Spatial heterogeneity of retinal structural and microvascular alterations across different degrees of myopia: a 17-sector ETDRS analysis using wide-field SS-OCTA

PurposeTo investigate the spatial heterogeneity of retinal structural and microvascular alterations across different degrees of myopia using wide-field swept-source OCTA (SS-OCTA) combined with 17-sector ETDRS analysis.MethodsA total of 131 participants (131 eyes) with myopia were categorized into low (n = 45), moderate (n = 37), and high myopia groups (n = 49) . Wide-field SS-OCTA was used to quantify retinal vessel density and retinal thickness across 17 ETDRS sectors in superficial capillary plexus (SCP), deep capillary plexus (DCP), full retinal layer, and different retinal thickness layers. GEE models were applied to evaluate the effects of myopia severity, retinal region, and their interactions. Bonferroni-adjusted pairwise comparisons were performed to identify region-specific differences among groups.ResultsSignificant group × region interactions were observed for both retinal vessel density and retinal thickness across all analyzed layers (all P < 0.05), indicating marked spatial heterogeneity in myopia-associated retinal remodeling. Retinal thickness alterations involved a broader range of ETDRS sectors and retinal layers, whereas vessel density reductions were predominantly localized to foveal and parafoveal regions, particularly within the DCP and full retinal layers. Furthermore, directional spatial patterns were observed: retinal thickness alterations may appeared more pronounced in parafoveal nasal and inferior sectors as well as temporal perifoveal sectors, while vessel density reductions tended to be greater in parafoveal nasal and inferior regions.ConclusionRetinal structural and microvascular alterations associated with increasing myopia severity exhibit substantial spatial heterogeneity rather than uniform changes across the macula. Retinal thickness alterations involved a broader range of sectors, whereas vessel density changes were more localized to central and parafoveal regions. Furthermore, potential directional differences in regional involvement were observed.Refined 17-sector ETDRS analysis enables identification of localized retinal vulnerability and potential directional susceptibility. These findings may facilitate  monitoring of myopia-related retinal remodeling.