[The effect of acute and persistent ocular hypertension on ultrastructure in rabbit tissues of anterior chamber angle].

Sclero-circular compression operation was performed on 20 unilateral rabbit eyes to make a model of intraocular hypertension which persisted for 3 days, 1, 3 and 4 weeks respectively in 4 groups of rabbits and another 4 rabbits were used as normal controls. The trabecular meshwork and aqueous plexus of the experimental rabbits' eyes were examined under transmission electron microscope on various post-operative days: 3 days, 1, 3 and 4 weeks. It was discovered that the corneo-scleral and uveal trabecular meshworks were obviously distended and their core collagenous and elastoid fibers were hyperplastic, the phenomenon being more marked with the prolongation of the duration of the intraocular hypertension. Many endothelial cells were detached from the trabecular cords and freely located in the intertrabecular spaces. Persistent hyperplasia of collagenous fibers and accumulation of extracellular plague materials occurred in the endothelial meshwork, leading to its compactness. The giant vacuoles in the endothelial cells lining the inner wall of the canal of aqueous plexus were gradually decreased in number and the cytoplasm of the cells became attenuated and some fenestrations appeared. The results show that the main site of the resistance of the aqueous outflow occurring during intraocular hypertension is at endothelial meshwork and the above experimental morphological changes are quite similar to those of glaucoma patients.