Neuroretinal rim area and visual field in glaucoma

Abstract
The correlation between visual field and neuroretinal rim area of the optic disc was studied in 70 eyes of 44 patients with suspected or definite glaucoma. Visual field analysis was performed by automated perimetry with the Octopus 2000R, using the program G1; the neuroretinal rim area of the disc was measured by the “Optic Nerve Head Analyzer.” All eyes with a glaucomatous loss within the central sector of the visual field showed a significantly reduced neuroretinal rim area in the corresponding, i.e., the temporal quadrant of the disc. The reverse conclusion, however, was not valid: If there is a significantly reduced neuroretinal rim area in the temporal quadrant of the optic disc, one cannot predict the presence or absence of visual field loss. Actually, both high and low values are found in the neuroretinal rim area even if no visual field loss is detectable by the Octopus G1 program. There are two clinical consequences based on this result: (1) follow-up examinations of the disc structure that show increasing loss of the neuroretinal rim area may establish the diagnosis of glaucoma even at a stage where no visual field loss can be detected. Therefore, analysis of the disc structure may be more sensitive than analysis of the visual field, especially in patients who only show elevated intraocular pressure and no other signs of glaucoma. (2) If there is already a definite visual field loss due to glaucoma, the effect of antiglaucomatous therapy should be monitored by visual field analysis rather than by analysis of the optic nerve head.