Global inequality in eye health: Country-level analysis from the global burden of disease study

Objectives. We assessed global inequality in eye health by using data on the global burden of disease measured in disability-adjusted life years (DALYs). Methods. We estimated the burden of eye disease by calculating the sum of DALYs (from the Global Burden of Disease study, 2004 update) due to trachoma, vitamin A deficiency, glaucoma, cataract, refractive errors, and macular degeneration. We assessed the geographic distribution of eye disease in relation to economic status and etiology by calculating the Gini coefficient, the Theil index, and the Atkinson index. Results. The global burden of eye disease was estimated at 61.4 million DALYs worldwide (4.0% of total DALYs). Vitamin A deficiency and trachoma were distributed more unevenly than were noncommunicable eye diseases, regardless of economic status. For noncommunicable eye diseases, the major contributor was refractive errors, regardless of economic status. The most uneven distribution was observed for cataract (high-income countries) and refractive errors (middle- and low-income countries). Conclusions. Creating new eye health service for refractive errors and reducing the unacceptable eye health disparity in refractive errors should be the highest priorities for international public health services in eye care and eye health.