Abstract
Purpose: :
To study the changes in astigmatism after canaloplasty and to analyze its correlation with intraocular pressure (IOP) results.
Methods: :
26 selected eyes of 26 consecutive patients with primary open-angle glaucoma (POAG, n = 14) and pseudoexfoliative glaucoma (PEXG, n = 12) were included in this retrospective study. Canaloplasty comprised 360° catheterisation of Schlemm’s canal (SC) by means of a flexible microcatheter with distension of the canal by two tensioning 10-0 polypropylene sutures. Primary outcome measures included IOP, glaucoma medication usage, astigmatism and adverse events at 2 weeks, 4 weeks, 12 weeks and 24 weeks postoperatively. The study has received Institutional Review Board approval in form of Chairman procedure for the retrospective analysis of the data (No. 4564-CH).
Results: :
The mean preoperative IOP was 21,1 ± 5,8 mmHg. The mean IOP decreased to 14,25 mmHg ± 4,3 mmHg at 6 months. Best corrected visual acuity did not change significantly. Mean astigmatism preoperatively was 0,77 diopters (D) ± 0,5 D which increased to 3,3 D ± 1,7 D at 2 weeks postoperatively (p ≤ 0,05; Wilcoxon-Test). Thereafter, the astigmatism underwent a spontaneous decline, reaching 1,9 D ± 0,8 D at 4 weeks and 1,2 D ± 0,74 D at 12 weeks postoperatively. Six months after canaloplasty mean astigmatism reached the preoperative range of 0,86 D ± 0,52 D. Mean astigmatism at 2 weeks correlated significantly with IOP at 6 months (r = 0,59, p = 0,005; Spearman). A logistic regression analysis including glaucoma diagnosis, age, preoperative IOP, hyphema, and bleb formation delivered significant result for mean astigmatism at 2 weeks.
Conclusions: :
The change of astigmatism after canaloplasty follows a clear time course with a maximum at two weeks reaching preoperative values at six months. Our results indicate that the amount of surgically induced astigmatism might be helpful to predict outcome of canaloplasty in terms of IOP reduction.
Keywords: intraocular pressure • astigmatism • clinical (human) or epidemiologic studies: outcomes/complications