Visual Function Measurements in Eyes with Diabetic Retinopathy: An Expert Opinion on Available Measures

Topic Visual function impairment from diabetic retinopathy can have a considerable impact on patient’s quality of life. Best-corrected visual acuity (BCVA) is most commonly used to assess visual function and guide clinical trials. However, BCVA is affected late in the disease process, is not affected in early disease, and does not capture some of the visual disturbances described by patients with diabetes. Clinical relevance The goal of this report is to evaluate the relationship between diabetic retinal disease (DRD) and visual function parameters to determine which if any of them may be used in a future DRD staging system. Methods The visual functions working group was one of 6 areas of DRD studied as part of the DRD Staging System update, a project of the Mary Tyler Moore Vision Initiative (MTM Vision). The working group identified 12 variables of possible interest, seven of which were judged to have sufficient preliminary data to suggest an association with DR to warrant further review; microperimetry, static automated perimetry (SAP), ERG oscillatory potentials, flicker ERG, low luminance VA (LLVA), contrast sensitivity (CSF) and best-corrected visual acuity (BCVA). The objective field analyzer (OFA) was added after subsequent in-person workshops. Results Currently, the only visual function test available for immediate use is BCVA; the remaining tests are either promising (within 5 years) or have potential (>5 years) use. Besides BCVA, most visual function tests had a limited role in current clinical care, however LLVA, CSF, Flicker ERG and OFA demonstrated potential for screening and research purposes. Conclusion Although current visual function tests are promising, future prospective studies involving patients with early and more advanced retinopathy are necessary to determine if these tests can be used clinically or as endpoints for clinical studies.