title: Photoreceptor structure and function in patients with congenital achromatopsia.
abstract: OBJECTIVE
  To assess photoreceptor structure and function in patients with congenital achromatopsia.
  
  
  METHODS
  Twelve patients were enrolled. All patients underwent a complete ocular examination, spectral-domain optical coherence tomography (SD-OCT), full-field electroretinographic (ERG), and color vision testing. Macular microperimetry (MP; in four patients) and adaptive optics (AO) imaging (in nine patients) were also performed. Blood was drawn for screening of disease-causing genetic mutations.
  
  
  RESULTS
  Mean (± SD) age was 30.8 (± 16.6) years. Mean best-corrected visual acuity was 0.85 (± 0.14) logarithm of the minimal angle of resolution (logMAR) units. Seven patients (58.3%) showed either an absent foveal reflex or nonspecific retinal pigment epithelium mottling to mild hypopigmentary changes on fundus examination. Two patients showed an atrophic-appearing macular lesion. On anomaloscopy, only 5 patients matched over the entire range from 0 to 73. SD-OCT examination showed a disruption or loss of the macular inner/outer segments (IS/OS) junction of the photoreceptors in 10 patients (83.3%). Seven of these patients showed an optically empty space at the level of the photoreceptors in the fovea. AO images of the photoreceptor mosaic were highly variable but significantly disrupted from normal. On ERG testing, 10 patients (83.3%) showed evidence of residual cone responses to a single-flash stimulus response. The macular MP testing showed that the overall mean retinal sensitivity was significantly lower than normal (12.0 vs. 16.9 dB, P < 0.0001).
  
  
  CONCLUSIONS
  The current approach of using high-resolution techniques to assess photoreceptor structure and function in patients with achromatopsia should be useful in guiding selection of patients for future therapeutic trials as well as monitoring therapeutic response in these trials.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Genead
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Fishman
authors.forename: Jungtae
authors.initials: J
authors.lastname: Rha
authors.forename: Adam M
authors.initials: AM
authors.lastname: Dubis
authors.forename: Daniela Maria O
authors.initials: DM
authors.lastname: Bonci
authors.forename: Alfredo
authors.initials: A
authors.lastname: Dubra
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Stone
authors.forename: Maureen
authors.initials: M
authors.lastname: Neitz
authors.forename: Joseph
authors.initials: J
authors.lastname: Carroll
mesh_terms: D000293:Adolescent; D000328:Adult; D003119:Color Perception Tests; D003117:Color Vision Defects / Q000151:congenital / Q000235:genetics / Q000503:physiopathology*; D054815:Cyclic Nucleotide-Gated Cation Channels / Q000235:genetics; D004252:DNA Mutational Analysis; D004596:Electroretinography; D005091:Exons / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010775:Photic Stimulation; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology*; D016133:Polymerase Chain Reaction; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests
chemical_list: C518238:CNGA3 protein, human; C415904:CNGB3 protein, human; D054815:Cyclic Nucleotide-Gated Cation Channels