27. Garwaqy-Heat DF, Wollstein G, Hitchings RA. Aging changes of the optic nerve head in relation to open angle glaucoma. Brit J Ophthtalmol. 1997; 81: 840-845

27. Garwaqy-Heat DF, Wollstein G, Hitchings RA. Aging changes of the optic nerve head in relation to open angle glaucoma. Brit J Ophthtalmol. 1997; 81: 840-845