The effect of exfoliation on surgically induced astigmatism in patients after trabeculectomy

Abstract

Purpose: Our aim was to compare the effects of exfoliation (XF) on surgically induced astigmatism (SIA) in patients with primary open-angle glaucoma (POAG) and exfoliation glaucoma (XFG) after trabeculectomy.Materials and Methods: Twenty-one eyes with POAG and 22 eyes with XFG were included in this prospective clinical study. The eyes had uncomplicated initial trabeculectomy with 5-fl uorouracil (5-FU). All cases underwent a complete ocular examination including corneal topography at baseline and at postoperative fi rst, third, and sixth months. SIA was calculated by the vector analysis method using the Holladay-Cravy-Koch formula.Results: The mean SIA values were 0.92±0.35 diopter (D), 0.96±0.34 D, and 0.82±0.34 at the fi rst, third, and sixth months, respectively, in the POAG group and 1.17±0.43 D, 1.25±0.44 D, and 1.05±0.42 D at the fi rst, third, and sixth months, respectively, in the XFG group. Signifi cant differences existed between the groups at postoperative fi rst and third months, but no signifi cant difference was observed at the sixth month (p=.040, p=.027, p=.061, respectively). At the sixth month, with the rule (WTR) astigmatism rates were 76% in the POAG group and 45% in the XFG group (p=.039). Signifi cant correlations were found between the SIA values, and intraocular pressure changes were observed at the fi rst and sixth months (r=-0.502, p=.017; r=-0.520 p=.013) in the XFG group.Conclusion: SIA values in XFG patients after trabeculectomy were higher in the early period compared to POAG patients. This may be due to local infl ammation caused by XF and its effect on corneal biomechanics.