The occurrence frequency of the linear artifact in the present study was 81.88%. In some cases of APACG, the transparency of refractive media was affected by factors such as corneal edema and glaucomatous fleck, resulting in poor image quality. In these cases, the linear artifact could not be observed. In cases with relatively clear refractive media, such as PACS, CPACG and POAG, the rates were higher. In cases with clear refractive media, such as CSC and in the control group, the rate was 100%. The linear artifact can also be detected in many published literatures on EDI OCT, although it has never been reported20–24. This demonstrated that the incidence of the linear artifact was high and that the visibility of the linear artifact was affected by the opacity of refractive media.