Abstract
Purpose: :
The purpose of this study is to evaluate choroidal thickness using spectral domain optical coherence tomography (SD OCT) imaging both before three and six months after initiation of treatment with intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF)agents in patients with wet age-related macular degeneration (AMD).
Methods: :
A retrospective chart review was done to identify patients with wet AMD who underwent SD OCT imaging with Cirrus HD-OCT (Carl Zeiss Meditech, Dublin, CA) prior to first-time intravitreal injection of a VEGF inhibitor (with either bevacizumab or ranibizumab) and repeat SD OCT scanning 3 and 6 months post-injection. Patients with concurrent macular pathology in the injected eye were excluded. Choroidal thickness measurements were manually performed on all scans using the Cirrus linear measurement tool at 500 µm intervals, 2500 µm temporal and nasal to the fovea by two independent observers. Measurements were compared using a paired t-test and analysis of variance in Prism 5 (GraphPad Software, La Jolla, CA).
Results: :
A total of twenty two eyes of 22 patients were included in this study. Average subfoveal choroidal thickness pre treatment was 202.1µm ± 102.0µm (mean ±standard deviation). Average subfoveal choroidal thickness at 3 months follow up was 188.6µm ± 102.5µm. Average subfoveal choroidal thickness at 6 months follow up was 168.7µm ± 85.9µm. There was a statistically significant difference between pre-treatment and 6 months follow up (p=0.011). There was not a statistically significant difference between pre-treatment and 3 months follow up (p=0.0838). The mean difference in subfoveal choroidal thickness by pairs between pre treatment and 6 months follow up is 18.0µm (95% CI 4.7µm to 31.3µm).
Conclusions: :
Over 3 months, use of intravitreal anti-VEGF injections in the therapy of wet ARMD does not appear to be associated with significant thinning of the choroid. However, over 6 months, intravitreal anti-VEGF does appear to be associated with significant thinning of the choroid. Further follow up with a larger sample size is ongoing to confirm this finding.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • choroid • age-related macular degeneration