It is a challenge trying to understand what issues surround the enigma in child eye health called CVI, trying to decipher how to assess the patient properly while also intervening successfully with tangible improvement.
This is explained in a succinct yet simple to understand manner by our CVI expert, brought to you by NIPOSS: Committed to Academic and Practical Excellence.
Lecturer: Niranjan Pehere, DNB, Fellowship in Pediatric Ophthalmology , FICO(Hon)
Liberia eye center-LVPEI, JFK MEDICAL CENTER, Monrovia, Liberia.
Panelist: Adedayo Adio FWACS, Consultant Pediatric Ophthalmologist
University of Port Harcourt teaching hospital, Nigeria.
Chairperson, Nigerian Pediatric Ophthalmology and Strabismus Society (NIPOSS)
We have 36 states, we’re in the western part of Africa. The capital is Abuja. And we’re over 200 million population. And to take care of this largely young population, we have about 40 pediatric ophthalmologists, which is less than 10% of the total number of ophthalmologists in the country, working in 21 centers. And we have quite busy clinics, as you can see.
These are all the topics we’ve been featuring so far. We started before the epidemic, so this is not related to epidemics. This is just to make sure that we spread information as we are getting information here, spread it to all the people all over the world. The topic is CVI and before we talk about how to connect the assessments with interventions, I’ll be telling you just briefly, what CVI is all about. And some of the symptoms so that we can have a good background. I know many of you may be aware of what this is. But you know when a child is born, every mother expects that their child will be okay in every aspect, regardless of whatever happened. Even if she labored for three days before she had the baby. And we all know that the first few years of life is very critical and particularly the events surrounding the birth of a child. And any problem or disability that is present or that develops within that period, needs to be detected early so that we can start management early.
So that brings us to the topic of CVI, cortical visual impairment. This is a form of visual impairment caused by a brain problem. It’s not really an eye problem. A lot of people have used other terms loosely, cortical blindness. But we know that not all people that have CVI are blind completely. We also have neurological visual impairment is one of the other terms that is used. But this includes a side of cortical visual impairment, some other common disabilities also like hemiparesis, hemiplegia, and some other neurological problems. Then we also have delayed vision maturation, which is quite different also. The only thing about this is that after a while, it resolves, after a few months. But cortical visual impairment tends to be a little bit permanent, it may change, may improve, but definitely most of the time the features that we see in all these thing are really a bit more longer lasting. And it’s certainly not ocular visual impairment. But we know that some have both cortical visual impairment and also a form of ocular visual impairment.
So what are the causes? Like I said, most of the events that surround birth may be responsible. Some of this may be asphyxia or hypoxia, ischemic episodes that happened no matter how brief, can have some effect on the brain. We also have development brain defects. Then head injuries, sometimes even during birth, some injury can happen. Or you might have an acquired head injury within the period that is very critical. Then we also have hydrocephalus, I have several patients who have this causing their CVI. We also have stroke involving the occipital lobe and then also infections like meningitis and encephalitis.
Now, I was looking at some of the causes of CVI, because from the pediatric neurology clinic that send patients to me in my clinic. Surprisingly we have an increasing number of patients who have meningitis as a cause of CVI. And this is quite interesting and I think we need to look into this a little bit more closely.
What are some of the clinical features that may be there? We have variable vision. Sometimes if they’re in a new environment, sometimes from period to period in a day. Sometimes one eye may be even worse in times of the visual acuity than the other. And they may have a limited field of view. A patient I was examining yesterday came in for early intervention. Sometimes we have just central vision, you have to bring the object right up close to their face. Or they might not even be central, just a little bit off center, so you have to locate the working field of this patient. And some of these patients who have CVI may see moving objects a lot better than stationary objects. Sometimes when you are moving the object, when the object is stationary they will see that and then they bump into some of these things. If you use a shiny object, things that have a reflective surface, they might see it a lot better than when you just have a bland object there.
Then we have face blindness, or prosopagnosia, in which case the parents may not, they say they can’t recognize faces, features, they wouldn’t know who the person is. But they can do every other thing perfectly well. Sometimes they can recognize print, they can write, do many things, but they can’t recognize faces.
They also have problems with color and contrast. and this related to the fact that the fibers that observe color are a lot more difficult to stop when some of these things happen. And red and yellow colors are a lot more easier to see for them. So this is usually exploited when handling this patient.
And then these patients that have CVI can only deal with one or two things at the same time. So we have to keep it simple for these patients. Sometimes they can’t even do two things at the same time. They have to look at an object and look away and then you reach out to take an object. So it’s a little bit disconcerting to parents and even to managing staff, if they are not aware of things like this.
And then in a crowd, familiar faces are much easier to see, a familiar object is much easier to see for them. So for this, sometimes they dislike crowds, they don’t like clutter, they might throw a tantrum when they are in a crowd, or everywhere is destabilized or disorganized.
And then sometimes, this may be accompanied by epilepsy, so you have to check for all these things. Generally, if we detect it early, it will enable early intervention. And parents, usually they are very anxious, “Can the brain be repaired, can it repair itself, can anything good come from this child?”
You know, and really children with disabilities are at risk of delay. And early intervention service is extremely essential. And this will help them to be able to achieve, at least be able to take care of themselves, they can communicate with people, they can cope, they can actually take care of their primary needs without having to depend on someone else or those who are able to do that.
However, many people, many children are not able to access these services. There was a whole idea trying to find out how many people may have these services available in Nigeria? We found out just about two centers are able to offer these services, because very few people are interested, this topic is not a clearly defined one like cataracts, like glaucoma. And their parents also expect a dramatic response. And then of course, investigations are expensive in places where they have to pay out of pocket.
And we have just one center in particular doing that and that is the TLEC. You can see a child doing that, for the purposes of picture taking we had to put on the light. Most of these things we are doing and evaluating, intervening in a child, in a dark environment.
And it’s really up to us to make determination, to make up our mind if you want to change your practice.
So to help us today, for our third quarterly NIPOSS webinar this year, we have Dr. Niranjan Pehere. I met him when I was in my training in LVPEI in 2014. He’s very passionate about children who are CVI. He’s going to be talking about connecting the assessments with intervention in very practical terms. For us to know him better, he’s a pediatric ophthalmologist, he has special interest in this area, like I said. He has completed a two year fellowship as far back as 2010. And he was working in Vijayawada in a tertiary eye care center related to LVP in southern India. Also he set up, under one roof, all the different people that should take care of children with CVI. Which is a herculean task, you should know. Without having to move from one place to the other, raising funds to help these children, irrespective of their inability or ability to pay.
He’s been working there, he has led committees to set up national programs. And he recently completed a three month fellowship at the Great Ormond Street Hospital to look at children like this. And right now he’s working in Africa, in Liberia, in Monrovia, actually he’s leading the Liberia Eye Center, that’s the only modern eye care facility in that area. And apart from treating children that have all these different problems, he’s also involved with residency training programs and is working with neonatal intensive care units and the pediatrics departments, slowly developing services in Africa for children with CVI.
So help me to welcome Dr. Niranjan Pehere. He’s going to be talking to us about CVI, connecting assessments with interventions. So I will stop sharing my slides and then Dr. Pehere, please go on and do what you know how to do best. Thank you very much.
[Niranjan] Thank you so much, Adio, for this kind introduction and this opportunity to interact with people from so many countries about the topic that is so close to our hearts. Good morning, good afternoon, good evening to everyone, depending on which time zone you are. And without wasting time, let’s go on to the topic.
The topic is cerebral visual impairment, connecting assessment to interventions. First of all, let me bring gratitude to my mentors who have transferred this knowledge to me. The first and foremost is Professor Gordon Dutton from Glasgow, Professor Lea Hyvarinen from Finland, Professor Elisa Fazzi from Brescia, Italy, and Dr. Linda Lawrence from Salina, the U.S.
