Atherosclerotic disease and serum risk factors in phenotypes of age-related macular degeneration (AMD)

Abstract

Purpose : Attempts to characterize the connection between AMD and atherosclerotic disease (ASD) and its risk factors have yielded conflicting and inconclusive results, but there has been a growing appreciation of the distinction between subretinal drusenoid deposits (SDD) and soft drusen (SD) subtypes in AMD. Here, we investigate whether the SDD and SD subtypes of AMD show differences in prevalence of ASD or levels of vascular serum risk factors.

Methods : Volume spectral-domain optical coherence tomography (SD-OCT) scans, self-reported health history questionnaire, and blood samples were obtained for 200 subjects with AMD. The presence of SDD or SD or mixed subtype was judged by two retina specialists. The presence of ASD was determined by reported history of angina, stroke, transient ischemic attack, amaurosis fugax, stenting or bypass surgery, documented carotid artery stenosis >50%, or abnormal stress test results. Categorical variables were compared across groups using chi-square testing, while continuous variables were compared using Kruskal-Wallis non-parametric testing with posthoc Mann-Whitney U testing for subgroup analysis.

Results : SD-OCT analysis showed that 103 subjects had pure SD, 26 had pure SDD, and 71 subjects had a mixed subtype. The prevalence of ASD was 15.5% for pure SD, 26.8% for mixed subtype, and 38.5% for pure SDD (p=0.028 for pure SD vs pure SDD). Subfoveal choroidal thickness in the right eye was 196 (153-240), 148.5 (118.75-189), and 145 (108.5-173.5) for the SD, mixed, and pure SDD groups respectively (p<0.001). There was no significant difference in serum lipid levels among the groups; however, there was a significant difference among the groups in high sensitivity C-reactive protein (hsCRP) level (p=0.042): hsCRP was 1.17 (0.6-2.4), 1.72 (0.96-3.72) and 2.09 (0.775-4.115) for the pure SD, mixed SD/SDD, and pure SDD groups respectively.

Conclusions : These findings contribute to a growing body of evidence that SDD and SD phenotypes associate with different risk factors, and that the SDD subtype may have a more robust relationship with ASD, potentially through inflammatory processes related to higher levels of hsCRP found in this subtype. Further studies based on AMD subtype may further elucidate separate risk factors and disease mechanisms underlying these different types of AMD.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

Serum lipid levels and atherosclerotic disease by AMD sub-type