The role of optical coherence tomography angiography in evaluating recurrent macular edema secondary to central retinal vein occlusion after intravitreal injection of ranibizumab / 中华眼底病杂志

ABSTRACT

Objective:To observe the differences of macular microvascular structure between recurrent and non-recurrent macular edema (ME) secondary to central retinal vein occlusion (CRVO) after intravitreal injection of ranibizumab (IVR), and to preliminarily analyze the correlation between recurrence and ME.Methods:A prospective clinical observational study. Forty-five patients (45 eyes) diagnosed as CRVO with ME were included in this study in Tianjin Medical University Eye Hospital from January 2020 to December 2021. There were 22 males (22 eyes) and 23 females (23 eyes). All cases were unilateral. The average age was 61.11±10.88 years old. All patients received IVR treatment once a month for 3 consecutive months. ME were regressive after the initial three treatments. The patients were divided into recurrent group (21 cases, 21 eyes) and non-recurrent group (24 cases, 24 eyes) based on ME recurrence at 6 months after ME resolution. All patients underwent best corrected visual acuity (BCVA), intraocular pressure, and optical coherence tomography angiography (OCTA). OCTA was used to scan the macula in the area of 3 mm×3 mm, and the vessel density (VD) of superficial capillary plexus (SCP), deep capillary plexus (DCP), fovea and parafovea before and after treatment was measured. Foveal retinal thickness, foveal avascular zone (FAZ) area, perimeter of FAZ (PERIM), avascular index of FAZ (AI), VD within 300 μm width of FAZ range (FD-300). Foveal VD included superficial and deep retinal VD (SFVD, DFVD); parafoveal VD included superficial and deep retinal VD (SPFVD, DPFVD). Taking the initial three treatments as the observation time point, the changes of the parameters of the two groups were compared. Comparison between the recurrent and non-recurrent group was performed by two independent sample t-tests. Receiver operating characteristic (ROC) curve analysis was used to measure the area under the curve (AUC) of VD for predicting the recurrence of ME. Results:There were no significant differences in age ( t=1.350), IOP ( t=1.929), SFVD ( t=-1.716), DFVD ( t=-1.143), CRT ( t=-1.207) and AI ( t=1.387) between the recurrent and non-recurrent group ( P>0.05). There were significant differences in times of anti-VEGF therapy ( t=5.912), BCVA ( t=5.003), SVD ( t=-4.617), SPFVD ( t=-4.110), DVD ( t=-5.503), DPFVD ( t=-4.772), FAZ area ( t=2.172), PERIM ( t=2.606) and FD-300 ( t=-3.501) between the recurrent and non-recurrent group ( P<0.05). ROC curve analysis showed that the AUC of DVD in predicting the recurrence of ME was highest, with 0.921, and the threshold was 37.65%. The sensitivity and specificity were 91.7% and 85.7%, respectively. Conclusions:The SVD, SPFVD, DVD, DPFVD and FD-300 in the recurrence group are significantly lower than those in the non-recurrence group, while the FAZ area and PERIM are significantly higher than those in the non-recurrence group. DVD≤37.65% can be used as the best threshold for predicting the recurrence of ME.