Choroidal structural changes in different intermediate AMD patterns

Purpose: To report variation of choroidal thickness (CT) and choroidal vascularity index (CVI) in subjects with drusen and subjects with reticular pseudodrusen (RPD) compared with healthy individuals using the Spectral-domain (SD)-Optical Coherence Tomography with enhanced depth imaging (EDI) system. Design: A prospective, observational, cross-sectional study. Subjects: Eighty-four participants. Methods: The patients were imaged using the Heidelberg Spectralis device (Heidelberg Engineering, Heidelberg, Germany) with EDI mode. EDI-OCT images were exported and then imported into image analysis ImageJ software (National Institutes of Health, Bethesda) and a semiautomated algorithm was used for subsequent quantitative analysis. Main outcome measures: This study evaluated two choroidal parameters: (i) choroidal thickness (CT); (ii) choroidal vascularity index (CVI). Results: CT analysis was performed in three different regions: (i) foveal region, (ii) parafoveal region; (iii) perifoveal region. All the analyzed regions were significantly decreased in RPD pattern, as compared with both the drusen group (p < .005) and healthy eyes (p < .005). CVI was significantly decreased in the RPD pattern, as compared with healthy eyes (p < 0.001). However, the drusenoid pattern did not have statistical significance in comparison with the control group suggesting the lower incidence of this pattern on choroidal vasculopathy. Conclusions: We report CT and CVI difference in RPD and drusen eyes. The RPD pattern seems to be a consequence of an alteration in the choroidal vascularity resulting in severe ischemia and excessive hypoxia inducing an increased risk of late AMD compared to the drusenoid pattern.

Automated summary

The study investigated choroidal thickness and choroidal vascularity index in eyes with drusen and RPD compared with healthy individuals using the SD-OCT with EDI system. Results showed significant decreases in both CT and CVI in RPD eyes, but not in eyes with drusen. This suggests that RPD may be associated with altered choroidal vascularity leading to increased risk of late AMD compared to eyes with drusen.