Correlation between structural characteristic of myopia and other variables are summarized in
Table 2. Axial length, spherical equivalent, and posterior scleral profiles (disc-foveal angle, disc torsion, disc tilt ratio, and PPA/disc area ratio) were checked for correlation. Lower superficial and deep VD in the peripapillary region showed significant correlation with longer axial length (
P = 0.017 and
P = 0.011) and greater PPA/disc area ratio (
P = 0.047 and
P = 0.035). Lower macular deep VD also showed significant correlation with longer axial length (
P = 0.009). Smaller fluctuation of macular deep VD showed significant correlation with longer axial length, greater disc tilt ratio, and greater PPA/disc area ratio (
P = 0.022,
P = 0.024, and
P = 0.044). Comparison between patients with glaucoma with mild and moderate to severe myopia are summarized in
Table 3. The moderate to severe myopia group showed significantly lower initial deep VD in the peripapillary and macular area compared to the mild myopia group. Additionally, the moderate to severe myopia group showed significantly greater deep VD fluctuation in the macular area compared to the mild myopia group. We further classified the patients into three groups to check the tendency of VD and fluctuation of VD according to the degree of myopia. As the degree of myopia gets greater, the initial deep VD decreases in the peripapillary and macular area (
Fig. 1A). The peripapillary deep VD was significantly lower in the severe myopic group compared to the mild (
P = 0.023) and moderate myopia group (
P = 0.001). However, the fluctuation of deep VD gets greater as the degree of myopia gets greater in both the absolute value (
Fig. 1B) and the percentage value of the deep VD (
Fig. 1C). Superficial VD fluctuation was significantly lower in the severe myopia group compared to the mild and moderate myopia group, however, deep VD fluctuation was significantly greater in the severe myopia group compared to the mild (
P < 0.001) and moderate myopia group (
P < 0.001). To summarize, total deep VD decreases as the degree of myopia increases and shows correlation with the posterior pole profiled related to myopia. However, the fluctuation of VD has a tendency to get greater as the degree of myopia increases.