Electrodiagnosis of dichromacy

Author(s)

Salgueiro Barboni, Mirella Telles ^{[1, 2]} ; Hauzman, Einat ^{[3, 2]} ; Nagy, Balazs Vince ^{[4, 2]} ; Gomes Martins, Cristiane Maria ^[2] ; Aher, Avinash J. ^[5] ; Tsai, I, Tina ; Oliveria Bonci, Daniela Maria ^{[3, 2]} ; Ventura, Dora Fix ^{[3, 2]} ; Kremers, Jan ^{[6, 7]}

Affiliation

^[1] Semmelweis Univ, Dept Ophthalmol, Budapest - Hungary

^[2] Univ Sao Paulo, Dept Expt Psychol, Av Prof Mello Moraes 1721, BR-05508030 Sao Paulo - Brazil

^[3] Inst Israelita Ensino & Pesquisa Albert Einstein, Sao Paulo - Brazil

^[4] Budapest Univ Technol & Econ, Dept Mechatron Opt & Engn Informat, Budapest - Hungary

^[5] Univ Hosp, Dept Ophthalmol, Erlangen - Germany

^[6] Tsai, Tina, I, Univ Hosp, Dept Ophthalmol, Erlangen - Germany

^[7] FAU Erlangen Nurnberg, Dept Biol Anim Physiol, Erlangen - Germany

• Document type: Journal article
• Source: VISION RESEARCH; v. 158, p. 135-145, MAY 2019.
• Web of Science Citations: 0

Abstract

Retinal and cortical signals initiated by a single cone type can be recorded using the spectral compensation (or silent substitution) paradigm. Moreover, responses to instantaneous excitation increments combined with gradual excitation decreases are dominated by the response to the excitation increment. Similarly, the response to a sudden excitation decrement dominates the overall response when combined with a gradual excitation increase. Here ERGS and VEPs were recorded from 34 volunteers {[}25.9 +/- 10.4 years old (mean +/- SD); 25 males, 9 females] to sawtooth flicker (4 Hz) stimuli that elicited L- or M-cone responses using triple silent substitution. The mean luminance (284 cd/m(2)) and the mean chromaticity (x = 0.5686, y = 0.3716; CIE 1931 color space) remained constant and thus the state of adaptation was the same in all conditions. Color discrimination thresholds along protan, deutan, and tritan axes were obtained from all participants. Dichromatic subjects were genetically characterized by molecular analysis of their opsin genes. ERG responses to L-cone stimuli were absent in protanopes whereas ERG responses to M-cone stimuli were strongly reduced in deuteranopes. Dichromats showed generally reduced VEP amplitudes. Responses to cone-specific stimuli obtained with standard electro-physiological methods may give the same classification as that obtained with the Cambridge Colour Test and in some cases with the genetic analysis of the L- and M-opsin genes. Therefore, cone-specific ERGS and VEPs may be reliable methods to detect cone dysfunction. The present data confirm and emphasize the potential use of cone specific stimulation, combined with standard visual electrodiagnostic protocols. (AU)

• FAPESP's process: 14/26818-2 - Development and implementation of visual evaluation methods: clinical applications and animal models
• Grantee: Dora Selma Fix Ventura
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 16/22007-5 - Optimization of the visual functional ability in patients with macular diseases using visual training programs
• Grantee: Mirella Telles Salgueiro Barboni
• Support Opportunities: Scholarships abroad - Research
• FAPESP's process: 16/04538-3 - Dystrophin and the human visual system: study of the visual phenotypes of Duchenne muscular dystrophy patients
• Grantee: Dora Selma Fix Ventura
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/25743-9 - Expression of opsins and melanopsins in snakes' retinas: molecular genetics and immunohistochemistry
• Grantee: Einat Hauzman
• Support Opportunities: Scholarships in Brazil - Post-Doctoral