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.

Accuracy of an artificial intelligence-based mobile application for detecting cataracts: Results from a field study

Purpose: To assess the accuracy of e?Paarvai, an artificial intelligence?based smartphone application (app) that detects and grades cataracts using images taken with a smartphone by comparing with slit lamp?based diagnoses by trained ophthalmologists. Methods: In this prospective diagnostic study conducted between January and April 2022 at a large tertiary?care eye hospital in South India, two screeners were trained to use the app. Patients aged >40 years and with a best?corrected visual acuity <20/40 were recruited for the study. The app is intended to determine whether the eye has immature cataract, mature cataract, posterior chamber intra?ocular lens, or no cataract. The diagnosis of the app was compared with that of trained ophthalmologists based on slit?lamp examinations, the gold standard, and a receiver operating characteristic (ROC) curve was estimated. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were computed. Results: The two screeners used the app to screen 2,619 eyes of 1,407 patients. In detecting cataracts, the app showed high sensitivity (96%) but low specificity (25%), an overall accuracy of 88%, a PPV of 92.3%, and an NPV of 57.8%. In terms of cataract grading, the accuracy of the app was high in detecting immature cataracts (1,875 eyes, 94.2%), but its accuracy was poor in detecting mature cataracts (73 eyes, 22%), posterior chamber intra?ocular lenses (55 eyes, 29.3%), and clear lenses (2 eyes, 2%). We found that the area under the curve in predicting ophthalmologists’ cataract diagnosis could potentially be improved beyond the app’s diagnosis based on using images only by incorporating information about patient sex and age (P < 0.0001) and best?corrected visual acuity (P < 0.0001). Conclusions: Although there is room for improvement, e?Paarvai app is a promising approach for diagnosing cataracts in difficult?to?reach populations. Integrating this with existing outreach programs can enhance the case detection rate.

The economic and social costs of visual impairment and blindness in India

Purpose: To provide a current estimate of the economic and social costs (or welfare costs) of visual impairment and blindness in India. Methods: Using evidence from the recently conducted Blindness and Visual Impairment Survey across India, the Lancet Global Health Commission on Global Eye Health and other sources, we developed an economic model that estimates the costs of reduced employment, elevated mortality risk, education loss for children, productivity loss in employment, welfare loss for the unemployed, and caregiver costs associated with moderate and severe visual impairment (MSVI) and blindness. Probabilistic sensitivity analyses were also conducted by varying key parameters simultaneously. Results: The costs of MSVI and blindness in India in 2019 are estimated at INR 1,158 billion (range: INR 947–1,427 billion) or $54.4 billion at purchasing power parity exchange rates (range: $44.5–67.0 billion), accounting for all six cost streams. The largest cost was for the loss of employment, whereas the the second largest cost was for caregiver time. A more conservative estimate focusing only on employment loss and elevated mortality risk yielded a cost of INR 504 billion (range: INR 348–621 billion) or $23.7 billion (range: $16.3–29.2 billion). Conclusion: Poor eye health imposes a non?trivial recurring cost to the Indian economy equivalent to 0.47% to 0.70% of GDP in the primary scenario, a substantial constraint on the country’s growth aspirations. Furthermore, the absolute costs of poor eye health will increase over time as India ages and becomes wealthier unless further progress is made in reducing the prevalence of MSVI and blindness

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.

Best practice eye care models.

Since the launching of Global Initiative, VISION 2020 “the Right to Sight” many innovative, practical and unique comprehensive eye care services provision models have evolved targeting the underserved populations in different parts of the World. At places the rapid assessment of the burden of eye diseases in confined areas or utilizing the key informants for identification of eye diseases in the communities are promoted for better planning and evidence based advocacy for getting / allocation of resources for eye care. Similarly for detection and management of diabetes related blindness, retinopathy of prematurity and avoidable blindness at primary level, the major obstacles are confronted in reaching to them in a cost effective manner and then management of the identified patients accordingly. In this regard, the concept of tele-ophthalmology model sounds to be the best solution. Whereas other models on comprehensive eye care services provision have been emphasizing on surgical output through innovative scales of economy that generate income for the program and ensure its sustainability, while guaranteeing treatment of the poorest of the poor.