Quantitative analysis of visual field and optic disk in glaucoma: retinal nerve fiber bundle-associated analysis

Background: A study was performed to evaluate whether visual field analysis using a perimetric nerve fiber bundle map gives information additional to global visual field indices and cumulative defect curves for early glaucoma diagnosis. Methods: One hundred and four control subjects, 124 patients wi th ocular hypertension (OHT), 97 patients with high-tension glaucoma withou t visual field defects (preHTG) and 91 patients with open-angle glaucoma wi th visual field defects [30 low-tension glaucoma (LTG), 61 high-tension gla ucoma (HTG)I were included in this study. Correlation analyses were perform ed between (a) global visual field indices and total neuroretinal rim (NRR) area; (b) local mean values of four visual field areas and the NRR area of the corresponding four optic disk sectors; and (c) local mean values of 10 perimetric nerve fiber bundles (PNFB1-10) according to Weber and Ulrich (1 991) and the four optic disk sectors. The correlations were adjusted for gl obal mean defect and total NRR. Results: There were no significant correlat ions between NRR area and visual field in control subjects or in patients w ith OHT or preHTG for all three analyses. Significant correlations were fou nd between the global visual field indices and the total NRR area for LTG a nd HTG. Significant correlations between local mean defects and NRR area of corresponding optic disk sectors were found only in LTG for the superior a nd inferior visual field area and the PNFB covering these areas. Conclusion : The method used for visual field analysis and sectorization of the optic disk does not give additional information on visual field defects in patien ts with normal global visual field indices and a normal cumulative defect c urve. The nerve fiber bundle-related visual field analysis allows the topog raphical determination and quantification of glaucomatous damage.