title: Choroidal imaging in inherited retinal disease using the technique of enhanced depth imaging optical coherence tomography.
abstract: OBJECTIVE
  The aim of this study is to image and describe the in vivo choroidal changes in various retinal dystrophies using the technique of enhanced depth imaging (EDI) optical coherence tomography (OCT) and to correlate these findings with the clinical appearance. Associations between choroidal change and genotype, visual acuity and results of retinal electrophysiology are also explored.
  
  
  METHODS
  Retrospective observational case series.
  
  
  METHODS
  Twenty patients attending the medical retina clinics at Moorfields Eye Hospital underwent EDI OCT choroidal scans as part of the scanning protocol when they underwent OCT imaging with the Spectralis HRA and OCT. The choroidal images were obtained by moving the Spectralis camera close enough to obtain an inverted image of the retina. The scans were read by two experienced OCT readers assessing the choroidal thickness as well as the choroidal contour for focal areas of choroidal thinning corresponding to the areas of RPE/outer retinal atrophy. The spectrum of patients included those with Stargardt macular dystrophy, macular dystrophies secondary to known mutations such as peripherin/RDS, uncharacterised macular dystrophies, Best disease, bifocal chorioretinal atrophy, Bietti crystalline retinal dystrophy and choroideraemia.
  
  
  RESULTS
  The choroidal appearance was symmetrical in all patients who had both eyes scanned. Ten patients showed no choroidal thinning, five had focal mild to moderate choroidal thinning, three had focal severe choroidal thinning, and two patients had diffuse severe choroidal thinning. There was no association between choroidal thinning and visual acuity [Fisher's exact test, p = 0.350 (right eye), p = 1.000 (left eye)], or extent of retinal dysfunction on electrophysiology (Fisher's exact test, p = 1.000).
  
  
  CONCLUSIONS
  Enhanced depth imaging using spectral domain OCT can be used to identify choroidal changes in inherited retinal disease. The pattern of choroidal change correlates well with the clinical appearance. It appears that the extent and pattern of choroidal thinning is dependent on the stage of the disease in some cases, and in others the causative gene defect.
authors.affiliation: Moorfields Eye Hospital, City Road, EC1V2PD, London, UK. jonathan_yeoh@hotmail.com
authors.forename: Jonathan
authors.initials: J
authors.lastname: Yeoh
authors.forename: Waheeda
authors.initials: W
authors.lastname: Rahman
authors.forename: Fred
authors.initials: F
authors.lastname: Chen
authors.forename: Claire
authors.initials: C
authors.lastname: Hooper
authors.forename: Praveen
authors.initials: P
authors.lastname: Patel
authors.forename: Adnan
authors.initials: A
authors.lastname: Tufail
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Webster
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Moore
authors.forename: Lyndon
authors.initials: L
authors.lastname: Dacruz
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics; D000293:Adolescent; D000328:Adult; D002648:Child; D002829:Choroid / Q000473:pathology*; D015862:Choroid Diseases / Q000175:diagnosis*; D004594:Electrophysiology; D005838:Genotype; D006801:Humans; D007381:Intermediate Filament Proteins / Q000235:genetics; D008562:Membrane Glycoproteins / Q000235:genetics; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics; D064531:Peripherins; D011518:Proto-Oncogene Proteins / Q000235:genetics; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D058499:Retinal Dystrophies / Q000235:genetics* / Q000503:physiopathology; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult; D000076202:c-Mer Tyrosine Kinase
chemical_list: C056475:ABCA4 protein, human; D018528:ATP-Binding Cassette Transporters; D007381:Intermediate Filament Proteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; C578994:PRPH protein, human; C578997:PRPH2 protein, human; D064531:Peripherins; D011518:Proto-Oncogene Proteins; C097072:MERTK protein, human; D020794:Receptor Protein-Tyrosine Kinases; D000076202:c-Mer Tyrosine Kinase