Evaluation of a telemedicine-enabled universal eye health delivery model in rural southern India

OBJECTIVES

To evaluate the accuracy of tele-ophthalmic examination (TOE) for common ocular conditions in comparison with the gold-standard in-person examination (IPE) for diagnosis and treatment advice.

METHODS

In a prospective, diagnostic accuracy validation study, we recruited 339 consecutive new patients, aged ≥16 years, visiting a vision centre (VC) associated with Aravind Eye Hospital in south India during January and February, 2020. All participants underwent the TOE, followed by IPE on the same visit. The in-person ophthalmologist was masked to the TOE diagnosis and treatment advice. Data were analysed via the sensitivity specificity of TOE versus the gold-standard IPE.

RESULTS

TOE achieved high sensitivity and specificity for identifying normal eyes with 87.4% and 93.5%, respectively. TOE had high sensitivity for cataracts (91.7%), infective conjunctivitis (72.2%), and moderate sensitivity for pterygium (62.5%), DR (57.1%), non-serious injury (41.7%), but low sensitivity for glaucoma (12.5%). TOE had high specificity ranging from 93.5% to 99.8% for all diagnoses. The sensitivity for treatment advice ranged from 58.1% to 77.2% and specificity from 96.9% to 100%.

CONCLUSIONS

The TOE in VCs has acceptable accuracy to an IPE by an ophthalmologist for correctly identifying and treating major eye ailments. Through providing universal eye care to rural populations, this model may contribute to work toward achieving Universal Health Coverage, which is a linchpin of the health-related U.N. Sustainable Development Goals (SDG).

Evaluation and model to achieve sex parity in cataract surgical coverage in Theni district, India

BACKGROUND/AIMS

To propose an approach to determine the target ratio of cataract surgical rates (CSRs) of female to male subpopulations to increase sex parity in cataract surgical coverage (CSC), based on the sex gap in cataract burden and incidence, and demonstrate its application to Theni district, India.

METHODS

A population-based longitudinal study between January 2016 and April 2018. We recruited 24 327 participants using random cluster sampling. We conducted detailed eye examinations of 7087 participants aged ≥40 years (4098 females, 2989 males). We fit exponential models to the age-specific and sex-specific cataract burden and estimated annual incidence rates. We developed a spreadsheet-based planning tool to compute the target CSR ratio of female to male subpopulations.

RESULTS

Among those aged ≥40 years, cataract burden was 21.4% for females and 17.5% for males (p<0.05). CSC was 73.9% for females versus 78.6% for males (p<0.05), with an effective CSC of 52.6% for females versus 57.6% for males (p<0.05). Treating only incident cataracts each year requires a target CSR ratio of female to male subpopulations of 1.30, while addressing in addition 10% of the coverage backlog for females and 5% for males requires a target CSR ratio of 1.48.

CONCLUSIONS

The female population in Theni district, as in many low-income and middle-income countries, bears a higher cataract burden and lower CSC. To enhance sex parity in coverage, both the higher number of annual incident cataracts and the larger backlog in females will need to be addressed.

Bridging the Camera Domain Gap With Image-to-Image Translation Improves Glaucoma Diagnosis

Purpose

The purpose of this study was to improve the automated diagnosis of glaucomatous optic neuropathy (GON), we propose a generative adversarial network (GAN) model that translates Optain images to Topcon images.

Methods

We trained the GAN model on 725 paired images from Topcon and Optain cameras and externally validated it using an additional 843 paired images collected from the Aravind Eye Hospital in India. An optic disc segmentation model was used to assess the disparities in disc parameters across cameras. The performance of the translated images was evaluated using root mean square error (RMSE), peak signal-to-noise ratio (PSNR), structural similarity index (SSIM), 95% limits of agreement (LOA), Pearson's correlations, and Cohen's Kappa coefficient. The evaluation compared the performance of the GON model on Topcon photographs as a reference to that of Optain photographs and GAN-translated photographs.

Results

The GAN model significantly reduced Optain false positive results for GON diagnosis, with RMSE, PSNR, and SSIM of GAN images being 0.067, 14.31, and 0.64, respectively, the mean difference of VCDR and cup-to-disc area ratio between Topcon and GAN images being 0.03, 95% LOA ranging from -0.09 to 0.15 and -0.05 to 0.10. Pearson correlation coefficients increased from 0.61 to 0.85 in VCDR and 0.70 to 0.89 in cup-to-disc area ratio, whereas Cohen's Kappa improved from 0.32 to 0.60 after GAN translation.

Conclusions

Image-to-image translation across cameras can be achieved by using GAN to solve the problem of disc overexposure in Optain cameras.

