Anterior Segment Optical Coherence Topography (AS-OCT) and Corneal Topography Changes after Trabeculectomy in Patients Presenting with Primary Open Angle Glaucoma

Background: Primary open-angle glaucoma (POAG) is a progressive optic neuropathy characterized by elevated intraocular pressure (IOP) and damage to the optic nerve. Trabeculectomy is a common surgical intervention aimed at reducing IOP and preserving vision in patients with POAG. Aim of the work: This study aimed to investigate the changes in anterior segment optical coherence topography (AS-OCT) and corneal topography following trabeculectomy in patients diagnosed with primary open-angle glaucoma. Patients and Methods: A prospective study was conducted on twenty eyes of twenty patients with POAG undergoing trabeculectomy. AS-OCT and corneal topography measurements were obtained preoperatively and then three months post-operative to assess changes in the anterior segment and corneal parameters. Results: A statistically significant increase was observed in ΔK2 (median ₌ 44.41, IQR ₌ 43.86-44.57), Δastigmatism (median ₌ 2.44, IQR ₌ 1.7-3.11), ΔACD-OCT (2.11±0.38), and ΔACA-OCT (20.8±5.01) when compared with ΔK2 (median ₌ 43.47, IQR ₌ 43.01-43.69), Δastigmatism (median ₌ 1.11, IQR ₌ 0.47-1.97), ΔACD-OCT (2.62±0.39), and ΔACA-OCT (30.9±7.8) pre-operatively. No statistically significant changes were found regarding ΔK1, Avg K, and A. Conclusion: Astigmatism is the main reason for the diminution of visual acuity (VA) that is detected in the early weeks after operations. Decreases in anterior chamber (AC) depth and AC angle occur in the first week after trabeculectomy, reaching baseline levels before surgery after one month.