Specially medicated contact lenses loaded with vitamin E can keep glaucoma medicine near the eye — where it can treat the disease — almost 100 times longer than possible with current commercial lenses, scientists reported today at the ACS National Meeting.
Glaucoma is second only to cataracts as the leading cause of vision loss and blindness in the world. It affects almost 67 million people. Eye drops that relieve the abnormal build-up of pressure inside the eye that occurs in glaucoma, are a mainstay treatment.
"The problem is within about two to five minutes of putting drops in the eye, tears carry the drug away and it doesn't reach the targeted tissue," said Anuj Chauhan, a chemical engineer at the University of Florida . "Much of the medicine gets absorbed into the bloodstream, which carries it throughout the body where it could cause side effects. Only about one to five percent of drugs in eye drops actually reach the cornea of the eye."
Chauhan and colleagues have developed a new extended-release delivery approach incorporating vitamin E into contact lenses. The invisible clusters, or aggregates, of vitamin E molecules form what Chauhan describes as "transport barriers." that slow down the elusion of the glaucoma medication from the lens into the eye. The drug released from the lens into the eye stays in the tears far longer than the 2-5 minutes with eye drops, leading to more effective therapy.
"These vitamin structures are like 'nano-bricks'," Chauhan said. "The drug molecules can't go through the vitamin E. They must go around it. Because the nanobricks are so much bigger than the drug molecules – we believe about a few hundred times bigger – the molecules get diverted and must travel a longer path. This increases the duration of the drug release from the lenses."
Clinical trials of the new lenses are expected to begin within a year to 2 years.
In research with laboratory animals, the lenses containing vitamin E nanobricks administered drugs up to 100 times longer than most commercial lenses. The lenses could be designed for continuous wear for up to a month, Chauhan said. In addition to treating glaucoma, the contacts could help other eye conditions, such as cataract and dry eye. Cataract is a clouding of the lens of the eye, and dry eye involves decreased production of tears. It affects about 2 in 10 people and can lead to more severe eye problems.
"Vitamin E is a proven nutraceutical that in small amounts is good for the eye because of its ant-oxidant properties. Also Vitamin E presence in the contact lenses blocks UV radiation, leading to increased protection against the UV light. Our research has shown that the vitamin can be loaded into the lenses without any reduction in transparency. We believe it could be helpful in disease treatment and in prevention as well," he said.
Citation: Cheng-Chun Peng, Jinah Kim, Anuj Chauhan, 'Extended delivery of ophthalmic drugs by contact lenses containing nanobarriers of vitamin E', ACS National Meeting, March 2010
- PHYSICAL SCIENCES
- EARTH SCIENCES
- LIFE SCIENCES
- SOCIAL SCIENCES
Subscribe to the newsletter
Stay in touch with the scientific world!
Know Science And Want To Write?
- Moderate Pot Use By Adolescents Doesn't Hurt IQ
- Science Left Behind: The Anti-Vaccine Update Update
- Finding Fracking Fluids In The Environment
- Ashes And Vegetables: The Diet Of Roman Gladiators Was Rather Poor
- Dopamine Receptor Agonist Drugs Linked To Gambling And Hypersexuality
- What's Hiding Under The Clouds Of Venus - Heavy Metal Frost?
- Manly Men And Feminine Women Are Not Evolutionary Mandates - They Are Urban Ones
- "Not mine, many post anon cuz if you block by IP you'll surely block by name. BTW I've posted all..."
- "California voting is variable? No, it isn't, redistricting pushed the 36% of the state that are..."
- "I am quite familiar with California's immunization uptake data, which is reported annually for..."
- "It's already been done, do a search for uMobileCam, I believe that it is free...."
- "No, none of them are mine, many post as anonymous because if you'll block by IP you'll surely block..."
- An end to fat shaming? The 50 year DNA mystery of metabolic dysfunction may soon be solved
- Egg freezing: a smart career move?
- Despite resistance, China will dominate future of GMOs
- Should Science and Nature run advertorial by wacky Dr. Bronner’s that misleads on GMOs?
- Jack the Ripper’s identity remains a mystery after error in DNA analysis revealed
- Seed patent primer: Is the use of GMOs preventing farmers from reusing their seeds?
- Special UO microscope captures defects in nanotubes
- When the isthmus is an island: Madison's hottest, and coldest, spots
- Researchers identify new cell signaling pathway thought to play role in rheumatoid arthritis
- In disease outbreak management, flexibility can save lives and money
- Flexibility in disease outbreak management could save lives and money