These are the references, from there I mostly pick up my concepts and these are the two extremely helpful websites, the CVI Society and CVI Scotland. I strongly recommend all of you to refer to these websites.
This is the outline of my talk. First, we’ll just briefly touch upon what CVI is about. Just to summarize what Adio has already spoken. And then we’ll go on to connect assessment with interventions, basically for two broad subgroups of CVI. That is low functioning CVI and high functioning CVI.
So to define. CVI is a verifiable visual dysfunction which cannot be attributed to disorders of anterior visual pathways or potentially co-occurring ocular impairment. Essentially what it means is that there is some problem with vision, which cannot be attributed to any ocular problem, or any disorder of anterior visual pathway.
Then what is it due to? It is due to damage or malfunctional visual pathways and visual centers in the brain, specifically those posterior to the lateral geniculate body. So that the seat of impairment, somewhere in the brain, areas which crosses the vision. Which may be accentuated by associated disorders of control of eye movements. Some problem with eye movements is also an integral part of the CVI. So CVI is something that cannot be explained by the ocular problem and there is some evidence of damage to the visual centers in the brain, and there is mostly associated problems with the eye movements. So that is, in essence, what CVI is.
Now there is some confusion about these two terminologies: cortical visual impairment versus cerebral visual impairment. Slowly the consensus is growing that cerebral is a more comprehensive and appropriate term because when you say cortical it references the cerebral cortex. But if we really look at the causes of CVI, that Adio had just enumerated, one of the most common causes, periventricular leukomalacia, because of prematurity, and it affects the white matter which is not a part of the cerebral cortex. And there are several other areas of the brain like the brain stem, cerebellum, which can cause CVI. So we feel that cerebral is a more comprehensive and appropriate term.
A better way to say is CVIs, that is several individual impairments. Because it is an umbrella term which covers several visual-related difficulties. When you say that a child has CVI, all that it means is that the seat of visual impairment is brain. We need to characterize it further in detail to understand what exactly is bothering the child.
Under the umbrella of CVI, we have loss of visual acuity, visual acuity defect, or visual field inattention, poor contrast sensitivity, oculomotor issues, visual agnosias, motion perception difficulties, visuo-spacial difficulties, visual inattention. There are so many things that come under this umbrella of CVI and we need to specify what exactly is the child’s problem.
And it is a spectrum. So at one end of the spectrum, we have a child who cannot even look at the light. And we call it low functioning CVI. And at the other end of the spectrum we have a child who can see, but cannot process and use that information in a meaningful way. That is called high functioning CVI. Although these two are the extremes of the spectrum, it does not mean that they cannot coexist. A child who has low functioning CVI can also have difficulty with processing of that information. They can definitely coexist.
Now, with this little background, let’s move on to connecting assessments to interventions, first with the low functioning CVI. At the outset, we would like to say that CVI is a medical condition only until a diagnosis is made. Because the diagnosis of CVI can only be made by a medical doctor. Only a doctor can say that this kind of visual impairment cannot be attributed to eyes and there’s something more here. But after that, it is completely a habilitational or educational condition. Meaning that there is no medicine, there is no surgery which can take care of CVI. So we have to get into habilitational more to understand what are the child’s difficulties and how can we work around it?
While it is mostly a habilitative condition, one must not lose the sight of treatable problems that the child may have. It is not uncommon to see children with CVI whose ocular problems have been unaddressed for years and years. There are several reasons for it. Number one, it is not so easy to examine the children. Number two, many times, even if they have been diagnosed to have the problems, many physicians tend to think that treating the child with this kind of a brain problem is not going to help. But that is so unfair because it is like adding a disability on top of a pre-existing disability. Getting a good comprehensive ocular examination done and treating all the treatable problems is a very, very essential part of treating CVI.
