Visual Field Defects in Glaucoma

Abstract

Glaucoma, is a group of diseases caused by several factors characterized by progressive, irreversible structural changes at the optic disc and retinal nerve fiber layer, and the functional loss in the visual field. The primary purpose of the ophthalmologist is to determine the level of the loss of retinal nerve fibers during the glaucoma diagnosis and the follow-up; and to prevent and to stop the progression of nevre fiber loss. Conventional methods used for glaucoma diagnosis and follow-up are intraocular pressure measurements, subjective examination of the optic nerve head and visual field test. Intraocular pressure measurement is not enough alone for glaucoma diagnosis, because it shows diurnal variation, individual differences and it is only one of several risk factors. Subjective evaluation of the optic nerve head, the interobserver variability of the assessment and individual differences of optic disc size and type should reduce its reliability. The visual field test is one of the indispensable assessment methods. For today, it is still the gold standard method for the diagnosis and the follow-up of glaucoma, and to determine clinically the visual function. Even if it is a subjective test, and the short-and long-term fluctuations should decrease the reliability of the test. In this article, the types of visual field loss in glaucoma are discussed in the light of the current literature. © 2012 OMU.