Topometry of glaucomatous optic nerve head: Does the reduction of the rim area of the optic nerve head correspond to the location of visual field losses?
T. U. Bartke, S. C. Keller, A. F. Scheuerle, R. O. W. Burk
For a long time the relationship between morphology of the optic nerve head and glaucomatous function loss is an object of clinical glaucoma research. Aulhorn and Harms published already in 1960 a systematic study about the relationship of defined changes of the glaucomatous optic nerve head and corresponding visual field losses. The purposes of our studies were to perform precisely three-dimensional measurements of the rim area in temporal superior and inferior octants in correspondance to visual field losses.
Methods: 111 eyes of 111 patients were examined by means of Octopus-perimetry and topometry of 10° image sector with the Heidelberg Retina Tomograph (HRT). Except of an age-related collectve of nomal probationeers we studied patients with localized (group A) and comprehensive (group C) visual field losses superior and inferior (groups B and D) to the horizontal line, respectively.
Results: The averaged rim area in the temporal upper octant was 0.187±0.043mm2 for normal persons and 0.134±0.041mm2, 0.092±0.045mm2, 0.109±0.042mm2 and 0.087±0.043mm2 for groups A, B, C and D, respectively. In spite of the groups with comprehensive visual field losses including more than one quadrant (groups C and D) differences were statistically significant, U-test of Mann and Whitney, p<0.05. Only the control group as well as the groups with visual field losses inferior to the horizontal line showed a significant correlation between rim area of the temporal superior (RFTS) and the temporal inferior (RFTI) octant, Searmans rank correlation, p<0.01. The groups A and B with localized visual field damage showed a significant correlation between RFTS and mean defect MD of Octopus-perimetry. There was a very strong correlation between the examined group and the evaluated parameters RFTS, RFTI, MD and CPSD, p< 0.001.
Conclusions: Patients with glaucomatoous altered optic nerve head show a significant reduction of rim area in the temporal superior and inferior octants in comparison with normal probationeers, corresponding to visual field loss findings.
Dept. of Ophthalmology, University of Heidelberg, INF 400, D-69120 Heidelberg