Abstract
Abstract: :
Purpose: The lamina cribrosa as bottom of the optic cup in the optic nerve head faces the intraocular space on its interior side and the optic nerve and the cerebrospinal fluid space (CSF) on its outer surface. Since the lamina cribrosa acts as a pressure barrier between the intraocular space and the retrobulbar space of the optic nerve, it is exposed to a pressure gradient. It may thus have importance for the pathogenesis of ocular diseases related to the intraocular pressure and cerebrospinal fluid pressure, such as the glaucomas. The purpose of the present study was to study the anatomical relationship between the lamina cribrosa and the cerebrospinal fluid space in the retrobulbar region. Methods: The study included 20 globes enucleated for malignant melanoma (n=10) with a normal optic nerve, or enucleated due to painful absolute secondary angle-closure glaucoma (n=10). For all eyes, anterior-posterior PAS stained histological sections through the center of the cornea and the center of the optic disc were available. These sections were morphometrically evaluated. Results: In the normal eyes and the glaucoma eyes, the part of the lamina cribrosa exposed to the CSF space was located close to the optic disc border. This lamina cribrosa part was significantly (P<0.01) wider in the glaucoma eyes than in the normal eyes. Contrary, the shortest distance between the intraocular space and the CSF space, and the thickness of the lamina cribrosa were significantly (P<0.001) longer and greater in the normal eyes than in the glaucoma eyes. Conclusions: The measurements of the lamina cribrosa including the measures of the anatomical relationship between the intraocular space and the CSF space differ significantly between normal eyes and glaucoma eyes. These data may be of importance for the pathogenesis of glaucomatous optic neuropathy including the normal pressure glaucomas.
Keywords: optic disc • anatomy • intraocular pressure