE (15.7 ± 3.8 mmHg) (p < 0.0001). At the 12-month follow-up, reductions in IOP and the number of medications were more pronounced in the TMH-CE (6.6 mmHg, 27.6% and -1.1, respectively) group than Inject-CE (2.7 mmHg, 12.4% and -0.7, respectively) (p < 0.0001 and p = 0.0034), while the IOP and medication-number levels were identical between TMH-CE (13.0 ± 3.3 mmHg and 1.3 ± 0.9, respectively) and Inject-CE (12.9 ± 2.6 mmHg and 1.9 ± 0.9, respectively) (p = 0.88 and p > 0.99, respectively). The TMH-CE group exhibited a higher ACF, a higher frequency of layered hyphema, and a greater anterior chamber floating red blood cells score in the early postoperative periods. Despite these differences, the changes in BCVA, ACF, and CECD were equivalent between the two groups in later follow-up periods. TMH-CE provides a more significant IOP reduction and medication-number reduction compared to Inject-CE, while Inject-CE shows quicker BCVA recovery. This study provides valuable insights for ophthalmologists choosing the most suitable surgical approach for glaucoma and cataract patients.

Child eye health in Ethiopia: a mixed methods analysis of policy and commitment to action

BACKGROUND

Child eye health is a serious public health issue in Ethiopia, where children under the age of 15 account for over half of the population. Our aim was to review Ethiopian health policy and practice to reveal approaches and commitment to promotion and delivery of child eye health services.

METHODS

We conducted a mixed-methods situational analysis employing documentary analysis and key informant interview methods. Government publications touching on any element of child eye health were included. Key informants were eligible if they were leaders, authorities, researchers or clinicians involved in child health. Data was combined and analysed by narrative synthesis, using an adaptation of the Eye Care Situation Analysis Tool as a framework.

FINDINGS

Eleven documents developed by the Ministries of Health and Education were included and interviews with 14 key informants were conducted. A focus on child eye health was lacking in key health policy documents, demonstrated by limited allocation of funds, a shortage of human resources, and a subpar referral system across all levels of child eye care.

CONCLUSION

The study identified several gaps and limitations in child eye health in Ethiopia. There is a need for health policies that strengthen ownership, finance and partnerships for improved coordination, and collaboration with line ministries and other stakeholders to improve child eye health services in Ethiopia.

Save our Sight (SOS): a collective call-to-action for enhanced retinal care across health systems in high income countries

With a growing aging population, the prevalence of age-related eye disease and associated eye care is expected to increase. The anticipated growth in demand, coupled with recent medical advances that have transformed eye care for people living with retinal diseases, particularly neovascular age-related macular degeneration (nAMD) and diabetic eye disease, has presented an opportunity for health systems to proactively manage the expected burden of these diseases. To do so, we must take collective action to address existing and anticipated capacity limitations by designing and implementing sustainable strategies that enable health systems to provide an optimal standard of care. Sufficient capacity will enable us to streamline and personalize the patient experience, reduce treatment burden, enable more equitable access to care and ensure optimal health outcomes. Through a multi-modal approach that gathered unbiased perspectives from clinical experts and patient advocates from eight high-income countries, substantiated perspectives with evidence from the published literature and validated findings with the broader eye care community, we have exposed capacity challenges that are motivating the community to take action and advocate for change. Herein, we propose a collective call-to-action for the future management of retinal diseases and potential strategies to achieve better health outcomes for individuals at-risk of, or living with, retinal disease.

Using Objective Vision Measures to Explore the Association of Vision Impairment With Cognition Among Older Adults in the United States

PURPOSE

To evaluate the association between vision impairment (VI) and cognitive function using objective measures.

DESIGN

Cross-sectional analysis with a nationally representative sample.

METHODS

The association between VI and dementia was investigated in a US population-based, nationally representative sample of Medicare beneficiaries, the National Health and Aging Trends Study (NHATS), a nationally representative sample of Medicare beneficiaries aged ≥65 years, using objective vision measures. Exposures included distance VI (>20/40), near VI (>20/40), contrast sensitivity impairment (CSI) (<1.55), any objective VI (distance and near visual acuity, or contrast), and self-reported VI. The main outcome measure was dementia status defined based on survey reports, interviews, and cognitive tests.

RESULTS

A total of 3026 adults were included in this study; the majority were female (55%) and White (82%). The weighted prevalence rates were 10% for distance VI, 22% for near VI, 22% for CSI, 34% for any objective VI, and 7% for self-reported VI. Across all measures of VI, dementia was more than twice as prevalent in adults with VI compared to their peers without (P < .001 for all). In adjusted models, all measures of VI were associated with higher odds of dementia (distance VI: OR 1.74, 95% CI 1.24-2.44; near VI: OR 1.68, 95% CI 1.29-2.18; CSI: OR 1.95, 95% CI 1.45-2.62; any objective VI: OR 1.83, 95% CI 1.43-2.35; self-reported VI: OR 1.86, 95% CI 1.20-2.89).

CONCLUSIONS

In a nationally representative sample of older US adults, VI was associated with increased odds of dementia. These results suggest that maintaining good vision and eye health may help preserve cognitive function in older age, although more research is needed to investigate the potential benefits of interventions that focus on vision and eye health on cognitive outcomes.