The University of New Mexico received a $2.8 million grant in September from the National Institutes of Health to study diabetic blindness, also known as diabetic retinopathy.

According to Dr. Arup Das, the the division chief in the Ophthalmology Division at UNM Hospital, diabetic retinopathy is the leading cause of blindness in Americans aged 20 to 64.

There are two types of diabetic blindness, Das said. There is mild diabetic retinopathy and moderate diabetic retinopathy.

Mild diabetic retinopathy occurs when new blood vessels in the eye develop, but they constrict and hemorrhage fluid.

Moderate diabetic retinopathy takes this a step further — scar tissue builds up where the blood vessels are leaking and can lead to pressure felt behind the eyes and retinal detachment.

“One of the questions I’m asking in the grant is why some patients develop this proliferative disease while other patients do not,” Das said. “I would say almost 50 percent of patients of diabetic retinopathy get proliferative disease.”

Currently there are treatments for diabetic retinopathy, Das said. One is called the anti-vascular endothelial growth factor (VEGF) injection.

Das said this injection in the eye works to prevent hemorrhaging and can lead to vision improvement, but patients would have to get this shot monthly. Unfortunately, not all patients experience the same results.

“30 percent of the patients who do this get good results,” Das said. “We do not know when somebody walks in my clinic — there is no way to tell who will respond (positively).”

Understanding how genes affect this disease, Das said, is important for administering the most effective treatment.

“What are the genes, what are the factors that determine who gets this proliferative disease?”

Another question Das said he wants to answer is why some people with diabetes who do not control their sugar intake are less at risk of blindness while others have a greater risk.

Das said under the grant his research will collect DNA samples from three populations — Hispanics, urban Native Americans and Caucasians. The DNA will be studied at the Translational Genomics Research Institute (TGen) in Phoenix, Arizona.

Sampathkumar Rangasamy, a Ph.D. and research assistant professor, is a co-investigator researching genetics at TGen.

For Rangasamy — a type I diabetic — diabetic retinopathy research is his passion.

“(Being a diabetic is) what motivated me to choose diabetes as my research,” Rangasamy, Das’ former post-doctoral student, said.

Rangasamy said he has lived with diabetes for more than 30 years and has not had any complications from it.

However, that can change.

“Still, it is not easy to prove any diabetic complications early, especially as a type I diabetic,” Rangasamy said.

Rangasamy said he hopes UNM’s research will provide answers to the genetic relationship between diabetic retinopathy and developing a better understanding into this disease.

According to the International Diabetes Federation, there are about 425 million adults living with diabetes — by 2045, that number is expected to rise to 629 million.

Anthony Jackson is a staff reporter with the Daily Lobo. He can be contacted at or on Twitter @TonyAnjackson.