The Aston Randomised Controlled Trial (Aston RCT)

Age-related macular degeneration (AMD) is a leading cause of visual impairment, with growing interest in nutritional supplementation as a potential strategy to slow disease progression, particularly in the early and intermediate (dry) stages. This chapter describes the design and methodology of a small-scale randomised clinical trial investigating the effects of nutritional supplementation in individuals with dry AMD.

The chapter outlines the rationale for the study, including existing evidence and gaps relating to nutritional interventions in AMD. Key elements of the trial design are detailed, including participant eligibility criteria, randomisation procedures, intervention composition, and outcome measures. Particular attention is given to the selection of functional and structural endpoints, alongside strategies to ensure methodological rigour, including masking, adherence monitoring, and data collection protocols.

Consideration is also given to ethical approval, feasibility within a small cohort, and challenges associated with conducting nutritional trials, such as variability in baseline diet and long-term follow-up requirements. The chapter highlights the importance of robust study design in generating meaningful clinical evidence, even in smaller trials.

Overall, this work provides a practical framework for designing and implementing clinical trials of nutritional interventions in AMD, with relevance for researchers and clinicians in ophthalmology and optometry.