The effect of silicone ocular surgical devices on serum IgG binding to silicones

Abstract

PURPOSE: To determine whether silicone materials used in retinal detachment repair and cataract surgery increase serum IgG binding to silicone and identify correlations with complications of ocular surgery. METHODS: Serum from 49 patients who had ocular surgery using silicone materials was examined. Patient groups included scleral buckling (n = 25), silicone oil tamponade (n = 3), scleral buckling and silicone oil tamponade (n = 9), and silicone lens implants after cataract extraction (n = 12). Convalescent samples for all patients and preoperative samples from 19 patients (18 scleral buckling and one silicone oil tamponade) were examined. Postoperative complications were monitored for up to 108 months (mean, 10.7 months; mode, 1.5 months; range, 1 to 108 months). Samples were evaluated for the extent of IgG binding to silicones using a micromodification of a previously described enzyme-linked immunosorbent assay method. RESULTS: In 19 patients, IgG binding levels in preoperative samples were 21 arbitrary units (AU) or less. Of the 25 buckling patients, one developed complications; however, in all patients the postoperative levels of IgG binding to silicone were low (2.2 to 20.0 AU). Although four silicone lens patients developed mild complications, none displayed postoperative IgG binding levels of greater than 20 AU. Three patients who underwent both scleral buckling and silicone oil tamponade developed complications; one of these patients, who was also noted to have systemic connective tissue disease, had a significant elevation in postoperative serum IgG binding to silicone. CONCLUSIONS: Statistically significant elevations of serum IgG binding to silicone were noted postoperatively in only one patient who had a systemic connective tissue disease. The complication rate and frequency of enhanced serum IgG binding to silicone was low, making correlations to surgical complications difficult. Examination of matched samples suggested that if ocular exposure to silicone implants enhances the level of serum IgG binding to silicones, it must be a rare event that should not alter the clinical use of these important devices.