Effect of glaucoma surgery on the progression rate and pattern in glaucoma patients with myopia

Abstract

PURPOSE. To evaluate the effect of myopia on the changes of visual field (VF) and retinal nerve fiber layer (RNFL) thickness after glaucoma surgery. METHODS. Patients with primary open-angle glaucoma who underwent glaucoma surgery due to uncontrolled IOP, with at least four VF and optical coherence tomography (OCT) examinations before and after surgery (total of eight VF and OCT examinations), and followups of at least 4 years, were enrolled and classified according to axial length. Disc ovality ratio, degree of disc torsion, and ratio between peripapillary atrophy area and disc area were measured from disc photographs. The rate of change of the VF parameters and RNFL thickness was determined by using a linear regression analysis and compared according to the degree of myopia. RESULTS. A total of 63 eyes with myopia and 46 eyes without myopia were analyzed. The rate of change in the sensitivity of the central VF (within 108 region) and temporal RNFL thickness differed significantly between the myopic and nonmyopic groups (P < 0.01 and P < 0.01, respectively). Axial length (P < 0.01), magnitude of IOP change after surgery (P < 0.01), the presence of postoperative hypertensive phase (P < 0.01), and peripapillary atrophy to disc area ratio (P < 0.01) were significantly related to the change of the central VF and temporal RNFL thickness. CONCLUSIONS. Myopic eyes with large peripapillary atrophy relative to the disc area seem to show greater central VF progression and temporal RNFL thinning after glaucoma surgery when they are exposed to large IOP change of glaucoma surgery.