Formerly blind / Pawan Sinha

Surgery on blind children in India gives them the light of their eyes for the first time in their lives and reveals how vision works in the brain

My mother always kept a small blue glass bowl with coins by the door of our house in New Delhi. When she left the house, she would take a few coins to give them as alms to the poor of the city, whom it is impossible not to encounter. One can very quickly become indifferent to the human suffering so common in India, so I have always been impressed by her unwavering adherence to this ritual.

 

The bowl sat unused for several months as my mother battled cancer. When I returned to visit India in 2002, a year after her death, I noticed that the bowl was among the few things my father had kept. I had no idea that she would change my life.

One winter afternoon while visiting India, I left the house to visit a friend, took some coins out of the bowl and put them in my pocket. It was very cold, and I was glad to find a taxi with windows that close all the way, something that is not taken for granted in New Delhi. After a few minutes, the taxi stopped at the intersection. The traffic was surprisingly light, and I saw a small family huddled on the side of the road. I took out the coins, opened the window, and motioned for them to come closer.

They came to me to seal. The two children were holding on to their mother's sari. The sight of the dirty, barefoot children, with only rags of thin cotton cloth for their bodies, was heart-wrenching. I felt even more humiliated when I noticed that the children, who were six or seven years old, were also blind. While the little family stood trembling outside the taxi, I saw the cataracts in the children's eyes. I was surprised, until then I had only seen it in older people. The traffic light changed to green. I placed the coins in the mother's hand and watched the family disappear with the mass exodus. In the days that followed, the faces of these children disturbed my peace. I tried to learn everything I could about blindness in children in India. What I read was shocking.

India is home to one of the world's largest groups of blind children, approximately 400,000 in number. The disability together with the revolting poverty greatly reduces their quality of life. Worse than that, the death rate among this population is alarmingly high. The World Health Organization estimates that up to 60% of children die in the first year after losing their eyesight. Less than 10% of these children receive any education. The fate of blind girls is even more difficult. Many of them are imprisoned at home and undergo physical or sexual abuse.

These figures are disturbing even when they are to themselves, but they stuck out to me even more when I read that a large part of this suffering can be prevented; The blindness of almost 40% of the children can be treated or prevented. But many of the children do not get medical treatment because the treatment centers are in the big cities and almost 70% of the population of India lives in villages. A blind child in a rural family living in poverty is therefore expected to have a tragic, dark and short life.

I read the numbers and couldn't believe it. After all, I grew up in India, how come I didn't know this problem? And how is it possible that such things still exist, contrary to the common belief that India is a rising economic superpower? I decided to fly to India again. I visited villages near Delhi, in the southern state of Andhra Pradesh, and at the mouth of the Ganges in West Bengal. The many blind children I met convinced me that the statistics were indeed based on facts. And the abject poverty I saw in these villages helped me understand why so many of these children are left untreated.

My experience that winter afternoon in New Delhi marked the beginning of a personal journey that has yet to end. I'm done saying help these blind children see. And being a scientist, I realized that this was an important opportunity to answer one of the most challenging questions in neuroscience: how does the brain learn to see?

The answer to the question body

Since my graduate studies At MIT, the vision question both fascinated and frustrated me. How does this confusing jumble of colors, brightnesses and textures that meets our retina every waking moment organize itself into a collection of objects that has meaning and becomes, for example, the outlines of a dancer's arm and upper body, and the blue and green of her checkered skirt?

The main approach to studying the development of the visual system involves experiments on toddlers. Although it produced valuable results, it also suffered from some significant shortcomings. These experiments are difficult to perform. A baby's limited ability to understand and respond and even stay awake for a long time greatly limits the range of reasonable questions that can be asked. Another complicating factor is the changes that can occur simultaneously in related but distinct subsystems of the brain as the child grows. For example: areas that control motivation, concentration, and eye movement control.

Knowing all this, I found myself in the summer of 2002 grappling with two seemingly unrelated questions: How does the brain learn to interpret visual information? And how, with the experience in New Delhi still fresh in my mind, can I help provide vision-restoring surgeries for children blind from birth?

