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

PURPOSE: To compare the retinal nerve fiber layer (RNFL) defects in early glaucomatous eyes between highly and non-highly myopic eyes. METHODS: 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. RESULTS: 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). CONCLUSIONS: These findings suggest that highly myopic eyes are more susceptible to papillomacular bundle damage in early glaucoma.