Does melatonin have any effect on the development or progression of AMD?

Melatonin opposes several processes that are known to mediate age-related macular degeneration (AMD). Studies in both animal models and humans have suggested that melatonin possesses potent antioxidant, anti-inflammatory, antiangiogenic and mitochondrial-protective properties. These may counteract many of the key pathologic processes that mediate AMD, such as oxidative damage, choroidal neovascularization and dysregulated apoptosis, making it a promising agent for targeting AMD. However, it is unclear whether melatonin supplementation can prevent the development or delay the progression of AMD.To examine this issue, a new U.S. study investigated the association between melatonin supplementation and the risk of the development or progression of AMD. The retrospective cohort study used data from a national database of electronic medical records from inpatient and outpatient healthcare organizations across the U.S.Patients aged ≥ 50 years, ≥ 60 years and ≥ 70 years were grouped based on no history of AMD (AMD-naive group) and history of nonexudative AMD (nonexudative AMD group). Patients were then classified into either a melatonin group or a control group based on the presence of medication codes for melatonin (i.e., the presence of at least 4 instances of melatonin records that each occurred at least 3 months apart). Propensity score matching was performed to match the cohorts based on demographic variables, comorbidities and nonmelatonin hypnotic medication use.After propensity score matching, the melatonin and the control cohorts were compared to evaluate the risk ratios (RRs) and the 95% confidence intervals (CIs) of having an outcome. For the AMD-naive group, the outcome was defined as a new diagnosis of any AMD, whereas for the nonexudative AMD group, the outcome was progression to exudative AMD.Results showed the following:121,523 patients were in the AMD-naive group (4,580 in the melatonin cohort after propensity score matching, mean age 68.24 years; 56.5% female) and 116,675 were in the control cohort (4,580 after propensity score matching, mean age 68.17, 58.5% female).In the AMD-naive group, melatonin use was associated with a reduced risk of developing AMD (RR, 0.42; 95%CI, 0.28–0.62). 66,253 patients aged ≥ 50 years were in the nonexudative AMD group (4,064 in the melatonin cohort after propensity score matching, mean age 80.21 years; 61.1% female) and 61,903 in the control cohort (4,064 patients after propensity score matching; mean age 80.31 years; 62.3% female).In the nonexudative AMD group, melatonin was associated with a reduced risk of AMD progression to exudative AMD (RR, 0.44; 95%CI, 0.34–0.56). Results were consistent among subsets of individuals aged ≥ 60 years (AMD-naive cohort: RR, 0.36 [95%CI, 0.25–0.54]; nonexudative AMD cohort: RR, 0.38 [95% CI, 0.30–0.49]) and for those ≥ 70 years (AMD-naive cohort: RR, 0.35 [95%CI, 0.23–0.53]; nonexudative AMD cohort: RR, 0.40 [95%CI, 0.31–0.51]).In this study, melatonin use was associated with a decreased risk of development and progression of AMD. The authors point out that variances in confounding factors such as lifestyle and healthcare access must be considered when interpreting their results. However, the consistency of their findings across the different age groups lends support to the potential benefits of melatonin against AMD, even among older populations. The authors note that earlier research studies found that nocturnal melatonin levels naturally decline with age, reaching markedly low levels after the age of 60 years. This natural decline coincides with the age that patients are most susceptible to AMD. As a result, melatonin could play a protective role against the age-related changes that can predispose older individuals to AMD.The authors conclude that the findings of their study provide a rationale for further research on the efficacy of using melatonin as a preventive therapy against AMD. With our aging population and the increasing prevalence of AMD, expanding research in this area could provide substantial public health value.Reference:Jeong H, Shaia JK, Markle JC, et al. Melatonin and risk of age-related macular degeneration. JAMA Ophthalmol 2024; Published online June 6, 2024. (accessed June 6, 2024).

Does melatonin have any effect on the development or progression of AMD?

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