Anti-vascular endothelial growth factor (VEGF) treatments significantly improve periarterial capillary-free zone (paCFZ) parameters in patients with branch retinal vein occlusion (BRVO) and macular edema, according to research published in Eye and Vision.
Researchers retroscopically assessed treatment-naïve patients with macular edema secondary to BRVO (n=54; mean age, 60.56±9.18 years; 35 men) presenting to a single center between 2018 and 2020. Among participants with BRVO, 36 patients had ischemic BRVO and 18 patiens had nonischemic BRVO. A group of 30 age- and sex-matched control individuals were also used in the analysis (mean age, 60.92±5.22 years; 18 men). The treatment group underwent 12X12 mm2 wide-field swept-source optical coherence tomography angiography (SS-OCTA) at baseline and at 3, 6, and 12 months after receiving intravitreal ranibizumab injections. The primary outcome measures were changes to the paCFZ and the paCFZ area to artery area (P/A) ratio.
In eyes with BRVO, significant improvements in best-corrected visual acuity (BCVA; mean, 65.67 vs 53.56 Early Treatment Diabetic Retinopathy Study (ETDRS) letters), central retinal thickness (CRT; mean, 262.50 vs 581.70 micrometers (μm)), first-order artery paCFZ area (mean, 0.41 vs 0.54 millimeters (mm)2), first-order artery P/A ratio (mean, 0.89 vs 1.14), second-order artery paCFZ (mean, 0.73 vs 0.96 mm2; P <.01), and second-order artery P/A ratio (mean, 1.41 vs 1.83) were observed 12 months after anti-VEGF treatment compared with baseline (P <.01 for all). Anti-VEGF treatment did not affect first- or second-order artery areas.
Eyes with ischemic BRVO had higher P/A ratios in first- (mean, 1.19 vs 1.04; P =.02) and second- (mean, 1.96 vs 1.57; P =.01) order arteries at baseline compared with eyes with nonischemic BRVO. Similar trends in paCFZ and P/A ratio improvement at 12 months were observed in both groups (all P <.01).
P/A ratio in the first-order artery correlated with baseline CRT (r, 0.366; P =.006), CRT improvement at 12 months (r, 0.366; P =.007), baseline BCVA (r, −0.370; P =.005), and BCVA improvement at 12 months (r, −0.437; P =.001). Similar correlations were observed for second-order artery P/A ratio.
Significant predictors for BCVA at 12 months were baseline BCVA (β, 0.840; P <.001) and P/A ratio in first- (β, −0.163; P =.003) and second- (β, −0.242; P =.041) order arteries.
“Wide-field SS-OCTA shows that anti-VEGF therapy can lead to a significant improvement in the paCFZ parameters in BRVO,” according to the researchers. “Smaller baseline P/A ratios on SS-OCTA tend to predict better visual outcomes at 12 months after anti-VEGF therapy.”
Study limitations include a retroscopic nature, a lack of assessments of other macular parameters, and possible image magnification errors due to insufficient axial length data.
Tang W, Liu W, Guo J, et al. Wide‑field swept‑source OCT angiography of the periarterial capillary‑free zone before and after anti‑VEGF therapy for branch retinal vein occlusion. Eye Vis. Published online July 2, 2022. doi:10.1186/s40662-022-00297-z