Purpose:
The purpose of this study was to report preliminary results of corneal topographic changes induced from mini ExPress glaucoma surgery with Mitomycin-C (MMC) for treatment of glaucoma with or without combined phacoemulsification with a 6 month follow-up.
Methods:
This study was a retrospective, observational analysis of 58 eyes from 44 patients that underwent mini Ex-PRESS glaucoma surgery (MES) with MMC with or without phacoemulsification and intraocular lens (IOL) implantation. Pre and post-operative corneal topography was measured with the IOLMaster. Age of patient and number of glaucoma drops used preoperatively were documented. Preoperative and postoperative measurements of keratometry, intraocular pressure (IOP) at different time points, post-operative interventions, and complications were recorded. Surgically induced astigmatism was calculated and reported.
Results:
The postoperative IOP measurements were significantly different compared with pre-operative with an average drop of 18.3 mmHg at post-operative week 1, and stabilized at 15.5 mmHg below the pre-operative mean for up to 6 months. Mean pre-operative IOP was 28, and at 1 year was 13, representing a 46% decrease. Both the flat keratometry measurement (K1) and the steep keratometry measurement (K2) at week 1 are significantly different than that at pre-operation (p = 0.002, p < 0.0001, respectively). Additionally, the K1 and K2 measurements at month 1 are statistically different than at week 1 (p = 0.003, 0.001, respectively). K1 measurements at month 1, month 3, and month 6 are not significantly different than pre-operation. K2 measurements at week 1 and month 1 are significantly different than that at pre-operation (p < 0.0001 and p = 0.001 respectively). The mean surgically induced astigmatism is 2.52D postoperatively at week 1, and then shows a steady decline back to the pre-operative value at 3 months and stabilizes through the 6 month measuring period. Axis shows significant variability at 1 week and 1 month follow-up, but no significant change in axis beyond 3 months postoperatively.
Conclusions:
Initial surgically induced astigmatism from MES completely decays back to baseline at 3 months, which is sooner than previously reported with small flap trabeculectomy. Our data also reveals that the axis of the astigmatism, although not statistically significant beyond 1 month post-operatively, continues to be variable and likely clinically significant through the six month follow-up period.
Keywords: anterior segment • topography • intraocular pressure