Visual Psychophysics / Physiological Optics - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group – Visual Psychophysics / Physiological Opticscones but may not be immune to rod hue biases. Here, we determinewhich biases are found for foveal stimuli presented on a CRT display.Methods: On a CRT display, a 1-s duration test disk of 0.5°, 1.0°, or2.0° diameter alternated with a 3-s duration array of 0.25° fixationdots placed 4° from fixation, all on a black background. Sevenobservers adjusted the hue of the test disk around the RGB phosphormixture triangle, to yield each of the 4 unique hues, Ured, Ugreen,Ublue, and Uyellow. Light levels ranged from 0.05 - 0.17 (CIE2°) or0.08 - 0.03 (CIE10°) cd/m 2 .Results: 1°-2°-diameter foveal test disks (a) produced rod green biasat Uyellow for most observers, (b) favored rod green bias at Ublueover the rod red biases shown in prior extrafoveal studies, and (c)produced less consistent rod hue biases at Ured and Ugreen. 0.5°diameterfoveal test disks produced no consistent rod hue biasesacross observers. Remaining rod hue biases tended to be small butsome observers showed larger idiosyncratic effects for a specificunique hue.Conclusions: 1°-2°-diameter foveal disks on a CRT displayproduced relatively strong rod green bias, mediated by rod interactionwith L & M cones, presumably in midget/parvo pathways. Incontrast, these foveal stimuli disadvantaged rod influence mediatedby S cones, presumably in small-bistratified/konio pathways,producing only weak/inconsistent rod red bias at Ublue and rod bluebias at Ured and Ugreen. 0.5°diameter disks disadvantaged all rodhue biases, but with individually idiosyncratic exceptions for someobservers.Commercial Relationships: Katharina G. Foote, None; Steven L.Buck, NoneProgram Number: 3024 Poster Board Number: C0187Presentation Time: 8:30 AM - 10:15 AMFundus-controlled two-color adaptometry with theMicroperimeter MP1Wadim Bowl, Birgit Lorenz. Department of Ophthalmology, Justus-Liebig-University, Giessen, Germany.Purpose: To provide fundus-controlled two-color adaptometry ofmesopic vision with an existing device without modifying the CEmarkedMicroperimeter MP1 itself. Rod and cone sensitivity can bemeasured and differentiated on defined retinal positions the examineris most interested in.Methods: An external filter holder was imposed on the objective lensof the MP1 (Nidek, Padova, Italy) and fitted with filters to modifybackground and stimulus intensity. Light output of the MP1 wasreduced by Schott RG780 and BG3 filters outside the instrument tocreate the stimulus colors red and blue, which were used alternatingin this examination. Absorption of infrared light by these filters islow thereby minimizing problems with fundus observation by thebuilt-in infrared camera system. After bleaching with a GanzfeldColorDome (Espion E2, Diagnosys LLC, Lowell, MA, USA) with aluminous intensity of 3000 cd/m2 for 5 minutes, twenty normalsubjects were investigated with a pattern covering 3 spots at theposterior pole of the retina (3 blue spots at 12° nasal; 3 red spots at 0°and 1°). The test was repeated every 3 minutes during the first 15minutes and every 5 minutes until 45 minutes of dark-adaptation.Thresholds were determined using a 200 ms red Goldmann IVstimulus and a blue Goldmann III stimulus employing the built-in 4-2strategy in a dark room.Results: In the first 5 minutes a slight increase of median lightincrement sensitivity (LIS) was measured for the red stimulus. Withfurther dark-adaptation, LIS to red stimuli remained at about 7 dB.For blue stimuli LIS increased considerably during the first tenminutes. With processing time sensitivity to blue stimuli reached aplateau at 15 dB. Both measurements showed typical characteristicsof dark-adaptation-curves.Conclusions: Two-color fundus-controlled adaptometry with acommercial MP1 without internal changes to the device provides aquick and easy examination of rod and cone function during darkadaptation at defined retinal loci. Under the mesopic lightingconditions chosen, LIS for blue stimuli is determined by the rodpathway. LIS for red stimuli is mediated by the cone pathway. Themethod should be helpful to identify rod vs. cone function in theposterior pole in early stages of retinal degenerations.Commercial Relationships: Wadim Bowl, None; Birgit Lorenz,Optos (F)Support: German Research Counsil (DFG LO457/10-1)Program Number: 3025 Poster Board Number: C0188Presentation Time: 8:30 AM - 10:15 AMColor Discrimination and Visual Perimetry Evaluation inMultiple Sclerosis and Neuromyelitis OpticaPhelipe A. Paixao 1, 2 , Lorena B. Botelho Vergara 1, 2 , Lucas Daniel A.Almeida Fernandes 1, 2 , Eliza Maria C. Lacerda 1, 3 , Givago S. Souza 1,3 , Hideraldo Luis Souza Cabeça 5 , Alexandre A. Rosa 2, 4 , Luiz CarlosL. Silveira 1, 3 . 1 Nucleo de Medicina Tropical, Universidade Federaldo Para, Belem, Brazil; 2 Instituto de Ciencias da Saude, UniversidadeFederal do Para, Belem, Brazil; 3 Instituto de Ciencias da Biologicas,Universidade Federal do Para, Belem, Brazil; 4 Hospital UniversitarioBettina Ferro de Souza, Universidade Federal do Para, Belem, Brazil;5 Neurologia, Hospital Ophir Loyola, Belem, Brazil.Purpose: To compare visual performance in color discrimination andvisual perimetry of patients with multiple sclerosis (MS) andneuromyelitis optica (NMO) with or without optic neuritis (ON).Methods: Patients with MS (9 subjects, 17 eyes, 37±9.7 years old)and with NMO (10 subjects, 18 eyes, 36.1±11.8 years old) werestudied with biomicroscopy, fundoscopy, and visual acuitymeasurements. Color vision was evaluated with the full test protocolof Colour Assesment and Diagnosis (CAD) Test. The diameter of thecircle with equivalent area of the color discrimination ellipses wasmeasured. Visual perimetry was evaluated by Central 30-2 ThresholdTest of the Humphrey Visual Field Analyzer. The two patient groupswere compared to each other and to an age- and gender-matchedcontrol group. Statistical analyses used: tolerance intervals, binomialtest, two-way ANOVA, α=0.05.Results: After the ophthalmologic evaluation, it was observed that 4eyes from patients with MS and 6 eyes from patients with NMO hadON. Color discrimination. 2/4 eyes from patients with MS and ONand 4/10 eyes from patients with MS without ON had colordiscrimination above the upper tolerance limit for controls. 1/6 eyesfrom patients with NMO and ON and 1/9 eyes from patients withNMO without ON had color discrimination above the upper tolerancelimit for controls. Regardless of ON presence, MS had significantlymore eyes with altered color discrimination results than NMO(p