title: Peripapillary retinal nerve fiber layer thinning in patients with autosomal recessive cone-rod dystrophy.
abstract: OBJECTIVE
  To evaluate peripapillary retinal nerve fiber layer (RNFL) thickness using spectral-domain optical coherence tomography in patients with autosomal recessive cone-rod dystrophy (CRD).
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Eleven patients (22 eyes) with CRD were studied, including 4 patients with identified ABCA4 gene mutations. Peripapillary RNFL thickness was measured in 16 segments from 4 quadrants. The analyses were based on age and disc size-adjusted normative data. An abnormal thinning was considered when RNFL thickness measurements were less than the fifth percentile in at least 2 of 4 segments in a quadrant. Mean RNFL thickness was compared quantitatively with normative data obtained from 134 subjects.
  
  
  RESULTS
  Eight patients (73%) had peripapillary RNFL thinning in at least 1 quadrant of at least 1 eye, including 3 of 4 patients with known ABCA4 gene mutations. Peripapillary RNFL thinning in the temporal quadrant was seen most commonly in 11 (79%) of 14 eyes with thinning in at least 1 quadrant. Significant thinning of the overall peripapillary RNFL was observed in CRD patients compared with controls (P = .0002). Subgroup analysis showed that 8 (89%) of 9 patients who were older than 40 years had thinning in at least 1 quadrant of at least 1 eye.
  
  
  CONCLUSIONS
  Peripapillary RNFL thinning was observed commonly in our patients with autosomal recessive CRD. The results confirm that the inner retinal structures can be affected in outer retinal disease. Careful evaluation of the inner retina may be important in determining the success rate of potential treatments for predominantly outer retinal diseases.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL 60612, USA.
authors.forename: Sirichai
authors.initials: S
authors.lastname: Pasadhika
authors.forename: Gerald A
authors.initials: GA
authors.lastname: Fishman
authors.forename: Rando
authors.initials: R
authors.lastname: Allikmets
authors.forename: Edwin M
authors.initials: EM
authors.lastname: Stone
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D005808:Genes, Recessive; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology*; D012162:Retinal Degeneration / Q000175:diagnosis* / Q000235:genetics*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence
chemical_list: C056475:ABCA4 protein, human; D018528:ATP-Binding Cassette Transporters