Translational Relevance

Our approach enhances the generalizability of deep learning diagnostic models, ensuring their performance on cameras that are outside of the original training data set.

Cataract surgery workload estimates in Theni district, India

BACKGROUND/AIMS

To estimate the annual cataract surgery workload in Theni district, Tamil Nadu, India based on current utilisation of cataract services, prevalence of blindness and vision impairment (VI), and cataract burden-reduction goals.

METHODS

We conducted a population-based longitudinal study between January 2016 and April 2018. We recruited 24 327 participants based on a random cluster sampling method; 7127 participants were ≥40 years. During the year following initial enrolment, we tracked utilisation of eye care services; and at the end of the 1-year period, we conducted a detailed eye examination of participants age ≥40.

RESULTS

In the sample age ≥40 years, 13.0% had a visually significant cataract, and 17.8% had prior cataract surgery in at least one eye. The prevalence of cataract blindness based on presenting visual acuity in the better eye (PVABE)<3/60 was 0.34% and VI (PVABE<6/12) was 9.92%. 3.10% of the study population had obtained cataract surgery during 1 year, resulting in a cataract surgical rate of 9085. We estimated the effective cataract surgical coverage (eCSC) to be 54.5% and the CSC to be 75.7%, implying a sizeable quality gap. Prevalence, utilisation and coverage varied by age and gender. We estimated that a goal of eliminating the backlog of VI (PVABE<6/12) in 5 years would increase the annual cataract surgery workload by 11.5% from the current level.

CONCLUSIONS

Our estimates of cataract surgery workloads under different scenarios can provide a useful input into planning of eye health services in Theni district.

Methods for a population-based Comprehensive Eye care Workload Assessment (CEWA) study in Southern India

Eye care programs, in developing countries, are often planned using the prevalence of blindness and visual impairment, often estimated from Rapid Assessment of Avoidable Blindness (RAAB) surveys. A limitation of this planning approach is that it ignores the annual overall eye care requirements for a given population. Moreover, targets set are arbitrary, often influenced by capacity rather than need. To address this lacunae, we implemented a novel study design to estimate the annual need for comprehensive eye care in a 1.2 million populations. We conducted a population-based longitudinal study in Theni district, Tamil Nadu, India. All permanent residents of all ages were included. We conducted the study in three phases, (i) household-level enumeration and enrollment, (ii) basic eye examination (BEE) at household one-year post-enrollment, and (iii) assessment of eye care utilization and full eye examination (FEE) at central locations. All people aged 40 years and above were invited to the FEE. Those aged <40 years were invited to the FEE if indicated. In the main study, we enrolled 24,327 subjects (58% aged below 40 years and 42% aged 40 years and above). Of those less than 40 years, 72% completed the BEE, of whom 20% were referred for FEE at central location. Of the people aged ≥40 years, 70% underwent FEE. Our study design provides insights for appropriate long-term public health intervention planning, resource allocation, effective service delivery, and designing of eye care services for resource-limited settings.

Quality of vital event data for infant mortality estimation in prospective, population-based studies: an analysis of secondary data from Asia, Africa, and Latin America

INTRODUCTION

Infant and neonatal mortality estimates are typically derived from retrospective birth histories collected through surveys in countries with unreliable civil registration and vital statistics systems. Yet such data are subject to biases, including under-reporting of deaths and age misreporting, which impact mortality estimates. Prospective population-based cohort studies are an underutilized data source for mortality estimation that may offer strengths that avoid biases.

METHODS

We conducted a secondary analysis of data from the Child Health Epidemiology Reference Group, including 11 population-based pregnancy or birth cohort studies, to evaluate the appropriateness of vital event data for mortality estimation. Analyses were descriptive, summarizing study designs, populations, protocols, and internal checks to assess their impact on data quality. We calculated infant and neonatal morality rates and compared patterns with Demographic and Health Survey (DHS) data.

RESULTS

Studies yielded 71,760 pregnant women and 85,095 live births. Specific field protocols, especially pregnancy enrollment, limited exclusion criteria, and frequent follow-up visits after delivery, led to higher birth outcome ascertainment and fewer missing deaths. Most studies had low follow-up loss in pregnancy and the first month with little evidence of date heaping. Among studies in Asia and Latin America, neonatal mortality rates (NMR) were similar to DHS, while several studies in Sub-Saharan Africa had lower NMRs than DHS. Infant mortality varied by study and region between sources.

CONCLUSIONS

Prospective, population-based cohort studies following rigorous protocols can yield high-quality vital event data to improve characterization of detailed mortality patterns of infants in low- and middle-income countries, especially in the early neonatal period where mortality risk is highest and changes rapidly.

