Diabetic retinopathy: Screening
- David K McCulloch, MD
David K McCulloch, MD
- Clinical Professor of Medicine
- University of Washington
- Section Editors
- David M Nathan, MD
David M Nathan, MD
- Editor-in-Chief — Endocrinology
- Section Editor — Diabetes Mellitus
- Professor of Medicine
- Harvard Medical School
- Jonathan Trobe, MD
Jonathan Trobe, MD
- Section Editor — Ophthalmology
- Professor of Ophthalmology and Visual Sciences
- Professor of Neurology
- University of Michigan Kellogg Eye Center
Retinopathy is a major cause of morbidity in patients with diabetes . The vast majority of patients who develop diabetic retinopathy (DR) have no symptoms until the very late stages (by which time it may be too late for effective treatment). Because the rate of progression may be rapid, and therapy can be beneficial for both symptom amelioration and reduction in the rate of disease progression, it is important to screen patients with diabetes regularly for the development of retinal disease.
Issues related to screening for DR will be reviewed here. The pathogenesis, clinical findings, natural history, and treatment of this disorder are discussed separately. (See "Diabetic retinopathy: Pathogenesis" and "Diabetic retinopathy: Classification and clinical features" and "Diabetic retinopathy: Prevention and treatment".)
RATIONALE FOR SCREENING
Screening for diabetic retinopathy (DR) is important because the majority of patients who develop DR have no symptoms until macular edema (ME) and/or proliferative diabetic retinopathy (PDR) are already present. In addition, the efficacy of laser photocoagulation in preventing visual loss from PDR and ME is well established in randomized trials (see "Diabetic retinopathy: Prevention and treatment", section on 'Panretinal photocoagulation' and "Diabetic retinopathy: Prevention and treatment", section on 'Focal laser photocoagulation'). However, laser therapy is more beneficial in preventing visual loss than reversing diminished visual acuity. Thus, early detection through screening programs and appropriate referral for therapy is important to preserve vision in individuals with diabetes.
METHOD OF SCREENING
For the initial screening examination, we prefer evaluation by an ophthalmologist or optometrist who is experienced with diagnosing and treating diabetic retinopathy (DR). In certain settings (eg, when previous exams have been normal or when there is a shortage of eye care specialists), subsequent examinations can be done with retinal photographs if there is a trained photographer and reader. A comprehensive exam is required for follow-up of abnormalities detected on retinal photographs. These recommendations are consistent with American Diabetes Association (ADA) guidelines .
Ophthalmoscopy is a reasonable screening method when performed by well-trained personnel on dilated fundi. The accuracy of ophthalmoscopy is substantially lower when performed by primary care physicians . As an alternative, seven-field stereoscopic fundus photography is another acceptable method, but also requires both a trained photographer and a trained reader. Fundal photography compares favorably with ophthalmoscopy (performed by an experienced ophthalmologist, optometrist, and ophthalmic technician) . In one study of 1949 patients participating in the Wisconsin Epidemiology Study of Diabetic Retinopathy, there was almost complete agreement between the three observers in 86 percent of cases.
- Frank RN. Diabetic retinopathy. N Engl J Med 2004; 350:48.
- Standards of medical care in diabetes--2015: summary of revisions. Diabetes Care 2015; 38 Suppl:S4.
- O'Hare JP, Hopper A, Madhaven C, et al. Adding retinal photography to screening for diabetic retinopathy: a prospective study in primary care. BMJ 1996; 312:679.
- Moss SE, Klein R, Kessler SD, Richie KA. Comparison between ophthalmoscopy and fundus photography in determining severity of diabetic retinopathy. Ophthalmology 1985; 92:62.
- Taylor CR, Merin LM, Salunga AM, et al. Improving diabetic retinopathy screening ratios using telemedicine-based digital retinal imaging technology: the Vine Hill study. Diabetes Care 2007; 30:574.
- Kirkizlar E, Serban N, Sisson JA, et al. Evaluation of telemedicine for screening of diabetic retinopathy in the Veterans Health Administration. Ophthalmology 2013; 120:2604.
- Ahmed J, Ward TP, Bursell SE, et al. The sensitivity and specificity of nonmydriatic digital stereoscopic retinal imaging in detecting diabetic retinopathy. Diabetes Care 2006; 29:2205.
- Vujosevic S, Benetti E, Massignan F, et al. Screening for diabetic retinopathy: 1 and 3 nonmydriatic 45-degree digital fundus photographs vs 7 standard early treatment diabetic retinopathy study fields. Am J Ophthalmol 2009; 148:111.
- Bragge P, Gruen RL, Chau M, et al. Screening for presence or absence of diabetic retinopathy: a meta-analysis. Arch Ophthalmol 2011; 129:435.
- Chasan JE, Delaune B, Maa AY, Lynch MG. Effect of a teleretinal screening program on eye care use and resources. JAMA Ophthalmol 2014; 132:1045.
- Fong DS, Aiello L, Gardner TW, et al. Retinopathy in diabetes. Diabetes Care 2004; 27 Suppl 1:S84.
- American College of Physicians, American Diabetes Association, American Academy of Ophthalmology. Screening guidelines for diabetic retinopathy. Clinical Guideline. Ophthalmology 1992; 99:1626.
- Malone JI, Morrison AD, Pavan PR, et al. Prevalence and significance of retinopathy in subjects with type 1 diabetes of less than 5 years' duration screened for the diabetes control and complications trial. Diabetes Care 2001; 24:522.
- Klein R. Screening interval for retinopathy in type 2 diabetes. Lancet 2003; 361:190.
- Klein R, Klein BE, Moss SE, Cruickshanks KJ. The Wisconsin Epidemiologic Study of diabetic retinopathy. XIV. Ten-year incidence and progression of diabetic retinopathy. Arch Ophthalmol 1994; 112:1217.
- Younis N, Broadbent DM, Vora JP, et al. Incidence of sight-threatening retinopathy in patients with type 2 diabetes in the Liverpool Diabetic Eye Study: a cohort study. Lancet 2003; 361:195.
- Thomas RL, Dunstan F, Luzio SD, et al. Incidence of diabetic retinopathy in people with type 2 diabetes mellitus attending the Diabetic Retinopathy Screening Service for Wales: retrospective analysis. BMJ 2012; 344:e874.
- Vijan S, Hofer TP, Hayward RA. Cost-utility analysis of screening intervals for diabetic retinopathy in patients with type 2 diabetes mellitus. JAMA 2000; 283:889.
- Emanuele N, Sacks J, Klein R, et al. Ethnicity, race, and baseline retinopathy correlates in the veterans affairs diabetes trial. Diabetes Care 2005; 28:1954.
- Javitt JC, Canner JK, Frank RG, et al. Detecting and treating retinopathy in patients with type I diabetes mellitus. A health policy model. Ophthalmology 1990; 97:483.
- Javitt JC, Aiello LP, Chiang Y, et al. Preventive eye care in people with diabetes is cost-saving to the federal government. Implications for health-care reform. Diabetes Care 1994; 17:909.