title: Optoelectrophysiological stimulation of the human eye using fundus-controlled silent substitution technique.
abstract: We design, characterize, and apply a novel optoelectrophysiological setup for a fundus-controlled silent substitution technique that accounts for interindividual variability in retina morphology and simultaneously monitors the stimulation site under investigation. We connect a digital color liquid crystal on silicon projector, an electron-multiplying imager, and a light-emitting diode to a fundus camera. The temporal and spatial characterization reveal a maximal contrast loss of 7% for the highest stimulation frequency (30 Hz) and maximum cutoff spatial frequencies of ∼120 cycles∕deg. Two silent substitution flash sequences are applied to modulate selective activity in the short-wavelength-sensitive cone (S-cone) and combined long- and middle-wavelength-sensitive cone (LM-cone) pathways. Simultaneously, the visual evoked potentials are recorded. The data are compared to the grand average responses from a previous study that employed standard computer-screen presentation and showed very good latency matches. All the volunteers in the present examination exhibit differences between the S-cone and LM-cone evoked potentials (parameters mean values: peak-to-peak amplitude, N1 latency, and P1 latency for S-cone∕LM-cone responses: 8 μV∕15 μV, 113 ms∕89 ms, 170 ms∕143 ms). We demonstrate that the developed optoelectrophysiological setup simultaneously provides imaging, functional stimulation, and electrophysiological investigation of the retina.
authors.affiliation: Ilmenau University of Technology, Institute of Biomedical Engineering and Informatics, Ilmenau, Thuringia, Germany. sascha.klee@tu-ilmenau.de
authors.forename: Sascha
authors.initials: S
authors.lastname: Klee
authors.forename: Dietmar
authors.initials: D
authors.lastname: Link
authors.forename: Patrick
authors.initials: P
authors.lastname: Bessler
authors.forename: Jens
authors.initials: J
authors.lastname: Haueisen
mesh_terms: D000328:Adult; D003119:Color Perception Tests / Q000295:instrumentation*; D003117:Color Vision Defects / Q000175:diagnosis*; D004569:Electroencephalography / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005246:Feedback; D005260:Female; D006801:Humans; D008297:Male; D019721:Ophthalmoscopes; D010775:Photic Stimulation / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity