Diabetic Retinopathy News

New Device Shines Light on the Eye
To Detect Glucose Levels

SAN DIEGO, November 2009 — Finger-pricking may become a thing of the past for diabetics when development is completed of a device that reads glucose levels by shining light on one eye for less than a second.

The consumer-friendly device would operate like binoculars, displaying a glucose reading digitally. It is being developed by Freedom Meditech (San Diego, Calif.), which is also pursuing commercialization of a screening device for eye care professionals.

A pre-clinical study on rabbits showed a mean absolute percent error for glucose prediction of less than 13 percent, compared with an estimated 32 percent error common with the finger stick blood test.

Nearsightedness May Reduce Risk of Diabetic Retinopathy

SINGAPORE, November 2009 — Small, inconclusive studies have suggested that nearsightedness (myopia) has a protective effect against diabetic retinopathy (DR). A recent study of 675 diabetics included an additional measurement, axial length (measurement of the front of the eye to the back).

Less risk of DR, especially severe DR, was found in people whose nearsightedness resulted from both longer axial length and deeper anterior eye chamber. This was true whether the myopia was mild or severe.

The researchers speculated that the protective effect resulted from characteristics found in myopia, such as atrophy of the retina, choroid or vitreous. Even though they cause vision problems, these conditions may reduce retinal metabolic needs and increase oxygen circulation in the back of the eye, which would lower risk of DR.

Results of this study were presented at this year's joint meeting of the American Academy of Ophthalmology and the Pan-American Association of Ophthalmology.

Diabetics Who Receive Good Medical Care Less Likely To Lose Vision

DURHAM, N.C., October 2009 — In a study, people with diabetes mellitus who received recommended levels of care for their disease had much lower rates of low vision or blindness from diabetic retinopathy and other diabetes-related eye diseases than did those who didn't receive the care.

"Recommended levels of care" was defined as receiving each of the following services 0.75 times per year on average: examination by a physician, examination by an ophthalmologist or optometrist, urinalysis and measurements of hemoglobin A1c level and lipid levels.

The study included 5,989 diabetes mellitus patients whom Duke University School of Medicine researchers followed for up to three years. It was reported in the journal Ophthalmology in August.

Controlling Arginase Levels in the Blood May Help
Combat Diabetic Retinopathy

AUGUSTA, Ga., September 2009 — Researchers know that nitric oxide can reduce injury from inflammation. But high blood levels of arginase reportedly reduce nitric oxide availability, thereby allowing the damage to occur. Arginase is a liver enzyme that plays a part in digestion, converting the amino acid arginine to urea.

High levels of arginase in the blood can indicate cardiovascular disease, as well as inflammation in the kidneys and other organs. Recently scientists found that it is also an indicator of early blood vessel damage in the eyes. This knowledge is especially useful in detecting the retinal blood vessel inflammation caused by diabetes.

The scientists, from the Medical College of Georgia and Charlie Norwood Veterans Affairs Medical Center, say they would like to find new drugs that maintain arginase at healthy levels.

The study report was published in The American Journal of Pathology in August.

Antihypertensive Drugs Slow Diabetic Eye Injury

MINNEAPOLIS & ST. PAUL, July 2009 — Recently a five-year study examined the ability of certain antihypertensive medications to slow diabetic kidney damage in people with type 1 diabetes and found that they were not effective.

So what does this have to do with the eyes? A surprise finding was that participants did show a significant slowing of the progression of diabetic eye injury, by 65 percent for one drug (enalapril) and 70 percent for the other (losaran).

Still to be determined is the age at which a diabetic person should take these kinds of drugs and for how long.

Researcher Michael Mauer, MD, of the University of Minnesota Medical School, published the results this month in New England Journal of Medicine.

Sleep Apnea Linked to Retinopathy

OXFORD, England, June 2009 — People with type 2 diabetes who have retinopathy should also be screened for obstructive sleep apnea (OSA), says a new study.

Retina images of 118 men with type 2 diabetes revealed retinopathy in 54 percent of those who had OSA and 31 percent of those without OSA, a statistically significant finding according to researchers.

Poor glucose control and high blood pressure are related to diabetic retinopathy, but in the study OSA was more strongly linked to retinopathy than either of those two factors.

Symptoms of OSA include snoring, breathing lapses during sleep and sleepiness during the daytime. The researchers said that the OSA treatment of continuous positive airway pressure would be studied in the future as a possible way to delay the development of diabetic retinopathy.

Study results were presented at the American Thoracic Society's recent international conference.

