Is the peripapillary retinal perfusion related to myopia in healthy eyes? A prospective comparative study

OBJECTIVES The aim of this study was to evaluate the peripapillary and parafoveal perfusion of young, healthy myopic subjects with spectral domain optical coherence tomography (OCT) angiography. DESIGN A prospective comparative study was conducted from December 2014 to January 2015. SETTING Participants recruited from a population-based study performed by the Eye, Ear, Nose and Throat Hospital of Fudan University in Shanghai. PARTICIPANTS A total of 78 Chinese normal subjects (78 eyes) with different refraction were included. Myopia was divided into 4 groups on the basis of the refractive status: 20 eyes with emmetropia (mean spherical equivalent (MSE) 0.50D to -0.50D), 20 eyes with mild myopia (MSE -0.75D to -2.75D), 20 eyes with moderate myopia (MSE -3.00D to -5.75D), and 18 eyes with high myopia (MSE≤-6.00D). MAIN OUTCOME MEASURES Peripapillary and parafoveal retinal and choroidal perfusion parameters and their relationships with axial length (AL) and retinal nerve fibre layer (RNFL) thickness were analysed. RESULTS Significant differences were found for the retinal flow index and vessel density in the peripapillary area among the 4 groups, but not in the parafoveal area. The high myopia group had the lowest peripapillary retinal flow index and vessel density. In addition, there was a negative correlation (β=-0.002, p=0.047) between the AL and peripapillary retinal flow index and a positive correlation between RNFL thickness and the peripapillary retinal perfusion parameters (flow index: β=0.001, p=0.006; vessel density: β=0.350, p=0.002) even after adjustment for other variables. CONCLUSIONS Highly myopic eyes have a decreased peripapillary retinal perfusion compared with emmetropic eyes. Such vascular features might increase the susceptibility to vascular-related eye diseases.