Abstract
Abstract: :
Purpose: To compare the effect on intra–ocular pressure (IOP) of trabeculectomy with mitomycin–C (trabMMC) to phacotrabeculectomy with mitomycin–C (phacotrabMMC) in glaucoma patients at increased risk for filtering surgery failure. Methods: A cohort study was conducted of one–hundred and ninety–one glaucomatous eyes that underwent either trabMMC (85 patients) or phacotrabMMC (105 patients) for failed medical therapy over a seven–year period. Intra–operative MMC (0.3mg/ml) time was titrated according to patient risk for filtering surgery failure. Baseline pre–operative data was collected within three months of the date of surgery. The primary outcome was difference in mean post–operative IOP over two years between the two groups. Other outcomes studied include difference in mean IOP drop from baseline over two years and difference in post–operative complication rates, including day 1 IOP spike, delayed hypotony, hyphema, uveitis and endophthalmitis. Analysis was performed with generalized linear models, controlling for confounders. Results: The mean IOP at baseline was 26.1 +/– 9.1 mmHg in the trabMMC group and 20.3 +/– 7.0 mmHg in the phacotrabMMC group. The mean post–operative IOP ranged from 13.2 mmHg to 15.5 mmHg amongst the two groups over the two–year follow–up period. There was no statistically significant difference in mean IOP between the two groups at any of the follow–up times, except at six months in which mean IOP was lower in the phacotrabMMC group than in the trabMMC group (13.2 +/– 4.2 mmHg vs. 15.5 +/– 6.8 mmHg p=.013). The decrease in mean IOP from baseline was significantly greater in the trabMMC group than in the phacotrabMMC group by about 4–6 mmHg at all follow–up times. There was no significant difference in post–operative complication rates between the two groups. Conclusions: TrabMMC and phacotrabMMC, using a specific MMC protocol, appear to be equally safe and effective in bringing IOP to an acceptable level over the follow–up period of this study in glaucoma patients at increased risk for filtering surgery failure, although trabMMC seems to confer substantially greater IOP–lowering from baseline.
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: outcomes/complications • trabecular meshwork