Can drusen growth in age-related macular degeneration be slowed by oral curcumin?

Abstract

Purpose : Drusen size is a hallmark of AMD progression to geographic atrophy (GA) or choroidal neovascularization (CNV) leading to loss of vision. Drusen formation accompanies retinal pigment epithelium atrophy and is a risk factor for disease progression. Although the cause remains unclear, drusen size predicts the likelihood of progression to advanced AMD. In this study, we evaluated the effect of oral curcumin, an inhibitor of the innate immune receptor TLR4, on drusen size and disease progression over the course of one year in a cohort of pre-advanced AMD subjects.

Methods : Participants with pre-advanced AMD (n=18) were recruited from the office of Zaparackas and Knepper, Ltd. in Chicago, IL after IRB approval and informed consent. Pre-advanced AMD was defined as the presence drusen ≥ 63 µm in width without GA or CNV. Participants were provided oral curcumin at a dose of 2660 mg/day and imaged using ocular coherence tomography (OCT) at baseline and every 3 months for 1 year. The primary outcome was macular drusen volume. As an internal control, drusen size was measured up to 6 months prior to beginning oral administration of curcumin. Drusen volume was measured manually using ImageJ software. Macular regions were defined using the 1, 3, and 6 mm grid. The cohort was classified as responder or non-responder using an arbitrary cutoff of ± 10% change.

Results : After one year, total macular drusen volume decreased from 0.0204 to 0.0184 mm³ (-9.8%, P=0.009), foveal drusen volume decreased from 0.0092 to 0.0079 mm³ (-13.9%, P=0.03), parafoveal volume decreased from 0.0086 to 0.0078 mm³ (-9.1%, P=0.10), and perifoveal volume increased (30.9%, P=0.08). In the 6 months prior to beginning the study, the growth rate of total macular drusen volume was 0.0035 mm³/year, consistent with natural history studies in the literature (Folgar, 2016) and significantly higher than the rate after beginning curcumin of -0.0020 mm³/year (P=0.002). The percent of responders and non-responders was 56% and 19%, respectively, which was significantly different from the expected percentages of 12% and 48%, respectively, found in the literature (P=0.0005; Yehoshua, 2011). Importantly, no subjects developed GA or CNV after 1 year.

Conclusions : These preliminary results, though limited, may demonstrate the efficacy of RQC in slowing the growth of drusen in AMD – a finding that would be very promising as it may reduce the risk of disease progression.

This is a 2021 ARVO Annual Meeting abstract.