Figures provided by the National Eye Institute reveal that corneal infectious diseases have compromised the sight of over 250 million people worldwide. Of these, 6 million have become blind.
Results of animal experiments, however, show promise in the use of stem cells from a patient's undamaged eye for treating the potentially blinding scarring of the cornea.
Stem cells have the ability to renew themselves and are capable of differentiating themselves into specialized cells with special functions.
Corneal surgeon Sayan Basu from the L.V. Prasad Eye Institute in Hyderabad, India came up with a technique for obtaining ocular stem cells using tissue samples from the limbus, a region between the eye's cornea and the sclera, the white of the eye.
Basu and colleagues used this technique to collect and culture cells. After making sure that the cells were corneal stem cells, the researchers placed them in laboratory mice with corneal injury. The researchers glued the cells to the injured site using a gel of fibrin, a protein present in blood clots that is often used as a surgical adhesive. The researchers likewise had a group of mice that did not receive the experimental treatment.
After four weeks, the researchers found that in mice that were treated, their scarred corneas healed and became clear again. The corneas of the untreated mice, on the other hand, remained clouded.
"Even at the microscopic level, we couldn't tell the difference between the tissues that were treated with stem cells and undamaged cornea," said study researcher James Funderburgh from the University of Pittsburgh School of Medicine.
The researchers likewise said that the stem cells appeared to have induced healing beyond the immediate area where they are placed, suggesting that the cells do not just replace the lost tissue. They also produce factors that promote regeneration.
Basu explained that the patient's own cells taken from the unaffected site could eliminate rejection problems, and this could be helpful particularly for patients who live in places where there are no corneal tissue banks for transplants.
"Because the limbus can be easily biopsied from either eye of an affected individual and LBSCs (Limbal biopsy-derived stromal cells) capable of corneal stromal remodeling can be expanded under xeno-free autologous conditions, these cells present a potential for autologous stem cell-based treatment of corneal stromal blindness," the researchers wrote in their study published in Science Translational Medicine on Dec. 10.