The Role of Prostaglandins in the Progression of Diabetic Retinopathy

Objective of the research study: 1. To measure anterior chamber and vitreous ketorolac (Acuvail®) concentrations after topical administration in patients undergoing routine vitrectomy to determine the ability of the medication to penetrate into the anterior chamber and vitreous cavity, and to compare these levels to the IC50 for the cyclooxygenase-1 and -2 enzymes (COX-1 and COX-2) 2. To measure vitreous concentrations of prostaglandin subtypes (PGE, PGD, PGF) and other inflammatory mediators (Interleukin-1β \[IL-1β\], IL-6, IL-8, tumor necrosis factor \[TNF\]-α, VEGF) in both diabetic and nondiabetic patients undergoing vitrectomy 3. To determine if topical ketorolac (Acuvail®) can penetrate the anterior chamber and vitreous cavity sufficiently to decrease levels of intraocular inflammatory mediators that have been shown to be elevated in diabetic patients 4. To serve as a precursor to a 5-year longitudinal clinical trial to determine if chronically administered topical ketorolac (Acuvail®) can prevent, delay or slow diabetic retinopathy. Research hypothesis 1. Ketorolac (Acuvail®) will penetrate the anterior chamber and vitreous cavity sufficiently to achieve levels above the IC50 for COX-1 and COX-2 2. Prostaglandin and other inflammatory mediator levels in the anterior chamber and vitreous cavity will be significantly higher among diabetic patients than nondiabetic controls 3. Acuvail® can significantly lower anterior chamber and vitreous cavity levels of prostaglandins and other inflammatory mediators in diabetic patients