Assessment of OCT-Based Macular Curvature and Its Relationship with Macular Microvasculature in Children with Anisomyopia

INTRODUCTION

To evaluate the intraocular differences in optical coherence tomography (OCT)-based macular curvature index (MCI) among children with anisomyopia and to investigate the relationship between MCI and the macular microvasculature.

METHODS

Fifty-two schoolchildren with anisometropia > 2.00 D were enrolled and underwent comprehensive examinations including cycloplegic refraction, axial length (AL), and swept source OCT/OCT angiography. OCT-based MCIs were determined from horizontal and vertical B-scans by a customized curve fitting model in MATLAB R2022 at 1-mm-, 3-mm-, and 6-mm-diameter circles at fovea. Characteristics and topographic variation of MCI was analyzed, and the relationships with microvascularity and its associated factors were investigated.

RESULTS

MCI achieved high reliability and repeatability. There were overall larger MCIs in the more myopic eyes than the less myopic eyes in 1-mm-, 3-mm-, and 6-mm-diameter circles at fovea (all p < 0.001). For the topographic variation, horizontal MCI was significantly greater than vertical MCI (all p < 0.001), and was the largest in 6-mm circle, followed by 3-mm and 1-mm circles. Stronger correlation of horizontal MCI with myopic severity than vertical MCI was found. Partial Pearson's correlation found MCI was negatively associated with deep capillary plexus (DCP) vessel density (p = 0.016). Eyes with a higher MCI in a 6-mm circle were more likely to have longer AL (p < 0.001), lower DCP vessel density (p = 0.037), and thinner choroidal thickness (ChT) (p = 0.045).

CONCLUSION

Larger MCI was found in the more myopic eyes of children with anisomyopia and was significantly associated with smaller DCP density, suggesting that MCI was an important indicator of myopia-related retinal microvascularity change, and it could be a valuable metric for myopia assessment in children.

Macular curvature in vertical cross sections of optical coherence tomography in school age children

Although the underlying mechanism of macular curvature remains unclear, it has been linked to various ocular diseases. However, changes in macular curvature during growth have not been thoroughly investigated. This study aimed to investigate macular curvature in children of different ages and its association with axial length. A total of 122 right eyes of healthy elementary school students (Group E; 8-9 years old; 61 males and 61 females) and 173 right eyes of healthy junior high school students (Group J; 12-13 years old; 83 males and 90 females) were included. Axial length, color fundus photographs, and optical coherence tomographic vertical cross-sectional images of the macula were obtained and used for analysis. The macular curvature was plotted as the retinal pigment epithelium and fitted to a second-degree polynomial equation using ImageJ software, to calculate the macular curvature. The Mann-Whitney U test compared macular curvature and axial length between the E and J Groups. The association between the macular curvature and axial length was determined using Spearman's correlation analysis. Group J's axial length and macular curvature were significantly greater than Group E's (p < 0.001). Macular curvature was significantly positively correlated with axial length in Group J (r = 0.40, P < 0.001) but not in Group E (r = 0.08, P = 0.40). These findings suggest a possible increase in macular steepness during this period. Further longitudinal cohort studies are needed to confirm these results.