Predictors for Visual Outcome After Silicone Oil Removal in Eyes with Complicated Retinal Detachment
Numerous studies have demonstrated that silicone oil (SO) tamponade is effective in reattaching the retina following severe proliferative vitreoretinopathy (PVR). Pars plana vitrectomy (PPV) with SO tamponade has become a standard technique in complicated retinal detachment surgery. Retained SO in the eye, however, leads to emulsification and consequent complications such as cataract, glaucoma, keratopathy, and retinopathy. Therefore, SO is considered a temporary tamponade agent and needs to be removed after a period of stable anatomical attachment. A matched-pair cohort analysis has revealed significantly better visual acuity after oil removal than with oil tamponade. Therefore, following a period of successful retinal reattachment, silicone oil removal (SOR) is recommended to avoid potential sight-threatening complications
Although impressive anatomical success rates (72–96%) after SOR have been reported, only 35–76% of patients achieved visual acuity of ≥20/200. Functional success rates are not similar to anatomical success rates due to a variety of factors. This study by Tangpontirak et al aimed to address this knowledge gap by investigating the functional success rate of SOR after successful primary procedure with SO tamponade, and the predictive factors associated with functional outcomes.
A total of 182 eyes with complicated retinal detachment that had undergone SOR were retrospectively reviewed. Snellen best-corrected visual acuity (BCVA), intraocular pressure (IOP) and complications were recorded at baseline, 1 day, 1 month and 3 months postoperatively. Good visual outcome was defined as best-corrected visual acuity of ≥20/200 at 3 months visit. Factors predicting visual outcome were evaluated using univariate and multivariate analysis.
After SOR, anatomical retinal reattachment was noted in 165 eyes (90.66%). Good visual outcome (VA ≥ 20/200) was achieved in 104 eyes (57.14%) at 3 months after SOR. For the eyes that remained attached after SOR, the percentage of good visual outcome was 63.03%. With univariate and multivariate analysis, visual acuity before SOR (p< 0.001), circumferential peripheral retinopexy (p=0.037), additional endolaser during SOR (p=0.004), and pseudophakia status at the last follow up (p=0.021) were associated with visual outcome. Complications after SOR included redetachment (9.4%), hypotony (6.6%) and bullous keratopathy (1.7%).
The present study identified BCVA before SOR as a predictor of good visual outcome after SOR. Visual improvement during the repair of complicated retinal detachment using SO tamponade occurs in two steps corresponding with the two-stage procedure. Visual impairment due to retinal detachment is alleviated to a certain degree after the primary PPV procedure as the retina reattaches with SO tamponade, depending on the presence of macula on or off. Optical properties of SO in the vitreous result in high refractive errors which preclude good visual results. The SOR procedure improves visual acuity via SO removal and subsequent cataract surgery with intraocular lens (IOL) placement further improves visual outcomes. Therefore, visual acuity before SOR and pseudophakia status may be predictors for good visual outcome after SOR. Our study demonstrates anatomical success of 90.66% and functional success of 57.14% after SOR. Good BCVA before SOR and pseudophakia status at the last follow up were predictors for good visual outcomes, whereas circumferential peripheral retinopexy and additional endolaser during SOR were predictors for poor visual outcomes. Knowledge of these predictors may help to fully inform patients and to enhance clinical decision-making by ophthalmologists
Source: Tangpontirak et al; Clinical Ophthalmology 2022:16 4335–4343
https://doi.org/10.2147/OPTH.S396188
