What is epidemiology?

Put simply, epidemiology is the study of how often diseases occur in different groups of people and why. It is often referred to as population research. To help understand why disease occurs, why certain people suffer from a condition and why others are unaffected it is sometimes useful to analyse data on large numbers of people within a particular geographical area be it a country, district etc.

Researchers carry out studies to discover if there is any correlation with factors that might indicate the causes of illness. In vision research, epidemiological information is used to plan and evaluate strategies firstly to prevent illness and furthermore to guide to the management of patients in whom disease has already developed. In the past, large population studies have been used to prove the dangers of smoking, exposure to asbestos and effect of diet on heart disease.

Globally, one of the most interesting population based studies currently underway is for age-related macular degeneration (AMD). The Age Related Eye Disease Study part 2 (AREDS2) is designed to assess the effects of oral supplementation of macular xanthophylls (lutein and zeaxanthin) and / or long-chain omega-3 fatty acids (docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]) on the progression to advanced age-related macular degeneration (AMD).

Currently there is much interest in how modifying your lifestyle may prevent blindness. Studies have shown that the single most important step a person can take to prevent further sight loss in AMD is to give up smoking.

On the positive side there is modest evidence to suggest that anti-oxidants like vitamin C or zinc may help prevent or slow the development of AMD. However, researchers do not rule out possible toxic effects of using these artificial supplements.

Projects Supported By Fighting Blindness

2006 – Spatial profile of macular pigment in relation to risk for age related macular degeneration – Mr Stephen Beatty, Waterford IT

Important Population Studies

AREDS 1 (The Age-Related Eye Disease Study 1): http://www.nei.nih.gov/amd/

AREDS 2 (The Age-Related Eye Disease Study 2): http://www.areds2.org/

The Blue Mountains Eye Study (BMES) was the first large population-based assessment of visual impairment and common eye diseases of a representative older Australian community sample: http://www.cvr.org.au/bmes.htm