Type of viral infection of eye associated with disease causing blindness in the elderly

May 21, 2012

A team of researchers, including a scientist from the Viral Immunology Center at Georgia State University, have found that a type of herpesvirus infection of the eye is associated with neovascular age-related macular degeneration (AMD), a disease that causes blindness in the elderly.

The scientists found that human cytomegalovirus, a type of herpesvirus, causes the production of vascular endothelial growth factor, or VEGF, a signal protein that regulates the formation of new blood vessels.

With the formation of new blood vessels, retinal tissue destruction occurs, leading to the development of "wet" AMD and eventually, vision loss and blindness. The results were published in , a journal of the Public Library of Science.

"Prior to this work, cofactors for the development of AMD included genetics, a high fat diet and smoking. Now, we are adding an infections agent as another cofactor," said Richard D. Dix, professor at the Georgia State Viral Immunology Center's Ocular Virology and Immunology Laboratory.

The research team includes Dix, Scott W. Cousins, Diego G. Espinosa-Heidmann, Daniel M. Miller, Simone Pereira-Simon, Eleut P. Hernandez, Hsin Chien and Courtney Meier-Jewett.

Affiliated research institutions include the Duke University Eye Center, the Bascom Palmer Eye Institute of the University of Miami Miller School of Medicine, the Viral Immunology Center at Georgia State, and the Department of Ophthalmology at the Emory University School of Medicine.

Human cytomegalovirus is a common herpesvirus, said Dix, who is also an adjunct professor of ophthalmology at the Emory University School of Medicine. About 80 percent of the population is estimated to have antibodies for the virus, and it is often acquired during childhood.

If a person has a normal, healthy immune system, the virus becomes latent in the cells of bone marrow and blood, he said. But in the elderly, the immune system's function is reduced, the virus proliferates, and the production of VEGF increases.

Identifying human cytomegalovirus as a cofactor in the development of AMD opens up new paths for the treatment of AMD, Dix said. One route could include reducing the viral load – the amount of the human cytomegalovirus in the blood stream – by treatment with an antiviral drug known as ganciclovir.

Additional research paths include looking at the genetics involved in the upregulation of VEGF by human .

"If we can knock down a certain gene or genes of the virus that stimulates VEGF production, we might be able to decrease it production and minimize AMD," Dix said.

Explore further: Report shows risk of blindness halved over last decade

More information: Cousins SW, Espinosa-Heidmann DG, Miller DM, Pereira-Simon S, Hernandez EP, Chien H, Meier-Jewett, and Dix RD (2012) Macrophage Activation Associated with Chronic Murine Cytomegalovirus Infection Results in More Severe Experimental Choroidal Neovascularization. PLoS Pathog 8(4): e1002671. doi:10.1371/journal.ppat.1002671

Related Stories

Report shows risk of blindness halved over last decade

January 19, 2012
Age-related macular degeneration (AMD) is the most frequent cause of blindness in the Western World. A report from the University of Copenhagen and Glostrup Hospital in Denmark published today shows the number of new cases ...

The genetic basis for age-related macular degeneration

February 23, 2012
Age-related macular degeneration (AMD) is one of the leading causes of blindness worldwide, especially in developed countries, and there is currently no known treatment or cure or for the vast majority of AMD patients. New ...

Researchers find that inhibiting microRNAs may help prevent degenerative eye disorders

June 7, 2011
Blocking two tiny molecules of RNA – a chemical cousin of DNA – appears to suppress the abnormal growth of blood vessels that occurs in degenerative eye disorders, UT Southwestern Medical Center researchers have ...

Recommended for you

Combination of type 2 diabetes and sleep apnoea indicates eyesight loss within four years

July 4, 2017
Research led by the University of Birmingham has discovered that patients who suffer from both Type 2 diabetes and obstructive sleep apnoea are at greater risk of developing a condition that leads to blindness within an average ...

Nearly 60% of pinkeye patients receive antibiotic eye drops, but they're seldom necessary

June 28, 2017
A new study suggests that most people with acute conjunctivitis, or pinkeye, are getting the wrong treatment.

Magnetic implants used to treat 'dancing eyes'

June 26, 2017
A research team has successfully used magnets implanted behind a person's eyes to treat nystagmus, a condition characterised by involuntary eye movements.

Drug shows promise against vision-robbing disease in seniors

June 21, 2017
An experimental drug is showing promise against an untreatable eye disease that blinds older adults—and intriguingly, it seems to work in patients who carry a particular gene flaw that fuels the damage to their vision.

Reproducing a retinal disease on a chip

June 15, 2017
Approximately 80% of all sensory input is received via the eyes, so suffering from chronic retinal diseases that lead to blindness causes a significant decrease in the quality of life (QOL). And because retinal diseases are ...

New gene therapy for vision loss proven safe in humans

May 16, 2017
In a small and preliminary clinical trial, Johns Hopkins researchers and their collaborators have shown that an experimental gene therapy that uses viruses to introduce a therapeutic gene into the eye is safe and that it ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.