VITRECTOMY WITH SILICONE OIL OR LONG-ACTING GAS IN EYES WITH SEVERE PROLIFERATIVE VITREORETINOPATHY - RESULTS OF ADDITIONAL AND LONG-TERM FOLLOW-UP - SILICONE STUDY REPORT-11

Background: The Silicone Study evaluated the outcomes of vitreoretinal surgery for retinal detachment with proliferative vitreoretinopathy ( PVR). Objective: To evaluate short-term (up to 36 months) outcomes in eyes randomized to silicone oil or perfluoropropane gas and long-term (up to 72 months) outcomes in eyes with attached maculas at 36 months. Design: Prospective, randomized, multicentered surgical trial. Settin g: Community- and university-based vitreoretinal practices. Patients: Two-hundred sixty-five eyes with PVR randomized to perfluoropropane ga s and silicone oil with follow-up through 3 years (cohort 1) and 249 e yes with attached maculas at 36 months (121 eyes randomized to long-ac ting gas [either sulfur hexafluoride or perfluoropropane] and 128 eyes randomized to silicone oil) with follow-up up to 6 years (cohort 2). Both cohorts consisted of eyes that had and had not undergone vitrecto my for PVR (groups 1 and 2, respectively) before randomization. Of the 265 eyes in cohort 1, 24-month follow-up data were available for 218 eyes (82%) and 36-month follow-up data were available for 196 eyes (74 %). Of 208 eyes in cohort 2, 48-month follow-up data were available fo r 146 eyes (70%), 60-month follow-up data for 119 eyes (57%), and 72-m onth follow-up data for 73 eyes (35%). Interventions: Vitrectomy surge ry for PVR with a long-acting gas or silicone oil as the intraocular t amponade. Main Outcome Measures: Changes in visual acuity, recurrent r etinal detachment, and incidence of complications. Results: In group 1 of cohort 1, compared with oil-treated eyes, gas-treated eyes had a h igher rate of complete retinal reattachment from 18 to 36 months (P<.0 5). No other differences were found. In group 2 of cohort 1, no notabl e differences were found between treatment arms. In cohort 2, during 6 years of follow-up, attachment of the macula was maintained for all e yes. No notable differences in the rates of complete retinal attachmen t, visual acuity of 5/200 or better, or glaucoma were found between tr eatment groups. In contrast, gas-treated eyes had more hypotony (P<.00 1). Silicone oil-treated eyes that underwent subsequent surgery were m ore likely to have the oil retained (P=.02). Compared with oil-retaine d eyes, oil-removed eyes had higher rates of complete posterior attach ment (P=.01) and of a visual acuity of 5/200 or better (P<.001) and le ss keratopathy (P<.05). Compared with oil-removed eyes, gas-treated ey es had a worse visual acuity outcome (P<.05) and more hypotony (P<.01) . Conclusion: The Silicone Study showed that silicone oil and perfluor opropane gas were equal in most respects for the management of retinal detachments with PVR. Success in the first surgery for PVR is paramou nt for obtaining better visual results. Overall, surgery for PVR had a high likelihood of retinal reattachment, and if anatomically and visu ally successful at 3 years, there is an excellent chance that the resu lts will be maintained over the long-term.