Rapid and cost-effective method to assess vision disorders in a population

The aim was to develop a means of rapidly assessing eye health in a cost- and time-effective way to monitor changes over time.

Key features of the five main eye diseases that cause vision loss in Australia were assessed. Participation was volunteer-based from randomly selected Melbourne suburbs. Recruitment was by mail. Anterior segments and fundi were photographed with a digital non-mydriatic fundus camera. Visual fields were tested with Frequency Doubling Technology. A questionnaire collected information about demographics, general health and lifestyle. Findings from this rapid assessment were compared with those from a population-based study.

A total of 1695 people, aged between 70 and 79 years (mean 74), were recruited. The rates and causes of visual impairment were similar between the rapid assessment method and the population-based study. Among the 134 people (8%) with visual impairment at presentation, 98 (73%) had undercorrected refractive error, 17 (13%) had age-related macular degeneration, 11 (8%) had cataract, 2 (2%) had diabetic retinopathy and 2 (2%) had glaucoma. Screening costs per participant were only about AU$145, compared with AU$433 in the Melbourne Visual Impairment Project (VIP). The application of Frequency Doubling Technology as well as the use of a non-mydriatic digital camera for fundus and lens photography resulted in an average examination time of less than half the time needed in the VIP. Data collection took 3 months rather than 4 years in the VIP.

The rapid assessment method was efficient in time and cost and produced results comparable to a normal population-based survey. Repeating the study design for a similarly sampled group every 2 years would allow the assessment of changes in the prevalence of undiagnosed eye disease.