98th Annual Meeting DOG 2000

P 366

Localization of early perimetric functional loss in preperimetric open angle glaucoma (preOAG)

A. G. M. Jünemann, P. Martus, A. Bergua, M. Wisse, M. Korth

Purpose: The course of functional damage in open-angle glaucoma (OAG) can be asymmetric between right and left eyes of one patient. The normal visual field in preOAG with perimetric OAG in the contralateral eye should be more advanced than in bilateral preOAG. Thus the diagnosis of perimetric open angle glaucoma in the contralateral eye can be used as a model for early functional damage in open-angle glaucoma without perimetric defects in white-on-white perimetry (preOAG). The aim of this study was the localization of early visual field alteration using retinal nerve fiber bundle (RNFB) analysis.

Method: 210 eyes of 105 patients with bilateral preOAG (age: 48.7±11.8 years, MD: 0.61±1.27 dB, CLV: 1.63±2.11 dB²) and 24 eyes of 24 patients with preOAG in one eye and OAG in the contralateral eye were included (age: 57.1±11.1 years, MD: 1.14±1.04 dB, CLV: 2.31±3.6 dB²). Critera for preOAG: glaucomatous optic disc (stereo color slides), normal visual field (Octopus G1 program, MD, CLV, Bebié-curve) and IOP>21. Critera for OAG: glaucomatous optic disc, pathologic visual field and IOP > 21 mmHg. Groups were matched concerning age and IOP. Quantitative evaluation of optic disc by planimetry of stereo color photographs. Visual fields analysis: Global MD and local MD of 10 clusters of retinal nerve fiber bundles (RNFB 1-10) according to Weber and Ulrich (1). Statistics: Receiver operating characteristics (ROC) analysis: AZ score (area under the ROC-curves) and p-values (Mann-Whitney-test).

Results: MD: 0.64 (p=0.021), RNFB 3: 0.646 (p=0.019), RNFB 7: 0.647 (p=0.018), RNFB 8: 0.692 (p=0.002), RNFB 9: 0.667 (p=0.009), RNFB 10: 0.664 (p=0.002). No significant (p>0.1) differences in CLV, RNFB1, 2, 4, 5, 6 between both groups.

Discussion: Early functional damage in normal visual fields are located in the Bjerrum area. The proposed model is useful for the analysis of early functional damage in glaucoma. The nerve fiber bundle related visual field analysis is helpful in localization and quantification of minimal differences in visual fields.

1) Weber J, Ulrich H. Perimetric nerve fiber bundle net. Int Ophthalmol 1991; 15: 193-200
Supported by DFG grant (SFB 539)
Department of Ophthalmology, University Erlangen-Nuernberg, Schwabachanlage 6, D-91054 Erlangen