Topographic Optic Disc Changes After Successful Trabeculectomy Evaluated Using Spectral Domain Optical Coherence Tomography

Abstract

To investigate topographic optic disc changes after surgical intraocular pressure (IOP) reduction in adults with open angle glaucoma (OAG). Optic discs of patients with advanced primary open angle or exfoliation glaucoma were imaged using optical coherence tomography within 1 week before trabeculectomy. Patients were rescanned 1 week, 1 month, and 1 year after surgery. Maximum cup depth (MCD), and average cup depth (ACD) were calculated. Twenty-two eyes from 20 patients (age, 70.5 ± 10.6 years; average mean defect of visual field, -15.0 ± 9.8 dB) were followed up for 1 year. The IOP decreased from 22.1 ± 2.8 mmHg at baseline to 11.5±2.6 mmHg 1 year following surgery (P<0.001). One-week and 1-month postoperative IOPs were 11.2 ± 2.8 and 11.2 ± 3.5 mmHg, respectively (P<0.001). Compared to the baseline values (356 ± 172 μm), postoperative ACD showed a significant decrease at 1 week (312 ± 164 μm; P<0.001) and 1 month (338 ± 175 μm; P=0.007) after surgery, but not at 1 year (339 ± 176 μm; P=0.354). Similarly, MCD significantly decreased from baseline (477 ± 190 μm) 1 week (431 ± 203 μm; P=0.029) and 1 month (448 ± 198 μm; P=0.047) after the surgery, but not after 1 year (479 ± 188 μm; P=1.0). Trabeculectomy reduces IOP in eyes with advanced OAG, which induces topographic optic disc changes. Such optic disc changes became less pronounced over time and were no longer detectable 1 year after surgery.