Impact of practicing internal benchmarking on continuous improvement of cataract surgery outcomes: a retrospective observational study at Aravind Eye Hospitals, India

OBJECTIVE

We aim to assess the effectiveness of a cataract surgery outcome monitoring tool used for continuous quality improvement. The objectives are to study: (1) the quality parameters, (2) the monitoring process followed and (3) the impact on outcomes.

DESIGN AND PROCEDURES

In this retrospective observational study we evaluated a quality improvement (QI) method which has been practiced at the focal institution since 2012: internal benchmarking of cataract surgery outcomes (CATQA). We evaluated quality parameters, procedures followed and clinical outcomes. We created tables and line charts to examine trends in key outcomes.

SETTING

Aravind Eye Care System, India.

PARTICIPANTS

Phacoemulsification surgeries performed on 718 120 eyes at 10 centres (five tertiary and five secondary eye centres) from 2012 to 2020 were included.

INTERVENTIONS

An internal benchmarking of surgery outcome parameters, to assess variations among the hospitals and compare with the best hospital.

OUTCOME MEASURES

Intraoperative complications, unaided visual acuity (VA) at postoperative follow-up visit and residual postoperative refractive error (within ±0.5D).

RESULTS

Over the study period the intraoperative complication rate decreased from 1.2% to 0.6%, surgeries with uncorrected VA of 6/12 or better increased from 80.8% to 89.8%, and surgeries with postoperative refractive error within ±0.5D increased from 76.3% to 87.3%. Variability in outcome measures across hospitals declined. Additionally, benchmarking was associated with improvements in facilities, protocols and processes.

CONCLUSION

Internal benchmarking was found to be an effective QI method that enabled the practice of evidence-based management and allowed for harnessing the available information. Continuous improvement in clinical outcomes requires systematic and regular review of results, identifying gaps between hospitals, comparisons with the best hospital and implementing lessons learnt from peers.

Access to eye care during the COVID-19 pandemic, India

OBJECTIVE

To study the impact of the coronavirus disease 2019 (COVID-19) pandemic on outpatient visits to eye care facilities in south India.

METHODS

We used data on 7.69 million outpatient visits to primary (i.e. vision centres), secondary and tertiary Aravind Eye Care System's centres between January 2019 and June 2021. We compared outpatient numbers and outpatients' age and sex between the pandemic period and the pre-pandemic period in 2019 for all centres, whereas vision and ophthalmic assessments were compared for vision centres only.

FINDINGS

During the first wave, the number of outpatient visits at tertiary, secondary and vison centres was 39% (647 968/1 656 296), 60% (170 934/283 176) and 73% (180 502/246 282) respectively, of 2019 levels. During the second wave, outpatient visits at tertiary, secondary and vision centres were 54% (385 092/710 949), 73% (88 383/121 739) and 79% (121 993/154 007), respectively, of 2019 levels. The proportion of outpatients who were female or younger than 20 years or older than 60 years was significantly lower during the first and second waves than in 2019 (P < 0.0001 for all). The proportion of outpatients whose worse eye vision was poorer than 5/60 or who required referral was significantly higher (P < 0.0001 for both).

CONCLUSION

Restrictive measurements led to declines in outpatient visits, however the decline was less at secondary and vision centres than at tertiary centres. Easy access to specialized ophthalmic care via telemedicine and the relative proximity of these centres to communities helped reduce barriers to access.

Keeping an eye on eye care: monitoring progress towards effective coverage

The eye care sector is well positioned to contribute to the advancement of universal health coverage within countries. Given the large unmet need for care associated with cataract and refractive error, coupled with the fact that highly cost-effective interventions exist, we propose that effective cataract surgery coverage (eCSC) and effective refractive error coverage (eREC) serve as ideal indicators to track progress in the uptake and quality of eye care services at the global level, and to monitor progress towards universal health coverage in general. Global targets for 2030 for these two indicators were endorsed by WHO Member States at the 74th World Health Assembly in May, 2021. To develop consensus on the data requirements and methods of calculating eCSC and eREC, WHO convened a series of expert consultations to make recommendations for standardising the definitions and measurement approaches for eCSC and eREC and to identify areas in which future work is required.

Investigation of the Accuracy of a Low-Cost, Portable Autorefractor to Provide Well-Tolerated Eyeglass Prescriptions: A Randomized Crossover Trial

PURPOSE

To compare patient preferences for eyeglasses prescribed using a low-cost, portable wavefront autorefractor versus standard subjective refraction (SR).

DESIGN

Randomized, cross-over clinical trial.

