title: Optical coherence tomographic angiography of choroidal neovascularization ill-defined with fluorescein angiography.
abstract: OBJECTIVE
  To evaluate the morphological structure of ill-defined choroidal neovascularisation (CNV) with traditional fluorescein angiography (FA) compared with optical coherence tomographic angiography (OCTA).
  
  
  METHODS
  A retrospective case series study of 11 eyes with ill-defined CNV on FA was performed. Eyes were scanned with commercially available spectral-domain optical coherence tomography (OCT) (70 000 A-scans/s). The split-spectrum amplitude-decorrelation angiography (SSADA) algorithm was used to distinguish blood flow from static tissue. En face OCT angiograms were compared with FA.
  
  
  RESULTS
  Eleven cases of ill-defined CNV on FA were identified from 10 study participants. Mean age of the participants was 74.5±6.8 years. Six cases had late leakage from undetermined source (LLUS) and five had fibrovascular pigment epithelial detachment (FVPED). Combining cross-sectional structural OCT with OCT angiograms, all cases were found to have type 1 CNV that corresponded to occult CNV with FA. In all cases of occult CNV on FA, distinct vascular structures were visible with OCTA in the outer retinal/retinal pigment epithelium slab. The mean CNV vessel area was 2.61±3.65 mm2. The mean CNV vessel area in cases with FVPED was larger than that in cases with LLUS (4.69±4.72 mm2compared with 0.85±0.90 mm2, Mann-Whitney p value=0.04).
  
  
  CONCLUSIONS
  Although the sample size is small to draw conclusions and the nature of work is retrospective and descriptive, OCTA has the potential to improve visualisation of ill-defined CNV with dye-based angiography, including occult CNV.
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Malihi
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Yali
authors.initials: Y
authors.lastname: Jia
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Simon S
authors.initials: SS
authors.lastname: Gao
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Christina
authors.initials: C
authors.lastname: Flaxel
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Andreas K
authors.initials: AK
authors.lastname: Lauer
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hwang
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Wilson
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: David
authors.initials: D
authors.lastname: Huang
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
authors.forename: Steven T
authors.initials: ST
authors.lastname: Bailey
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002829:Choroid / Q000098:blood supply; D020256:Choroidal Neovascularization / Q000000981:diagnostic imaging*; D003430:Cross-Sectional Studies; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*
keywords: Choroid; Imaging; Neovascularisation