Wide-field swept-source optical coherence tomography angiography (SS-OCTA) in the assessment of retinal vessel density and thickness in 4-to 16-year-old myopic children

Purpose: To analyze the characteristics of macular retinal vessel density and thickness in children with myopia. Methods: A cross-sectional study was conducted. A total of 228 children aged 4 -16 years who visited the Ineye Hospital of Chengdu University of Traditional Chinese Medicine from September 2022 to November 2023 were included. Those with -0.5D < spherical equivalent (SE) < +2.0D were included in the non -myopia group (150 eyes), those with - 3.0D < SE < -0.5D were included in the low myopia group (246 eyes), and those with SE < - 3.0D were included in the moderate -to -high myopia group (60 eyes). All subjects underwent cycloplegic refraction, IOLmaster500, and Wide -field SS-OCTA (to exclude some peripheral retinal degeneration). Multiple linear regression analysis was used to analyze the correlation between macular ETDRS subfield of full retinal thickness (FRT), outer, inner retinal thickness (ORT, IRT), retinal vessel density (VD), deep and superficial retinal vessel density (DVD, SVD), and SE, axial length (AL). Results: There were statistically significant differences ( P < 0.05) in FRT in the central fovea (1 mm diameter)and perifovea (Diameter 3 to 6 mm) among the non -myopia group, low myopia group, and moderate -to -high myopia group. The three groups also showed statistically significant differences ( P < 0.05) in VD in the central fovea and parafovea with a diameter of 1 to 3 mm (except the lower part). In multiple linear regression analysis adjusted for gender and age, SE and AL were found to be correlated with FRT in all ETDRS regions (except the central fovea) ( P < 0.01), and SE and AL were correlated with IRT in the central fovea and perifovea, respectively ( beta range - 2.302 to 1.652; P < 0.05). SE and AL were also correlated with ORT in the parafovea and perifovea, respectively ( beta range -4.371 to -2.344; P < 0.05). AL was negatively correlated with VD in the central fovea and parafovea (except the inferior region) ( P < 0.05), as well as with DVD in all ETDRS regions ( beta range -1.314 to - 1.031; P < 0.05). AL was only negatively correlated with SVD in the parafoveal nasal region ( beta = -0.633, P < 0.05). Additionally, the correlation between AL and DVD, ORT was higher than that with SVD, IRT. Conclusion: The more severe the myopia, the longer the AL, the thinner the FRT in the perifovea, and the lower the VD in both the fovea and parafovea in children. In addition, DVD and ORT were more significantly correlated with AL, suggesting that they may be more closely related to the growth of AL.