Effects of posterior staphyloma on choroidal structure in myopic adults: a retrospective study

Background Studies on the choroid of myopic eyes with posterior staphyloma have shown that choroidal thickness decreased. This retrospective study further analysed the effects of posterior scleral staphyloma on choroidal blood vessels and matrix components compared to non-pathological myopia. Methods In this cross-sectional study, ninety-one eyes were divided into pathological (posterior staphyloma) and non-pathological myopia. The latter was further divided into three groups (Group 1: 26 mm [less than or equal to] axial length; Group 2: 24 mm [less than or equal to] axial length < 26 mm; Group 3: 22 mm [less than or equal to] axial length < 24 mm). Choroidal thickness, total choroidal area, luminal area, stromal area, and choroidal vascularity index were calculated. Results The CVI in N1, N2, I1, S2 of the posterior staphyloma group were lower than those of group 1 (both P < 0.05). The mean height of posterior staphyloma was associated with mean CT (Pearson correlation: r = -0.578, P = 0.039) but not with the mean CVI in posterior staphyloma group. In all groups, the mean choroidal thickness, total choroidal area, luminal area, and stromal area were significantly associated with axial length (P < 0.001), and the mean choroidal vascularity index was significantly associated with the mean choroidal thickness (P < 0.001). Conclusion The choroidal structure of pathological myopia with posterior staphyloma and non-pathological myopia with longer axial length demonstrates alterations in which choroidal vessels are more impaired than the stroma. A lower choroidal vascularity index should be alert to pathological changes for myopia with axial length > 26 mm. Keywords: Choroidal vascularity index, Posterior staphyloma, Myopia, Axial growth