PARTICIPANTS

Patients aged 18 to 40 years presenting with refractive errors (REs) to a tertiary eye hospital in Southern India.

METHODS

Participants underwent SR followed by autorefraction (AR) using the monocular version of the QuickSee device (PlenOptika Inc). An independent optician, masked to the refraction approach, prepared eyeglasses based on each refraction approach. Participants (masked to refraction source) were randomly assigned to use SR- or AR-based eyeglasses first, followed by the other pair, for 1 week each. At the end of each week, participants had their vision checked and were interviewed about their experience with the eyeglasses.

MAIN OUTCOME MEASURES

Patients preferring eyeglasses were chosen using AR and SR.

RESULTS

The 400 participants enrolled between March 26, 2018, and August 2, 2019, had a mean (standard deviation) age of 28.4 (6.6) years, and 68.8% were women. There was a strong correlation between spherical equivalents using SR and AR (r = 0.97, P < 0.001) with a mean difference of -0.07 diopters (D) (95% limits of agreement [LoA], -0.68 to 0.83). Of the 301 patients (75.2%) who completed both follow-up visits, 50.5% (n = 152) and 49.5% (n = 149) preferred glasses prescribed using SR and AR, respectively (95% CI, 45.7-56.3; P = 0.86). There were no differences in demographic or vision characteristics between participants with different preferences (P > 0.05 for all).

CONCLUSIONS

We observed a strong agreement between the prescriptions from SR and AR, and eyeglasses prescribed using SR and AR were equally preferred by patients. Wider use of prescribing based on AR alone in resource-limited settings is supported by these findings.

Effectiveness of Teleretinal Imaging-Based Hospital Referral Compared With Universal Referral in Identifying Diabetic Retinopathy: A Cluster Randomized Clinical Trial

Question

Does screening for diabetic retinopathy by teleretinal imaging in physician offices in India lead to higher adherence to eye hospital referral and a greater yield of diabetic retinopathy cases compared with a strategy of referral of all eligible patients with diabetes?

Findings

In a cluster randomized clinical trial of 801 patients with diabetes, proportionately more patients in the teleretinal group attended the hospital eye examination and had confirmed diabetic retinopathy compared with the control group.

Meaning

The results suggest that, in the Indian setting, teleretinal screening is an effective approach for identifying diabetic retinopathy.

Importance

Studies in high-income countries provide limited evidence from randomized clinical trials on the benefits of teleretinal screening to identify diabetic retinopathy (DR).

Objective

To evaluate the effectiveness of teleretinal-screening hospital referral (TR) compared with universal hospital referral (UR) in people with diabetes.

Design, Setting, and Participants

A cluster randomized clinical trial of 8 diabetes clinics within 10 km from Aravind Eye Hospital (AEH), Madurai, India, was conducted. Participants included 801 patients older than 50 years. The study was conducted from May 21, 2014, to February 7, 2015; data analysis was performed from March 12 to June 16, 2015.

Interventions

In the TR cohort, nonmydriatic, 3-field, 45° retinal images were remotely graded by a retinal specialist and patients with DR, probable DR, or ungradable images were referred to AEH for a retinal examination. In the UR cohort, all patients were referred for a retinal examination at AEH.

Main Outcomes and Measures

Hospital-diagnosed DR.

Results

Of the 801 participants, 401 were women (50.1%) (mean [SD] age, 60.0 [7.3] years); mean diabetes duration was 8.6 (6.6) years. In the TR cohort, 96 of 398 patients (24.1%) who underwent teleretinal imaging were referred with probable DR (53 [13.3%]) or nongradable images (43 [10.8%]). Hospital attendance at AEH was proportionately higher with TR (54 of 96 referred [56.3%]) compared with UR (150 of 400 referred [37.5%]). The intention-to-treat analysis based on all patients eligible for referral in each arm showed that proportionately more patients with TR (36 of 96 [37.5]%) were diagnosed with DR compared with UR (50 of 400 [12.5%]) (unadjusted risk ratio [RR], 3.00; 95% CI, 2.01-4.48). These results were little changed by inclusion of covariates (RR, 2.72; 95% CI, 1.90-3.91). The RR was lower in the per-protocol analysis based on all patients who adhered to referral (covariate-adjusted RR, 1.75; 95% CI, 1.12-2.74). Diagnoses of DR were predominantly mild or moderate nonproliferative DR (36 in TR and 43 in UR). In the UR arm, there were 4 cases of severe nonproliferative DR and 2 cases of proliferative DR. Age (RR, 0.98; 95% CI, 0.95-0.99), female sex (RR, 0.79; 95% CI, 0.64-0.98), and hypertension diagnosis (RR, 0.81; 95% CI, 0.68-0.95) were factors associated with lower attendance. Those with higher secondary educational level or more were twice as likely to attend (RR, 2.00; 95% CI, 1.32-3.03).

