Purpose
Silicone oil is an effective tamponade in complex retinal detachment, including proliferative vitreoretinopathy (PVR), giant retinal tear (GRT) and proliferative diabetic retinopathy(PDR). However prolonged tamponade is associated with cataract, glaucoma, and reduced visual acuity. Whenever possible silicone oil is removed within a few months of its insertion. Although removal of silicone oil (ROSO) reduces the risk of complications, a few patients experience an unexplained drop in visual acuity, despite an apparently normal fundus. The purpose of this study was to estimate the incidence of this complication, and to identify any risk factors associated with it.
Methods
Retrospective case note review of 115 removal of silicone oil patients treated by 4 tertiary vitreoretinal consultants in the West of Scotland regional centre at Gartnavel General Hospital
Results
115 patients were included. Indications for silicone oil were PVR (68, 59%), PDR (14, 12%), Giant retinal tear (19, 17%). Following ROSO, 21 (18.3%) eyes redetached. Redetachment was not associated with the following risk factors: type of oil, duration of tamponade, 360 degree laser, retinectomy, PVR, PDR, GRT, or number of operations. The median LogMar (Fig.1) at presentation was 2.6, improving to 1.0 before ROSO (Mann-Whitney, p = 0.0005), and 0.78 after ROSO (Mann-Whitney, p = 0.0084). In the 94 eyes that remained attached, corrected vision improved by ≥0.3 LogMar units in 39 (41.1%, 95% ci 31.2-51.6%), and worsened by ≥0.3 LogMAR in 5 (5.3%, 95% ci 2.0 - 12.6%). 50 patients (52.6%, 95% ci 42.2 - 62.9%)had little change in VA. In four eyes (4.3%, 95%ci 1.4-11.2%) there was no apparent cause for the loss of vision. Vision deterioration or improvement following ROSO was not associated with presenting visual acuity, indication for silicone oil, type of oil, duration of tamponade, 360 degree laser, retinectomy, or number of operations.
Conclusions
VA is improved or stabilized in most patients having ROSO. Although unexplained reduction in vision is a well-known complication, this is the first report that attempts to estimate the incidence. Our data suggests that the complication may be more common than originally thought. All patients undergoing ROSO should be informed of the risk of unexplained visual loss as well as the risk of redetachment.