2.3. SS-OCT Data Acquisition

All study subjects were imaged using the SS-OCT (Triton DRI-OCT, Topcon, Inc, Tokyo, Japan) preoperatively and at 1 week (W1), 1 month (M1), and 3 months (M3) postoperatively, and the OCT scans were tracked at all follow-up visits. All images were acquired in the morning considering the diurnal variation of choroid vasculature. Images with a signal strength index of more than 40 and no residual motion artifacts were saved for further analysis. CT was defined as the distance between the outer boundary of retinal pigment epithelium/Bruch's membrane and the chorioscleral interface, and the CT values were obtained with the built-in software of the SS-OCT device (Topcon FastMap, version 10.13.003.06). The foveal CT was defined as the CT value in the center circle in the standard ETDRS grid; the parafoveal CT was defined as the arithmetic average value of CT in subregions in the annulus with an outer diameter of 3.0 mm and an inner diameter of 1.0 mm in the standard ETDRS grid; the perifoveal CT was defined as the arithmetic average value of CT in subregions in the annulus with an outer diameter of 6.0 mm and an inner diameter of 3.0 mm in the standard ETDRS grid.