Outcome and number of cataract surgeries in India: policy issues for blindness control

Purpose: To assess what impact attention to quality of cataract surgery and postoperative follow up can have on cataract blindness in India, and to estimate the number of surgeries needed to eliminate cataract blindness in India. Methods: In a population-based sample of 5268 persons in two rural areas in the state of Andhra Pradesh, India, data on the visual outcome of cataract surgery were obtained on 129 eyes of 106 persons operated previously. These were compared with the visual outcome of cataract surgery performed during 1999 in 2394 eyes of 2213 persons at two new rural eye centres set up in these areas that pay particular attention to the quality of eye care. Blindness in an eye was defined as presenting distance visual acuity less than 6/60, and in a person as this acuity level in the better eye. These data were extrapolated to India. Results: In the population-based sample, of the 129 operated eyes, 51 (39.5%) were blind after surgery, which included 41 (31.8%) from cataract surgery-related causes. Of the 106 persons in the population sample who had had cataract surgery in one or both eyes, 26 (24.5%) were still blind. In contrast, for the cataract surgery at the two rural eye centres paying attention to quality, 3.1% of the eyes and 1.8% of the persons were blind soon after surgery, but these figures could increase 2.6 times over the lifetime of these persons. The 3.5 million cataract surgeries in India in 2000 are estimated to result in 0.32 million persons having blindness averted over their lifetime. To eliminate cataract blindness in India, an estimated 9 million good-quality cataract surgeries are needed every year during 2001-2005, increasing to over 14 million surgeries needed every year during 2016-2020 on persons most likely to go blind from cataract. Conclusions: The number of persons in whom blindness is being averted due to cataract surgery in India is currently a very small fraction of the number blind from cataract. If adequate attention is given to the quality of eye care, for the current number of cataract surgeries in India it should be possible to increase by threefold the number in whom blindness can be averted with cataract surgery. In addition to improving quality, the annual number of cataract surgeries has to be at least threefold the current number during 2006-2010 if cataract blindness in India is to be eliminated.