0535 GMT October 22, 2019
The disease, diabetic retinopathy, is the most common cause of vision loss in working-age adults in the United States. Diabetic eye disease occurs when the normal blood vessels in the eye are replaced over time with abnormal, leaky, fragile blood vessels that leak fluid or bleed into the eye, damaging the light-sensitive retina and causing blindness. Forty to 45 percent of Americans with diabetes have diabetic retinopathy, Medical Xpress said.
Laser-sealing eye blood vessels can save central vision, but this often sacrifices peripheral and night vision, according to Akrit Sodhi, an assistant professor of ophthalmology at the Johns Hopkins University School of Medicine. Several recently developed drugs — bevacizumab, ranibizumab and aflibercept — can help treat these blood vessels by blocking the action of VEGF, a so-called growth factor released as part of a chain of signals in response to low oxygen levels, which stimulates the growth of new, often abnormal, blood vessels. But studies have shown that although these drugs slow progression to proliferative diabetic retinopathy, it does not reliably prevent it.
Looking for an explanation, postdoctoral fellow Savalan Babapoor-Farrokhran, M.D., and Kathleen Jee, tested levels of VEGF in samples of fluid from the eye taken from healthy people, people with diabetes who did not have diabetic retinopathy and people with diabetic retinopathy of varying severity.
While levels of VEGF tended to be higher in those with proliferative diabetic retinopathy, some of their fluid had less VEGF than did the healthy participants. But even the low-VEGF fluid from patients with proliferative diabetic retinopathy stimulated blood vessel growth in lab-grown cells.
"The results suggested to us that although VEFG clearly plays an important role in blood vessel growth, it's not the only factor," Sodhi said.