title: Correlation between choroidal thickness and degree of myopia assessed with enhanced depth imaging optical coherence tomography.
abstract: OBJECTIVE
  To assess the choroidal thickness in different degrees of myopia using enhanced depth imaging optical coherence tomography (EDI-OCT) compared with healthy subjects.
  
  
  METHODS
  We included 240 patients with myopia and 60 emmetropes as controls. Participants underwent full ophthalmologic examination, axial length measurement, and EDI-OCT imaging of the choroid. Choroidal thickness (CT) was measured at 5 locations, including subfoveal (SFCT), 2 mm nasal, temporal, upper, and lower to fovea.
  
  
  RESULTS
  Choroidal thickness was significantly lower in myopic eyes compared to controls. Regardless of the degree of myopia, nasal regions showed the lowest CT with decremental pattern with advance of myopia (low myopia 279.00 ± 24.50 µm, moderate myopia 269.58 ± 20.69 µm, high myopia 189.58 ± 25.95 µm, advanced myopia 96.75 ± 24.83 µm). Highest CT was variable according to the degree of myopia with decremental pattern with advance of myopia (low myopia in subfoveal region 354.40 ± 35.14 µm, moderate myopia in temporal region 337.87 ± 35.75 µm, high myopia in lower region 312.15 ± 38.90 µm, and advanced myopia in upper region 201.25 ± 18.27 µm). Axial length showed significant negative correlation with SFCT and CT in different studied regions.
  
  
  CONCLUSIONS
  Different degrees of myopia showed thinner choroidal thickness than that of normal control eyes with decremental thinning with progress of myopia. This might be secondary to the longer axial length, which was the determining factor in some locations such as subfoveal, nasal, and upper CT.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Ain Shams University, Cairo - Egypt.
authors.forename: Amany A
authors.initials: AA
authors.lastname: El-Shazly
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Ain Shams University, Cairo - Egypt.
authors.forename: Yousra A
authors.initials: YA
authors.lastname: Farweez
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Ain Shams University, Cairo - Egypt.
authors.forename: Marwa E
authors.initials: ME
authors.lastname: ElSebaay
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Ain Shams University, Cairo - Egypt.
authors.forename: Walid M A
authors.initials: WMA
authors.lastname: El-Zawahry
mesh_terms: D000293:Adolescent; D000328:Adult; D002829:Choroid / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D005584:Fovea Centralis / Q000473:pathology; D006801:Humans; D008297:Male; D009216:Myopia / Q000175:diagnosis*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*; D055815:Young Adult