Our understanding of diabetic retinopathy (DR) has increased dramatically with the availability of new information and advent of new technology. However, the original diabetic retinal disease staging system, developed over five decades ago, has not been updated to reflect these advancements. So says a group of retina subspecialists, arguing for an update to DR staging protocols in a recent editorial published in the journal Ophthalmology.
Both the ETDRS and international DR grading scales can predict disease progression to sight-threatening outcomes, the authors argue, but they are limited in their overall capabilities. The severity scales evaluate the vascular component of DR without taking the peripheral retina into account. They are unable to measure pathophysiologic or neurodegenerative changes prior to DR presentation or document neovascularization changes in proliferative DR. Further, they cannot assess the visual effectiveness of different DR treatments or grade the severity of diabetic macular edema, another common cause of vision loss in diabetic patients.
Knowing that failure to address these shortcomings could have devastating visual effects, the authors recommend incorporating additional validated assessments to improve our ability to diagnose the disease, detect progression and treat accordingly for the most successful visual outcomes.
The team notes that a revised staging system should target vision loss risk, patient quality of life, prognosis prediction and therapy response. “Ideally, an updated staging system will address retinal, neural and vascular pathology and their contributions to visual function in the context of systemic influences, such as diabetes type, glycemic control, blood pressure, renal disease and anemia,” they write in their editorial.
The authors highlight the importance of testing different variables for inclusion in the new system in prospective cohorts of patients. Joseph Pizzimenti, OD, an expert in retina care and systemic disease, echoes that sentiment. “It is true that there are some limitations to current DR staging systems,” he says. “Any new scale needs to first and foremost be based on the most rigorous, recent clinical research evidence.” Dr. Pizzimenti acknowledges the breadth of this information and data and suggests an app-based staging system with a simple-to-use interface for the most optimal results.
A multidimensional, comprehensive approach could reveal phenotypic variability not offered by the current grading scales and provide patient-specific information to guide DR management.
“The road toward developing, testing and implementing an updated staging system for DR will necessitate involvement of multiple stakeholders, including scientists, clinicians, regulatory agencies and patients,” the editorial concludes. “The ultimate test of the system’s value will lie in demonstrating measurable benefits to patients with diabetes and improvement in functional outcomes for this vulnerable population.”
Sun JK, Aiello LP, Abramoff MD, et al. Updating the staging system for diabetic retinal disease. Ophthalmology. November 17, 2020. [Epub ahead of print].