Cécité: actualité internationale

La cécité...
Actualité internationale
2008

février

A Visionary Approach Using Stem Cells to Repair Eye Damage

STEM CELL RESEARCH at the LV Prasad Eye Institute in Hyderabad, India, involves the generation of reparative tissue in the laboratory, which is used to replace damaged or diseased tissue.

REHAB: At the LV Prasad Eye Institute, a child learning how to read uses a handheld magnifier in one of the two near-vision examination rooms.

     New eye research center in India aims to fix visual impairments with the help of stem cells
     A new vision research center opening in India today becomes the latest in a handful of facilities dedicated to exploring the potential of adult eye stem cells to repair vision damage. The Champalimaud Center for Translation Eye Research (C-TRACER), part of the LV Prasad Eye Institute in Hyderabad, India, will continue research begun by LV Prasad scientists, who use eye stem cells from living adults to grow new cells that are then implanted into damaged
     The center's goal is to restore vision to some portion of the 65 million people worldwide—about 1 percent of the world population—considered to be legally blind, which the National Federation of the Blind defines as a central visual acuity of 20 / 200 or less in the stronger eye, even when aided by a corrective lens. Especially in developing countries in Africa and Asia, "most of these people are needlessly blind," says D. Balasubramanian, research director for both LV Prasad and the new facility.
     Some of these people have vision problems caused by currently untreatable diseases, he notes, but others simply because they cannot afford or do not have access to relatively simple fixes such as surgery to remove cataracts (clouding of eye lenses).
     Balasubramanian says the research center, which is being funded by the philanthropic Champalimaud Foundation in Lisbon, will be critical to improving eye care in his country where an estimated 15 million people suffer from eyesight woes, many of them genetic. "Hundreds of millions of Indians marry within their community," says Balasubramanian, a former director of the Center for Cellular and Molecular Biology and dean of the University of Hyderabad. "So there is a lot of inherited blindness that is gene-derived. Almost one in every 4,000 live births in India [for example] seems to produce congenital glaucoma."

     Among the disorders that Balasubramanian has targeted is retinitis pigmentosa, a group of inherited diseases that cause degeneration of the retina (in the back of the eye where millions of photoreceptors capture light rays that the brain turns into images). "There is no cure for this and it is certainly a genetic disease," he says. People with retinitis pigmentosa experience a gradual decline in their vision because the eye's photoreceptor cells slowly die off.
     C-TRACER researchers are trained to think in terms of the full cycle of developing treatments—from laboratory to operating room to clinical rehabilitation, or, as Balasubramanian says, "from bench to bedside." One example of this research is the practice of using stem cells taken from a healthy eye's limbus, the area around the corneastem cells are stored, to create a layer of healthy cells to replace damaged ones in the cornea, the transparent, dome-shaped layer of cells covering the front of the eye.
     Ophthalmologists do this by creating a patch of cells from a surgically removed slice of the limbus and stitching it to the damaged cornea. Similar limbal stem cell transplant work has been done by physicians at the University of Melbourne's Center for Eye Research Australia and the Bernard O'Brien Institute of Microsurgery in Fitzroy, Australia.
     Although the stem cell approach was not invented at LV Prasad, the institute has treated about 500 patients with a success rate of nearly 75 percent, Balasubramanian says. C-TRACER and LV Prasad has also tuned its work to pay particular attention to the genetic conditions that lead to visual impairment. C-TRACER will open with a staff of five scientists, 22 graduate students and six clinical researchers. The facility occupies 16,000 square feet (1,485 square meters) on the LV Prasad institute's fifth floor, but plans are to expand to 25,000 square feet (2,320 square meters) by 2009.
     Champalimaud-funded C-TRACER in an effort to prevent and treat vision-related disease and illness in Portugal, Portuguese-speaking countries and throughout the developing world. The four-year-old foundation also offers a $1.48 million (1 million euro) Champalimaud Vision Award annually to researchers who have provided "major breakthroughs in the understanding of vision or in the alleviation of visual impairment and blindness," says foundation executive committee member João Botelho.
     This year, the foundation will further its philanthropic medical research support by breaking ground on the Champalimaud Center for the Unknown, a Lisbon research center slated to open in October 2010 and serve as the foundation's international headquarters.
     In addition to the funds that LV Prasad received from Champalimaud to create C-TRACER, the institute will also receive $1 million in funding over the next five years from the Indian Ministry of Science & Technology's Department of Biotechnology.