ALLERGY, RESPIRATORY
Overweight Moms More Likely to Have Asthmatic Kids
Using Music and Sports to Improve Kids' Asthma
'Safe' Ozone Levels May Not Be for Some
ALTERNATIVE MEDICINE
Acupuncture May Not Help Hot Flashes
Eight Spiritual Universal Principles in the Art of Practice
Ginkgo No Shield Against Alzheimer's
ANIMAL CARE
Rest Easy. When It Comes to Swine Flu, Your Pet Is Safe
'Comfort Dogs' Come to Emotional Rescue
Animals Respond to Acupuncture's Healing Touch
BONES & JOINTS
Many Americans Fall Short on Their Vitamin D
Using a Balloon to Repair a Broken Back
Rheumatoid Arthritis a Threat to the Heart
CANCER
Smoking Exposure Now Linked to Colon, Breast Cancers
Gene Screen May Predict Colon Cancer's Return
Scams and Shams That Prey on Cancer Patients
CAREGIVING
MRSA Infections Spreading to Kids in Community
Children's Bath Products Contain Contaminants
Memory Loss Help from Brain Supplement Prevagen
CIRCULATORY SYSTEM
Common Antioxidant Might Slow Parkinson's
Support Network May Play Role in Benefits of Drinking
Salt Boosts Blood Pressure in High-Risk Patients
COSMETIC
Gum Chewing May Cut Craving for Snacks
Wrinkle Fillers Need Better Label Warnings: FDA Panel
Health Tip: After Liposuction
DENTAL, ORAL
Amino Acid May Be Key to Strong Teeth
Laser Technology Spots Cavities Before They Start
Sports Drinks May Be Tough on Teeth
DIABETES
Chamomile Tea May Ward Off Diabetes Damage
Spices, Herbs Boost Health for Diabetics
Exercise Protects Black Women From Type 2 Diabetes
DIET, NUTRITION
Even in 'Last Supper,' Portion Sizes Have Grown
Fasting on Alternate Days May Make Dieting Easier
Herb Shows Potential for Rheumatoid Arthriti
DISABILITIES
Review Finds Marijuana May Help MS Patients
Could Your Cell Phone Help Shield You From Alzheimer's?
ENVIRONMENTAL HEALTH
Air Pollution May Cause Appendicitis: Study Reveals
Cats Can Trigger Eczema in Some Infants
Air Quality Better in Northeast, Midwest
EYE CARE, VISION
Kids' Eye Injuries From Golf Clubs Rare But Severe
Decorative Halloween Eye Lenses May Pose Serious Risks
Thyroid Problems Boost Glaucoma Risk
FITNESS
'Safe' Ozone Levels May Not Be for Some
Vigorous Treadmill Workout Curbs Appetite Hormones
Exercise in Adolescence May Cut Risk of Deadly Brain Tumor
GASTROINTESTINAL PROBLEMS
Soothing Imagery May Help Rid Some Kids of Stomach Pain
Gum Chewing May Speed Colon Surgery Recovery
Intestinal Bacteria Trigger Immune Response
GENERAL HEALTH
Quit Smoking the Holistic Way
Adults Need To Get Thier Food Facts Straight
Swine Flu Loves a Crowd
HEAD & NECK
Many Children Will Outgrow Headaches
Zen May Thicken Brain, Thwart Pain
Ski Helmets Encouraged for All
HEALTH & TECHNOLOGY
Study Suggests Link Between Cell Phones and Brain Tumors
Airport Full Body Scanners Pose No Health Threat: Experts
Subway Defibrillators Save Lives
HEARING
Noise Hurts Men's Hearing More, Study Shows
Summer Sounds Can Lead to Hearing Loss
HEART & CARDIOVASCULAR
Toothbrushing May Stave Off Heart Woes
Most Fast-Food French Fries Cooked in Unhealthiest Oil
Kids With Vitamin D Deficiency Linked to Heart Trouble
INFECTIOUS DISEASE
Dry Weather Boosts Odds of Flu Outbreaks
Surgical Masks Could Prevent Flu, Maybe
Swine Flu Now Reported in All 50 States
INFERTILITY
Obesity May Affect Fertility in Young Womene
KID'S HEALTH
Frequent Feedings May Be Making Babies Fat
Traffic Seems to Make Kids' Asthma Worse
Coconut Oil May Help Fight Childhood Pneumonia
MEN'S HEALTH
Sunlight May Help Protect Men From Kidney Cancer
Noise Hurts Men's Hearing More, Study Shows
Whole Grains, Bran May Fight Hypertension in Men
MENTAL HEALTH
Have a Goal in Life? You Might Live Longer
Musicians' Brains Tuned to Emotions in Sound
Heal Your Life® Tips for Living Well
PAIN
Tai Chi May Help Ease Fibromyalgia
Acupuncture, Real or Fake, Eases Back Pain
Alleviating Rheumatoid Arthritis
PHYSICAL THERAPY
PREGNANCY
Prenatal Stress May Boost Baby's Asthma Risk
Yoga's Benefits Outweigh Risks for Pregnant Women
Acupuncture May Relieve Acid Indigestation In Pregnancy
SENIORS
Want Better Health in the New Year, Add Exercise to Your Day
Fitness Fades Fast After 45
A Little Alcohol May Stave Off Alzheimer's
SEXUAL HEALTH
SLEEP DISORDERS
Better Sleep, Grades Seem to Go Up
Lose Weight, Sleep Apnea May Improve
6 to 8 Hours of Shut-Eye Is Optimal for Health
WOMEN'S HEALTH
Natural Oils Help Lower Body Fat For Some
Caffeine in Pregnancy Associated With Low Birth Weight Risk
Alternative Treatments May Boost IVF Success
Add your Article

