Evaluation of changes in choroidal neovascularization secondary to age-related macular degeneration after anti-VEGF therapy using spectral domain optical coherence tomography

Abstract

Purpose: To evaluate the changes in choroidal neovascularization (CNV) after anti-VEGF therapy for treatment of age-related macular degeneration (AMD) using spectral domain optical coherence tomography (SD OCT).

Materials and methods: This retrospective study included 65 eyes of 65 patients with CNV secondary to AMD. All patients underwent SD OCT before and 4 weeks after three intravitreal injections of bevacizumab (bevacizumab group) or ranibizumab (ranibizumab group). The diameter and thickness of CNV were measured from SD OCT images.

Results: Retinal edema was completely resolved in 57%, partially resolved in 28% and unchanged in 15% of all post-injection SD OCTs. The resolution rate of retinal edema was not significantly different between the bevacizumab and ranibizumab group (p = 0.960). In all CNV types, the diameter of CNV did not show significant change after treatment; the average diameter changed from 2923 to 2888 μm in classic CNV and from 2378 to 2338 μm in occult CNV in bevacizumab group; from 2691 to 2580 μm in classic CNV and from 2731 to 2337 μm in occult CNV in ranibizumab group. However, the thickness of CNV showed a significant reduction in classic CNV of both the bevacizumab group (from 301 to 233 μm, p = 0.012, reduction rate 22%) and the ranibizumab group (from 258 to 213 μm, p = 0.025, reduction rate 17%). In occult CNV, the thickness of CNV showed a significant reduction only in the ranibizumab group (from 163 to 146 μm, p = 0.033, reduction rate 10%).

Conclusions: Anti-VEGF therapy for the treatment of AMD may reduce the thickness of CNV and thus result in morphologic stability of CNV. Although morphologic regression of CNV is not achieved, further CNV growth could be arrested with anti-VEGF therapy.