Cataract patients in a defined Swedish population 1986-1990. II. Preoperative observations.

With the Cataract Analysis System (CAS) we have analyzed 5.878 consecutive patients undergoing cataract operations from 1986 through 1990. The material is complete enough to be regarded as representative of the cataract surgery performed in the Lund Health Care District cataract surgery referral region during this period. There has been a striking increase in the number of operations, in 1990 reaching 3.6 per 1000 inhabitants in the referral region. A number of demographic factors have been analyzed previously, and the preoperative status of the patients is reported in this paper. In 1986, the cataract patients showed more visual impairment than in 1990, but the average age at surgery did not change between the years. We therefore suggest that the increase in the number of patients which were operated on represents a new category that was added. During the period, the planned refraction has changed towards emmetropia, presumably reflecting several kinds of improvements in the procedure. About 78 per cent of the population had a preoperative astigmatism < 1.5 D. As expected males had slightly longer eyes than women, and their corneal curvature was also slightly less.