Posterior capsular opacification with hydrogel, polymethylmethacrylate, and silicone intraocular lenses: two-year results of a randomized prospective trial

• Published in: American journal of ophthalmology 2000-05, Vol.129 (5), p.577-584
• Main Authors: Hollick, Emma J, Spalton, David J, Ursell, Paul G, Meacock, Will R, Barman, Sarah A, Boyce, James F
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Capsulorhexis; Cataract - epidemiology; Cataract - etiology; Cohort Studies; Female; Humans; Hydrogel, Polyethylene Glycol Dimethacrylate - adverse effects; Laser Therapy; Lens Capsule, Crystalline - pathology; Lens Capsule, Crystalline - surgery; Lens Implantation, Intraocular; Lenses, Intraocular - adverse effects; Male; Middle Aged; Polymethyl Methacrylate - adverse effects; Silicone Elastomers - adverse effects; Visual Acuity
• ISSN: 0002-9394; 1879-1891
• DOI: 10.1016/S0002-9394(99)00447-X

PURPOSE: To compare the visual outcome, percentage of posterior capsular opacification, and laser capsulotomy rates with polymethylmethacrylate, silicone, and hydrogel intraocular lens implants at 1 and 2 years postoperatively. METHODS: Ninety-three eyes of 93 patients were randomized to receive a polymethylmethacrylate, silicone, or hydrogel intraocular lens implant. A standardized surgical protocol was followed by a single surgeon using phacoemulsification 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 and 2 after surgery. At each assessment, best-corrected logMAR visual acuity and Pelli-Robson contrast sensitivity were measured. Posterior capsular opacification was objectively assessed by digital retroillumination imaging with 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 polymethylmethacrylate, 46%; and for silicone, 17%. Hydrogel intraocular lenses were associated with 17% more posterior capsule opacification than were polymethylmethacrylate lenses (95% confidence interval, 1–33; P = .037) and 45% more than were 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 required an Nd:YAG laser posterior capsulotomy at 2 years, compared with 14% with polymethylmethacrylate, whereas no patients with silicone lenses needed a capsulotomy ( P = .014). Visual acuity was not significantly different among the three groups, but patients with silicone intraocular lenses had significantly better contrast sensitivity than those with hydrogel lenses ( P = .046). CONCLUSIONS: Intraocular lenses made of this specific hydrogel were associated with a significantly higher degree of posterior capsular opacification and more laser capsulotomies than polymethylmethacrylate and silicone intraocular lenses.