Evaluation Of Microvascular Changes In The Macular Area Of Eyes After Rhegmatogenous Retinal Detachment Surgery By Optical Coherence Tomography Angiography

Objective: To analyze the relationship between the microvascular changes in the macular area of eyes and postoperative best corrected visual acuity(BCVA)after rhegmatogenous retinal detachment(RRD)by using optical coherence tomography angiography(OCTA).Methods: The subjects were sixteen patients(16 eyes)diagnosed with RRD,in the Ophthalmology clinic of the First Affiliated Hospital of China Medical University from June 2018 to September 2019.According to the scope of preoperative retinal detachment,the patients were divided into two groups: macula-off group(n=10)and macula-on group(n=6).They all underwent vitrectomy with oil tamponade for RRD and had successful retinal reattachment.All patients underwent BCVA examination(using the international standard visual acuity chart),anterior slit-lamp examination,fundus examination after mydriasis,B-ultrasound and OCT before the surgery.OCT and OCTA were performed 3months after the surgery to measure the foveal avascular zone(FAZ)area,central macular thickness(CMT)and the vascular density(VD)was calculated.The contralateral eyes did the same examinations as the control group.The BCVA of the affected eye before and after treatment,the FAZ area,VD and CMT of the superficial retinal capillary plexus(SCP)and the deep retinal capillary plexus(DCP)of the affected eyes and healthy eyes were compared and analyzed.Correlation analysis was performed between postoperative BCVA and the FAZ area and VD of SCP and DCP.Results: Postoperative Log MAR BCVA in the macula-off group was larger than preoperative Log MAR BCVA(difference 0.53±0.615,t=2.726,P=0.023).The FAZ areas in the SCP and DCP of the affected eyes(SCP: 0.49±0.13mm2,DCP:0.57±0.13mm2)were significantly larger than those of healthy eyes(SCP: 0.34±0.05mm2,DCP: 0.38±0.05mm2)following surgery.Among them,the difference between the macula-off group and the healthy eyes was more significant(SCP: difference0.19±0.14mm2,t=4.491,P=0.002;DCP: 0.22±0.13mm2,t=5.141,P=0.001).The vascular density(VD)in the SCP and DCP of the affected eyes were significantly lower than those of healthy eyes(decreased by 4.34 ± 4.31%,t=4.002,P=0.001 and 5.61 ± 3.70%,t=6.058,P<0.001,respectively).Among them,the difference between DCP of the macula-off group and the healthy eyes was more significant(6.05±4.00,t=4.780,P=0.001).The postoperative BCVA was negative correlated with the FAZ area of SCP(r= 0.783,P=0.007)and DCP(r = 0.750,P=0.013)in the macula-off group,but not with the FAZ area of SCP and DCP in the macula-on group,and had no correlation with the VD of SCP and DCP in the two groups.Conclusion: The FAZ area of the DCP increased and the VD decreased most in the RRD patients with macula-off,indicating the ischemia and hypoxia of the deep capillary plexus is more serious,which may affect the recovery of postoperative visual acuity,and there was a negative correlation between BCVA and FAZ area in macula-off group.