Asymmetric response to ranibizumab in mixed choroidal neovascularization in a neovascular age-related macular degeneration diagnosed on OCT angiography – case report

Background To present a case report of a patient with a mixed choroidal neovascular membrane (CNV) with an asymmetric response to ranibizumab diagnosed on optical coherence tomography angiography (OCTa). Case presentation A 61-year-old male was referred to our department in September 2017 due to decreased vision in his left eye. Best-corrected visual acuity (BCVA) was 43 Early Treatment Diabetic Retinopathy Study (ETDRS) letters in the left eye. Macular edema was present in the left eye, and a mixed CNV was identified on the OCTa. Therapy with intravitreal ranibizumab was commenced. After 5 ranibizumab injections, the BCVA was 42 ETDRS letters, and considerable intraretinal edema was still present. OCTa showed a resolution of the type 2 lesion of the mixed CNV; however, the type 1 lesion had continued to grow. The patient was then switched to intravitreal aflibercept. After 3 monthly aflibercept injections, the BCVA improved to 53 ETDRS letters, and a reduction of the edema was observed on the optical coherence tomography (OCT). OCTa showed a decrease in both the area and vessel density in the type 1 lesion of the CNV. Therapy with aflibercept was continued; however, while the intraretinal edema continued to improve, atrophy developed in the macula and the BCVA worsened to 43 ETDRS letters. Conclusions Ranibizumab nonresponse in a neovascular age-related macular degeneration is not uncommon. However, to our knowledge, this is the first described case of an asymmetric response to ranibizumab in a mixed CNV. While the type 2 lesion of the CNV reacted swiftly to the ranibizumab therapy, the type 1 lesion continued to grow. As with some other cases of ranibizumab resistance, switching to aflibercept proved effective.