For the past few years, I’ve been dazzled by high-tech treatments for blindness. The first DNA Science blog post was about stem cells to treat Stargardt’s macular dystrophy, and the most recent about gene therapy for choroideremia, with the tales of several children becoming able to see for the first time in between. My book is about gene therapy for Leber congenital amaurosis. All rare diseases.
But I hadn’t heard of the astonishing Project Prakash until I read a short article, “Restoring Vision through ‘Project Prakash’: The Opportunities for Merging Science and Service,” in the December 17 PLOS Biology.
The brainchild of Pawan Sinha, Ph.D., professor of vision and computational neuroscience in the department of brain and cognitive sciences at MIT, Project Prakash is a humanitarian/scientific effort that is enabling children and young adults in India, congenitally blind from cataracts, to see. They’re among the 20 million people worldwide who are called “curably blind” or “needlessly blind.” Poverty prevents most of them from being able to see.
Dr. Sinha grew up in New Delhi, and went to graduate school at MIT. He started Project Prakash in 2002 after a trip to rural villages in India where he witnessed the sad scope of the problem of congenital cataracts – a very treatable condition. A grant from the National Eye Institute enabled him to assemble the team to provide cataract surgery, costing $300 per patient. He tells the story vividly in Scientific American.
“Prakash” is Sanskrit for “light.” So far the project has screened more than 40,000 children in India and treated more than 450. And it’s a small group. “The Prakash team includes 10 scientists, 5 clinicians, and 5 outreach personnel. It has been very gratifying to forge this collaboration across national boundaries and between clinicians and scientists,“ said Dr. Sinha.
A child born blind in India faces enormous stigma, and many parents do not pursue treatment – or don’t realize it’s even possible. In the U.S., a child born with cataracts would have surgery before his or her first birthday, leaving plenty of time for the nervous system to learn to integrate visual images into meaningful perceptions. Still, the surgery isn’t as easy as it is for the average older-age cataract patient in the U.S., who loses vision over many years and recovers it rapidly because the brain once learned to interpret images. The ophthalmologist breaks up and removes pieces of the hardened, opaque lens and replaces it with a synthetic lens. For children that means general anesthesia and a one-to-two day recovery. My mother was in and out for her cataract surgeries in a day.
Project Prakash is “a joint scientific and humanitarian effort.“ The humanitarian part is obvious. The scientific gain is in following a unique pediatric cohort who can reveal how a visually naïve brain begins to process and integrate images. Such research is typically done in infants, who can’t communicate what they’re seeing in a way that an 8 or 12 year old can. The oldest patients are in their twenties.
The participants in Project Prakash are challenging a long-held idea: that age of 7 or 8 is the upper limit beyond which a brain attached to sightless eyes can no longer become able to see. But the project has shown clearly that even a person who hasn’t seen for 15 to 20 years, since birth, can begin to make more visual sense of the world.
The investigations include behavioral observations, such as visual acuity and facial recognition, as well as non-invasive brain imaging to follow responses of the cortex to new visual information. The researchers used iPads to test contrast sensitivity.
Becoming able to see after removal of congenital cataracts is profound, but not instantaneous. At first, a newly-sighted person sees vague parts of a scene that, just shapes, that over time come into focus. By six months, shapes corresponding to different colors begin to emerge. “Our results show remarkable plasticity and vision continues to improve in many children long after the surgery,” said Peter J. Bex, PhD, a member of the Prakash team from the Schepens Eye Research Institute.
One particular type of experiment hit home with me, because I have synesthesia. This is a mixing of the senses that is especially common among writers and other creative types – to me, days of the week have specific colors and textures. My brain stamps a visual perception on a time concept. Synesthesia is thought to reflect an unusual overlapping of the cortical areas devoted to multiple senses.
Dr. Sinha and colleagues discovered that two days after children have cataract surgery and became able to see, they really can’t, in the sense of recognizing objects. A child could, with vision blocked, touch two objects and describe and discriminate them. The eyes couldn’t recognize an object that was quite familiar by touch. But it took only a week for those senses to merge. That wasn’t expected to be possible. An article just published in
PNAS Early Edition describes some of the recent results.
It’s wonderful that there is so much going on in vision research that I write about it often but can’t keep up. Check out the Foundation Fighting Blindness website. Stem cell therapies. Gene therapies and the spin-off of “optogenetics” that endows various cell types with the ability to sense light. The bionic retina. New drugs for age-related macular degeneration. And of course Project Prakash.
I think my favorite pair of words is “formerly blind.” I’m glad we’re hearing it more often.