PATHOPHYSIOLOGY OF GLAUCOMA

The pathophysiology of intraocular pressure elevation-whether due to open-angle or to angle-closure mechanisms-will be discussed as each disease entity is considered (see below). The effects of raised intraocular pressure within the eye are common to all forms of glaucoma, their manifestations being influenced by the time course and magnitude of the rise in intraocular pressure.

The major mechanism of visual loss in glaucoma is ganglion cell atrophy, leading to thinning of the inner nuclear and nerve fiber layers of the retina and axonal loss in the optic nerve. The optic disk becomes atrophic, with enlargement of the optic cup (see below). The iris and ciliary body also become atrophic, and the ciliary processes show hyaline degeneration.

In acute angle-closure glaucoma, the intraocular pressure reaches 60-80 mm Hg, resulting in ischemic damage to the iris with associated corneal edema and optic nerve damage.

10.1036/1535-8860.ch11

Customer Privacy Policy Copyright ©2002-2003 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use and Notice. Additional credits and copyright information. For further information about this site contact tech_support@accessmedicine.com. Last modified: November 08, 2002 .