Dietary zinc intake is associated with macular fluid in neovascular age-related macular degeneration
2019 Royal Australian and New Zealand College of Ophthalmologists Importance: Numerous dietary factors have been shown to reduce progression from early to late age-related macular degeneration (AMD), however, little is known on their impact in patients diagnosed with late-stage disease. Background: To determine whether a dietary intake high in antioxidants and zinc, fruits, vegetables and fish is associated with favourable clinical outcomes in patients with neovascular AMD (nAMD) undergoing anti-vascular endothelial growth factor therapy. Design: Cross-sectional study carried out at a private ophthalmology clinic. Participants: Five hundred forty-seven participants with nAMD. Methods: Diet was determined using a validated food frequency questionnaire. Presence of intra-retinal and sub-retinal fluid (IRF, SRF), pigment epithelial detachment and central macular thickness (CMT) were recorded from ocular coherence tomography images. Main Outcome Measures: Fluid presence, mean CMT and visual acuity. Results: Participants with daily zinc intake below (n = 91) vs above (n = 333) 8.1 mg had greater odds of SRF being present, multivariable-adjusted odds ratio (OR) of 0.56 (95% CI 0.36-0.96). This association was stronger in persons with at least 6 months of treatment, OR of 0.32 (95% CI 0.14-0.75). In the entire cohort, participants in the lowest or first quartile compared to those in the upper three quartiles of zinc intake combined had significantly greater mean CMT (254.81 μm vs 232.15 μm, respectively, multivariable-adjusted P =.03). Conclusions and Relevance: Low dietary zinc intake was associated with a greater likelihood of SRF presence, particularly in those treated for at least 6 months, and increased macular thickness in treated eyes with nAMD.