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

PURPOSE: To 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.

METHODS

A 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.

RESULTS

Significant 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 retinal remodeling associated with myopia. 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.

CONCLUSION

Retinal structural and microvascular alterations associated with increasing myopia severity exhibited substantial spatial heterogeneity across the macula. Retinal thickness changes involved more extensive sectors, whereas vessel density alterations were relatively localized to central and parafoveal regions. The refined 17-sector ETDRS analysis enables detailed characterization of spatial retinal remodeling and may help identify regions potentially associated with increased vulnerability during myopia progression. These findings provide a basis for future studies exploring imaging approaches for risk assessment of retinal changes associated with myopia. However, further longitudinal validation across different platforms is required before their potential clinical application in monitoring myopia progression can be established.