Implants Can Help Eyes Oxygen-Deprived From Diabetic Retinopathy

OAK RIDGE, Tenn., April 2009 — A new surgical procedure may help retinal tissue that's oxygen-deprived due to restricted blood flow caused by diabetic retinopathy. This could slow or prevent the vision damage that results from diabetic retinopathy.

Researchers are implanting small electrodes in the eye that provide short pulses of current. This stimulates oxygen production while suppressing production of potentially harmful chlorine.

By implanting a "ground" electrode behind the ear, the surgeons can also keep constant pH in the treatment area.

The project team includes researchers from Oak Ridge National Laboratory, the University of Southern California and the University of Tennessee.

New Imaging Technology Instantly Detects Eye Diseases

OAK RIDGE, Tenn., February 2009 — A new screening device photographs and transmits images of a person's retina to a central database, where early signs of eye diseases such as diabetic retinopathy can be detected instantly.

Researchers say the technology, developed at the Department of Energy's Oak Ridge National Laboratory (ORNL), could become a powerful screening tool for eye doctors. The device uses a central database of images to sort and instantly match new photographs with those that contain specific signs of retinal eye diseases.

"Once we've taken pictures of the eyes, we transmit that information to our database, where it is compared to thousands of images of known retinal disease states," said Ken Tobin, leader of the ORNL team that developed the technology. "From there, the computer system is able to determine whether the patient passes the screening, or it provides a follow-up plan that includes seeing an ophthalmologist."

The National Eye Institute funded the research, led on the medical side by Edward Chaum, MD, ophthalmologist and Plough Foundation professor of retinal diseases at the University of Tennessee Health Science Center.

"Right now, with 21 million diabetics in the United States, we need to be screening 400,000 patients for diabetic eye disease every week," Chaum said. "Less than half of these diabetics receive the recommended annual eye exam, which is absolutely essential to minimize serious eye complications and potential blindness."

Chaum said the automated screening tool eventually could be in widespread use worldwide, including remote and rural areas.

Avastin Helps Cataract Patients With Diabetic Retinopathy

DHAHRAN, Saudi Arabia, February 2009 — Saudia Arabia researchers say a drug (bevacizumab) injected into the eye at the end of cataract surgery helped delay or halt progression of diabetic retinopathy (DR) in patients already diagnosed with the eye disease.

Bevacizumab is an anti-cancer drug known commercially as Avastin, often used off label to treat advanced age-related macular degeneration. The drug prevents growth of abnormal blood vessels in the retina to help prevent scarring and resulting blindness.

The Saudi Arabia study involved 68 eyes of 68 cataract patients with diabetic retinopathy. Half of patients received Avastin injections at the end of cataract surgery, while the other half did not. After six months, researchers observed significant impediment of DR progression in the Avastin group with these results:

Only four of 35 eyes in the Avastin group had DR progression, compared with 15 of 33 eyes in the control group.
Only two eyes had progression of diabetic maculopathy in the Avastin group, compared with 17 in the control group.

Study results appeared in the January issue of the Journal of Cataract & Refractive Surgery.

Diabetic Eye Disease Numbers Likely To Triple by 2050

ATLANTA, January 2009 — Researchers predict that the number of Americans 40 and older with diabetic retinopathy will triple to 16 million by 2050.

The study by U.S. Centers for Disease Control and other researchers says the number of people with vision-threatening diabetic eye disease also will triple, to 3.4 million during the same time period.

Researchers say the growing number of Americans with diabetes means a greater prevalence of resulting eye diseases, including diabetic retinopathy, cataracts and glaucoma.

"Efforts to prevent diabetes and to optimally manage diabetes and its complications are needed," study authors said.

Research results were published in the December issue of Archives of Ophthalmology.

Major Study Finds Most People With Type 1 Diabetes Develop Eye Disease

MADISON, Wis., November 2008 — Most people diagnosed with type 1 diabetes developed some form of diabetic retinopathy during a 25-year study conducted by University of Wisconsin researchers.

Risk factors for developing diabetic retinopathy included higher blood sugar levels, blood pressure and body mass, along with male gender. People with higher blood sugar levels also were at increased risk of developing more severe proliferative diabetic retinopathy (PDR).

Study results found that:

Among 955 insulin-dependent people, 97 percent developed diabetic retinopathy (DR).
The disease continued to progress in 83 percent of those diagnosed with DR.
In those with DR, 42 percent developed the proliferative or more damaging form of the eye disease.

