title: Differential optical densities of intraretinal spaces.
abstract: OBJECTIVE
  To test the hypothesis that hyporeflective spaces in the neuroretina found on optical coherence tomography (OCT) examination have different optical reflectivities according to whether they are associated with exudation or degeneration.
  
  
  METHODS
  Retrospective analysis of eyes with idiopathic perifoveal telangiectasia (IPT), diabetic macular edema (DME), idiopathic central serous chorioretinopathy (CSC), retinitis pigmentosa (RP), or cone dystrophy (CD) and eyes of healthy control subjects. OCT scans were performed. Raw scan data were exported and used to calculate light reflectivity profiles. Reflectivity data were acquired by projecting three rectangular boxes, each 50 pixels long and 5 pixels wide, into the intraretinal cystoid spaces, centrally onto unaffected peripheral RPE, and onto the prefoveolar vitreous. Light reflectivity in the retinal pigment epithelium (RPE), vitreous, and intraretinal spaces for the different retinal conditions and control subjects were compared.
  
  
  RESULTS
  Reflectivities of the vitreous and the RPE were similar among the groups. Hyporeflective spaces in eyes with exudation (DME, RP, and CSC) had higher reflectivity compared with the mean reflectivity of the vitreous, whereas the cystoid spaces in the maculae of the eyes without exudation (CD and IPT) had a lower reflectivity than did the normal vitreous.
  
  
  CONCLUSIONS
  Analysis of the light reflectivity profiles may be a tool to determine whether the density of hyporeflective spaces in the macula is greater or less than that of the vitreous, and may be a way to differentiate degenerative from exudative macular disease.
authors.affiliation: Department of Ophthalmology, Bern University Hospital and University of Bern, Bern, Switzerland. daniel.barthelmes@gmx.ch
authors.forename: Daniel
authors.initials: D
authors.lastname: Barthelmes
authors.forename: Florian K P
authors.initials: FK
authors.lastname: Sutter
authors.forename: Mark C
authors.initials: MC
authors.lastname: Gillies
mesh_terms: D000328:Adult; D003560:Cysts / Q000175:diagnosis*; D003941:Diagnostic Techniques, Ophthalmological; D004596:Electroretinography; D005122:Exudates and Transudates; D005260:Female; D005451:Fluorescein Angiography; D006801:Humans; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000473:pathology*; D012164:Retinal Diseases / Q000175:diagnosis*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*