title: Correlation between subfoveal choroidal thickness and the severity or progression of nonexudative age-related macular degeneration.
abstract: OBJECTIVE
  To investigate the correlation between subfoveal choroidal thickness (SFChT) and the severity or progression of nonexudative AMD.
  
  
  METHODS
  One hundred seventy-six eyes of 114 patients with nonexudative AMD were included in this study. These eyes were divided into stages I through IV, based on the Age-Related Eye Disease Study (AREDS) classification of fundus findings. Using enhanced depth imaging from spectralis domain optical coherence tomography (SD-OCT), the central retinal thickness (CRT), SFChT, and parafoveal choroidal thickness (PFChT) were measured. The area of geographic atrophy (GA) was measured from fundus autofluorescence (FAF) images, and the progression of GA was calculated using RegionFinder software.
  
  
  RESULTS
  The age-adjusted SFChT levels were lower at later stages of nonexudative AMD. These measurements were as follows: 266.68 ± 12.60 (stage I: 28 eyes), 263.34 ± 9.87 (stage II: 48 eyes), 200.55 ± 8.83 (stage III: 71 eyes), and 188.34 ± 13.72 (stage IV: 29 eyes) (P = 0.0028). The age-adjusted SFChT was also negatively correlated with the best corrected visual acuity (BCVA) (estimate, -0.001; P = 0.0006). Among 16 eyes with GA at baseline, SFChT showed a negative correlation with the baseline area of GA (r = 0.5521, P = 0.0133). In addition, GA progressed more rapidly during the mean follow up of 22.19 ± 9.08 months when the SFChT was lower at baseline (r = 0.5658, P = 0.0112).
  
  
  CONCLUSIONS
  Subfoveal choroidal thickness is closely related to the BCVA, the severity of nonexudative AMD, as well as the rate of GA progression. Subfoveal choroidal thickness may be a predictor of disease progression in GA cases.
authors.affiliation: Department of Ophthalmology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jin Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Lee
authors.forename: Joo Yong
authors.initials: JY
authors.lastname: Lee
authors.forename: Young Hee
authors.initials: YH
authors.lastname: Yoon
mesh_terms: D000368:Aged; D002829:Choroid / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005451:Fluorescein Angiography; D005500:Follow-Up Studies; D005584:Fovea Centralis / Q000473:pathology*; D005654:Fundus Oculi; D057092:Geographic Atrophy / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity
keywords: geographic atrophy; nonexudative age-related macular degeneration; subfoveal choroidal thickness