Abnormal Outer Choroidal Vasculature in Amblyopia

Abstract

Purpose Several studies have indicated morphological changes in the choroid in amblyopia cases. This study investigates whether choroidal vasculature was different among amblyopic and fellow eyes in unilateral amblyopia patients and healthy eyes, using en face images acquired via swept-source optical coherence tomography (SS-OCT). Design Prospective, observational case-control study. Methods This study included 14 consecutive patients with unilateral amblyopia and 22 age- and axial length-matched healthy eyes. Using SS-OCT, we obtained en face images of choroidal vasculature midway through the subfoveal inner and total choroid, corresponding to the vasculature of the choriocapillaris and Sattler's layer (inner choroid) and Haller's layer (outer choroid), respectively. We analyzed the en face images of the inner and outer choroidal vascular areas in 3 × 3 mm squares adjusted from 6 × 6 mm squares, using Littmann's magnification correction, after binarization of the images as a portion of the whole area. Results The outer choroidal vascular areas were larger in both amblyopic and fellow eyes than in healthy eyes (both P < 0.001), although there were no significant differences in inner (56.35 ± 2.46% and 56.27 ± 3.75%, respectively) or outer (61.49 ± 4.95% and 61.48 ± 3.73%, respectively) choroidal vascular area between amblyopic and fellow eyes (P=0.98 and 0.91, respectively). An outer choroidal vascular area of 59% was set as an appropriate cutoff value for distinguishing patients from controls. Conclusions The outer choroidal vascular area was larger in both amblyopic eyes and fellow eyes compared to healthy eyes. Our findings may help clarify the etiology of amblyopia.

Choroidal vessel density in unilateral hyperopic amblyopia using en-face optical coherence tomography

“…Therefore, novel findings may be obtained by using indices other than BCVA (e.g., accommodation) in the investigation of the relationship between amblyopia and CVD in the future. Several reports have examined choroidal vascular structures in patients with amblyopia [10][11][12][13]. In reports using analyses by binarization of a single-section OCT image, Nishi et al found that the luminal area was significantly larger and the stromal area was significantly smaller in amblyopic eyes than in control hyperopic eyes [10].…”

“…On the basis of analyzing binarized en-face OCT images, Terada et al reported that the outer choroidal vascular areas (i.e., CVD of Haller’s layer) were larger in both amblyopic (61.49 ± 4.95%) and fellow eyes (61.48 ± 3.73%) than in healthy eyes (55.69 ± 1.83%) [ 11 ]. They also indicated that the cutoff for distinguishing between amblyopic patients and controls was 59%.…”

“…Recently, a new method other than thickness has been developed to evaluate choroidal structures, focusing on choroidal vasculature using binarization analyses [8,9]. Some studies have suggested changes in choroidal vasculature in amblyopic eyes, but insufficient knowledge has been accumulated [10][11][12][13]. The purpose of the present study was thus to investigate the clinical significance of evaluating choroidal vascular density (CVD) in patients with amblyopia.…”

Choroidal vessel density in unilateral hyperopic amblyopia using en-face optical coherence tomography

“…Several reports have examined choroidal vascular structures in patients with amblyopia [10,11,12,13]. In reports using analyses by binarization of a single-section OCT image, Nishi et al found that the luminal area was signi cantly larger and the stromal area was signi cantly smaller in amblyopic eyes than in control hyperopic eyes [10].…”

“…Recently, a new method other than thickness has been developed to evaluate choroidal structures, focusing on choroidal vasculature using binarization analyses [8,9]. Some studies have suggested changes in choroidal vasculature in amblyopic eyes, but insu cient knowledge has been accumulated [10,11,12,13]. The purpose of the present study was thus to investigate the clinical signi cance of evaluating choroidal vascular density (CVD) in patients with amblyopia.…”