Session Title: Vitreoretinal Surgery II
Session Date/Time: Friday 12/09/2014 | 14:30-16:00
Paper Time: 15:02
Venue: Boulevard C
First Author: : A.Ramezani IRAN
Co Author(s): : H. Ahmadieh A. Rozegar M. Soheilian M. Entezari S. Moradian H. Nikkhah
This study was undertaken to evaluate the probable confounding factors affecting the results of the eyes with advanced diabetic retinopathy underwent vitrectomy plus silicone oil (SO) injection. Meanwhile, the anatomical and functional outcomes as well as the complications of these eyes were studied.
Ophthalmology department of a university hospital. Ophthalmic Research Center of Shahid Beheshti University of Medical Sciences and Imam Hossein Medical Center.
In this retrospective study, 236 eyes of 214 patients that underwent vitrectomy plus SO injection for complications of proliferative diabetic retinopathy in two university hospitals with more than 3 months follow-ups were included. Surgeries generally were performed by means of a standard 3-port 20-gauge pars plana vitrectomy technique. Combined vitrectomy and cataract surgery were performed in 22 eyes (11.5%). In all cases, SO was injected either manually or by pump. Three types of SO were used: light 1000 cs SO in 34%, light 5000 cs SO in 62.6%, and heavy SO in 3.4%. Pre- and postoperative data from patients’ files such as best-corrected visual acuity (VA), slit-lamp examination findings, intraocular pressure (IOP), fundus findings, and echographic features were recorded for analyses. Indications for vitrectomy, reasons for SO injection, type of used SO, and the time of SO removal were noted as predictors for outcome. In this study, we evaluated visual and anatomical outcomes, the rate and time of SO removal, and any potential complications after intervention. Mean follow-up time was 54 and 64 weeks in eyes with and without SO removal, respectively. A total of 154 eyes had SO removal before the last visit and 82 had SO in place.
At the final visit, total, partial, and no retinal attachment were observed in 205 (86.9%), 25 (10.6%), and 6 (2.5%) eyes, respectively. Most of the eyes with final partial or no attachment had the indication of combined tractional and rhegmatogenous retinal detachment (T&R RD) for surgery. Two main reasons of T&R RD and developing of iatrogenic breaks for SO injections were significantly (P=0.007) associated with less chance of final total attachment (75.7% and 80.7%, respectively) compared to the reason of unreleased TRD (92.3%). The SO types did not significantly affect the anatomical outcomes neither before SO removal nor at the final visit. The time of SO removal did not also affect the final anatomical outcome. Mean VA was 1.92 logMAR at the initial presentation that improved to 1.78 logMAR before SO removal and 1.65 logMAR at final follow-up. Only final retinal nonattachment and initial macular involvement were associated with poor VA outcome. Postoperative complications included lens opacity progression (54.2% of phakic eyes), optic atrophy (17%), glaucoma (8.9%), hypotonia (2.5%), keratopathy (2.1%), iris neovascularization (0.9%) and phthisis bulbi (0.4%).
It was demonstrated that although anatomical outcomes were acceptable in the eyes with severe diabetic retinopathy treated by vitrectomy with SO injection; the functional prognosis was not that satisfying. However, mean VA improved significantly postoperatively and persisted for a long period of time. Retinal break was an important factor in determining the anatomical success in these cases. It might either present before surgery as a combined rhegmatogenous and tractional RD or induce iatrogenically at the time of operation. The outcome of diabetic vitrectomy with SO does not depend on the SO type and its time of removal. Therefore, retaining SO for a longer period of time in such cases might not have any influence on the outcome. Functional outcomes in these cases depend mostly on the initial macular and final retinal attachments. Cataract and ocular hypertension were the most frequent complications in this study.