Corneal endothelial cell loss after multiple vitreoretinal procedures and the use of silicone oil

BACKGROUND AND OBJECTIVE: Corneal decompensation and complications are a frequent cause of visual loss after vitreoretinal surgery. This paper presents data regarding endothelial cell loss in aphakic and pseudophakic silicone oil filled eyes when oil was retained for many months. This study updates our previous investigation on the subject. PATIENTS AND METHODS: The corneal endothelial cell count of 10 eyes of 10 consecutive patients who had undergone vitreoretinal surgery, including fluid-gas exchange and ultimately silicone oil placement, were obtained. The patients underwent an average of 2.7+/-0.9 vitreoretinal procedures before the final procedure which induced the placement of silicone oil in the vitreous cavity. All had inferior iridectomies. The endothelial cell density measurements were obtained an average of 1 year after silicone oil placement. In all eyes, the oil was felt necessary for long term tamponade and therefore was not removed. The cell density of the operated eye was compared to the fellow eye, none of which had undergone silicone oil placement. RESULTS: Both gas and retained silicone oil contribute to the loss of corneal endothelial cell density. The average endothelial cell loss in the 10 eyes with oil retained for an average of 10+/-12 months was 68.8 +/-31.4%, as compared to the fellow eye. The average cell loss was higher in the three eyes with silicone oil in the anterior chamber (range 44 to >95%). Pseudophakic eyes fared better, on average, than aphakic eyes (51.66+/-28% vs. 66.63+/-26.3%) with respect to cell loss. Five aphakic eyes and 1 pseudophakic eye developed corneal edema. CONCLUSIONS: Endothelial cell loss occurs after vitreoretinal surgery and is exacerbated by long term silicone oil retention. The corneal endothelial cell damage is probably cumulative from procedure to procedure. Endothelial cell loss may be pronounced in eyes without a physical barrier between the anterior segment and the vitreous cavity, and in eyes where oil migrates into anterior chamber.