Factors influencing cataract formation after Nd:YAG laser peripheral iridotomy.

PURPOSE The benign nature of Nd:YAG laser peripheral iridotomy (LPI) has recently been questioned because of increased cataract formation and other complications. This retrospective study includes 522 consecutive eyes of 275 individuals (group 1) on whom LPI was performed between January 1, 1991, and December 31, 2000, for which at least 5 years of complete follow-up was available. METHODS Patients were all operated on by a single surgeon using a Zeiss Meditec Nd:YAG laser for all procedures. Total energy delivered, degree of cataract at time of LPI and at last visit, interval to cataract surgery if needed, intraocular pressure (IOP), use of ocular and systemic medications, and associated medical and ocular conditions were recorded. One hundred-fifty eyes of 75 individuals without evidence of glaucoma were used for comparison of outcomes (group 2). RESULTS Group 1A consisted of 146 eyes (27.9%) that underwent cataract surgery 5.9 (95% CI, 5.6-6.3) years after LPI. The remaining 376 eyes composed group 1B. Groups 1A and 1B differed significantly in patient age, grade of cataract at time of LPI, and length of follow-up. Groups 1 and 2 differed significantly in patient age and frequency of use of topical medication to control IOP, but not in frequency of cataract surgery. CONCLUSIONS LPI does not increase the incidence of cataract surgery, and cataract surgery should not be used as primary therapy for angle-closure glaucoma. Patients who have LPI are at greater risk of requiring therapy to control IOP, even if they have a successful procedure.