title: Differential monocular vs. binocular pupil responses from melanopsin-based photoreception in patients with anterior ischemic optic neuropathy.
abstract: We examined the effect of anterior ischemic optic neuropathy (AION) on the activity of intrinsically photosensitive retinal ganglion cells (ipRGCs) using the pupil as proxy. Eighteen patients with AION (10 unilateral, 8 bilateral) and 29 age-matched control subjects underwent chromatic pupillometry. Red and blue light stimuli increasing in 0.5 log steps were presented to each eye independently under conditions of dark and light adaptation. The recorded pupil contraction was plotted against stimulus intensity to generate scotopic and photopic response curves for assessment of synaptically-mediated ipRGC activity. Bright blue light stimuli presented monocularly and binocularly were used for melanopsin activation. The post-stimulus pupil size (PSPS) at the 6th second following stimulus offset was the marker of intrinsic ipRGC activity. Finally, questionnaires were administered to assess the influence of ipRGCs on sleep. The pupil response and PSPS to all monocularly-presented light stimuli were impaired in AION eyes, indicating ipRGC dysfunction. To binocular light stimulation, the PSPS of AION patients was similar to that of controls. There was no difference in the sleep habits of the two groups. Thus after ischemic injury to one or both optic nerves, the summated intrinsic ipRGC activity is preserved when both eyes receive adequate light exposure.
authors.affiliation: 1] Department of Ophthalmology, University of Lausanne, Hôpital Ophtalmique Jules Gonin and Asile des Aveugles Foundation, Avenue de France 15, Lausanne, Switzerland 1004 [2] Department of Ophthalmology, Medical School of the University of Crete, Greece Eye Clinic, University Hospital of Heraklion, Crete Greece, 71013 Voutes Heraklion Crete, Greece.
authors.forename: Chrysanthi
authors.initials: C
authors.lastname: Tsika
authors.affiliation: Department of Ophthalmology, University of Lausanne, Hôpital Ophtalmique Jules Gonin and Asile des Aveugles Foundation, Avenue de France 15, Lausanne, Switzerland 1004.
authors.forename: Sylvain V
authors.initials: SV
authors.lastname: Crippa
authors.affiliation: Department of Ophthalmology, University of Lausanne, Hôpital Ophtalmique Jules Gonin and Asile des Aveugles Foundation, Avenue de France 15, Lausanne, Switzerland 1004.
authors.forename: Aki
authors.initials: A
authors.lastname: Kawasaki
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D018917:Optic Neuropathy, Ischemic / Q000378:metabolism / Q000503:physiopathology*; D010786:Photoreceptor Cells / Q000378:metabolism / Q000473:pathology*; D011680:Pupil / Q000502:physiology; D012165:Retinal Ganglion Cells / Q000378:metabolism / Q000473:pathology*; D017299:Rod Opsins / Q000502:physiology; D012890:Sleep / Q000502:physiology; D011795:Surveys and Questionnaires; D015348:Vision, Binocular; D015349:Vision, Monocular; D000099210:Melanopsin
chemical_list: D017299:Rod Opsins; D000099210:Melanopsin