The deficit in cataract surgery in England and Wales and the escalating problem of visual impairment: epidemiological modelling of the population dynamics of cataract

Background-The pool of old cases of cataract, the expected new cases, and t he shortfall in cataract surgery and consequently the numbers dying with po or vision without the benefit of cataract surgery are regarded as escalatin g problems worldwide. Successive governments and the professional ophthalmi c bodies have not had the wherewithal to estimate the magnitude or interact ion of these elements in the population of the UK, This study kras collecte d and applied the best available epidemiological data on cataract prevalenc e, incidence and service utilisation, and demography to address the problem of control of the cataract pool in the population of England and Wales. Methods-Data from recent surveys undertaken by the authors, both on prevale nce of vision impairing cataract and on patterns of cataract surgery, were used together with demographic and service utilisation information obtained from government departments. These were integrated within a holistic model , which was run under varied assumed levels and patterns of service provisi on, Results-The study shows that there is a serious pool of unoperated vision i mpairing cataract in the population aged 65 and older, reflecting a shortfa ll in cataract surgery. Continuing with the present level and pattern of se rvice provision, the pool will increase to over 2.5 million by the year 200 1. In addition, more than 700 000 will die with unoperated impaired vision. Conclusions-Targeting of existing or new additional operations to those bel ow the visual acuity of 6/12 will have relatively little effect on numbers dying without surgery, but should have a substantial controlling effect on the pool of vision impairing cataract in the population.