title: Pupil responses derived from outer and inner retinal photoreception are normal in patients with hereditary optic neuropathy.
abstract: We compared the pupil responses originating from outer versus inner retinal photoreception between patients with isolated hereditary optic neuropathy (HON, n = 8) and healthy controls (n = 8). Three different testing protocols were used. For the first two protocols, a response function of the maximal pupil contraction versus stimulus light intensity was generated and the intensity at which half of the maximal pupil contraction, the half-max intensity, was determined. For the third protocol, the pupil size after light offset, the re-dilation rate and re-dilation amplitude were calculated to assess the post-light stimulus response. Patients with HON had bilateral, symmetric optic atrophy and significant reduction of visual acuity and visual field compared to controls. There were no significant mean differences in the response curve and pupil response parameters that reflect mainly rod, cone or melanopsin activity between patients and controls. In patients, there was a significant correlation between the half-max intensity of the red light sequence and visual field loss. In conclusion, pupil responses derived from outer or inner retinal photoreception in HON patients having mild-to moderate visual dysfunction are not quantitatively different from age-matched controls. However, an association between the degree of visual field loss and the half-max intensity of the cone response suggests that more advanced stages of disease may lead to impaired pupil light reflexes.
authors.affiliation: Department of Ophthalmology, University of Lausanne, Fondation Asile des Aveugles, Hôpital Ophtalmique Jules Gonin, Avenue de France 15, 1004 Lausanne, Switzerland. Electronic address: aki.kawasaki@fa2.ch.
authors.forename: Aki
authors.initials: A
authors.lastname: Kawasaki
authors.affiliation: Department of Ophthalmology, University of Lausanne, Fondation Asile des Aveugles, Hôpital Ophtalmique Jules Gonin, Avenue de France 15, 1004 Lausanne, Switzerland. Electronic address: sylvie.collomb@hotmail.com.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Collomb
authors.affiliation: Department of Ophthalmology, University of Lausanne, Fondation Asile des Aveugles, Hôpital Ophtalmique Jules Gonin, Avenue de France 15, 1004 Lausanne, Switzerland. Electronic address: lorette.leon@fa2.ch.
authors.forename: Lorette
authors.initials: L
authors.lastname: Léon
authors.affiliation: Solar Energy and Building Physics Laboratory, ENAC, Swiss Federal Institute of Technology Lausanne, Station 18, 1015 Lausanne, Switzerland. Electronic address: mirjam.munch@epfl.ch.
authors.forename: Mirjam
authors.initials: M
authors.lastname: Münch
mesh_terms: D000328:Adult; D003623:Dark Adaptation; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D015418:Optic Atrophies, Hereditary / Q000503:physiopathology*; D011680:Pupil / Q000502:physiology*; D012025:Reflex, Pupillary / Q000528:radiation effects; D012165:Retinal Ganglion Cells / Q000378:metabolism; D055211:Retinal Photoreceptor Cell Inner Segment / Q000502:physiology*; D055214:Retinal Photoreceptor Cell Outer Segment / Q000502:physiology*; D017299:Rod Opsins / Q000378:metabolism; D055815:Young Adult; D000099210:Melanopsin
chemical_list: D017299:Rod Opsins; D000099210:Melanopsin
keywords: hereditary optic neuropathy; intrinsically photosensitive retinal ganglion cells; melanopsin; pupil; pupil light reflex