Conclusions and Relevance

The proportionate yield of DR cases was higher in the TR arm, confirming the potential benefit, at least in the setting of eye hospitals in India, of a targeted referral approach using teleretinal screening to identify patients with DR.

Trial Registration

ClinicalTrials.gov identifier: NCT02085681

Quality of eyeglass prescriptions from a low-cost wavefront autorefractor evaluated in rural India: results of a 708-participant field study

Objective

To assess the quality of eyeglass prescriptions provided by an affordable wavefront autorefractor operated by a minimally trained technician in a low-resource setting.

Methods and Analysis

708 participants were recruited from consecutive patients registered for routine eye examinations at Aravind Eye Hospital in Madurai, India, or an affiliated rural satellite vision centre. Visual acuity (VA) and patient preference were compared between trial lenses set to two eyeglass prescriptions from (1) a novel wavefront autorefractor and (2) subjective refraction by an experienced refractionist.

Results

The mean±SD VA was 0.30±0.37, –0.02±0.14 and −0.04±0.11 logarithm of the minimum angle of resolution units before correction, with autorefractor correction and with subjective refraction correction, respectively (all differences p<0.01). Overall, 25% of participants had no preference, 33% preferred eyeglass prescriptions from autorefraction, and 42% preferred eyeglass prescriptions from subjective refraction (p<0.01). Of the 438 patients 40 years old and younger, 96 had no preference and the remainder had no statistically significant difference in preference for subjective refraction prescriptions (51%) versus autorefractor prescriptions (49%) (p=0.52).

Conclusion

Average VAs from autorefractor-prescribed eyeglasses were one letter worse than those from subjective refraction. More than half of all participants either had no preference or preferred eyeglasses prescribed by the autorefractor. This marginal difference in quality may warrant autorefractor-based prescriptions, given the portable form factor, short measurement time, low cost and minimal training required to use the autorefractor evaluated here.

Prevalence and risk factors for myopia and other refractive errors in an adult population in southern India

PURPOSE

To investigate prevalence and risk factors for myopia, hyperopia and astigmatism in southern India.

METHODS

Randomly sampled villages were enumerated to identify people aged ≥40 years. Participants were interviewed for socioeconomic and lifestyle factors and attended a hospital-based ophthalmic examination including visual acuity measurement and objective and subjective measurement of refractive status. Myopia was defined as spherical equivalent (SE) worse than -0.75 dioptres (D), hyperopia as SE ≥+1D and astigmatism as cylinder <-0.5.

RESULTS

The age-standardised prevalences of myopia, hyperopia and astigmatism were 35.6% (95% CI: 34.7-36.6), 17.0% (95% CI: 16.3-17.8) and 32.6 (29.3-36.1), respectively. Of those with myopia (n = 1490), 70% had advanced cataract. Of these, 79% had presenting visual acuity (VA) less than 6/18 and after best correction, 44% of these improved to 6/12 or better and 27% remained with VA less than 6/18. In multivariable analyses (excluding patients with advanced cataract), increasing nuclear opacity score, current tobacco use, and increasing height were associated with higher odds of myopia. Higher levels of education were associated with increased odds of myopia in younger people and decreased odds in older people. Increasing time outdoors was associated with myopia only in older people. Increasing age and female gender were associated with hyperopia, and nuclear opacity score, increasing time outdoors, rural residence and current tobacco use with lower odds of hyperopia. After controlling for myopia, factors associated with higher odds of astigmatism were age, rural residence, and increasing nuclear opacity score and increasing education with lower odds.

CONCLUSIONS

In contrast to high-income settings and in agreement with studies from low-income settings, we found a rise in myopia with increasing age reflecting the high prevalence of advanced cataract.

Use of Cooking Fuels and Cataract in a Population-Based Study: The India Eye Disease Study

BACKGROUND

Biomass cooking fuels are commonly used in Indian households, especially by the poorest socioeconomic groups. Cataract is highly prevalent in India and the major cause of vision loss. The evidence on biomass fuels and cataract is limited.

OBJECTIVES

To examine the association of biomass cooking fuels with cataract and type of cataract.

METHODS

We conducted a population-based study in north and south India using randomly sampled clusters to identify people ≥ 60 years old. Participants were interviewed and asked about cooking fuel use, socioeconomic and lifestyle factors and attended hospital for digital lens imaging (graded using the Lens Opacity Classification System III), anthropometry, and blood collection. Years of use of biomass fuels were estimated and transformed to a standardized normal distribution.

