What is the real cause of glaucoma?

摘要

Glaucoma can be defined as an optic nerve disease with typical morphological and functional changes . There are many risk factors associated with this neuropathy such as central corneal thickness (CCT), age, race, sex, intraocular pressure (IOP), optic nerve changes, refractive error, systemic diseases, family history and trauma . There are many observations, which can hardly be explained by direct effect of increasing IOP. One of them is that as many as 1 /6 of the patients with glaucomatous damage do not have increased IOP even with repeated testing. Also, Ocular hypertension is 10 times more common than glaucomatous neuropathy. Another conflict is that the presence and the progression of glaucomatous damage are weakly related to the level of IOP . These conflicts led us to find another factor more than IOP to describe development of glaucoma. CCT and scleral thickness have a moderately positive correlation . So, we use scleral thickness instead of CCT below. The incidence of glaucomatous damage in the same IOP conditions varies between different races and sexes therefore, scleral thickness and internal radius of the eye globe which also depend on race and sex can be considered as the factors that are responsible for glaucoma in theses conditions. In the eye globe as an idealized spherical shell, stress depends on IOP, inner radius of the eye globe, and scleral thickness .