New eye drops may stop vision loss from minor injuries and infections.
The outer surface of the eye, known as the cornea, is normally transparent. But eye injury or infection can lead to inflammation, known as keratitis, which can then result in scarring of the cornea.
Keratitis is a common eye condition and people who regularly wear contact lenses may experience the condition more frequently than those who don’t.
Existing treatments for keratitis are usually effective in mild to moderate cases, especially with prompt attention. But more severe infections or delayed treatment can lead to permanent vision damage.
Scientists from the University of Birmingham in the UK are now working on a gel eye drop that acts as a “therapeutic bandage” to help the cornea heal without scarring.
There are two types of keratitis. Infectious keratitis occurs when bacteria, fungi, or parasites infect the cornea and cause inflammation. This can happen when contact lenses aren’t cleaned properly or when they’re worn for too long.
You can also get an eye infection from contaminated water, such as while swimming in a river or lake. This is more likely if the cornea surface is already damaged, such as from wearing contact lenses too long.
Noninfectious keratitis involves an injury to the surface of the cornea, such as from dirt, wood shavings, or contact lenses.
Certain viruses, such as herpes, can also cause keratitis.
Infectious keratitis is treated with antibacterial, antifungal, or other eye drops to eliminate the infection.
Other drops or ointments may be used to prevent further damage to the eye during blinking. These may also be used for noninfectious keratitis to help the cornea heal.
Tyler Hall, MD, a corneal and cataract specialist at the University of Alabama at Birmingham, who was not involved in the study, said that while there are “good treatments to stop eye infections, there aren’t good treatments to prevent scarring, which is what significantly affects vision.”
How much a person’s vision is affected depends on the location of the scarring. When it’s in the center of the cornea, scarring can cause blurred vision.
“The majority of people are able to carry on with functional lives and the scarring doesn’t impact them much,” Hall said.
But Hall sees at least one or two people a month with an infection so serious that the only way to restore their vision is with a corneal transplant. The new eye drop could help prevent this.
The eye drop being developed by UK researchers consists of a fluid gel that contains a naturally occurring protein called decorin that promotes the healing of wounds.
When applied, the gel becomes more solid and shapes itself to the surface of the cornea. It remains there until slowly removed by blinking. This forms a sort of “bandage” for the cornea, protecting it from further damage and allowing it to heal.
Because the gel remains in place longer than other kinds of eye drops, it can be used to deliver decorin to the injury site without the need to frequently apply the medication.
The researchers found that using the gel alone reduced signs of scarring on the cornea after 7 to 10 days of treatment compared to conventional treatments. Adding decorin to the gel provided even better results.
The study, done on mice, was published in December in the journal Regenerative Medicine.
While Hall said the that study is “potentially very exciting,” he pointed out that the eye drops are in the preclinical phase, meaning there still needs to be more research done before doctors can begin prescribing this to people with eye injuries or infections.
In 2014, the Centers for Disease Control and Prevention estimated that almost 1 million clinical visits for keratitis occur each year in the United States.
Hall said keratitis is one of the more common preventable eye diseases, with “a significant number related to contact lens use.”
Infections can occur when the contact lens case isn’t stored properly, lenses aren’t replaced frequently enough, or lenses are worn overnight.
Proper contact lens use can reduce the risk of eye infections. It’s important to seek treatment promptly at the first sign of infection.
But some infections are so severe they can cause damage even with prompt treatment.
“The sooner the better,” Hall said. “But sometimes, regardless of adequate treatment, a visually significant scar occurs.”
If approved for use in humans, the new eye drops would offer another treatment option for more serious eye infections.
These drops would also provide a sight-saving option for people in the developing world, where “surgical interventions such as corneal transplants are not available,” said the UK researchers in a press release.
Infections and injury to the outer surface of the eye, known as the cornea, can cause scarring that leads to vision problems or blindness in extreme cases.
A new gel eye drop being tested reduces potentially sight-damaging scarring. Further testing in clinical trials need to be done before it can be available for use in humans.