A Brief Study about Choriocapillaris Vascular Density Changes: Healthy Vs. Advanced Exudative Age-related Macular Degeneration Previously Treated with Multiple Anti-VEGF Intravitreal Injections

Purpose: The aim of our study was to highlight the differences between choriocapillaris VD in healthy ae-AMD eyes by OCT-A.

Introduction: The introduction of OCT-A in clinical practice, we have continued to gain considerable advancements in our knowledge regarding age-related macular degeneration, mostly for the exudative type (AMD).

Method: In this observational, cross-sectional study, 21 healthy and 21 ae-AMD eyes, already treated with anti-VEGF, were enrolled. Angio-View retina patterns centered on fovea (6.4 × 6.4 mm) were acquired for all participants using Solix full-range OCT (Optovue Inc., Freemont, CA, USA). The main outcome was to compare choriocapillaris VD between healthy and ae-AMD eyes. Automated measurements of whole image choriocapillaris VD (%) and fovea grid-based (%) were collected for the analysis. Angio-View patterns were used to assess the flow area (mm2) of macular neovascularization (MNV) by contour flow measure algorithm. Best-corrected visual acuity (BCVA) of both groups was also used for the statistical analysis.

Results: The mean age was 60.9 (±8.3) in healthy and 73.33 (±15.05) in ae-AMD eyes. The mean BCVA (ETDRS letters) was 98.47 (±1.50) in healthy and 7.04 (±5.96) in ae-AMD eyes. The Mann–Whitney test comparing choriocapillaries VD for whole and fovea healthy and ae-AMD eyes showed statistical significance (p < 0.0001 (t = 4.91; df = 40) and p < 0.0001 (t = 6.84; df = 40), respectively). Regarding, the correlation between MNV and VD of choriocapillaries, neither whole nor fovea areas were statistically significant (F = 0.38 (R2 = 0.01) and 1.68 (R2 = 0.08), respectively). Furthermore, this study noted greater choriocapillaris non-perfusion in type 3 MNV. Considering the pathogenesis of type 3 MNV, it is particularly interesting to study the choriocapillaris.

Conclusions: Choriocapillaris VD showed a statistically significant reduction in comparison to healthy eyes in ae-AMD eyes. Choriocapillaris impairment can be seen in the early phase of MNV pathogenesis. Future applications would be useful to assess choriocapillaris VD in different MNV such as Type 1, Type 2, Combined Type1-Type 2, retinal angiomatous proliferation (RAP), and polypoidal choroidal vasculopathy (PCV).