RESULTS

Of the 7,518 people sampled, 94% were interviewed and 83% of these attended the hospital. Sex modified the association between years of biomass fuel use and cataract; the adjusted odds ratio (OR) for a 1-SD increase in years of biomass fuel use and nuclear cataract was 1.04 (95% CI: 0.88, 1.23) for men and 1.28 (95% CI: 1.10, 1.48) for women, p interaction = 0.07. Kerosene use was low (10%). Among women, kerosene use was associated with nuclear (OR = 1.76, 95% CI: 1.04, 2.97) and posterior subcapsular cataract (OR = 1.71, 95% CI: 1.10, 2.64). There was no association among men.

CONCLUSIONS

Our results provide robust evidence for the association of biomass fuels with cataract for women but not for men. Our finding for kerosene and cataract among women is novel and requires confirmation in other studies. Citation: Ravilla TD, Gupta S, Ravindran RD, Vashist P, Krishnan T, Maraini G, Chakravarthy U, Fletcher AE. 2016. Use of cooking fuels and cataract in a population-based study: the India Eye Disease Study. Environ Health Perspect 124:1857-1862; http://dx.doi.org/10.1289/EHP193.

Demand for Tertiary Eye Care Services in Developing Countries

PURPOSE

To analyze the experience of a large developing country tertiary ophthalmology system to identify generalizable information relevant for those planning similar centers elsewhere.

DESIGN

Retrospective utilization analysis.

METHODS

A historical review of the development of the Aravind Eye Care system was undertaken to evaluate the services provided by various tertiary services of the system. Demand for services is inferred based on the utilization statistics described below and distance traveled by patients to obtain services.

RESULTS

Utilization of subspecialty services increased logarithmically for 17 years in all specialties. At all centers except one historically focused on glaucoma, retina services had the highest demand among subspecialty surgical services. The proportion of tertiary care patients among all new outpatients (39% in 2009 and 45% in 2013) and the proportion of specialty surgical and treatment procedures among all procedures (30% in 1997 and 49% 2013) increased over time. More patients traveled long distances (>100 kilometers) to receive specialty services than to receive cataract services (30% vs 23%).

CONCLUSIONS

These observations suggest that in regions where tertiary services are not widely available, (1) patients demand (travel further for) tertiary care more than general ophthalmology services; (2) demand for services can expand rapidly for many years; (3) tertiary care services tend to grow over time as a proportion of all services provided; and (4) retina services are the most highly demanded subspecialty surgical services. In such settings, it is likely that considerable latent demand exists; planned tertiary eye centers should anticipate sustained growth of tertiary services.

Challenges of ophthalmic care in the developing world

Global blindness exacts an enormous financial and social cost on developing countries. Reducing the prevalence of blindness globally requires a set of strategies that are different from those typically used in developed countries. This was the subject of the 2013 Knapp symposium at the American Ophthalmological Society Annual Meeting, and this article summarizes the presentations of epidemiologists, health care planners, and ophthalmologists. It explores a range of successful strategies from the multinational Vision 2020 Initiative to disease-specific schemes in cataract, trachoma control, infectious corneal ulceration, cytomegalovirus retinitis, and retinopathy of prematurity. In each example, the importance of an attitudinal change set toward public health becomes clear. There is reason for optimism in the struggle against global blindness in large measure because of innovative programs such as those described here.

Cluster randomized trial to compare spectacle delivery systems at outreach eye camps in South India

PURPOSE

To study the optimal method for delivery of spectacles at eye camps to maximize procurement and use.

METHODS

A cluster randomized controlled trial, undertaken in the catchment districts of Aravind Eye Hospital - Theni, in the state of Tamil Nadu, India. Community eye camps (n = 21) were allocated to offer one of three types of service for purchase of spectacles to correct refractive error: (1) Issuance of a prescription only; (2) booking orders for spectacles with subsequent delivery; (3) on-the-spot fitting and dispensing of spectacles. Follow-up questionnaires were administered 6 weeks after interventions to assess patient outcomes. The primary outcome measured was spectacle procurement at follow-up 6 weeks post-screening. Secondary outcomes included use of and satisfaction with spectacles. Reasons for purchase/non-purchase were also assessed.

RESULTS

Compared to those who were issued only a prescription and adjusting for distance from base hospital, spectacle procurement was significantly higher for those allowed to book spectacles for subsequent delivery (odds ratio, OR, 8.79, 95% confidence interval, CI, 4.61-16.78) and for those receiving spectacles on the spot (OR 13.97, 95% CI 8.12-24.05). Among those with spectacles at 6 weeks, spectacle use was nearly universal and satisfaction with spectacles varied between 92 and 94% among the three different dispensing modalities.

