Investigation of choroidal vascular alterations in eyes with myopia using ultrawidefield optical coherence tomography angiography

Background/aims The study aims to evaluate choroidal vascular changes in younger patients with myopia using ultrawidefield swept-source optical coherence tomography angiography (SS-OCTA).Methods Overall, 724 eyes of 362 participants (177 males, 185 females, age: 32.43 +/- 6.20 years) underwent SS-OCTA imaging (24x20 mm). The eyes were divided into normal, low myopia (LM), moderate myopia (MM), high myopia and superhigh myopia groups according to the spherical equivalent refraction (SER). Changes in choroidal vascular thickness (ChVT) and density (ChVD) in nine grids of the fundus were analysed using the latest version of the built-in analysis software.Results Axial length (AL) showed a negative correlation with SER (r=0.822, p=0.000); ChVT and ChVD showed a negative correlation with AL (p <= 0.001) in all nine grids. In group analysis, compared with normal eyes, myopia affects ChVT earlier than ChVD, as observed in the LM and MM groups, respectively. The decrease in ChVT was most evident in the macular grid (beta = -34.20, p=0.000), whereas the decrease in ChVD was most evident in the optic disc grid (beta = -2.19, p=0.001).Conclusion Myopia has a significant impact on choroidal vascular structure, resulting in spatiotemporal differences. Using SS-OCTA with a new version of the built-in analysis software and a study with a larger sample cohort may aid in providing more authentic information on choroidal vascular changes in eyes with myopia.