Halo 194 (Jan 2018)
Glaucoma
Abstract
Glaucoma is defined as a chronical progressive optical neuropathy with morphological (excavation of the optic nerve head) and functional disturbances (defects in the field of vision). According to the WHO data 60 million people have been diagnozed with glaucoma worldwide, 4 million of whom are blind. Clinical glaucoma is classified as: primary, secondary and congenital. Intraocular pressure (IOP) is the fluid pressure inside the eye. Normal IOP is between 10 and 22 mmHg. It depends on the homeostasis between production and elimination of eye fluid. There are three mechanisms for production of eye fluid: diffusion, ultrafiltration and active secretion. Primary open angle glaucoma or simplex glaucoma develops due to slow clogging of drainage channels in the wall of the angle. Primarily, the normal ability of the eye to eliminate more than 2.2 microliters of fluid per minute is reduced. Risk factors for open angle glaucoma include: raised intraocular pressure, age of the patient, positive family history, race, central cornea thickness, pseudoexfoliation, miopia and vascular factors (local and systemic). Raised intraocular pressure is still considered to be the most important risk factor for glaucoma development.
