Differences of retinal nerve fiber layer thickness between normal and glaucoma-like optic disks (physiological cups) matched by optic disk area.

We matched by disk area size 23 eyes of patients with glaucoma-like disks (physiological cups) with normal ocular pressures and no visual field loss with 23 eyes of normal subjects. Using stereophotogrammetry we found a significant decrease in retinal nerve fiber layer thickness in the eyes with glaucoma-like disks compared to the normal eyes (P = 0.0081), especially in the nasal quadrant (18.1%). A similar significant decrease was noted in the neuroretinal rim area and a significant increase in cup volume, area, depth and slope for the total disk and its quadrants. The use of computerized image analysis also showed a significant increase in pallor area for glaucoma-like disks compared to normal disks. Eyes with glaucoma-like disks or physiological cups showed evidence of an optic neuropathy and may be manifesting the same damage to the optic nerve occurring in high pressure open angle glaucoma.