title: Assessing retinal structure in complete congenital stationary night blindness and Oguchi disease.
abstract: OBJECTIVE
  To examine retinal structure and changes in photoreceptor intensity after dark adaptation in patients with complete congenital stationary night blindness and Oguchi disease.
  
  
  METHODS
  Prospective, observational case series.
  
  
  METHODS
  We recruited 3 patients with complete congenital stationary night blindness caused by mutations in GRM6, 2 brothers with Oguchi disease caused by mutations in GRK1, and 1 normal control. Retinal thickness was measured from optical coherence tomography images. Integrity of the rod and cone mosaic was assessed using adaptive optics scanning light ophthalmoscopy. We imaged 5 of the patients after a period of dark adaptation and examined layer reflectivity on optical coherence tomography in a patient with Oguchi disease under light- and dark-adapted conditions.
  
  
  RESULTS
  Retinal thickness was reduced in the parafoveal region in patients with GRM6 mutations as a result of decreased thickness of the inner retinal layers. All patients had normal photoreceptor density at all locations analyzed. On removal from dark adaptation, the intensity of the rods (but not cones) in the patients with Oguchi disease gradually and significantly increased. In 1 Oguchi disease patient, the outer segment layer contrast on optical coherence tomography was 4-fold higher under dark-adapted versus light-adapted conditions.
  
  
  CONCLUSIONS
  The selective thinning of the inner retinal layers in patients with GRM6 mutations suggests either reduced bipolar or ganglion cell numbers or altered synaptic structure in the inner retina. Our finding that rods, but not cones, change intensity after dark adaptation suggests that fundus changes in Oguchi disease are the result of changes within the rods as opposed to changes at a different retinal locus.
authors.affiliation: Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Pooja
authors.initials: P
authors.lastname: Godara
authors.forename: Robert F
authors.initials: RF
authors.lastname: Cooper
authors.forename: Panagiotis I
authors.initials: PI
authors.lastname: Sergouniotis
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Diederichs
authors.forename: Megan R
authors.initials: MR
authors.lastname: Streb
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Genead
authors.forename: J Jason
authors.initials: JJ
authors.lastname: McAnany
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Webster
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Moore
authors.forename: Adam M
authors.initials: AM
authors.lastname: Dubis
authors.forename: Maureen
authors.initials: M
authors.lastname: Neitz
authors.forename: Alfredo
authors.initials: A
authors.lastname: Dubra
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Stone
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Fishman
authors.forename: Dennis P
authors.initials: DP
authors.lastname: Han
authors.forename: Michel
authors.initials: M
authors.lastname: Michaelides
authors.forename: Joseph
authors.initials: J
authors.lastname: Carroll
mesh_terms: D000293:Adolescent; D000328:Adult; D003623:Dark Adaptation / Q000502:physiology; D015785:Eye Diseases, Hereditary / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D051606:G-Protein-Coupled Receptor Kinase 1 / Q000235:genetics; D040181:Genetic Diseases, X-Linked / Q000175:diagnosis* / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009216:Myopia / Q000175:diagnosis* / Q000235:genetics; D009755:Night Blindness / Q000175:diagnosis* / Q000235:genetics; D009887:Ophthalmoscopy; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology*; D016133:Polymerase Chain Reaction; D011446:Prospective Studies; D017470:Receptors, Glutamate / Q000235:genetics; D051245:Retinal Bipolar Cells / Q000473:pathology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014785:Vision, Ocular; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: C576075:GRM6 protein, human; D017470:Receptors, Glutamate; D051606:G-Protein-Coupled Receptor Kinase 1; C496764:GRK1 protein, human