Choroidal structural changes correlate with neovascular activity in neovascular age related macular degeneration

PURPOSE. To correlate changes in choroidal thickness and vascularity index with disease activity in patients with neovascular age-related macular degeneration (nAMD). METHODS. Eyes diagnosed with AMD that had two sequential visits within 12 months and that had no choroidal neovascularization (CNV) or had inactive CNV at the first visit were included. Those that had active CNV at follow-up were enrolled as cases. Eyes that did not developed a CNV or that were still inactive at the second visit were enrolled as controls. Disease activity was based on optical coherence tomography (OCT) and fluorescein angiography findings. Subfoveal choroidal thickness (SCT), mean choroidal thickness (MCT), and choroidal vascularity index (CVI) were assessed on enhanced depth imaging OCT and compared between the baseline and follow-up visit. Subgroup analysis accounting for lesion type and previous treatment, if any, were performed. RESULTS. Sixty-five eyes from 60 patients (35 females) and 50 age-and sex-matched controls were included. At the active visit, cases had an increase from 164 +/- 67 mu m to 175 +/- 70 mu m in mean +/- SD SCT and from 144 +/- 45 mu m to 152 +/- 45 mu m in MCT (both P < 0.0001). The mean CVI also increased at from 54.5% +/- 3.3% to 55.4% +/- 3.8% (P = 0.04). Controls did not show significant changes in choroidal measurements between the two visits. Mean SCT, MCT, and CVI values were similar for previously treated and treatment-naive eyes. CONCLUSIONS. Choroidal thickness and CVI significantly increased with active disease in nAMD eyes. Changes in choroidal thickness may predict CNV development or recurrence before they are otherwise evident clinically.