CONCLUSION

Making spectacles available on the spot is important to ensure procurement in a context where availability and access to dispensing opticians is poor.

Advocacy for eye care

The effectiveness of eye care service delivery is often dependant on how the different stakeholders are aligned. These stakeholders range from the ministries of health who have the capacity to grant government subsidies for eye care, down to the primary healthcare workers who can be enrolled to screen for basic eye diseases. Advocacy is a tool that can help service providers draw the attention of key stakeholders to a particular area of concern. By enlisting the support, endorsement and participation of a wider circle of players, advocacy can help to improve the penetration and effectiveness of the services provided. There are several factors in the external environmental that influence the eye care services - such as the availability of trained manpower, supply of eye care consumables, government rules and regulations. There are several instances where successful advocacy has helped to create an enabling environment for eye care service delivery. Providing eye care services in developing countries requires the support - either for direct patient care or for support services such as producing trained manpower or for research and dissemination. Such support, in the form of financial or other resources, can be garnered through advocacy.

Prevalence and risk factors for vitamin C deficiency in north and south India: a two centre population based study in people aged 60 years and over

BACKGROUND

Studies from the UK and North America have reported vitamin C deficiency in around 1 in 5 men and 1 in 9 women in low income groups. There are few data on vitamin C deficiency in resource poor countries.

OBJECTIVES

To investigate the prevalence of vitamin C deficiency in India.

DESIGN

We carried out a population-based cross-sectional survey in two areas of north and south India. Randomly sampled clusters were enumerated to identify people aged 60 and over. Participants (75% response rate) were interviewed for tobacco, alcohol, cooking fuel use, 24 hour diet recall and underwent anthropometry and blood collection. Vitamin C was measured using an enzyme-based assay in plasma stabilized with metaphosphoric acid. We categorised vitamin C status as deficient (<11 µmol/L), sub-optimal (11-28 µmol/L) and adequate (>28 µmol/L). We investigated factors associated with vitamin C deficiency using multivariable Poisson regression.

RESULTS

The age, sex and season standardized prevalence of vitamin C deficiency was 73.9% (95% confidence Interval, CI 70.4,77.5) in 2668 people in north India and 45.7% (95% CI 42.5,48.9) in 2970 from south India. Only 10.8% in the north and 25.9% in the south met the criteria for adequate levels. Vitamin C deficiency varied by season, and was more prevalent in men, with increasing age, users of tobacco and biomass fuels, in those with anthropometric indicators of poor nutrition and with lower intakes of dietary vitamin C.

CONCLUSIONS

In poor communities, such as in our study, consideration needs to be given to measures to improve the consumption of vitamin C rich foods and to discourage the use of tobacco.

Inverse association of vitamin C with cataract in older people in India

Objective

To examine the association between vitamin C and cataract in the Indian setting.

Design

Population-based cross-sectional analytic study.

Participants

A total of 5638 people aged ≥60 years.

Methods

Enumeration of randomly sampled villages in 2 areas of north and south India to identify people aged ≥60 years. Participants were interviewed for socioeconomic and lifestyle factors (tobacco, alcohol, household cooking fuel, work, and diet); attended a clinical examination, including lens photography; and provided a blood sample for antioxidant analysis. Plasma vitamin C was measured using an enzyme-based assay in plasma stabilized with metaphosphoric acid, and other antioxidants were measured by reverse-phase high-pressure liquid chromatography.

Main Outcome Measures

Cataract and type of cataract were graded from digital lens images using the Lens Opacity Classification System III (LOCS III), and cataract was classified from the grade in the worse eye of ≥4 for nuclear cataract, ≥3 for cortical cataract, and ≥2 for posterior subcapsular cataract (PSC). Any cataract was defined as any unoperated or operated cataract.

Results

Of 7518 enumerated people, 5638 (75%) provided data on vitamin C, antioxidants, and potential confounders. Vitamin C was inversely associated with cataract (adjusted odds ratio [OR] for highest to lowest quartile = 0.61; 95% confidence interval (CI), 0.51–0.74; P=1.1×10⁻⁶). Inclusion of other antioxidants in the model (lutein, zeaxanthin, retinol, β-carotene, and α-tocopherol) made only a small attenuation to the result (OR 0.68; 95% CI, 0.57–0.82; P < 0.0001). Similar results were seen with vitamin C by type of cataract: nuclear cataract (adjusted OR 0.66; CI, 0.54–0.80; P < 0.0001), cortical cataract (adjusted OR 0.70; CI, 0.54–0.90; P < 0.002), and PSC (adjusted OR 0.58; CI, 0.45–0.74; P < 0.00003). Lutein, zeaxanthin, and retinol were significantly inversely associated with cataract, but the associations were weaker and not consistently observed by type of cataract. Inverse associations were also observed for dietary vitamin C and cataract.

