A comparison of anterior chamber and posterior chamber intraocular lenses after vitreous presentation during cataract surgery: the Department of Veterans Affairs Cooperative Cataract Study

PURPOSE: To compare the efficacy and safety of anterior chamber (AC) intraocular lenses (IOLs) and posted rior chamber (PC) IOLs implanted after vitreous presentation during extracapsular cataract extraction (ECCE). DESIGN: The study was a prospective, long,term, randomized clinical trial conducted at 19 Department of Veterans Affairs medical centers across the United States. METHODS: There were 438 eyes (438 patients) that met preliminary eligibility criteria, suffered vitreous presentation during ECCE (phacoemulsification or classical extracapsular technique), and had sufficient capsular support for a PC IOL without sutures after anterior vitrectomy randomized to either a PC IOL (230 patients) or an AC IOL (208 patients). Patients were examined at 3, 6, and 12 months post,surgery and yearly thereafter. Minimum follow-up was 1 year. The primary outcome measure of best-corrected visual acuity at 1 year was obtained by a masked certified examiner. RESULTS: More PC IOL patients (91%) achieved visual acuity of 20/40 or better at 1 year than AC IOL patients (79%), a highly significant difference (P = .003). There was no significant difference between the two groups for patient's rating of vision or adverse events. Over 84% of the PC IOL patients and over 77% of the AC IOL patients rated their vision as good or better at 1 year as opposed to only 7% giving such ratings before surgery. For at least one rating period during the first year, 13.2% of the combined study patients had cystoid macular edema, 8.5% had posterior capsule opacification, 5.7% had glaucoma, and 3.7% had retinal detachment. CONCLUSION: In the presence of sufficient capsular support, a PC IOL should he implanted after vitreous presentation during ECCE. (Am j Ophthalmol 2003; 136:1-9. (C) 2003 by Elsevier Inc. All rights reserved.).