title: The Effect of Retinal Melanin on Optical Coherence Tomography Images.
abstract: OBJECTIVE
  We assessed the effect of melanin on the appearance of hyperreflective outer retinal bands in optical coherence tomography (OCT) images.
  
  
  METHODS
  A total of 23 normal subjects and 51 patients with albinism were imaged using the Bioptigen high-resolution spectral-domain OCT. In addition, three wild type, three albino (slc45a2b4/b4), and eighttyrosinasemosaic zebrafish were imaged with the hand-held Bioptigen Envisu R2200 OCT. To identify pigmented versus nonpigmented regions in thetyrosinasemosaic zebrafish, en face summed volume projections of the retinal pigment epithelium (RPE) were created from volume scans. Longitudinal reflectivity profiles were generated from B-scans to assess the width and maximum intensity of the RPE band in fish, or the presence of one or two RPE/Bruch's membrane (BrM) bands in humans.
  
  
  RESULTS
  The foveal RPE/BrM appeared as two bands in 71% of locations in patients with albinism and 45% of locations in normal subjects (P= 0.0003). Pigmented zebrafish retinas had significantly greater RPE reflectance, and pigmented regions of mosaic zebrafish also had significantly broader RPE bands than all other groups.
  
  
  CONCLUSIONS
  The hyperreflective outer retinal bands in OCT images are highly variable in appearance. We showed that melanin is a major contributor to the intensity and width of the RPE band on OCT. One should use caution in extrapolating findings from OCT images of one or even a few individuals to define the absolute anatomic correlates of the hyperreflective outer retinal bands in OCT images.
  
  
  CONCLUSIONS
  Melanin affects the appearance of the outer retinal bands in OCT images. Use of animal models may help dissect the anatomic correlates of the complex reflective signals in OCT retinal images.
authors.affiliation: Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA ; Current affiliation: HudsonAlpha Institute for Biotechnology, 601 Genome Way, Huntsville, AL, USA.
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Wilk
authors.affiliation: Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Alison L
authors.initials: AL
authors.lastname: Huckenpahler
authors.affiliation: Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Ross F
authors.initials: RF
authors.lastname: Collery
authors.affiliation: Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Link
authors.affiliation: Department of Cell Biology, Neurobiology, & Anatomy, Medical College of Wisconsin, Milwaukee, WI, USA ; Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI, USA ; Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Carroll
keywords: COT; albinism; imaging; melanin; retina; zebrafish