Ascorbic acid concentration in rabbit vitreous measured by microdialysis with HPLC-electrochemical detection before and after vitreous surgery

Abstract Microdialysis with high performance liquid chromatography and electrochemical detection (HPLC–ECD) was used to measure ascorbic acid (AA) concentrations in rabbit vitreous before and after vitrectomy. A cellulose microdialysis probe was implanted in the vitreous humor, and after stabilization, AA measurements were made daily over a 10 day period. The effect of removing two-thirds of the vitreous by vitrectomy was examined. The effect of triamcinolone acetonide (TA) was evaluated in four groups of rabbits: Group 1, sub-tenon TA (20 mg) alone; Group 2, intravitreous TA (4 mg) alone; Group 3, sub-tenon TA (20 mg) after vitrectomy, and Group 4, intravitreous TA (4 mg) after vitrectomy. The results showed that the AA concentration after vitrectomy was significantly lower from days 2 to10 with a maximum reduction of 49.5% ( P