title: Classification of human retinal microaneurysms using adaptive optics scanning light ophthalmoscope fluorescein angiography.
abstract: OBJECTIVE
  Microaneurysms (MAs) are considered a hallmark of retinal vascular disease, yet what little is known about them is mostly based upon histology, not clinical observation. Here, we use the recently developed adaptive optics scanning light ophthalmoscope (AOSLO) fluorescein angiography (FA) to image human MAs in vivo and to expand on previously described MA morphologic classification schemes.
  
  
  METHODS
  Patients with vascular retinopathies (diabetic, hypertensive, and branch and central retinal vein occlusion) were imaged with reflectance AOSLO and AOSLO FA. Ninety-three MAs, from 14 eyes, were imaged and classified according to appearance into six morphologic groups: focal bulge, saccular, fusiform, mixed, pedunculated, and irregular. The MA perimeter, area, and feret maximum and minimum were correlated to morphology and retinal pathology. Select MAs were imaged longitudinally in two eyes.
  
  
  RESULTS
  Adaptive optics scanning light ophthalmoscope fluorescein angiography imaging revealed microscopic features of MAs not appreciated on conventional images. Saccular MAs were most prevalent (47%). No association was found between the type of retinal pathology and MA morphology (P = 0.44). Pedunculated and irregular MAs were among the largest MAs with average areas of 4188 and 4116 μm(2), respectively. Focal hypofluorescent regions were noted in 30% of MAs and were more likely to be associated with larger MAs (3086 vs. 1448 μm(2), P = 0.0001).
  
  
  CONCLUSIONS
  Retinal MAs can be classified in vivo into six different morphologic types, according to the geometry of their two-dimensional (2D) en face view. Adaptive optics scanning light ophthalmoscope fluorescein angiography imaging of MAs offers the possibility of studying microvascular change on a histologic scale, which may help our understanding of disease progression and treatment response.
authors.affiliation: Department of Ophthalmology, New York Eye and Ear Infirmary, New York, New York.
authors.forename: Michael
authors.initials: M
authors.lastname: Dubow
authors.forename: Alexander
authors.initials: A
authors.lastname: Pinhas
authors.forename: Nishit
authors.initials: N
authors.lastname: Shah
authors.forename: Robert F
authors.initials: RF
authors.lastname: Cooper
authors.forename: Alexander
authors.initials: A
authors.lastname: Gan
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Gentile
authors.forename: Vernon
authors.initials: V
authors.lastname: Hendrix
authors.forename: Yusufu N
authors.initials: YN
authors.lastname: Sulai
authors.forename: Joseph
authors.initials: J
authors.lastname: Carroll
authors.forename: Toco Y P
authors.initials: TY
authors.lastname: Chui
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Walsh
authors.forename: Rishard
authors.initials: R
authors.lastname: Weitz
authors.forename: Alfredo
authors.initials: A
authors.lastname: Dubra
authors.forename: Richard B
authors.initials: RB
authors.lastname: Rosen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000783:Aneurysm / Q000145:classification* / Q000175:diagnosis; D004867:Equipment Design; D005260:Female; D005451:Fluorescein Angiography / Q000379:methods*; D005654:Fundus Oculi; D006801:Humans; D008297:Male; D008875:Middle Aged; D019721:Ophthalmoscopes; D012161:Retinal Artery; D012164:Retinal Diseases / Q000145:classification* / Q000175:diagnosis; D012720:Severity of Illness Index
keywords: AOSLO; fluorescein angiography; microaneurysm