Stem Cells Repair Damaged Corneas in Mice

By Jennifer Thomas
HealthDay Reporter

FRIDAY, April 10 (HealthDay News) -- Stem cells injected into the eyes of mice with defective corneas returned the corneas to a more normal appearance, a new study has found.

Researchers hope the procedure might one day be an alternative to corneal transplants in humans. About 40,000 such transplants are done each year in the United States.

"The stem cells took the scar-like matrix, remodeled it and made it more like normal," said senior investigator James Funderburgh, an associate professor of ophthalmology at the University of Pittsburgh. "We were surprised and delighted."

A report on the study is in the April 9 online edition of the journal Stem Cells.

The cornea is the transparent, front layer of the eye that serves as a protective barrier and, along with the lens, helps focus light. Corneas can develop scar tissue from chronic inflammation caused by infections or other conditions and by injuries, such as chemical or thermal burns or other trauma.

Scar tissue can cause the cornea to lose its transparency, preventing it from focusing light, and this can lead to a loss of visual acuity, including cloudy, hazy vision sometimes described as looking through frosted glass.

"The only effective therapy is corneal transplant," Funderburgh said.

Several years ago, using human cadavers, Funderburgh and his colleagues collected stem cells from the stroma, a matrix of collagen fibers that gives the cornea its strength.

In a healthy cornea, the collagen fibers run parallel to each other and are highly organized. In a damaged cornea, the matrix is irregular and disorganized, he said.

After growing stem cell cultures in the lab, the researchers injected the stem cells into the eyes of mice bred to have defective corneas that mimic scar tissue in humans.

After three months, the stem cells had regenerated the collagen fibers, making the damaged corneas in the mice look normal, the researchers reported. After one year, the mice corneas still appeared normal.

Stem cells are being used in clinical trials in humans to regenerate other eye tissues, including the epithelium, said Dr. Richard Bensinger, an American Academy of Ophthalmology spokesman.

But he cautioned that the scar-like condition the mice have is different from scar tissue caused by an injury or infection in humans. The mice corneas contained "biochemically deficient tissue" that's missing a protein needed to correctly form the collagen matrix, he said.

A human eye with scar tissue is not missing a protein and has other issues.

"In mice, replacement of the missing protein restores the normal corneal architecture," Bensinger said. "Traumatized corneas in humans are not missing something but have too much of a broad array of proteins causing the scar. Treating such a scar with a replacement protein which happens to be one they already make is not likely to change the character of the scar."

Dr. Ivan Schwab, professor of ophthalmology and director of the Cornea and External Disease Service at the University of California, Davis, was more optimistic.

"Although many steps remain to bring this to a human trial level, this is a real biological step," Schwab said. "Not only does this provide new avenues for possible development of corneal tissues, but it offers new avenues for other tissues as well. This team is to be applauded for outstanding work."

Funderburgh said it will take about two years to develop stem cell cultures that would be suitable for testing in humans, after which they hope to begin clinical trials.

To date, there has not been a shortage of corneas for transplantation in the United States, although there have been shortages in countries where religious and cultural taboos discourage donating or using body parts from the dead.

However, the LASIK corrective eye surgery renders corneas unsuitable for transplantation, which could mean a shortage in years to come, Funderburgh said.

Transplanted corneas have a low risk of rejection, and patients don't even need to take immunosuppressant drugs, Bensinger said. But because of the characteristics of scar tissue, people with corneal injuries are often not good candidates for corneal transplants, and rejection rates among them are higher, he said.

More information

The U.S. National Eye Institute has more on the cornea.



SOURCES: James Funderburgh, Ph.D., associate professor, ophthalmology, University of Pittsburgh; Richard Bensinger, M.D., retired chairman, Eye Department, Swedish Hospital, Seattle; Ivan Schwab, professor of ophthalmology and director, Cornea and External Disease Service, University of California, Davis; April 9, 2009, Stem Cells

Last Updated: April 10, 2009

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