Indian Eye Institute Cures Blindness with Adult Stem Cells
By David Ewing Duncan, Fortune, October 25, 2007
Eye surgeon Virendar Sangwan has perfected a procedure so cutting-edge that most who have tried it have failed. Dr. Sangwan's colleague, Geeta Vemuganti, grows corneas in a petri dish from stem cells. Dr. Sangwan then surgically implants these corneas into patientsí eyes in an operating theater in the central Indian city of Hyderabad. Making the L.V. Prasad Eye Institute one of the most prolific facilities in the world using stem cells to regenerate tissue of any kind, Sangwan and Vemuganti perform about 80 corneal regeneration procedures a year together.
Stem cells from embryos are not used, instead, the Sangwan-Vemuganti team uses stem cells found in the tissues of living adults. The progress has been slow for other teams working with adult stem cells. All over the world they are trying to persuade cells to develop livers, brains, hearts, and other organs.
Other procedures remain experimental, but some success has been achieved in growing bone tissue and skin cells.
"A number of programs around the world have tried to perfect this treatment, but they have had bad outcomes," says University of Cincinnati eye surgeon and stem cell specialist Edward Holland.
"It's impressive what they are doing at Prasad."
Operations using corneas grown from stem cells are limited to only about a half-dozen programs in the world including Holland's program. This is in addition to the work being done in Hyderabad.
Located where the cornea touches the white of the eye, the treatment uses stem cells harvested from the limbus. A close relative or, preferably, a patient's good eye if possible, provides the cells called "limbic" and "conjunctiva" to treat those with damaged corneas.
The cells must grow into the epithelium, which is the lower area of the cornea. The cells are chemically adjusted in order to achieve this. In most cases, the transplanted cells take hold in the eye and continue to grow. Patients could still see clearly 40 months later in 56% of the cases originating at the Prasad Institute.
Nuthalapati Partha Saradhi hopes the same will happen to him. Someone jumped out of the shadows and threw acid at the now 47-year-old Nuthalapati and his wife while he was riding his motorbike through the nighttime streets of Hyderabad in 1993. Singing his eyes and destroying both corneas, the chemical scalded a large swath of flesh on Saradhi's face. His wife's eyes were unharmed, but she suffered severe burns. Up until he heard about Sangwan's procedure, he underwent multiple surgeries and skin grafts and spent 12 years as a blind man.
When he recalls the day his bandages came off after his operation in 2005, the formerly blind Saradhi tears up.
"I immediately had back the vision - very clear vision," he says. The first thing he saw was Sangwan, then his brother, wife, and children, including his youngest, born after the attack."
"I cried for about ten minutes," he recalls.
Saradhi must still wear a glass eye that was made at the institute in one of his eyes because it was too badly burned to be repaired.
"I am now able to drive a car," Saradhi says proudly, holding up his driver's license.
With skill in deducing how drugs are made in order to produce generic versions, Indians are well known for reverse engineering. But the eye technique was developed independently by Sangwan and Vemuganti, a pathologist, who together ran experiments in the lab and read papers.
Sangwan persuaded Vemuganti to try growing corneas in her lab since he had a number of patients with burned eyes who could not be helped with standard corneal transplants from cadavers.
"You know how to grow cells, and I know how to do the transplant surgery," Vemuganti recalls him saying. "Why don't we work together?" She smiles and shakes her head. "I had no clue if this was going to work."
Developing a platform on which to grow the corneas was Vemuganti's major innovation. With the size like a stack of coins, she first designed a circular glass tube.
"I had the handyman here cut the glass for me," she says.
Then she overlaid the glass with tissue from a human placenta, which is "a good surface to grow the corneas on," she says.
She watched the corneas begin to grow after adding a growth medium to the stem cells she had placed in four places around the circle.
Named after the Bollywood producer who provided initial funding, the Prasad Institute was founded in 1986. Ranging from LASIK procedures to cataract removal, the hospital performs 25,000 eye surgeries a year. Medical tourists from the U.S. and Europe visit the institute, but the number from this demographic is small compared to those who visit from the rest of Asia, Africa, and the Middle East.
Paying five-star-hotel rates for rooms, wealthy patients are served well at a luxurious and modern suite called the Pavilion. The corneal procedure is free for patients who have lower incomes. But costing about one-tenth of what is charged in the U.S. for similar treatment, those patients who are more affluent pay up to $1,500.
Sitting on the board of Cellerant, a leading stem cell company in San Carlos, California, venture capitalist Antoun Nabhan of Bay City Capital said commercial interest among stem cell companies for the procedure has been scant because of the perceived small volume of patients.
But ophthalmologist Ivan Schwab of the University of California at Davis says that corneal stem cell treatment may have wider applications.
"These stem cells are similar to others in the body that make mucous membrane," he says. "These techniques of growing stem cells might one day be used to treat mucous-membrane tissue in the sinuses, bladder, and other organs."
For now, though, it's corneas that are making an enormous difference in the lives of blinded Indians. With a brown iris and a clear cornea no longer opaque and sightless, a healthy eye gleams in Saradhi's face which remains scarred with wine-colored stains from the skin grafts.
"I was very much happy. My children are so very much happy," he says. "It was a miracle."