Macular Edema and Silicone Oil Tamponade

Purpose: To analyze the risk factors for inflammatory macular edema (ME) in a series of patients undergoing vitreoretinal surgery using Silicone Oil (SO) as a long-term tamponade. Materials and methods: We examined 118 consecutive eyes of 115 patients, mean age 57.8 years (range 39-79), suffering from various types of severe retinal detachment. Surgical procedures were carried out on all patients, and SO 1000cs was injected into the eye at the end of surgery to permit stable retinal reattachment. ME was classified as initial, medium and severe. The characteristics of ME were compared with various preoperative, intra-surgical and postoperative parameters. Statistical analyses were carried out using the T test and the Pearson correlation coefficient. Results: Twenty-six eyes were excluded. Twenty out of 92 eyes (22%) presented various types of ME. No significant correlation was found between ME and age or complication and duration of surgery. Significant correlation was found between ME and macular status before surgery and time length of intraocular permanence of SO. Conclusion: SO should be removed as soon as possible, in particular when the preoperative macular status is compromised. Decreased molecular transport in the vitreous space, permanence of inflammatory substances between SO and the macula, mechanical floating of SO and dangerous light exposure might be involved in the pathogenesis of ME.