Objective To explore the clinical characteristics of myopic macular retinoschisis (MRS) in an elder pathologic myopia population and the risk factors for different grades of MRS.

Methods 238 eyes of 238 patients with high myopia over 50 years old in the 2016 Shanghai Adult High Myopia Epidemiology Survey Project were enrolled in the cross-sectional study. MRS was classified into five groups: no macular retinoschisis (S0) group, extrafoveal retinoschisis (S1) group, foveal retinoschisis (S2) group, both fovea and extrafovea retinoschisis but not the entire macula (S3) group, and entire macula retinoschisis (S4) group. S0 group was set as the control group. Each participant underwent detailed ocular examinations. The grading of atrophic myopic maculopathy (AMM) was assessed. Swept-source optical coherence tomography (SS-OCT) was used to detect the incidence of epiretinal membrane (ERM) and vitreomacular traction (VMT) and to measure the macular scleral height (MSH).

Results MRS group comprised 89 eyes in 238 eyes (37.4%). No significant differences were found in age or sex between the MRS group and the non-MRS group. The nasal, temporal, and inferior MSH in the MRS group were significantly higher than those in the non-MRS group (P < 0.05). The incidence of ERM, VMT, and severe AMM above A2 was higher in the MRS group (P < 0.05). Among the different grades of MRS, the S2 group displayed a significantly shorter axial length (P < 0.001) and a significantly higher proportion of eyes with A0 or A1 (36.4%, P=0.046), which was similar to the S0 group.

Conclusions Long axial length, MSH, VMT, and severe AMM are risk factors for MRS. There might be different formation mechanisms of foveal retinoschisis and extrafoveal retinoschisis, which need to be further confirmed by a long-term cohort study.