INTRAOPERATIVE CRYSTALLIZATION ON THE INTRAOCULAR-LENS SURFACE

PURPOSE: To report a physician survey, laboratory studies, and clinica l observations of intraoperative crystallization on the surface of the intraocular lens (TOL). METHOD: We sent a survey to all ophthalmslogi sts in the states of Wyoming, Idaho, Montana, Utah, and Colorado askin g whether crystallization on the IOL surface had occurred in any of th eir patients and what viscoelastics, IOLs, and other solutions were us ed. All returned surveys were tabulated and analyzed by standard stati stical means. A sample of crystallization from an IOL on a glass slide submitted by a physician was analyzed to ascertain the relative eleme ntal composition. During in vitro laboratory studies, BSS Plus (Alcon Surgical, Fort Worth, Texas) and BSS (Alcon Surgical) were measured an d analyzed for precipitation. Healon GV (Pharmacia/Upjohn, Kalamazoo, Michigan) and calcium chloride were combined in various solutions and examined for precipitate formation. Silicone IOLs and plate silicone w ere placed in different BSS and BSS Plus solutions with different visc oelastics and varying calcium concentrations. In seven patients, promi nent crystallization on an IOL surface was examined, photographed, and followed for up to 3 years. RESULTS: Two hundred six surveyed ophthal mologists returned 181 surveys (88%) and reported 29,609 cataract surg eries, with IOL implantation with 22 eyes (0.07%) (22 patients) in whi ch intraoperative crystallization was observed on the IOL, surface dur ing 1993. The survey indicated there was a correlation with BSS Plus ( chi-square = 4.9, P = .0268) and silicone IOLs (chi-square = 6.8, P = .0093). The sample showed the cation to be calcium. CONCLUSION: Crysta llization on the IOL surface during cataract surgery is a rare occurre nce that may be associated with calcium as the cation related to an os motic gradient around the IOL with increased calcium concentration. If encountered surgically, the lens should be exchanged in the operating theater after irrigating the anterior chamber with BSS and completely filling the capsular bag with a low molecular weight viscoelastic. (A m J Ophthalmol 1998; 126:177-184; (C) 1998 by Elsevier Science Inc. Al l rights reserved.).