title: Choroidal thickness in relation to hypercholesterolemia on enhanced depth imaging optical coherence tomography.
abstract: OBJECTIVE
  To investigate the relationship of hypercholesterolemia and choroidal thickness in normal healthy volunteers.
  
  
  METHODS
  This was a cross-sectional observational study. Volunteers with no ocular abnormalities were examined using enhanced depth imaging optical coherence tomography. Choroidal and retinal thicknesses were measured at the fovea, and at 4 different locations 1 mm superior, inferior, temporal, and nasal to the fovea. Subjects were further divided into those with hypercholesterolemia (Group 1) and normal control subjects (Group 2) for subgroup analysis regarding the effect of hypercholesterolemia on choroidal thickness. Subjects with hypertension and diabetes were excluded.
  
  
  RESULTS
  A total of 322 eyes of 161 subjects were studied. Mean age was 59.9 years (range, 24-84 years). The mean subfoveal choroidal thickness was 261 ± 98.7 μm. Mean subfoveal choroidal thickness negatively correlated with age (r = -0.326; P = 0.001). The mean serum total cholesterol was 5.02 ± 0.98 mmol/L. In Group 1, it was 5.65 ± 1.15 mmol/L, while in Group 2, it was 4.72 ± 0.73 mmol/L. The difference was statistically significant (P = 0.003). Subjects in Group 1 tended to be older and have worse vision, although the difference did not reach statistical significance. The mean subfoveal choroidal thickness in Group 1 was 306 ± 111 μm, while that in Group 2 was 258 ± 97 μm. The difference was statistically significant (P = 0.041). The same difference was also found at the 1 mm nasal (P = 0.041) and 1 mm superior (P = 0.040).
  
  
  CONCLUSIONS
  The subfoveal choroidal thickness was found to be significantly higher in subjects with hypercholesterolemia. This has to be taken into account when analyzing choroidal thickness.
authors.affiliation: Eye Institute, University of Hong Kong, Hong Kong. ianyhwong@gmail.com
authors.forename: Ian Y
authors.initials: IY
authors.lastname: Wong
authors.forename: Raymond L
authors.initials: RL
authors.lastname: Wong
authors.forename: Paul
authors.initials: P
authors.lastname: Zhao
authors.forename: Wico W
authors.initials: WW
authors.lastname: Lai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002784:Cholesterol / Q000097:blood; D002829:Choroid / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D012029:Refraction, Ocular / Q000502:physiology; D012160:Retina / Q000033:anatomy & histology*; D041623:Tomography, Optical Coherence; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D002784:Cholesterol