98th Annual Meeting DOG 2000

V 663

Localisation of Myocilin/TIGR in eyes with primary open-angle glaucoma

E. R. Tamm, D. Konz, C. Flügel-Koch

Introduction: Mutations in the myocilin/TIGR gene are responsible for GLC1A-linked autosomal-dominant primary open-angle glaucoma (POAG). To study the role of myocilin/TIGR in other forms of POAG, we investigated the localization of myocilin/TIGR in eyes from donors with ocular hypertension and POAG by immunohistochemistry and compared that with eyes from normal donors.

Methods: Both eyes of 16 patients with POAG and ocular hypertension (OHT), and from 6 normal donors were fixed in 10 % formalin or 4 % paraformaldehyde and embedded in paraffin. Patient data were available from all eyes. Immunohistochemistry was performed with specific antibodies against human myocilin/TIGR and FITC-conjugated secondary antibodies.

Results: Immunolabeling for myocilin/TIGR in iris, cornea, sclera, ciliary body and retina in eyes with POAG did not show obvious differences to that of normal eyes. In the trabecular meshwork, intense staining was seen in the cribriform area of some eyes with POAG. In the lamina cribrosa of all eyes, positive staining was seen in optic nerve axons and astrocytes. This staining was significantly weaker in POAG and OHT than in normal eyes.

Discussion: Differences in myocilin/TIGR expression in trabecular meshwork and lamina cribrosa could contribute to the pathological process in POAG.

Supported by the Glaucoma Research Eye Donor Network of the Glaucoma Research Foundation and the DFG (Ta 115/11-1).
Department of Anatomy of the Friedrich Alexander University Erlangen-Nürnberg, Universitätsstr. 19, D-91054 Erlangen