Controversies in the management of neuromyelitis optica spectrum disorder.

Introduction: Neuromyelitis optica spectrum disorders (NMOSD) are autoimmune diseases of the central nervous system mainly involving the optic nerves and spinal cord. Many advances have been made in understanding the immunopathology of NMOSD and related clinical classification, nevertheless, open issues in management and effective therapeutic approaches still remain. Areas covered: In this article, the authors reviewed and discussed the scientific evidence in pathogenesis and pharmacological therapy of NMOSD addressing the more recent advances in new biological treatment option and therapeutic strategy that may help to improve management of this condition. Expert opinion: Despite current immunopathogenic evidence, NMOSD management represents a challenge due to the poor-validated diagnostic, prognostic and therapeutic biomarkers. A tailored approach is mandatory to improve the management of the different disease clinical settings.

Re-evaluation and quantification of the different sources of nerve fibres supplying the rat eye.

The denervation and/or the removal of peripheral nerve ganglia are useful surgical techniques for studying the source and distribution of peripheral nerves in all organs, including the eye. The amount and distribution of the remaining nerve fibres supplying the eye (after sectioning of various types of nervous fibres and/or removal of nerve ganglia) were evaluated in the rat. Male Sprague-Dawley rats were anaesthetized and one or more of the following nervous tissues were removed: superior cervical ganglion, main ciliary ganglion, pterygopalatine ganglion, trigeminal ganglion and the ophthalmic-maxillary nerve. In some animals, chemical sympathectomy was performed by administration of 6-OH dopamine. The eyes were cut in serial sections, but only three regions (cornea, iris and choroid) were harvested and submitted for various nerve fibre staining techniques. The results were quantified and statistically analysed. Superior cervical ganglionectomy and/or chemical sympathectomy induced the destruction of almost all the catecholaminergic nerve fibres in the three examined regions of the rat eye. Removal of the ciliary ganglion (partial parasympathectomy) caused the destruction of about 60% of the cholinergic nerve fibres of the same regions of the rat eye, while subtotal parasympathectomy destroyed about 80% of the cholinergic nerve fibres. Surgical transsection of the ophthalmo-maxillary nerve or the removal of the trigeminal ganglion led to a degeneration of almost all sensitive nerve fibres of the three examined regions of the rat eye. The denervation experiments confirmed the presence of the different types of nerve fibres (sympathetic, parasympathetic and sensitive) in the three studied structures of the rat eye.

Glycosaminoglycans in human trabecular meshwork: age-related changes.

Glycosaminoglycans play a central role in maintaining the normal outflow resistance in the human trabecular meshwork. We evaluated the possible morphological, histochemical and morphometrical age-related changes in glycosaminoglycans of the trabecular meshwork. Small human samples were drawn from 24 eyes after exitus from young and old humans. Samples were harvested from the anterior chamber of the eye, without any aesthetic damage for the face. They were divided into three fragments, each used for morphological, histochemical and ultrastructural staining. Quantitative analysis of images was performed to evaluate morphometrical data that were statistically analysed. Our findings demonstrate the following age-related changes: (1) deposition of fibrous granular material in the trabecular meshwork; (2) increased electron density of the structures; (3) strong decrease in the hyaluronic acid content, and (4) increase in sulphated proteoglycans. Glycosaminoglycans of human trabecular meshwork undergo age-related changes, as demonstrated by our morphological, histochemical and morphometrical results.