Posterior capsular opacification with hydrogel, polymethylmethacrylate, and silicone intraocular lenses: Two-year results of a randomized prospectivetrial

PURPOSE: To compare the visual outcome, percentage of posterior capsular op acification, and laser capsulotomy rates with polymethylmethacrylate, silic one, and hydrogel intraocular lens implants at 1 and 2 years postoperativel y. METHODS: Ninety-three eyes of 93 patients were randomized to receive a poly methylmethacrylate, silicone, or hydrogel intraocular lens implant. A stand ardized surgical protocol was followed by a single surgeon using phacoemuls ification with capsulorhexis; any patients with surgical complications were excluded, and all patients received standardized medication and follow-up. Patients were examined at days 1 and 7, months 1, 3, and 6, and years 1 an d 2 after surgery. At each assessment, best corrected logMAR visual acuity and Pelli-Robson contrast sensitivity were measured, Posterior capsular opa cification was objectively assessed by digital retroillumination imaging wi th the use of a dedicated software program and calculated as the percentage area of opacified capsule. Laser capsulotomy was performed if the eye had lost 2 lines of visual acuity with a clinically opaque capsule. RESULTS: At 2 years postoperatively, the mean percentage area of posterior capsular opacification for hydrogel lenses was 63%; for polymethylmethacryl ate, 46%; and for silicone, 17%, Hydrogel intraocular lenses were associate d with 17% more posterior capsule opacification than were polymethylmethacr ylate lenses (95% confidence interval, 1-33; P = .037) and 45% more than we re silicone lenses (95% confidence interval, 33-58; P < .0001) at 2 years. Polymethylmethacrylate lenses had 28% more posterior capsule opacification than silicone lenses (95% confidence interval, 13-43; P < .0001) at 2 years , Twenty-eight percent of patients with hydrogel intraocular lenses require d an Nd:YAG laser posterior capsulotomy at 2 years, compared with 14% with polymethylmethacrylate, whereas no patients with silicone lenses needed a c apsulotomy (P = .014). Visual acuity was not significantly different among the three groups, but patients with silicone intraocular lenses had signifi cantly better contrast sensitivity than those with hydrogel lenses (P = .04 6). CONCLUSIONS: Intraocular lenses made of this specific hydrogel were associa ted with a significantly higher degree of posterior capsular opacification and more laser capsulotomies than polymethylmethacrylate and silicone intra ocular lenses.(C) 2000 by Elsevier Science Inc. All rights reserved.