A randomised controlled trial investigating the effect of nutritional supplementation on visual function in normal, and age-related macular disease affected eyes:design and methodology [ISRCTN78467674]

Background: Age-related macular disease is the leading cause of blind registration in the developed world. One aetiological hypothesis involves oxidation, and the intrinsic vulnerability of the retina to damage via this process. This has prompted interest in the role of antioxidants, particularly the carotenoids lutein and zeaxanthin, in the prevention and treatment of this eye disease. Methods: The aim of this randomised controlled trial is to determine the effect of a nutritional supplement containing lutein, vitamins A, C and E, zinc, and copper on measures of visual function in people with and without age-related macular disease. Outcome measures are distance and near visual acuity, contrast sensitivity, colour vision, macular visual field, glare recovery, and fundus photography. Randomisation is achieved via a random number generator, and masking achieved by third party coding of the active and placebo containers. Data collection will take place at nine and 18 months, and statistical analysis will employ Student's t test. Discussion: A paucity of treatment modalities for age-related macular disease has prompted research into the development of prevention strategies. A positive effect on normals may be indicative of a role of nutritional supplementation in preventing or delaying onset of the condition. An observed benefit in the age-related macular disease group may indicate a potential role of supplementation in prevention of progression, or even a degree reversal of the visual effects caused by this condition.

Mixed methods research:don't "just do it"

Purpose The purpose of this paper is to identify some of the dilemmas involved in the debate on the how, when and why of mixed methods research. Design/methodology/approach The authors' starting point is formed by developments in the philosophy of science literature, and recent publications on mixed methods research outside of the management accounting domain. Findings Contrary to recent claims made in the management accounting literature, the authors assert that uncovering points of disagreement between methods may be as far as researchers can go by combining them. Being reflexive can help to provide a deeper understanding of the research process and the researcher's role in this process. Research limitations/implications The paper should extend the debate among management accounting researchers about mixed methods research. One of the lessons drawn is that researchers are actively immersed in the research process and cannot purge their own interests and views. Accepting this lesson casts doubt on what the act of research may imply and achieve. Practical implications The paper shows that combinations of research methods should not be made based on a "whatever works" attitude, since this approach ultimately is still infused with ontological and epistemological considerations that researchers have, and should try to explicate. Originality/value The value of this paper lies in the provision of philosophical underpinnings that have not been widely considered in the management accounting literature on mixed methods to date. © 2011 Emerald Group Publishing Limited. All rights reserved.