Evaluation of efficacy of combination therapy of intravitreal conbercept with posterior sub-Tenon triamcinolone acetonide for treatment of macular edema secondary to non-ischemic branch retinal vein occlusion

Objective

To evaluate the efficacy of combination therapy of intravitreal conbercept (IVC) with posterior sub-Tenon injection of triamcinolone acetonide (PSTA) in treating macular edema secondary to non-ischemic branch retinal vein occlusion (BRVO).

Methods

A nonrandomized controlled study was conducted.Fifty-nine patients (59 eyes) diagnosed with macular edema secondary to non-ischemic BRVO were enrolled in Heping Hospital Affiliated to Changzhi Medical College from October 2016 to November 2019.The subjects were divided into IVC group (28 eyes) and combination therapy of IVC with PSTA group (IVC+ PSTA group for short) (31 eyes). IVC group received IVC 0.5 mg and IVC+ PSTA group received IVC 0.5 mg combined with PSTA 40 mg as the initial therapy, then a pro re nata (PRN) IVC administration was adopted for the two groups.The mean best corrected visual acuity (BCVA) converted to the logarithm of the minimum angle of resolution unit, central macular thickness (CMT) and intraocular pressure (IOP) before and 1, 3, 6 months after injection were measured and compared.The number of repeated IVC injections and relevant complications were recorded.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Heping Hospital Affiliated to Changzhi Medical College (No.20160R9). Written informed consent was obtained from each subject prior to any medical examination.

Results

There was a statistically significant difference in BCVA between the two groups among different time points (F_group=0.464, P=0.498; F_time=25.454, P<0.001). Compared with before injection, the BCVA of both groups was significantly improved at each time point after injection (all at P<0.001). There was a statistically significant difference in CMT between the two groups among different time points (F_group=6.208, P=0.016; F_time=155.505, P<0.001). The CMT of both groups at each time point after injection was significantly smaller than that before injection, and the CMT in IVC+ PSTA group at 1 and 3 months after injection was smaller than that in IVC group (all at P<0.05). There was a statistically significant overall difference in IOP between the two groups (F_group=9.994, P=0.006; F_time=2.679, P=0.056). At 1 and 3 months after injection, the IOP in IVC+ PSTA group was higher than that in IVC group, showing statistically significant differences (both at P<0.01). There were 4 eyes with an IOP higher than 21 mmHg (1 mmHg=0.133 kPa) in IVC+ PSTA group.Within the 6-month follow-up, the mean number of repeated IVC injections of IVC group was 1.25±0.93, which was higher than 0.61±0.72 of IVC+ PSTA group, and the difference was statistically significant (P=0.039). No other ocular complication was observed in both groups.

Conclusions

Combination therapy of IVC with PSTA is effective in improving the BCVA and macular edema of patients with macular edema secondary to non-ischemic BRVO.A single PSTA injection can enhance the effect of conbercept in reliving macular edema in early months and reduce the number of repeated conbercept injections in the short term.

Figures&Tables

Retinal vein occlusion; Macular edema; Conbercept; Triamcinolone acetonide; Posterior sub-Tenon injection