I still remember the excitement that gripped me when I realized that these two questions complement each other: the answer to one lies in the other and vice versa. Monitoring the progress of a child who has recently begun to see can help us understand visual learning. And funding from scientific sources for such a research project could help provide treatments. I marveled at the perfect fit between these two needs, and selfishly, at their perfect fit with my life.

Upon my return to MIT, I presented to my colleagues a plan for research that combines both humanitarian and scientific objectives. Most of them were enthusiastic, but a few warned me against starting such an ambitious enterprise before I had tenure. I understood the risk, but I felt I had no choice but to continue with the plan.

I applied to the US National Eye Institute (belongs to the NIH, the US National Institutes of Health). I was a little worried that asking for funds from the US government for surgeries in India would be a lame start. The matter was also logistically complicated and there were no preliminary data on its applicability. But the examining committee saw the humanitarian and scientific potential of the initiative and granted me an exploratory grant to test the feasibility of the research. I was very excited. This was the first grant I received from the NIH and it strengthened my image of American science as a force that works for the benefit of the entire world, does not hesitate to encourage ventures that involve risk and does not succumb to narrow-mindedness.

The next step was to find a medical partner in India, a place where the blind children could be operated on and treated according to international standards. One ophthalmology center stood out above all: Dr. Shroff's Eye Hospital in New Delhi, which operates as a charitable institution. It has excellent conditions for pediatrics, and its doctors welcomed the opportunity to help blind children and engage in research.

All the attachment parts were now in place. And yet, we lacked a name that would reflect the dual purpose of providing insight and shedding light on scientific questions. It didn't require much thought. The word "light" in Sanskrit, the ancient Indo-European language, is "Prakash". We were therefore awarded a name with a pleasant repetition of sounds: Project Prakash (Project Prakash).

Will surgery help?

We started the project in several stages. First, we established centers for screening eye examinations in rural areas and located children, and sometimes young adults, who could benefit from treatment. A team of optometrists, ophthalmologists and other health professionals examined children in search of visual impairments (focusing problems), eye infections and treatable blindness (especially blindness due to impairment resulting from a birth defect or scarring damage to the cornea). The children selected as candidates for treatment went to the hospital in New Delhi for a more thorough examination. The examination included ophthalmoscopy (which allows a glimpse into the depth of the eye), eye ultrasound, and an assessment of the child's general health and suitability for surgery. After that, dates for surgeries were set in coordination with the children's guardians.

Surgery to remove a hernia in a child is much more complicated than in an adult. Pediatric surgeries require general anesthesia and frequent follow-up examinations. The surgical procedure involves breaking the opaque and hard lens, removing the fragments and taking them out through a small incision made at the edge of the cornea, and replacing the natural, damaged lens with an artificial lens. Project Prakash pays about 300 US dollars for each operation, and the children return for routine check-ups after the operation.

When we started the craft, I was troubled by one concern. I feared that our surgical intervention, despite the good intentions, was too late and useless. Could it be that the patients have already passed the crucial, early period in human life, when he makes intensive use of the eyes and the visual circuits in the brain, and after which the visual ability can no longer develop? This thought is not far-fetched. One English surgeon, William Cheselden, was the first to describe, in 1,728, a late onset of vision in a 13-year-old boy born with blindness in both eyes. Cheselden noticed that the boy's vision remained very poor even after the obstructing tissue was removed.

Controlled studies of visual impairment in animals paint a similarly bleak picture. Thorsten Wiesel and David Hubble, who later, in 1981, both won the Nobel Prize, described the very serious consequences of limiting vision at an early age in cats. In this context, it was natural to question the usefulness of eye surgery in late childhood.

Still, I felt it was worth giving the treatments a chance. Old sources, such as Cheselden's, should be treated with a degree of caution. It is quite likely that the unsuccessful outcome of the surgery was due to tissue damage caused by crude and old-fashioned surgical techniques to remove the tumor. Also, most of the animal studies looked at puppies that had one eye closed with stitches, while Prakash's children suffered from a disorder of concealment in both eyes. It's a bit strange, but blocking one eye causes a more severe impairment of vision in that eye than blocking both eyes. The question of whether any visual function can develop after treatment for blindness in late childhood remains largely open.

