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Abstract #8387 Published in IGR 5-1
Occurrence of catecholaminergic nerve fibers in the human uveoscleral tissue in conditions of normal and raised intraocular pressure
Cavallotti C; Pescosolido N; Artico M; Pacella E; Cavallotti DInternational Ophthalmology 2002; 24: 133-139
The distribution of catecholaminergic nerve fibers (CNF) in human uveoscleral tissue was studied in six human eyes with normal intraocular pressure (IOP) and in five eyes with increased pressure. The eyes with increased pressure had no visual field alterations and the patients did not have any glaucoma-related optic neuropathies. The amount of norepinephrine in these structures was also analyzed. Catecholaminergic nerve fibers were detected by means of fluorescence microscopy and were counted using the quantitative analysis of images. The results demonstrate that the occurrence of catecholaminergic nerve fibers (expressed in Conventional Units = C.U.) in human uveoscleral tissue is 15.4 ± 1.6 C.U. in eyes with normal IOP. In eyes with increased IOP, these values were 12.2 ±1.2 C.U. Moreover, the amount of norepinephrine in tissue homogenates of the same eyes was evaluated and found to be 21.7 ±1.3 μg/g tissue fresh weight of the human uveoscleral tissue in eyes with normal IOP. This value decreased to 18.8 ± 1.1 μg/g tissue fresh weight in the same tissue in conditions of raised IOP. In these experiments, the small number of eyes examined made it difficult to draw general conclusions. However, the role of human uveoscleral tissue was emphasized by the rich catecholaminergic innervation. A decrease of catecholaminergic nerve fibers and norepinephrine occurs when IOP is elevated. The modifications of these parameters, involved in the sympathetic control of aqueous humor outflow, may support the hypothesis of a possible relevant role for the human uveoscleral tissue in different pathological conditions.
Dr. C. Cavallotti, Department of Cardiovascular and Respiratory Science, University of Rome La Sapienza, Via Borelli 50, 00161 Rome, Italy. cavallotti@uniroma1.it
Classification:
2.8 Iris (Part of: 2 Anatomical structures in glaucoma)
2.9 Ciliary body (Part of: 2 Anatomical structures in glaucoma)