Conclusions

We found a strong association with vitamin C and cataract in a vitamin C–depleted population.

Financial Disclosure(s)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Prevalence of cataract in an older population in India: the India study of age-related eye disease

Purpose

To describe the prevalence of cataract in older people in 2 areas of north and south India.

Design

Population-based, cross-sectional study.

Participants

Randomly sampled villages were enumerated to identify people aged ≥60 years. Of 7518 enumerated people, 78% participated in a hospital-based ophthalmic examination.

Methods

The examination included visual acuity measurement, dilatation, and anterior and posterior segment examination. Digital images of the lens were taken and graded by type and severity of opacity using the Lens Opacity Classification System III (LOCS III).

Main Outcome Measures

Age- and gender-standardized prevalence of cataract and 95% confidence intervals (CIs). We defined type of cataract based on the LOCS III grade in the worse eye of: ≥4 for nuclear cataract, ≥3 for cortical cataract, and ≥2 for posterior subcapsular cataract (PSC). Any unoperated cataract was based on these criteria or ungradable dense opacities. Any cataract was defined as any unoperated or operated cataract.

Results

The prevalence of unoperated cataract in people aged ≥60 was 58% in north India (95% CI, 56–60) and 53% (95% CI, 51–55) in south India (P = 0.01). Nuclear cataract was the most common type: 48% (95% CI, 46–50) in north India and 38% (95% CI, 37–40) in south India (P<0.0001); corresponding figures for PSC were 21% (95% CI, 20–23) and 17% (95% CI, 16–19; P = 0.003), respectively, and for cortical cataract 7.6% (95% CI, 7–9) and 10.2% (95% CI, 9–11; P<0.004). Bilateral aphakia/pseudophakia was slightly higher in the south (15.5%) than in the north (13.2%; P<0.03). The prevalence of any cataracts was similar in north (73.8%) and south India (71.8%). The prevalence of unoperated cataract increased with age and was higher in women than men (odds ratio [OR], 1.8). Aphakia/pseudophakia was also more common in women, either unilateral (OR, 1.2; P<0.02) or bilateral (OR, 1.3; P<0.002).

Conclusions

We found high rates of unoperated cataract in older people in north and south India. Posterior subcapsular cataract was more common than in western studies. Women had higher rates of cataract, which was not explained by differential access to surgery.

Financial Disclosure(s)

The authors have no proprietary or commercial interest in any of the materials discussed in this article.

Quality-of-life and visual function assessment after phacoemulsification in an urban indian population

PURPOSE

To assess patients' quality of life (QoL) and overall visual function (VF) after phacoemulsification with intraocular lens (IOL) implantation in an urban Indian population.

SETTING

Iladevi Cataract & IOL Research Center, Ahmedabad, India.

METHODS

This prospective study comprised 300 patients with a mean age of 60.8 years +/- 9.2 (SD) who were evaluated preoperatively for visual acuity, QoL, VF, and demographic information. Postoperative evaluations included the same parameters with the addition of patient satisfaction. Also analyzed was the impact on the resumption of routine daily activities and professional work after phacoemulsification. Patients were divided into 2 categories: driving and nondriving. They were also categorized by profession and type and density of cataract. The relationship of patients' characteristics and QoL versus VF was determined by an analysis of variance and 99% confidence intervals. Effect sizes (change/difference / the standard deviation at baseline) were computed for intergroup longitudinal changes and intergroup differences.

RESULTS

Correlation analysis showed a highly significant positive correlation between logMAR scores with VF and QoL. Overall, VF changed more significantly than QoL in effect size on all subscales. Postoperatively, 13% of respondents reported difficulty performing routine work; 40% resumed their daily activities within 1 week and 55%, within 1 month. More than 42% resumed professional activities within 1 week after surgery; 53% took 1 week to 1 month. Eight-six percent were fully satisfied with the results of cataract surgery. Overall, 88% reported that VF and QoL were "a lot better" and 10% responded little they were "a little better" than before surgery.

CONCLUSIONS

Improvement in health-related QoL and VF occurred within 3 months of cataract extraction. The speed of visual acuity recovery after phacoemulsification matched the improvement across health-related QoL functions, resulting in rapid recovery of the patients' functional independence and health status.