Abstract
Purpose:
To examine the immediate effect of trabeculectomy on corneal curvature.
Methods:
Cross-sectional study. Eleven eyes from 11 patients (6 men, 5 females) with primary open angle glaucoma (POAG) were included in this study. All patients underwent glaucoma surgery because of uncontrolled intraocular pressure (IOP) despite maximal medical therapy. Nine eyes underwent standard trabeculectomy, while an Ex-press device was implanted under a sclera flap in 2 eyes. In all cases mitomycin C (MMC) was applied intra-operatively. The day before surgery and the first day postoperatively, the corneal curvature of each patient was evaluated by videokeratoscopy (TMS-4, Tomey, Nagoya, Japan). Student’s t-test and Pearson correlation were used for statistical analysis.
Results:
Mean age was 64.9 ± 13.6 years (mean ± SD, range: 36 to 80 years). Mean IOP was 27.8 ± 9.1 mmHg preoperatively and 16.6 ± 10.5 mmHg in the first day postoperatively. Mean preoperative and postoperative astigmatism values were 1.04 ± 0.77 and 4.63 ± 3.86 diopters respectively. The mean Surface Asimmetry Index (SAI) was 0.78 ± 0.29 preoperatively and 1.39 ± 0.39 postoperatively. Statistically significant (p<0.001) differences were found between preoperative and postoperative astigmatism values (1.04 ± 0.77) and (4.63 ± 3.86) respectively and between perpendicular corneal curvature radii. No statistical correlation between corneal curvature and IOP was found one day after surgery.
Conclusions:
The results of our study suggest that both standard trabeculectomy and Ex-press implantation under a scleral flap affect corneal curvature on the first day after surgery. This impacts on patients’ visual performance. Further studies are needed to clarify the role of both conjunctival and scleral sutures in determining such variations together with their long-term effects on visual acuity and quality of vision.
Keywords: 733 topography •
428 astigmatism •
568 intraocular pressure