Pattern of glaucomatous neuroretinal rim loss.

BACKGROUND: In advancing glaucomatous optic nerve damage, the area of the neuroretinal rim progressively diminishes, and its form continuously changes. This cross-sectional study was undertaken to establish a set pattern behind glaucomatous rim loss.
METHODS: The authors evaluated morphometrically stereo color optic disc photographs of 801 glaucomatous eyes and 496 visually normal eyes.
RESULTS: Compared with the visually normal eyes, glaucomatous neuroretinal rim loss occurred in all sectors of the optic disc with regional preferences depending on the stage of the disease. In the eyes with modest glaucomatous damage, rim loss was usually most pronounced in the inferotemporal disc region. In the eyes with moderately progressed glaucomatous changes, rim was decreased most markedly in the superotemporal sector, then in the temporal horizontal area, the nasal inferior region, and finally in the superior nasal sector. In very advanced glaucoma, rim remnants usually were present only in the nasal disc region. At that stage, they were significantly larger in the superior nasal region than in the nasal inferior area.
CONCLUSION: Other than occurring in a diffuse way, glaucomatous neuroretinal rim loss took place in a sequence of sectors. Generally, it began in the inferotemporal disc region and then progressed to the superotemporal, the temporal horizontal, the inferior nasal, and finally the superior nasal sectors. This correlates with the progression of visual field defects and the morphology of the lamina cribrosa. This finding may be important for "early" glaucoma diagnosis.