Pattern of Glaucomatous Optic Disc Damage in Primary Open-Angle Glaucoma

ABSTRACT

To identify the pattern of glaucomatous changes of the optic disc, the rim area to disc area ratio (RA/DA ratio) of 149 eyes (149 cases) with primary open-angle glaucoma (POAG) were measured and compared with that of 88 eyes (88 cases) of normal individuals. At all stages of the disease, glaucomatous rim loss was present in all sectors of the optic disc. The location of the most pronounced rim loss changed depending on the severity of the disease. In the early (RA/DA ratio > 61%; mean deviation(MD) -6.43+/-3.32dB) and medium (RA/DA ratio=41~60%; MD -7.54+/-5.65dB) glaucoma subgroups, rim loss was found predominantly at the inferior temporal and superior temporal disc region. In the advanced glaucoma subgroup (RA/DA ratio=40~21%; MD -18.27+/-8.40dB), the temporal horizontal disc region showed relatively marked rim loss. In the far advanced glaucoma subgroup (RA/DA ratio=20~0%; MD -25.91+/-5.40dB), the rim remnants were located mainly in the nasal disc sector, with a larger rim portion in the upper nasal region than in the lower nasal region. These results indicate that generally in POAG, the loss of neuroretinal rim was found to start predominantly in the inferior temporal and superior temporal disc region, and then the temporal horizontal, the inferior nasal, and the superior nasal disc sectors followed.