title: Abnormal cone structure in foveal schisis cavities in X-linked retinoschisis from mutations in exon 6 of the RS1 gene.
abstract: OBJECTIVE
  To evaluate macular cone structure in patients with X-linked retinoschisis (XLRS) caused by mutations in exon 6 of the RS1 gene.
  
  
  METHODS
  High-resolution macular images were obtained with adaptive optics scanning laser ophthalmoscopy (AOSLO) and spectral domain optical coherence tomography (SD-OCT) in two patients with XLRS and 27 age-similar healthy subjects. Retinal structure was correlated with best-corrected visual acuity, kinetic and static perimetry, fundus-guided microperimetry, full-field electroretinography (ERG), and multifocal ERG. The six coding exons and the flanking intronic regions of the RS1 gene were sequenced in each patient.
  
  
  RESULTS
  Two unrelated males, ages 14 and 29, with visual acuity ranging from 20/32 to 20/63, had macular schisis with small relative central scotomas in each eye. The mixed scotopic ERG b-wave was reduced more than the a-wave. SD-OCT showed schisis cavities in the outer and inner nuclear and plexiform layers. Cone spacing was increased within the largest foveal schisis cavities but was normal elsewhere. In each patient, a mutation in exon 6 of the RS1 gene was identified and was predicted to change the amino acid sequence in the discoidin domain of the retinoschisin protein.
  
  
  CONCLUSIONS
  AOSLO images of two patients with molecularly characterized XLRS revealed increased cone spacing and abnormal packing in the macula of each patient, but cone coverage and function were near normal outside the central foveal schisis cavities. Although cone density is reduced, the preservation of wave-guiding cones at the fovea and eccentric macular regions has prognostic and therapeutic implications for XLRS patients with foveal schisis. (Clinical Trials.gov number, NCT00254605.).
authors: Department of Ophthalmology, University of California at San Francisco, San Francisco, California 94143, USA. duncanj@vision.ucsf.edu
authors: Jacque L
authors: JL
authors: Duncan
authors: Kavitha
authors: K
authors: Ratnam
authors: David G
authors: DG
authors: Birch
authors: Sanna M
authors: SM
authors: Sundquist
authors: Anna S
authors: AS
authors: Lucero
authors: Yuhua
authors: Y
authors: Zhang
authors: Meira
authors: M
authors: Meltzer
authors: Nizar
authors: N
authors: Smaoui
authors: Austin
authors: A
authors: Roorda
mesh_terms: D000293:Adolescent; D000328:Adult; D002452:Cell Count; D004596:Electroretinography; D005091:Exons / Q000235:genetics*; D005136:Eye Proteins / Q000235:genetics*; D005584:Fovea Centralis; D006801:Humans; D007834:Lasers; D008297:Male; D009154:Mutation; D009887:Ophthalmoscopy; D010641:Phenotype; D016133:Polymerase Chain Reaction; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology*; D041441:Retinoschisis / Q000235:genetics* / Q000503:physiopathology; D012607:Scotoma / Q000175:diagnosis; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology
chemical_list: D005136:Eye Proteins; C108726:RS1 protein, human