Retinal Nerve Fiber Layer Defects in Highly Myopic Eyes with Early Glaucoma

Abstract

To compare the retinal nerve fiber layer (RNFL) defects in early glaucomatous eyes between highly and non-highly myopic eyes. Sixty-one highly myopic eyes (< -6.0 diopters [D]) of 61 patients and 55 non-highly myopic eyes of 55 patients with early visual field (VF) defects were studied. The angular locations and widths of the RNFL defects were measured from red-free fundus photographs. The RNFL defect closest to the fovea was designated the "nearest RNFL defect" of each hemisphere. In total, 131 RNFL defects were found in highly myopic eyes and 82 in non-highly myopic eyes. Twenty-seven (44.3%) of the 61 highly myopic eyes, but only 8 (14.5%) of the 55 non-highly myopic eyes had their nearest RNFL defects between 0° and 10° (P < 0.001). Although the frequencies of paracentral scotomas were comparable between the two groups, the rate of inferotemporal paracentral scotomas was significantly higher in the high myopia group (P = 0.02). The numbers of nearest RNFL defects in the superior hemisphere or extending over both hemispheres were significantly higher in the high-myopia group. Multiple logistic regression analyses showed that high myopia and the nearest RNFL defect involving the papillomacular bundle were significantly associated with paracentral scotomas (odds ratio [OR]: 4.78, P < 0.05, and OR: 5.31, P < 0.001, respectively). High myopia was significantly associated with the nearest RNFL defect involving the papillomacular bundle (OR: 2.95, P < 0.05). These findings suggest that highly myopic eyes are more susceptible to papillomacular bundle damage in early glaucoma.