Swept-source optical coherence tomography angiography in the course of anti-VEGF treatment of choroidal neovascularization subsequent to birdshot chorioretinopathy

Introduction
The aim of the study was to present swept-source optical coherence tomography (OCT) angiography in a case of birdshot retinopathy complicated by choroidal neovascularization (CNV).

Material and methods
59-year-old, HLA-A29 positive woman, treated for three years for birdshot chorioretinopathy with infliximab for systemic immunosuppression, presented to our clinic with decline in visual acuity in her left eye. Swept-source OCT and swept-source OCT angiography were performed additionally to fluorescein angiography and indocyanine green angiography. 0.05 ml of bevacizumab treatment was administered monthly for five months. Anti-VEGF treatment was administered with improvement in visual acuity, but without complete regression of CNV.

Results
At presentation visual acuity was 0.4 in her right eye and 0.1 in left eye. One month after anti- VEGF administration, we observed improvement of visual acuity to 0.3, with slight regression of the branched network on swept-source OCT angiography. After the second anti-VEGF injection visual acuity in this eye improved to 0.4. The fovea contour normalized and the hyperreflectivity in the swept-source OCT area above RPE corresponding to branched CNV disappeared.

Conclusions
Swept-source OCT angiography revealed two findings. First, we observed numerous hyporeflective spots visible in the superficial and deep retinal layer, but most pronounced in the choriocapillaries. Those are probably corresponding with the activity of the disease. Second, we observed CNV in one eye.