Abstract
Purpose :
Choroidal microvasculature exhibits a significant association with axial length (AL). AL changes with age and as myopia progresses, so long-term changes in choroidal microvasculature might be expected. We conducted a 1-year prospective longitudinal study to investigate changes in choroidal microvasculature indices using optical coherence tomography angiography (OCT-A) among healthy myopic and non-myopic children and young adults.
Methods :
Measurements including 3mm×3mm macular OCT-A enhanced depth scans, AL and refraction were collected at baseline and 1-year follow-up for 22 adults (18-30 years,12 myopes,10 non-myopes) and 21 children (6-15 years,11 myopes,10 non-myopes). Choriocapillaris (29 to 49 µm below retinal pigment epithelium (RPE)) and the deep choroidal layer (64 to 115 µm below RPE) en face OCT-A images were analysed to extract magnification-corrected choriocapillaris flow deficit density (FDDcc) and deep choroidal perfusion density (PDch) for sub-foveal and parafoveal zones. Changes over 1-year were compared between age groups and between refractive groups within the age groups using Mann-Whitney U.
Results :
The FDDcc and PDch did not change significantly over 1-year or differ between age groups (P>0.05), however significant differences between refractive subgroups were observed. AL and spherical equivalent refraction underwent significant changes (P<0.05), with larger AL changes in children (0.20±0.27mm) than adults (0.04±0.07mm). Parafoveal FDDcc changes were significantly associated with AL changes (P=0.01) (Figure 1) and refractive groups (P=0.01) and sub-foveal PDch changes associated with refractive groups (P=0.01) in adults but not in children. Between the refractive groups, changes in sub-foveal FDDcc and PDch and parafoveal FDDcc were significantly different (P<0.05) among adults, but not in children (Figure 2).
Conclusions :
Longitudinal changes in choroidal OCT-A indices were significantly associated with AL changes and refractive group only in adults, with myopes and non-myopes showing different magnitudes of change. These relationships were not found in children.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.