Cataract patients in a defined Swedish population 1986–1990

Abstract

Purpose: Cataract surgery is often followed by a posterior capsule opacification, usually treated with YAG laser capsulotomy, however, there are huge variations in the incidence figures available in the literature, from 18 to 50% (Sterling & Wood 1986). We have therefore analyzed the incidence of secondary cataracts in a population-based cohort of patients, as revealed by the number of YAG laser capsulotomies performed postoperatively. Methods: Data for all patients undergoing cataract surgery from 1986 up to and including 1990 in the Lund Health Care District were prospectively recorded, and 4722 patients were retrieved for analysis, using only one eye per patient. The patients had been operated on with extracapsular extraction (phacoemulsification or planned large incision procedure) or a combined trabeculectomy and cataract extraction procedure leaving an intact capsule after surgery. Death dates for each patient were obtained from the Swedish Bureau of Census up to and including 1991. Different risk factors were considered such as sex, age, preoperative axial length, preoperative average keratometry, preoperative intraocular pressure, glaucoma history, diabetes history, uveitis history (including both anterior and posterior uveitis), history of age related macular degeneration and a history of rheumatoid arthritis. We also considered the influence of factors connected to the operation itself on the incidence of secondary capsular haze: extraction mode (ordinary ECCE versus phacoemulsification or trabeculectomy) and the type of implant and the surgeon's surgical activity. Results: Besides age, four variables significantly influenced the risk of having postoperative YAG laser treatment. They were gender, iris sphincterotomy, operation date, and whether the patient came from a rural or an urban region. After about four to five years, the percentage of patients not having had a YAG laser capsulotomy was reduced to around 50% for women and 60% for men. These percentages were based on a survival analysis, minimizing the confounding effect of the limited life span of these elderly patients. Conclusions: In this material, the most important predisposing factors for YAG laser capsulotomy after extracapsular cataract surgery are: young age, female gender, if the patient was operated late in the period observed, and if the patient came from an urban area.