title: Retinal vascular layers in macular telangiectasia type 2 imaged by optical coherence tomographic angiography.
abstract: OBJECTIVE
  Macular telangiectasia type 2 (MacTel 2) is a rare disease in which abnormalities of the retinal vasculature play a key role. The vascular abnormalities are typically evaluated using fluorescein angiography, a modality with known defects in imaging the deeper layers of the retinal vasculature. Angiography based on optical coherence tomography can image vessels based on flow characteristics without dye injection and may provide improved information concerning the pathophysiology of MacTel 2.
  
  
  OBJECTIVE
  To investigate MacTel 2 using optical coherence tomographic angiography.
  
  
  METHODS
  Fourteen eyes of 7 patients with MacTel 2 were analyzed in a community-based retina practice. The flow imaging was based on split-spectrum amplitude decorrelation angiography, which can dissect layers of vessels in the retina. The inner retinal vascular plexus, the outer plexus, and deeper vascular invasion into the outer and subretinal spaces were optically dissected in en face images based on flow.
  
  
  METHODS
  Visualization and qualitative evaluation of the vascular layers of the retina as they may be affected by MacTel 2, both in terms of depth and topographic characteristics.
  
  
  RESULTS
  A consistent set of retinal vascular changes were seen in the eyes with MacTel 2. There was some loss of capillary density in the inner retinal vascular plexus but many more prominent alterations in the deep retinal vascular plexus. In milder forms of the disease, the deep plexus showed dilation and telangiectasis and, in more advanced cases, thinning and loss. The remaining vessels were elongated and widely spaced capillary segments. Invasion by new vessels into the outer and subretinal spaces occurred subjacent to the regions showing greatest flow imaging abnormalities in the inner and deep retinal vascular layers.
  
  
  CONCLUSIONS
  As evidenced by the patients in this study, important retinal vascular changes in MacTel 2 occur in the deep capillary plexus of the retina, a layer poorly visualized by fluorescein angiography and, to a lesser extent, in the inner vascular plexus. The proliferation of vessels in the outer and subretinal spaces may be in part compensatory for poor retinal perfusion by established vascular layers in the retina.
authors.affiliation: Vitreous Retina Macula Consultants of New York, New York.
authors.forename: Richard F
authors.initials: RF
authors.lastname: Spaide
authors.affiliation: Vitreous Retina Macula Consultants of New York, New York.
authors.forename: James M
authors.initials: JM
authors.lastname: Klancnik
authors.affiliation: Vitreous Retina Macula Consultants of New York, New York.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Cooney
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D002196:Capillaries / Q000473:pathology; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D015861:Retinal Neovascularization / Q000175:diagnosis* / Q000503:physiopathology; D058456:Retinal Telangiectasis / Q000175:diagnosis* / Q000503:physiopathology; D012171:Retinal Vessels / Q000473:pathology*; D041623:Tomography, Optical Coherence