Morphological characteristics of the subfoveal choroid and their association with visual acuity in postoperative patients with unilateral congenital cataracts

Abstract

Background: We aimed to evaluate the morphological characteristics of the subfoveal choroid and explore the possible association of these characteristics with best-corrected visual acuity (BCVA) in postoperative patients with unilateral congenital cataracts (CCs).

Methods: This was a cross-sectional study. Subfoveal choroidal structures were measured by spectral-domain optical coherence tomography with enhanced depth imaging (EDI-OCT). Several choroidal parameters, including subfoveal choroidal thickness (SFCT), total choroidal area (TCA), luminal area (LA), stromal area (SA) and choroidal vascularity index (CVI), were compared between pseudophakic and contralateral healthy eyes. Then, the choroidal parameters were compared between pseudophakic eyes with a poor BCVA (>0.3 logMAR) and those with a good BCVA (≤0.3 logMAR). The performance of the choroidal parameters in detecting a poor BCVA in pseudophakic eyes was evaluated by using the area under the receiver operating characteristic curve (AUC). A logistic regression model was used to assess the association between choroidal parameters and BCVA in postoperative patients with unilateral CCs.

Results: A total of 55 postoperative patients with unilateral CCs were included. The age was 6.67±2.64 years. Thinner SFCT and smaller TCA, LA, SA and CVI were observed in pseudophakic eyes than in contralateral healthy eyes. In addition, in pseudophakic eyes, those with a poor BCVA had a thinner SFCT and a smaller TCA, LA and SA than those with a good BCVA. TCA [AUC, 0.75; 95% confidence interval (CI), 0.62, 0.88], LA (AUC, 0.74; 0.61, 0.87) and SA (AUC, 0.74; 0.60, 0.87) showed acceptable discriminatory abilities on BCVA. Pseudophakic eyes with TCA ≤0.594 mm² [odds ratio (OR), 8.90; 95% CI: 1.99, 39.94; P=0.004], LA ≤0.402 mm² (OR 8.90; 95% CI: 1.99, 39.94; P=0.004) or SA ≤0.218 mm (OR, 6.53; 95% CI: 1.69, 25.27; P=0.007) were more likely to have a poor visual acuity.

Conclusions: The pseudophakic eyes in patients with unilateral CCs had thinner SFCT and smaller TCA, LA, SA and CVI than the contralateral healthy eyes. In pseudophakic eyes, smaller TCA, LA and SA values were associated with a poor visual acuity.

Keywords: Congenital cataracts (CCs); best-corrected visual acuity (BCVA); choroidal structures; optical coherence tomography with enhanced depth imaging.

Figure 1

Binarization analysis of an EDI-OCT image. (A) Original EDI-OCT image. (B) Segmented EDI-OCT image by using the image binarization approach. The subfoveal choroidal area with a width of 1,500 µm centered on the foveola was analyzed. EDI-OCT, optical coherence tomography with enhanced depth imaging.