 

Now see

The great American psychologist William James described the baby's perceptual world as a "blooming and humming commotion" preceding the maturation of the visual system. The question in the Prakash project was whether this period, the bombardment of color, form and movement, which is perhaps one of the early stages in normal visual development, would be parallel to the experience of Prakash's children who began to see when some of them were already in their 20s. Will their visual system get past the first, confused but necessary steps, and organize the incoming stream of images and imbue it with some meaning? The word "organize" has two meanings here. In order for a person to be able to "see", the different parts of the image must join a set of distinct objects in a process called intramodal organization. The second requirement is intermodal organization, that is, the interrelationship between vision and the other senses.

Our ability to divide an image into separate objects is so sharp that it seems to involve no effort. We open our eyes, and the world falls into place as an orderly collection of things. And here we found that the experience of Prakash's children shortly after they started seeing is different. Severe disabilities were discovered in the new seers. They have difficulty organizing the many areas of color and brightness into larger wholes. Many characteristics of ordinary objects, for example, the overlapping sections of two squares in a part of a sphere, which are separated by seams on the surface of the sphere, are seen as two completely separate objects and not as two components of one large structure. It seems that the field of vision of a person who has just begun to see is a kind of mosaic of many areas of color and brightness that have nothing to do with each other, similar to an abstract painting. This perceptual over-fragmentation makes it difficult to identify whole objects.

The difficulty of Prakash's patients raises a question that has occupied scientists for almost a century: what are the visual cues that allow a person to process complex images correctly? The answer, it seems, lies in the natural arrangement in which the brain organizes visual input, in the "grouping heuristic" (so-called "gestalt" grouping cues after the psychological research stream of the early 20th century). For example, one of the fundamental rules by which the visual system is designed associates ordered lines in an image into one group because they are likely to define the same object.

None of these cues seem to emerge in the Prakash children immediately after the onset of vision, but some interesting changes do occur over time. I well remember S. K., the first Prakash patient who taught us about this. He was a 29-year-old man we met in a crowded hostel for blind boys on the outskirts of New Delhi. A quick examination revealed that he suffers from congenital aphakia (from the Greek phakos - lens), a rare defect in which a child is born without eye lenses. S. K.'s visual world was very limited, much worse than what American law defines as blindness. He adapted to walking with a cane and to studying Braille. Amazingly, all that was needed to correct the aphakia were $20 glasses that compensate for the lack of natural lenses, glasses that S. K. couldn't afford.

We fitted S. K. with glasses and checked his vision. What immediately stood out was that, contrary to our naïve prediction, S. K. did not seem particularly enthused by the improved vision. His visual world, as the tests revealed, was a confusing mixture of many areas of different colors and brightnesses, and there was almost nothing to capture them into a coherent whole. Even simple line drawings such as a circle overlapping a square appeared to him as a group of oddly shaped pieces that fit together (and this despite the fact that he had previously known the concept of circle and square by touch). S. K. had difficulty sketching the outlines of whole objects in the photographs. Shadows and shadows, overlaps and concealments were obstacles he could not overcome.

It was interesting to discover that this confusing night of zones was woven into meaningful structures when one visual cue entered the picture: movement. Images that were too confusing for S. K. in their static state became decipherable when their constituent parts began to move. Videos in which S. K. is seen looking at the picture show this almost miraculous transformation that took place as a result of the movement.

We followed S. K.'s experience with vision for several months. He still had trouble deciphering frozen images. But just when we had already begun to come to terms with the idea that there might be no cure for S. K.'s image processing capabilities, things began to change. A year and a half after the first treatment, without any training other than exposure to the contractual world around him, S. K. began to show improvement. Now he was able to correctly process static images, and even expressed his joy at the improvement in vision. It was a most satisfying ending to a very exciting episode.

In other studies in children much younger than K, we saw a similar process. Many months after the difficulty of processing a static image, they begin to be able to organize what they perceive into tangible objects. The time needed to perfect this fitness, it seems, depends on the age at which the child receives the treatment. The young learn faster.

