Using social epidemiology to understand who stays blind and who gets operated for cataract in a rural setting.

Although worldwide data is incomplete, cataract is probably the leading cause of blindness in the world [l]. A recent review of global data on blindness suggests that of the estimated 42 million blind in the world, approx. 17 million are blind from cataract [2]. It is particularly tragic that cataract should cause such a large share of blindness because the surgical techniques for removing lenticular opacities are relatively simple, inexpensive and have been practised safely for many years in a variety of settings. It is, however, in precisely those areas of the world where the prevalence of cataract blindness is highest, that access to cataract surgery is limited. Even when cataract surgery is available, it is often underutilized. A recent study in India showed that less than 20% of cataract patients advised to have surgery actually came for the operation within a 2 year follow-up period [3]. In the United States, patients who have refused surgery for operable cataract form the second largest group of blind, after glaucoma [4]. A study of cataract blind in New York indicated that less than half of the cataract patients referred for the procedure ever had the operation [5]. This underutilization may be traced to several obstacles or barriers. The first barrier, especially important in developing countries, is access. The majority of cataract blind in developing countries live in rural areas, whereas most ophthalmic surgeons live in large cities [6]. The second barrier is education. Cataract is often popularly regarded as an irreversible and unavoidable result of the aging process. Misconceptions about cataract surgery and its outcome are often widespread, even when the patient is nominally aware of the procedure. Finally, even when the cataract patient is well informed about his or her condition and surgery is available. the patient may be reluctant to elect surgery because of real economic and logistical obstacles, or because of perceptions about the lack of opportunities for surgery. Cataract is thus not only the major cause of avoidable blindness. it is also a condition which poses serious geographic, educational, socio-economic and logistical challenges to any program aimed at reducing the prevalence of needless blindness. Information on what factors determine who utilizes cataract surgery is therefore essential to help deliver sight restoring surgery to this large under-served blind population.