الفهرس Only 14 pages are availabe for public view
 |  | from | 123 |  |  |
| | | from | 123 | | |
Abstract
Glaucoma is defined as an optic neuropathy that is characterized by specific structural findings in the optic disc and specific functional deficits detected by automated visual field testing. Raised intraocular pressure (IOP) is still recognized as an important risk factor, but it is not a defining characteristic of the disease (Foster at al, 2002). There are 3 levels of evidence that can be used for the diagnosis of glaucoma in cross-sectional surveys (Foster at al, 2002). 1. Vertical C/D ratio (VCDR) or VCDR asymmetry _97.5th percentile of the normal population plus visual field defect compatible with glaucoma 2. Severely damaged disc (VCDR _99.5th percentile of the normal population) plus no reliable visual field obtainable 3. No view of optic disc plus IOP _99.5th percentile of the normal population or evidence of previous filtering surgery Glaucoma can be classified according to the mechanism of damage into open angle and angle closure glaucoma. These can be further classified into primary or secondary to an ocular pathology such as neovascularization, trauma, uveitis and lens related problems (Foster at al, 2002)