COLOR AXIS EVALUATION OF THE FARNSWORTH-MUNSELL 100-HUE TEST IN PRIMARY OPEN-ANGLE GLAUCOMA AND NORMAL-PRESSURE GLAUCOMA

Background: It was the aim of the present study to analyze a separate color-axis evaluation of the Farnsworth Munsell 100-hue test (FM100) i n primary open-angle glaucoma (POAG) and normal pressure glaucoma (NPG ). Patients and methods: One eye of each of 112 individuals (age 35-65 years, visual acuity >20/28, myopia < -7.5 D) was included. The group s consisted of 62 normal subjects and 50 glaucoma patients (33 POAG an d 17 NPG). We evaluated the FM100 overall error score and the error sc ores of the protan, deutan and tritan axes. The results were compared with perimetric (Octopus G1 mean defect) and morphometric data of the optic disc. Results: All error scores were significantly higher in the glaucoma group than in the normal group. In an age-related evaluation , differences were significant in age groups above 45 years. No signif icant differences were found between the POAG and NPG groups. The sens itivity of the overall score to identify glaucoma was 62% (specificity 80%). In the glaucoma group the overall score and the protan score in creased significantly with the mean defect (r>0.3, P<0.01). Several sc ores increased slightly with decreasing neuroretinal rim area, but not on a significant level. Separate color-axis evaluations did not show any stronger correlations and did not reveal any differences between P OAG eyes and NPG eyes. This was true even for the tritan axis error. C onclusions: Although FM100 error scores are higher in glaucoma eyes an d increase with glaucomatous damage, they do not separate well. In the sample of this study, separate color-axis evaluation did not improve the diagnostic value. With the FM100 a different pattern of color visi on defects in POAG and NPG eyes could not be detected.