What is behind this improvement? The theory teaches that it is possible that movement is like a teacher who trains the visual system to process an image even when it is frozen according to the rule: "Parts that move together belong together". A person's visual system is able to eventually learn to associate images according to static features such as color and orientation.

It is understood that the brain does more than just identify the various factors in the visual space. He also connects them to the realm of sound, touch, smell and taste, thus creating a sensory panorama through the intermodal organization. The way vision is linked to other senses has occupied philosophers and neuroscientists for centuries. In 1688, the Irish scientist William Molina wrote to the British philosopher John Locke: "It is said that an adult, blind from birth, learned by the sense of touch to distinguish between a cube and a ball made of the same metal... Now suppose that the cube and the ball are placed before the blind man on a table and he is given a light for his eyes: Give Do you think, based on appearance alone, before touching the ball and the cube, that he would be able to tell the difference between them?"

Locke included Molina's question in the 1692 edition of his famous essay "Essay on the Reason of Man". Molina's question sharpened a series of fundamental questions: How do we connect the different senses and create a unified perception of reality? Are we born with this mental mapping of the world, or do we learn it from experience? Is it possible to purchase it at an advanced age? The exploration of these ideas by Locke, George Berkeley, David Hume, and other empiricists touches many of the central issues of modern neuroscience today.

By assessing the Prakash children's ability to link vision with the other senses, we had the opportunity to directly examine Molina's question. We work with children immediately after vision-giving surgery and engage them in a "match-to-example" experiment. The child sees or touches a simple object placed on an empty background (this is the "example") and then he is asked to identify it from two different objects that are shown to him in sight or given to him to touch.

The case of Y. S., a charming eight-year-old boy who suffered from congenital cataracts that were very opaque in both eyes, illustrates this with an example. Like most of the Prakash children, Y. S. began to feel comfortable within two days of the operation and was ready to work with the research team.

In the test, we used a barrier sheet that ensured that S. would not see his hands. Let him touch an object ("example") only for a short time and return it. Then he took the sample and another object in his hands and was asked to return the sample. Y. S. had no difficulty at all identifying the pattern in all the pairs of objects we presented to him. Similarly, in the contractual field alone, the results he achieved were perfect. However, in the crucial transfer task, visual identification of the objects he felt with his hands, the results were much worse. Four other children we worked with showed a similar pattern of results.

These findings led us to believe that the answer to Molina's question is apparently negative: there is no distinct transfer of information from touch to vision immediately after the restoration of vision. This question is very interesting, but there is an even more intriguing addition perhaps.

When we tested Y. S. a week later, we were amazed to discover that his performance on the transfer task had improved from a situation where the chances of success and failure were equal to a situation of almost complete success. A similar improvement was also observed in two other children we tested. Within a few weeks, Prakash's children begin to develop a good ability to identify the object they have touched, which shows a dormant ability to quickly learn the link between the senses. The recognition of this, it turns out, is good news both scientifically and therapeutically. We can learn from it that neural plasticity - the ability of the visual system, for example, to adapt to new experiences - is preserved even in late childhood and in young adults, and according to our experience eye surgeries will benefit the children.

This information laid the foundations for a plan for further in-depth research into the development of vision in late childhood. Working with Prakash subjects aged 6 to over 20, we surveyed a wide range of visual functions. The findings of these experiments so far show that several important aspects of vision, such as the degree of acuity (how refined the correctly decoded contractile patterns can be), spatial contrast (changes in acuity as a function of changes in contrast) and optical stability, are affected by prolonged deprivation. These disabilities probably remain forever since the relevant estimates do not reach normal levels even a year later.

However, when we examine functions that go beyond the aforementioned estimates, "higher" functions of the visual system, we find evidence of a considerable acquisition of skills, and in particular, the ability to differentiate between objects in the picture and to relate other senses to it. Prakash's children also improved in their ability to recognize faces and logically analyze the spatial arrangement of the objects they see.

new layout

These findings You start to sketch the outline of what can be achieved and what is impossible when a child begins to see at a late age. On the one hand, visual functions do not degenerate irreversibly when the eyes and brain are not exposed to intensive contractual processing in the "crucial period", which is estimated to be the toddler's first years. On the other hand, there is no doubt that early visual experience is important for the development of normal abilities such as good visual separation ability.

