ABSTRACT
Purpose: To investigate the choroidal vascularity index (CVI) and morphological features of the choroid in anisometropic amblyopia. Methods: In this prospective cross?sectional study, 39 patients with unilateral anisometropic amblyopic patients and 33 eyes of 33 healthy control participants were involved. These participants were examined in terms of axial length (AL), spherical equivalent (SE), central macular thickness (CMT), choroidal thickness (CT), total choroidal area (TCA), luminal area (LA), stromal area (SA), LA/SA ratio, and CVI. All parameters were compared between amblyopic eyes, healthy fellow eyes, and healthy control eyes. The Shapiro–Wilk tests, Chi?square test, the paired t?test, Wilcoxon signed?rank test, Mann–Whitney U test, Kruskal–Wallis test, and Pearson/Spearman correlation tests were used. Results: In the hyperopic patients; SE, subfoveal CT, nasal CT, temporal CT, TCA, LA, SA, and CMT were greater in amblyopic eyes than in healthy fellow eyes and control eyes (P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P < 0.001, respectively), and CVI, LA/SA ratio, and AL were smaller in amblyopic eyes than in healthy fellow eyes and control eyes ([P < 0.001, P = 0.006], P < 0.001, and P < 0.001, respectively). In the myopic patients, subfoveal CT, nasal CT, temporal CT, TCA, LA, SA values were statistically smaller in amblyopic eyes than in healthy eyes and control eyes ([P < 0.001, P = 0.002), [P = 0.004, P = 0.012], [P = 0.012, P = 0.032], [P < 0.001, P = 0.013], [P < 0.001, P = 0.024], and [P < 0.001, P = 0.047], respectively). The differences in the AL and choroidal parameters were due to myopia and hyperopia. Conclusion: The choroidal structural parameters of the amblyopic eyes were different from that of the healthy eyes.
ABSTRACT
AIM:To compare the choroidal parameters in children and adolescents with different refractive status, and to investigate the associations between ocular biometrics and choroidal parameters.METHODS:A cross sectional study. A total of 121 healthy children and adolescents(121 right eyes)aged 3-18 years treated in the Second People's Hospital of Hefei were collected. The data were divided into three groups according to spherical equivalent refraction(SER): emmetropia(-0.50<SER≤+1.75D), low myopia(-3.00<SER≤-0.50D)and moderate-to-high myopia(SER≤-3.00D). Ocular biometrics were measured by using the IOL Master. Data of the choroidal structures extracted from a 6mm sub-macular region centered on the fovea, including choroidal thickness(CT), the total choroidal area(TCA), luminal area(LA), stromal area(SA)and choroidal vascularity index(CVI)were determined by image binarization of the enhanced depth imaging-optical coherence tomography(EDI-OCT). Comparing all biology parameters among the three groups, associations among demographic factors, ocular parameters, and choroidal structures were evaluated by using multiple linear regression analysis.RESULTS:TCA, LA, SA and CT were all different among the three groups before age correction(all P<0.001), and CVI was not different(P >0.05). TCA, LA, SA, CT and CVI were found to be statistically different among the three groups after age correction(all P<0.001), and there were differences in pairwise comparisons of TCA, LA, SA and CT among the three groups(all P<0.001), which were the highest in emmetropic eyes and lowest in moderate-to-high myopic eyes, However, the CVI in pairwise comparisons among the three groups showed that only the moderate-to-high myopia group was significantly lower than the emmetropic group(P=0.014). Multiple regression analysis showed that the LA was significantly associated with SER(P=0.020), whereas CT were significantly associated with the axial length(AL)(P=0.028).CONCLUSIONS: The choroidal LA and CVI tend to decrease in children and adolescents with higher myopia, indicating that the decrease of sub-foveal choroidal blood flow may be related to the progression of myopia.
ABSTRACT
Purpose: To compare the accuracy of manual and automated binarization technique for the analysis of choroidal vasculature. Methods: This retrospective study was performed on a total of 98 eyes of 60 healthy subjects. Fovea-centered swept source optical coherence tomography (SS-OCT) scans were obtained and choroidal area was binarized using manual and automated image binarization technique separately. Choroidal vessel visualization in the binarized scans were subjectively graded (grades 0–100) by comparing them with the original OCT scan images by two masked graders. The subjective variability and repeatability was compared between two binarization method groups. Intergrader and intragrader variability was estimated using paired t-test. The degree of agreement between the grades for each observer and between the observers was evaluated using Bland–Altman plot. Results: The mean accuracy grades of the automatically binarized images were significantly (P < 0.001) higher (93.38% ± 1.70%) than that of manually binarized images (78.06% ± 2.92%). There was a statistically significant variability and poor agreement between the mean interobserver grades in the manual binarization arm. Conclusion: Automated image binarization technique is faster and appears to be more accurate in comparison to the manual method.