title: Adaptive optics microperimetry and OCT images show preserved function and recovery of cone visibility in macular telangiectasia type 2 retinal lesions.
abstract: OBJECTIVE
  To evaluate visual function and disease progression in the retinal structural abnormalities of three patients from two unrelated families with macular telangiectasia (MacTel) type 2.
  
  
  METHODS
  Adaptive optics scanning laser ophthalmoscopy (AOSLO) and AOSLO microperimetry (AOMP) were used to evaluate the structure and function of macular cones in three eyes with MacTel type 2. Cone spacing was estimated using histogram analysis of intercone distances, and registered spectral-domain optical coherence tomography (SD-OCT) scans were used to evaluate retinal anatomy. AOMP was used to assess visual sensitivity in and around areas of apparent cone loss.
  
  
  RESULTS
  Although overall lesion surface area increased, some initially affected regions subsequently showed clear, contiguous, and normally spaced cone mosaics with recovered photoreceptor inner/outer segment (IS/OS) reflectivity (two of two eyes). The AOMP test sites fell within three categories: normal-appearing cones (N), dimly reflecting cones (D), and RPE cell mosaics (R). At N sites, AOMP threshold values (arbitrary units [au]) increased with increasing eccentricity (slope = 0.054 au/degree, r(2) = 0.77). The N thresholds ranged from 0.04 to 0.27 au, D thresholds from 0.04 to 0.33 au, and R thresholds from 0.14 to 1.00 au. There was measurable visual sensitivity everywhere except areas without intact external limiting membrane (ELM) and with diffuse scattering in the IS/OS and posterior tips of the outer segments (PTOS) regions on OCT.
  
  
  CONCLUSIONS
  Visual sensitivity and recovery of cone visibility in areas of apparent focal cone loss suggests that MacTel type 2 lesions with a preserved ELM may contain functioning cones with abnormal scattering and/or waveguiding characteristics. (ClinicalTrials.gov number, NCT00254605.).
authors.affiliation: Duke University School of Medicine, Durham, North Carolina, United States Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States.
authors.forename: Qinyun
authors.initials: Q
authors.lastname: Wang
authors.affiliation: School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, United States.
authors.forename: William S
authors.initials: WS
authors.lastname: Tuten
authors.affiliation: School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, United States West Coast Retina Medical Group, San Francisco, California, United States.
authors.forename: Brandon J
authors.initials: BJ
authors.lastname: Lujan
authors.affiliation: Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Holland
authors.affiliation: Department of Ophthalmology, University of Utah Moran Eye Center, Salt Lake City, Utah, United States.
authors.forename: Paul S
authors.initials: PS
authors.lastname: Bernstein
authors.affiliation: Jules Stein Eye Institute, University of California, Los Angeles, Los Angeles, California, United States.
authors.forename: Steven D
authors.initials: SD
authors.lastname: Schwartz
authors.affiliation: Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States.
authors.forename: Jacque L
authors.initials: JL
authors.lastname: Duncan
authors.affiliation: School of Optometry and Vision Science Graduate Group, University of California, Berkeley, Berkeley, California, United States.
authors.forename: Austin
authors.initials: A
authors.lastname: Roorda
mesh_terms: D000328:Adult; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy / Q000379:methods; D020127:Recovery of Function; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D013683:Telangiectasia, Hereditary Hemorrhagic / Q000175:diagnosis* / Q000503:physiopathology; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields / Q000502:physiology*
keywords: AOMP; AOSLO; MacTel type 2; cone photoreceptors