title: A comparison between amblyopic and fellow eyes in unilateral amblyopia using spectral-domain optical coherence tomography.
abstract: OBJECTIVE
  To compare the macular retinal thickness and characteristics of optic nerve head (ONH) parameters in amblyopic and fellow eyes in patients with unilateral amblyopia.
  
  
  METHODS
  A total of 21 patients with unilateral amblyopia (14 patients with anisometropic amblyopia, four patients with strabismic amblyopia, and three patients with both) were examined using spectral-domain optical coherence tomography. The mean age of the patients was 8.5±3.5 years. The examined parameters included the mean macular (full, inner, and outer), ganglion cell complex and circumpapillary retinal nerve fiber layer (cpRNFL) thicknesses, and ONH parameters (rim volume, nerve head volume, cup volume, rim area, optic disc area, cup area, and cup-to-disc area ratio).
  
  
  RESULTS
  The amblyopic eyes were significantly more hyperopic than the fellow eyes (P<0.001). Among the macular retinal thickness parameters, the cpRNFL thickness (P<0.01), macular full retinal thickness (3 mm region) (P<0.01), and macular outer retinal thickness (1 and 3 mm regions) (P<0.05) were significantly thicker in the amblyopic eyes than in the fellow eyes, while the ganglion cell complex thickness, macular full retinal thickness (1 mm region), and macular inner retinal thickness (1 and 3 mm regions) were not significantly different. Among the ONH parameters, the rim area was significantly larger and the cup-to-disc area ratio was smaller in the amblyopic eyes than in the fellow eyes (P<0.05). None of the other ONH parameters were significantly different between the investigated eyes. The differences in the cpRNFL thickness and macular outer retinal thickness in the 1 mm region were significantly correlated with the difference in axial length (P<0.05, r=-0.48; P<0.01, r=-0.59, respectively) and refractive error (P<0.05, r=0.50; P<0.01, r=0.60, respectively). The other parameters were not significantly related to the difference in axial length, refractive error, or best corrected visual acuity.
  
  
  CONCLUSIONS
  We found significant differences in some of the morphological measurements between amblyopic and fellow eyes that appear to be independent of abnormalities in the visual cortex.
authors.affiliation: Department of Ophthalmology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Syunsuke
authors.initials: S
authors.lastname: Araki
authors.affiliation: Department of Ophthalmology, Kawasaki Medical School, Kurashiki, Japan ; Department of Sensory Science, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Kurashiki, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Miki
authors.affiliation: Department of Ophthalmology, Kawasaki Medical School, Kurashiki, Japan ; Department of Sensory Science, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Kurashiki, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Yamashita
authors.affiliation: Department of Ophthalmology, Kawasaki Medical School, Kurashiki, Japan ; Department of Sensory Science, Faculty of Health Science and Technology, Kawasaki University of Medical Welfare, Kurashiki, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Goto
authors.affiliation: Department of Ophthalmology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Haruishi
authors.affiliation: Department of Ophthalmology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ieki
authors.affiliation: Department of Ophthalmology, Kawasaki Medical School, Kurashiki, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Kiryu
keywords: anisometropic amblyopia; ganglion cell complex thickness; macular retinal thickness; peripapillary retinal nerve fiber layer thickness; strabismic amblyopia