title: Optical Coherence Tomography Angiography in Choroideremia: Correlating Choriocapillaris Loss With Overlying Degeneration.
abstract: Novel therapies for choroideremia, an X-linked recessive chorioretinal degeneration, demand a better understanding of the primary site(s) of cellular degeneration. Optical coherence tomography angiography allows for choriocapillaris (CC) imaging. We compared the extent of structural alterations of the CC, retinal pigment epithelium, and photoreceptors with multimodal imaging.
  
  
  
  In a clinical case series conducted from September 15, 2014, through February 5, 2015, 14 eyes of 7 male patients with choroideremia (median age, 34 years [interquartile range, 15-46 years]; age range, 13-48 years), 4 eyes of 2 women with choroideremia carrier state (both in mid-50s), and 6 eyes of 6 controls (median age, 42.5 years [interquartile range, 33-55 years]; age range, 24-55 years) underwent multimodal imaging with optical coherence tomography angiography and electroretinography. The mean (SD) macular CC density was 82.9% (13.4%) in patients with choroideremia, 93.0% (3.8%) in female carriers, and 98.2% (1.3%) in controls. The mean (SD) CC density in affected eyes was higher in regions with preserved (92.6% [5.8%]) vs absent (75.9% [12.6%]) ellipsoid zone (mean difference, 16.7%; 95% CI, 12.1% to 21.3%; P < .001). Seventeen of 18 eyes of the patients and carriers had outer retinal tubulations forming pseudopod-like extensions from islands of preserved ellipsoid zone. Outer retinal tubulations were associated with absence of underlying retinal pigment epithelium and were longer (r = -0.62; 95% CI, -0.84 to -0.19; P < .001) and more numerous (r = -0.71; 95% CI, -0.91 to -0.27; P < .001) in more severely affected eyes.
  
  
  
  These findings suggest that regional changes in CC density correlate with photoreceptor structural alterations in choroideremia. Although closely coupled, the results suggest that retinal pigment epithelium loss is more extensive than photoreceptor loss.
authors.affiliation: Department of Ophthalmology, Emory University, Atlanta, Georgia2Casey Eye Institute, Oregon Health & Science University, Portland.
authors.forename: Nieraj
authors.initials: N
authors.lastname: Jain
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland.
authors.forename: Yali
authors.initials: Y
authors.lastname: Jia
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland.
authors.forename: Simon S
authors.initials: SS
authors.lastname: Gao
authors.affiliation: Division of Biostatistics, Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland.
authors.forename: Xinbo
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland.
authors.forename: Richard G
authors.initials: RG
authors.lastname: Weleber
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland.
authors.forename: David
authors.initials: D
authors.lastname: Huang
authors.affiliation: Casey Eye Institute, Oregon Health & Science University, Portland.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Pennesi
mesh_terms: D000293:Adolescent; D000328:Adult; D002196:Capillaries / Q000473:pathology*; D002829:Choroid / Q000098:blood supply* / Q000473:pathology; D015794:Choroideremia / Q000000981:diagnostic imaging* / Q000473:pathology; D004596:Electroretinography; D005260:Female; D005451:Fluorescein Angiography; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D061848:Optical Imaging; D012162:Retinal Degeneration / Q000000981:diagnostic imaging* / Q000473:pathology; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D041623:Tomography, Optical Coherence; D055815:Young Adult