The first results are indeed launching a rich set of new studies, some of which may not be related to blindness at all. Based on the research of the Prakash project, we are developing software for the automatic detection of visual categories of objects, for example faces, in videos. Moreover, the disabilities we found in the children in the assimilation of visual information immediately after they began to see are similar in several aspects to the disabilities found in children with autism. From this possible affinity, a series of studies was derived in my laboratory seeking to examine the causes of sensory processing disorders in autistic people.

It seems that the journey ahead will be even more exciting than the path we have already taken. A question that arose for us recently concerns the relationship between the structure of the brain and the way it functions. We intend to use functional magnetic resonance brain imaging (fMRI) to detect changes in the cerebral cortex of a child who has recently begun to see and compare what happens when the treatment is done at different ages to determine what is the latest age at which the brain can reorganize. We may also be able to determine, when the surgery is done at a relatively late age, whether other senses, such as hearing or touch, have taken over the areas of the cortex normally reserved for visual processing.

The Parkash project faces difficult challenges, first and foremost expanding its scope and treatment programs and enabling the integration of the children into the normal systems of society. Our plans to deal with these challenges are ambitious. As a start, we propose to establish the "Prakash Child Center", an institution that will combine medical care, education and research. It will include a children's hospital, an advanced neuroscience research center and a rehabilitation unit for children after treatment, which will allow them to get the most benefit from the treatment they received.

The expansion effort of the project has resulted, as of today, in optimal screening tests of approximately 40,000 children from the most neglected and poorest villages in northern India. About 450 visually impaired children were analyzed and monitored, and more than 1,400 began receiving optical and drug treatments. But given the magnitude of the problem, this is only the beginning.

My students and I derived great satisfaction from the findings of the Prakash project, but the work in the project also affected us on deeper, personal levels. Each blind child we worked with brought a special story of hardship and social isolation. Equally special is the change that takes place in the life of each child after the treatment. S. K. returned to his country with renewed hope to achieve the goal dear to his heart: to become a school teacher. J. A., who was treated when he was 14 years old, is today able to move by himself in the traffic chaos of Delhi.

The same mother of three sons, all of whom were born with a disease and were treated last year, is no longer bullied in the village and is not slapped, a curse is placed on her head. Two brothers whose eyes have been seeing for a few months, after more than eight years of congenital blindness, are today enthusiastic about the possibility of moving to a school for sighted children.

Such transformations are, in a sense, a testament to the power of collaboration: the debt owed by the Prakash Project to the scientists, medical staff, educators and funders who joined together to advance both clinical and research science. And I myself, of course, am grateful for the blue glass bowl and the very special woman to whom it belonged.

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About the author

Pawan Sinha is a professor of computational neuroscience and vision science at MIT. He studies the mechanism and principles by which the brain recognizes objects and visual spaces.

in brief

in India Home to one of the world's largest groups of blind children: about 400,000 in number. Many of them receive no education at all and the girls often fall victim to physical and sexual abuse.

Being a neuroscientist, The author of the article decided to try to help children and young adults suffering from (poor) cataracts and give them the opportunity to see the world at a much older age than the age at which it was thought that the ability to see could develop.

Most surgeries were successful. Even in some patients who are more than 20 years old. The operation also provided the scientists and the team, which the author headed, with a new understanding of the functioning of the visual system.

first sight

Only parts and not whole

Tracing the boundaries of a child who has recently begun to see reveals a fragmented point of view even of two-dimensional cartoons. Each part of the overlapping squares is seen as a separate shape, as indicated by the red lines. The boy also saw parts of the cow and the ball, and their shadows, all outlined in green, as distinct objects. And therefore, he was unable to identify any of the objects in the pictures.

More on the subject

Pawan Sinha on How Brains Learn to See. TED, November 2009. www.ted.com/talks/pawan_sinha_on_how_brains_learn_to_see.html

The Newly Sighted Fail to Match Seen with Felt. Richard Held et al. in Nature Neuroscience, Vol. 14, no. 5, pages 551-553; May 2011.

Project Prakash Website: www.projectprakash.org

The article was published with the permission of Scientific American Israel