Vessel Density and Retinal Thickness from Optical Coherence Tomography Angiography as New Indexes in Adolescent Myopia

Abstract

Purpose. To evaluate and quantify blood perfusion and retinal thickness (RT) from the perspective of quadrants by optical coherence tomography angiography (OCTA) in adolescents with myopia and explore the relationship between axial elongation and related indexes of OCTA. Methods. A total of 88 subjects (149 eyes) with different degrees of myopia were included in this cross-sectional study. Vessel density (VD) and RT of quadrants in macular and peripheral regions were measured through OCTA. Results. The superficial VD (SVD) of the parainferior region was significantly correlated with axial length (AL) between the emmetropia (EM) group and high myopia (HI) group ( $P=0.012$ ). There were significant differences in deep VD (DVD) in all quadrants, except for the foveal, perifoveal, and peri-inferior regions ( $P>0.05$ ). However, there were significant alterations in the whole, parainferior, and perinasal regions ( $P=0.030$ , 0.023, and 0.035) in the low-to-moderate myopia (L–M) group compared with those in the HI group. There were significant differences in the RT in all quadrants, except for the foveal, paratemporal, and paranasal regions ( $P>0.05$ ) between the EM and L–M groups and the foveal region ( $P>0.05$ ) between the EM and HI groups. Nevertheless, only RT in the peri-inferior region of the L–M and HI groups showed significant differences. AL was negatively correlated with SVD in the perifoveal and parainferior regions (r = −0.179, $P=0.029$ ; r = −0.227, $P=0.005$ ) and inversely correlated with DVD and RT in almost all quadrants, except for the foveal region (r = −0.020, $P=0.811$ ; r = 0.135, $P=1.000$ ). Conclusion. DVD and RT were closely associated with the severity of myopia and might be new indexes in assessing and detecting myopia development via OCTA.