Removal of Silicone Oil: Retinal Redetachment and other Outcomes

Azam Ali M.D, Maria M. Choudhary M.D

Section of Department of Ophthalmology, Department of Surgery, Aga Khan University Hospital
Stadium Road, Karachi, Pakistan.

Objective: To evaluate the frequency of retinal redetachment in eyes undergoing removal of silicone oil endotamponade following pars plana vitrectomy for complicated retinal detachment and assess their visual acuity and possible prognostic factors.

Methods: The study is a retrospective file review of 173 consecutive cases that underwent pars plana vitrectomy with silicone oil tamponade for complex retinal detachment and subsequent removal of silicone oil (ROSO) at a tertiary care hospital in Pakistan. The hospital charts of patients that had followed up for a minimum duration of 03 months post ROSO were reviewed in detail. Their Best Corrected Visual Acuity (BCVA) and Intraocular Pressure (IOP) were noted along with any abnormal findings on examination of the anterior and posterior chambers were evaluated at each office visit post vitrectomy and post ROSO. The data was then evaluated for anatomic success (defined as a completely attached retina on fundoscopic examination) and frequency of redetachment. The outcome factors studied included anatomic success, BCVA and IOP pre and post ROSO

Results: Anatomic success was achieved in 167 (96.5%) of the 173 eyes after removal of silicone oil. The mean duration of silicone oil tamponade was 70 ± 48 weeks (Median 56, Mode 48 weeks). BCVA of greater than 20/100 was achieved in 83 (49.4%) patients at 3 months post ROSO. 10 patients had undergone previous unsuccessful retinal surgeries for detachment including vitrectomy with SF6 and scleral buckling. Levene's test for equality of variances was used to determine the association between previous unsuccessful retinal surgeries and redetachment following ROSO (p=0.523), duration of silicone oil and anatomic success (p=0.451) and the age at initial presentation and retinal redetachment (p=0.126). Mean IOP immediately before silicone oil removal was 22mmHg, 19 mmHg at 03 months after ROSO and 17mmHg 06 months post ROSO.

Conclusion: The frequency of retinal redetachment following removal of silicone oil in our study is 3.46%, which is the lowest that has ever been reported in literature. Aggressive and complete removal of the vitreous base, performing retinotomies, ensuring complete silicone oil fill for adequate tamponade and pre ROSO argon retinopexy can be identified as possible factors leading to our better anatomic results.