OCT angiography and sequential quantitative analysis of type 2 neovascularization after ranibizumab therapy

Abstract

Purpose: To study the precise structural aspects of a type 2 neovascular membrane in a patient with age-related macular degeneration (AMD) using optical coherence tomography (OCT) angiography and perform sequential quantitative analysis of the membrane after ranibizumab therapy.

Patients and methods: Split-spectrum amplitude-decorrelation (SSADA) OCT angiography macular cubes (3 × 3 mm) were acquired with a light source centered at 840 nm, a bandwidth of 45 nm, and an A-scan-rate of 70 000 scans per second. Visible pathologic vessels were outlined manually on average intensity projection en face images, and the area of the lesion and the vessel density were measured at baseline and follow-up.

Results: At baseline, the neovascular lesion measured 4.12 mm(2) and the vessel density was 19.83 mm(-1). Four weeks after the first, and 2 and 4 weeks after the second ranibizumab injection, OCT angiography revealed a progressively smaller vascular lesion (2.32, 1.77 and 1.64 mm(2)), and vessel density (10.24, 8.52 and 7.57 mm(-1)), although the large central trunks of the lesion were unchanged.

Conclusions: In this study, an obvious reduction in size and vessel density of the neovascular lesion was noted after treatment with ranibizumab using SSADA OCT angiography technology. Microvascular components can be delineated with precision, suggesting that this technique may be useful for the management of patients with neovascular AMD in a clinical setting as well as for future clinical trials.

Figure 1

(a) Color fundus photograph of the right eye showing macular hemorrhage. (b and c) Early and late frames of a fluorescein angiography showing classic type 2 neovascularization with central leakage and an adjacent pigment epithelium detachment at the temporal margin.

Figure 2

(a–h) OCT angiography of type 2 neovascularization of the right eye at baseline and at intervals after ranibizumab therapy. (a–d) OCT angiography of type 2 neovascularization with margins outlined at baseline and at 4-week and then 2-week intervals. Note the progressive reduction in the size of the membrane. (e–h) OCT angiography of type 2 neovascularization with color-coded capillary density analysis at baseline and at aforementioned follow-up intervals. Note the progressive reduction in capillary density of the membrane. (i–l) Corresponding spectral domain OCT scans at baseline and follow-up intervals after ranibizumab therapy.