Distribution of the Retinal Microcirculation Based on the Morphology of the Optic Nerve Head in High Myopia

To explore the retinal microvasculature of the optic nerve head and macula and their associations with the optic nerve head deformation in high myopia.

One hundred sixty-seven eyes from patients with high myopia (HM) were enrolled in a cross-sectional study. We have evaluated and measured characteristics like the tilt ratio of the optic disc, interpupillary vascular density (IVD), peripapillary vascular density (PVD), macular vascular density (MVD), subfoveal choroidal thickness (SFCT) and foveal avascular zone (FAZ). The subjects were classified as a non-tilt group (control group) and a tilt group based on the tilt index. The above parameters were utilized to compare the two groups. In addition, we collected the data from the subjects' right eyes to analyze variance, the Kruskal-Wallis test, and the least significant difference.

The patients were divided into the non-tilt group of ninety-one eyes and the tilt group of seventy-six eyes. We found that the IVD in the tilt group was more significant than in the non-tilt group (t = -2.794, P = .006). On the other hand, the PVD was less in the tilt group than in the non-tilt, especially in the NS, NI and IN directions (t_NS = 3.782; t_NI = 3.07; t_IN = 2.086; P < .05). Interestingly, the values of PVD were the highest in temporal, second in superior and inferior and lowest in nasal. Concerning the fovea-DMVD (including fovea, parafovea and perifovea), we characterized them as more minor in the tilt group when compared to those in the non-tilt group (P < .05).

Herein, we discovered that the retinal microvasculature differed significantly in patients with HM according to the ONH morphology. In this population, lower PVD and thinner SFCT were associated with higher odds of the tilted optic disc. In addition, the other two characteristics, the IVD and DMVD, were affected by the ONH deformation. Finally, we showed that PVD demonstrated better predictability of rapid myopic progression than MVD.