Abstract
Purpose: :
To investigate the incidence and cause of severe visual loss following removal of intraocular silicone oil (SiO) in patients who underwent uncomplicated vitrectomy and SiO injection for primary rhegmatogenous retinal detachment.
Methods: :
Retrospective consecutive case series of 16 eyes in 16 patients (9 SiO eyes, 7 gas eyes) with macula-on and visual acuity ≥ 6/12 before surgery, where SiO had been removed after successful re-attachment, cataract surgery had been performed and no re-detachment had occurred. Examinations included best-corrected ETDRS visual acuity (BCVA), fundus photography and high-definition optical coherence tomography (OCT) of the macular area.
Results: :
Preoperative visual acuity was identical in SiO eyes and gas eyes. Postoperative BCVA was significantly worse in SiO eyes (58 ETDRS letters) compared to gas eyes (83 ETDRS letters), p = 0.005. Three of 9 (33%) SiO eyes had final BCVA ≤ 36 letters (6/60 Snellen) and 6 of 9 (67%) had final BCVA ≤ 71 letters (6/12 Snellen). No gas eyes had final BCVA below 77 letters (6/9 Snellen). High-definition OCT revealed thinning of inner retinal layers (from outer plexiform layer to retinal nerve fibre layer) in the central 2000 microns of the macula in SiO operated eyes (5148 pixels) compared to gas operated eyes (6897 pixels), p < 0.002. No other visually significant structural differences were found between SiO eyes and gas eyes.
Conclusions: :
Severe visual loss after SiO removal was observed in 1/3 of patients with otherwise good visual potential. The visual loss was not associated with re-detachment, macular edema, or epiretinal membrane formation; however a significant reduction in inner retinal thickness indicates neuronal cell loss in the macular area as a possible explanation.
Keywords: retinal detachment • vitreoretinal surgery • imaging/image analysis: clinical