CATARACT PATIENTS IN A DEFINED SWEDISH POPULATION 1986-1990 - VI - YAG LASER CAPSULOTOMIES IN RELATION TO PREOPERATIVE AND SURGICAL CONDITIONS

Purpose: Cataract surgery is often followed by a posterior capsule opa cification, usually treated with YAG laser capsulotomy, however, there are huge variations in the incidence figures available in the literat ure, 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 perform ed postoperatively. Methods: Data for all patients undergoing cataract surgery from 1986 up to and including 1990 in the Lund Health Care Di strict were prospectively recorded, and 4722 patients were retrieved f or analysis, using only one eye per patient. The patients had been ope rated on with extracapsular extraction (phacoemulsification or planned large incision procedure) or a combined trabeculectomy and cataract e xtraction procedure leaving an intact capsule after surgery. Death dat es 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 histor y, uveitis history (including both anterior and posterior uveitis), hi story of age related macular degeneration and a history of rheumatoid arthritis. We also considered the influence of factors connected to th e operation itself on the incidence of secondary capsular haze: extrac tion 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 havi ng postoperative YAG laser treatment. They were gender, iris sphincter otomy. operation date, and whether the patient came from a rural or an urban region. After about four to five years, the percentage of patie nts not having had a YAG laser capsulotomy was reduced to around 50% f or women and 60% for men. These percentages were based on a survival a nalysis, minimizing the confounding effect of the limited life span of these elderly patients. Conclusions: In this material, the most impor tant predisposing factors for YAG laser capsulotomy after extracapsula r cataract surgery are: young age, female gender, if the patient was o perated late in the period observed, and if the patient came from an u rban area.