Timing of retinal redetachment after removal of intraocular silicone oil tamponade

PURPOSE: To evaluate the interval between removal of intraocular silicone o il tamponade and retinal redetachment after pars plana vitrectomy, and to i nvestigate factors influencing the length of the interval. PATIENTS AND METHODS: The retrospective study included 42 eyes of 42 consec utive patients who experienced a retinal redetachment after silicone oil ha d been removed 8.0 +/- 6.2 months after an initial pars plana vitrectomy in cluding intraocular silicone oil (5,000 centistokes) tamponade. Pars plana vitrectomy had been performed for proliferative vitreoretinopathy caused by complicated rhegmatogenous retinal detachment. RESULTS: The retina redetached 2 days to 5.5 months after silicone oil remo val (mean +/- SD, 1.3 +/- 1.4 months; median, 18 days). Thirteen (30%) of a ll 42 redetachments occurred in the first 9 days, 21 (50%) of all 42 retina l redetachments occurred in the first 18 days, and 32 (75%) of all 42 retin al redetachments occurred in the first 50 days. The interval between silico ne oil removal and retinal redetachment was statistically (by analysis of v ariance) independent of the method of silicone removal (transpupillary drai nage vs via pars plana sclerotomies), refractive error of the eye (P = .62) , time between initial pars plana vitrectomy and silicone oil removal (P = .99), visual acuity before silicone oil removal (P = .26), type of anesthes ia (P = .69), gender (P = .80), and age (P = .48) of the patients. CONCLUSION: The risk of retinal redetachment decreases steeply with increas ing time after silicone oil removal. Three to 5 months after oil removal, r etinal redetachment becomes unlikely, The time of retinal redetachment is s tatistically independent of the method of silicone oil removal, refractive error, time between the preceding pars plana vitrectomy and silicone oil re moval, visual acuity before silicone oil removal, type of anesthesia, and g ender and age of the patents. These data may be important for scheduling re examinations and for counseling patients in their planned activities after removal of intraocular silicone oil tamponade. (C) 1999 by Elsevier Science Inc. All rights reserved.