Researchers pointed out that people with a more recent diagnosis of diabetic retinopathy were less likely to have PDR, probably because of better and more modern management strategies aimed at controlling blood sugar and blood pressure.

Results of the Wisconsin Epidemiologic Study of Diabetic Retinopathy were published In the November issue of Ophthalmology.

Vision Loss More Likely With Diabetes

ATLANTA, October 2008 — Any adult with diabetes has an 11 percent chance of developing vision loss, according to U.S. Centers for Disease Control investigators.

A survey of 1,237 people with diabetes and 11,767 without also found that:

People without diabetes have a 5.9 percent chance of developing vision impairment.
Most vision impairment is correctable, with or without the diabetes association.
Older age, low income and inadequate health insurance also were linked to increased likelihood of vision impairment in all groups.

Study results were published in the October issue of Archives of Ophthalmology.

Pain Relief Drug May Benefit Diabetic Retinopathy and Glaucoma

AUGUSTA, Ga., September 2008 — Researchers say pentazocine, a narcotic drug commonly used for pain relief and memory stimulation, appears to have "phenomenal" benefits for restoring health of retinal cells damaged by potentially blinding eye diseases including diabetic retinopathy and glaucoma.

Medical College of Georgia School of Medicine investigators tested pentazocine on mice with retinas damaged by a type of diabetic eye disease.

Findings that describe dramatic, positive results were published in the September issue of Investigative Ophthalmology & Visual Science.

The eye's retina is a light-sensitive membrane responsible for receiving and transmitting images to the brain. These photos show a healthy retina, one damaged by diabetes and one damaged and then treated with the drug, pentazocine.

Study results suggest that pentazocine binds with proteins known as sigma receptors to enhance beneficial roles related to improved cell function and protection from damage.

Investigators say additional studies will involve using mice bred without sigma receptors to determine more precisely how pentazocine works to restore damaged retinal cells. Other scientists currently are exploring the role of sigma receptors in treatment of diseases such as Alzheimer's, brain tumors and depression.

New Diabetes Medication May Slow Eye Damage

LOS ANGELES, June 2008 — A new diabetes medication known as rosiglitazone may help slow development of abnormal blood vessels in the inner back of the eye (retina) that can cause blindness in diabetic retinopathy, according to the June issue of Archives of Ophthalmology.

Jules Stein Eye Institute researchers compared medical records of 124 people who were taking rosiglitazone with those of 158 individuals who did not receive the same treatment. All people studied had diabetes, and fewer than 10 percent had a severe form of diabetic eye disease that had not yet involved development of abnormal blood vessels associated with proliferative diabetic retinopathy.

In three years, only 19.2 percent of the rosiglitazone group and 47.4 percent of the control group had progressed to the proliferative form of diabetic retinopathy.

Researchers said more comprehensive studies are needed to confirm benefits of rosiglitazone as a treatment for diabetic retinopathy.

Gene Appears Linked to Diabetic Eye and Kidney Disease

SALT LAKE CITY, May 2008 — Severe diabetic eye and kidney diseases appear linked to inheritance of a specific gene called EPO (erythropoietin), according to research led by Kang Zhang, MD, PhD, director of the Division of Ophthalmic Genetics at Moran Eye Center and ophthalmology professor at the University of Utah.

Researchers made the discovery and isolated the gene after comparing 1,618 diabetics who had both severe diabetic eye disease (proliferative diabetic retinopathy) and end-stage renal or kidney disease with 954 diabetics who did not have these diseases.

Future treatments of diabetic eye disease may involve finding ways to inhibit the activity of the EPO gene, researchers said. Findings were published in the May 5 online edition of the Proceedings of National Academy of Sciences journal.

Protein in Blood Vessels May Help Treat Serious Eye Diseases

SALT LAKE CITY, March 2008 — Serious eye diseases such as diabetic retinopathy and macular degeneration (AMD) may be treated in the future through activating a certain blood vessel protein that can help reverse or prevent eye damage.

In experiments involving mice, University of Utah School of Medicine researchers found that activity of the protein, Robo4, prevented or reversed abnormal blood vessel growth in the inner back lining of the eye (retina), where vision processing occurs.

Abnormal blood vessel growth causes potentially blinding eye damage in both diabetic retinopathy and AMD.

"Many diseases are caused by injury or inflammation destabilizing blood vessels and causing them to leak fluid into adjacent tissues as well," said Dean Y. Li, MD, PhD, senior author of a study published March 16 in Nature Medicine online.