Epidemiologic aspects of cataract surgery. I. Trends in frequencies.

A 51% increase in number of cataract extractions during the period 1970-79 is found. Neither population growth nor changes in age structure could alone account for this increase. Other factors such as economic resource allocation, changes in indications for cataract surgery and increased demand appear to be involved in this increase. Two large danish data sources were examined to determine the age and sex specific cataract extraction rates 1977-79. These rates are found to be in part equivalent to rates reported from England but substantially lower than rates found in USA. The age and sex specific rates are used as basis for estimation of number of extractions year 2000. A 60 to 80% increase is likely because of population growth in the older age groups, extention of indications for cataract surgery and more demand for good vision in old age.