Screening provides a way to detect the presence of an eye disease at an early stage, or risk factors for its development, among larger numbers of people who are asymptomatic (i.e. are not experiencing any symptoms), but are at an increased risk of developing the disease.
Screening differs from diagnostic testing. Diagnostic testing is performed to confirm the presence or absence of a disease among individuals who are experiencing specific symptoms, such as vision loss.
People with diabetes are at increased risk of developing several eye diseases, including diabetic retinopathy (DR), cataract, and glaucoma. All of these diseases can cause vision loss or blindness in people with diabetes. However, DR is the most common (affecting 1 in 3 persons) and the most frequent cause of vision loss in the diabetic population. DR is also the leading cause of visual impairment and blindness in the working-age population worldwide.[2, 3]
Many patients with DR may not experience any visual symptoms until the later stages of disease when vision loss may be irreversible, even with treatment. There is strong evidence that the risk of vision loss or blindness from DR can be greatly reduced by screening individuals with diabetes for the early signs of sight-threatening DR, and ensuring they receive timely access to treatment.