Even the eyes of patients diagnosed with mild or moderate nonproliferative diabetic retinopathy (NPDR) show signs of extensive capillary remodelling in their retinas, according to a new study.
Researchers at Indiana University said the finding could help monitor patients with diabetes, specifically in regard to their sight. Additionally, they reported, “the results suggest that existing clinical classifications based on lower magnification clinical assessment may not adequately measure key vascular differences among individuals with NPDR”.
In a statement Dr. Ann Elsner, professor and associate dean in the IU School of Optometry and lead author of the study said, “We had not expected to see such striking changes to the retinas at such early stages. We set out to study the early signs, in volunteer research subjects whose eyes were not thought to have very advanced disease. There was damage spread widely across the retina, including changes to blood vessels that were not thought to occur until the more advanced disease states.”
“It is shocking to see that there can be large areas of retina with insufficient blood circulation,” reported Dr. Stephen Burns, also from the IU School of Optometry. “The consequence for individual patients is that some have far more advanced damage to their retinas than others with the same duration of diabetes.”
the results suggest that existing clinical classifications based on lower magnification clinical assessment may not adequately measure key vascular differences among individuals with NPDR
The researchers used a confocal adaptive optics scanning laser ophthalmoscope to observe the retinas of seven patients with NPDR. They wrote, “our results… make a strong case that the current classifications of diabetic retinopathy that are based on lower resolution and lower contrast imaging methods provide insufficient specific information about the status of the retina”. “Imaging with AO (Adaptive Optics) opens the possibility of distinguishing among patients who are undergoing retinal changes that permanently threaten sight.
“Further, our results clearly point out significant vessel remodelling in mild to moderate non-proliferative diabetic retinopathy, not limited to capillary dilation… these microvascular changes that include extensive blood vessel remodelling, non-perfusion, and vascular leakage resulting in small hard exudates, could hold the key for improved clinical classification of diabetic patients, better understanding of the mechanisms of diabetic retinopathy, and development of more effective therapies through better patient monitoring of pharmacological intervention using this technology.”
Reference
Stephen A. Burns, Ann E. Elsner, Toco Y. Chui, Dean A. Van Nasdale, Jr., Christopher A. Clark, Thomas J Gast, Victor E. Malinovsky, and Anh-Danh T. Phan. In vivo adaptive optics microvascular imaging in diabetic patients without clinically severe diabetic retinopathy.
