de Fine Olivarius et al. BMC Public Health 2011, 11:80 http://www.biomedcentral.com/1471-2458/11/80 R E S E A R C H A R T I C L E Open Access Prevalence and progression of visual impairment in patients newly diagnosed with clinical type 2 diabetes: a 6-year follow up study Niels de Fine Olivarius1*, Volkert Siersma1, Gitte Juul Almind1, Niels Vesti Nielsen2 Abstract Background: Many diabetic patients fear visual loss as the worst consequence of diabetes. In most studies the main eye pathology is assigned as the cause of visual impairment. This study analysed a broad range of possible ocular and non-ocular predictors of visual impairment prospectively in patients newly diagnosed with clinical type 2 diabetes. Methods: Data were from a population-based cohort of 1,241 persons newly diagnosed with clinical, often symptomatic type 2 diabetes aged ≥ 40 years. After 6 years, 807 patients were followed up. Standard eye examinations were done by practising ophthalmologists. Results: At diabetes diagnosis median age was 65.5 years. Over 6 years, the prevalence of blindness (visual acuity of best seeing eye ≤ 0.1) rose from 0.9% (11/1,241) to 2.4% (19/807) and the prevalence of moderate visual impairment (> 0.1; < 0.5) rose from 5.4% (67/1,241) to 6.7% (54/807). The incidence (95% confidence interval) of blindness was 40.2 (25.3-63.8) per 10,000 patient-years. Baseline predictors of level of visual acuity (age, age-related macular degeneration (AMD), cataract, living alone, low self-rated health, and sedentary life-style) and speed of continued visual loss (age, AMD, diabetic retinopathy (DR), cataract, living alone, and high fasting triglycerides) were identified. Conclusions: In a comprehensive assessment of predictors of visual impairment, even in a health care system allowing self-referral to free eye examinations, treatable eye pathologies such as DR and cataract emerge together with age as the most notable predictors of continued visual loss after diabetes diagnosis. Our results underline the importance of eliminating barriers to efficient eye care by increasing patients’ and primary care practitioners’ awareness of the necessity of regular eye examinations and timely surgical treatment. Background In Europe and the United States severe visual impair- ment may be 2-3 times more common among people with diabetes than in the general population [1,2], but this difference decreases with age [2]. Diabetic retinopa- thy (DR) is regarded as the cause of blindness in 5-15% of the blind in the general population [3-5] and in 30-50% of blind type 2 diabetic patients [6,7]. There are, however, huge regional differences in presumed causes of blindness across the world [8]. DR is considered the * Correspondence: olivarius@sund.ku.dk 1The Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Copenhagen, Denmark Full list of author information is available at the end of the article leading cause of blindness among people of working age in many countries [3-5], while age-related macular degeneration (AMD) is considered the leading cause in people over 65 years [3-5,9]. Diabetes with even mildly to moderately impaired sight has a negative impact on perceived quality of life and psychosocial functioning giving rise to feelings of vulnerability, worries about the future and loss of inde- pendence and mobility [10-12]. A sizeable proportion of type 2 diabetic patients fear visual loss intensely [13] and consider loss of vision the worst complication of diabetes [10]. For the health practitioner visual acuity is a ubiquitous and handy measure of visual function, but visual acuity is not a suitable measure of future visual loss as the sight-threatening eye pathologies often are © 2011 de Fine Olivarius et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.