Pathologic myopia is a leading cause of blindless worldwide. Therefore, a study presented at the American Society of Retina Specialists (ASRS) 2021 Annual Meeting looked to elucidate the vascular and structural changes in myopia on widefield swept source optimal coherence tomography angiography (WF-SS-OCTA).
This was a prospective, cross-sectional observational study in design. Between November 2018 and October 2020, researchers evaluated 75 eyes in 48 patients with high myopia (HM), 43 eyes in 31 patients with mild to moderate myopia (MM), and 68 eyes in 53 healthy age-matched controls at a single center. They assessed vessel density (VD) and vessel skeletonized density (VSD) of the superficial capillary plexus, deep capillary plexus and calculated whole retina as well as foveal avascular zone (FAZ) circularity, perimeter, and area, choroidal thickness (CT), and retinal thickness (RT).
After controlling for age and the presence of systemic hypertension, the results showed that HM and MM were associated with a statistically significant decrease in VD and VSD in all layers on 12×12 mm scans. Furthermore, the researchers noted, HM was associated with a VD decrease in every Early Treatment Diabetic Retinopathy Study subfield, with a larger decrease temporally in 12×12 mm scans. HM was also associated with increased FAZ perimeter and area and decreased circularity on 12×12 mm scans.
“Using WF-SS-OCTA in a large, comprehensive cohort, we identified a reduction in VD and VSD and structural changes associated with myopia. Decrease in VD and VSD was greater in the temporal quadrant and reductions in CT and RT were uneven across the retina,” the researchers noted. They added that future studies “may help identify risk factors for the progression of pathologic myopia and associated vision threatening complications.”
Source: Ludwig C, et al. Widefield Swept-Source Optical Coherence Tomography Angiography. Published for ASRS 2021; October 8-12, 2021, San Antonio, TX.