title: Evaluation of Macular Vascular Abnormalities Identified by Optical Coherence Tomography Angiography in Sickle Cell Disease.
abstract: OBJECTIVE
  To evaluate macular vascular flow abnormalities identified by optical coherence tomography angiography (OCT-A) in patients with various sickle cell genotypes.
  
  
  METHODS
  Prospective, observational case series.
  
  
  METHODS
  This is a single-institution case series of adult patients with various sickle cell genotypes. All patients underwent macular OCT-A (Avanti RTVue XR). Images were analyzed qualitatively for areas of flow loss and quantitatively for measures of foveal avascular area, parafoveal flow, and vascular density. The findings were compared by sickle cell genotype and retinopathy stage and correlated to retinal thickness and visual acuity.
  
  
  RESULTS
  OCT-A scans of 82 eyes from 46 patients (60.9% female, mean age 33.5 years) were included. Sickle cell genotypes included 27 patients with hemoglobin SS (58.7%), 14 SC (30.4%), 4 beta-thalassemia (8.7%), and 1 sickle trait (2.2%). Discrete areas of flow loss were noted in 37.8% (31/82) of eyes overall and were common in both SS (40.0%, 20/50 eyes) and SC (41.7%, 10/24 eyes). Flow loss was more extensive in the temporal and nasal parafoveal subfields of the deep plexus with sickle SC or proliferative retinopathy. Retinal thickness measurements correlated with vascular density of the fovea, parafovea, and temporal and superior subfields. Visual acuity correlated with foveal avascular zone area and parafoveal vascular density in the superficial and deep plexi.
  
  
  CONCLUSIONS
  Areas of abnormal macular vascular flow are common in patients with various sickle cell genotypes. These areas may be seen at any retinopathy stage but may be more extensive with sickle SC or proliferative retinopathy.
authors.affiliation: Retina Division, Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland.
authors.forename: Ian C
authors.initials: IC
authors.lastname: Han
authors.affiliation: Retina Division, Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland.
authors.forename: Mongkol
authors.initials: M
authors.lastname: Tadarati
authors.affiliation: Retina Division, Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland.
authors.forename: Katia D
authors.initials: KD
authors.lastname: Pacheco
authors.affiliation: Retina Division, Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland. Electronic address: ascott28@jhmi.edu.
authors.forename: Adrienne W
authors.initials: AW
authors.lastname: Scott
mesh_terms: D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications* / Q000175:diagnosis; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005654:Fundus Oculi; D006801:Humans; D008266:Macula Lutea / Q000098:blood supply*; D008297:Male; D011446:Prospective Studies; D012164:Retinal Diseases / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D012171:Retinal Vessels / Q000002:abnormalities* / Q000503:physiopathology; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity