Assessment of Color Vision Anomalies with the VEP

We have employed the VEP in an effort to develop an objective and sensitive technique for studying the basic mechanisms underlying color vision as well as those underlying color vision anomalies. In addition to the common congenital color defiicits, we have applied this technique to a wide variety of acquired color vision anomalies. For example, many ocular diseases, including glaucoma, diabetic retinopathy, retinitis pigmentosa and central serous choroidopathy are characterized by a loss of short wavelength sensitivity (Marre and Marre, 1972; Sandberg and Berson, 1977; Adams et al., 1982; Adams et al., 1987; Greenstein et al. 1989). In many cases, color vision changes can occur prior to overt symptoms as evidenced from conventional clinical tests. Thus, measures which reveal the selective losses would be advantageous for early detection and treatment of such diseases. Most previous studies involved psychophysical thresholds; few have attempted to objectively quantify color losses at suprathreshold levels. In addition, a unifying framework within which selective pathway losses can be compared has been lacking.