Using Electroretinography for Glaucoma Diagnosis

Abstract

It has been suggested that up to 35% of retinal ganglion cells (RGCs) are lost before visual field defects become apparent.1 Automated perimetric testing is the current gold standard for diagnosis.1 This concept led to the theory of an “RGC reserve” with structural damage preceding functional loss in early glaucoma. However, as more advanced techniques for assessing both RGC structure and function have been developed, evidence has arisen indicating that RGC dysfunction may precede the structural loss of these cells. This suggests the potential for more effective early detection techniques. Digital imaging techniques (e.g., retinal tomography, scanning polarimetry, and optical coherence tomography) that attempt to detect structural changes in the optic nerve and RGC nerve fiber layer have become very popular as complimentary to functional perimetric testing for early glaucoma. In this chapter, however, we will discuss developments regarding electrophysiological measures of RGC loss or dysfunction to detect and monitor glaucoma. Glaucoma is a disease in which such early detection and early therapeutic intervention are critical for preventing progression and loss of vision.