Changes in the postoperative foveal avascular zone in patients with rhegmatogenous retinal detachment associated with choroidal detachment

Background Rhegmatogenous retinal detachment associated with choroidal detachment (RRDCD) refers to the detachment of the ciliary body and choroid from the sclera along with retinal detachment. The recovery of visual function is often far worse after surgical treatment of RRDCD than following anatomical reduction for complicated reasons. Some scholars have suggested that oxidative stress may cause serious damage to cells when the detached retina becomes reduced to the choroid-retinal pigment epithelium complex and consequentially has an abnormal blood supply, which may limit the recovery of vision after surgery. Aims To observe changes in the blood flow in the macula in patients with RRDCD who underwent pars plana vitrectomy (PPV) for retinal reattachment and silicone oil filling. Methods This retrospective, cohort-controlled study included 35 patients with RRDCD who underwent PPV for the first time and whose retinas were successfully reattached from January 2017 to May 2018. Another 36 patients with rhegmatogenous retinal detachment (RRD) who underwent PPV for the first time and had their retina reattached as well as 40 normal eyes were assessed as controls. The best corrected visual acuity (BCVAs; logMAR) and intraocular pressure were recorded at 1 day, 1 week, 1 month, and 3 months after the operation was recorded. Optical coherence tomography angiography was used to measure the area of the foveal avascular zone. Results At each time point after the operation, the area of the superficial plexus foveal avascular zone was not significantly different between the RRDCD and RRD groups. The area of the deep plexus foveal avascular zone (DFAZ) continued to enlarge after the operation in the RRDCD group but did not significantly change in the RRD group. A comparison of the two groups revealed that the DFAZ area was significantly larger in the RRDCD group than in the RRD group. The changes in DFAZ area in the RRDCD group were significantly different between 1 day to 1 month postoperatively (t = 0.054,P < 0.001), but there was no significant difference in the change from 1 to 3 months postoperatively (t = 0.014,P = 0.063). The correlation between BCVA at 3 months and DFAZ area one day after the operation in the RRDCD group was significant. Conclusion Choroidal lesions in RRDCD patients may have an acute pathological effect on ischaemia of the deep retinal capillary network. The DFAZ area in RRDCD patients can be used to predict and evaluate postoperative visual acuity.