One may not be familiar with the habilitative strategies but this is something that we all can do as ophthalmologists. So that’s the most important part of intervention that we should be doing. Now coming to the assessment of the child from CVI point of view. Something beyond our regular ocular examination.
This is the kind of performa that we recommend. And we develop this as a part of a working group program of India. I will not go into much details because of the time constraint, but the reason for putting up this is one. That is don’t jump onto examining the vision directly. First we need to have a good overview of the child’s overall systemic condition. Various abilities beyond eyes and that sets the ground for vision evaluation. If we go directly to the vision evaluation, one is likely to get frustrated because the responses of the child may not be as we expect. But needs to have a good idea about what is the child’s intellectual capacity, or how is their hearing, are there any sensory issues? All those things need to be first taken care of before going in for vision, otherwise one is likely to get lost.
Now, how do you assess? Because if you really look at the literature, textbooks, there are so many tests described. Which of these do we select for the child that is in front of us? So this is the kind of guidelines that we followed that we should not do anything that will not act to the plan on intervention. Something maybe quite good to know scientifically, like say, doing a VEP for a child who is very low functioning. It may give you some idea about the visual acuity. But does it really help you to design an intervention plan? Very less likely. Because we have very few limited resources, we should invest them wisely.
We should not do anything that will not add to the plan of the intervention strategies. The results of the test should be such that one can explain the results to the mother, or the caregiver, in a language that they can understand and apply. There is no point in having some numbers or some graphs which you are not able to translate to the mother in the language that she can understand.
And these tests need to be simple, time-effective, cost-effective, and yet, informative. Simple, because it is not necessary that doctor only has to do all this. Because of time constraints and various problems, doctors may not be able to give that much time to every child. So we need to train a cadre of staff who can apply this test and come out with meaningful information, so they got to be simple. They got to be time-effective. Because we have loads of children to deal with, so they should not be something that take a long time and cost effective because we have limited resources. But yet they give the information that we need.
Assessment has to lead to an intervention plan and intervention should be such that it becomes a part of the routine of the child. And this has to become completely parent-centered approach. That whatever we do, is something that parents can repeat at home at their ease. And that is what is the parent-centered approach. Because in other words, it is very unlikely that child would be able to come to the center for interventions often. Our home-based intervention programs are also a distant reality in many of our countries. So the best way is to educate the parents and train them to apply these principles at home.
This is the thought process that we recommend for working with intervention plans we suggest. Let us go by asking first, why, then how, and then what? Instead of going outward in, that is what, how and why. The reason behind this is first we need to understand why this particular vision-related problem exists. The child is unable to look at the face. Why is it happening? Is it because of acuity for an ocular cause? Have we really dealt with it well, or is there something with the occipital lobe? Is there any field problem, is there any contrast sensory-related problem? Or is there something with the posterior parietal lobes, temporal lobes? What is it?
So first we need to figure out what is the cause that is why this particular problem is happening? Then how do we work around it? Once you know why is it happening, then think of solutions of working around it. And then what? With this background of information, what exactly needs to be done in the child’s routine so this problem is taken care of? So if you follow this why, how and what approach, for every difficulty that the parents come with, or you notice during your examination, we will be able to come up with our own intervention plan.
For this why, how and what pattern of thinking, we need to have some background about how brain processes vision. So without going into detail, just briefly. When the visual information reaches the occipital lobe, it processes it for visual acuity, visual field, color perception, and contrast sensitivity. Then this information flows in two directions: ventral stream and dorsal stream. Ventral stream, that is temporal lobes, tells us who this person is, what is this text, object, shape, routes that you’re looking at. That is recognition. Posterior parietal lobes, they analyze the visual environment and give us the three dimensional map of the visual world around us. They help us to give attention to the object of interest and guide the body movements towards objects. That is visually-guided body movements.
These lobes are in constant interaction with the frontal lobes, which are responsible for decision making. They choose the object of interest. And they also help us to move our eyes and head towards the object. So that is frontal lobes. Now, all the machinery requires a very stable frame of reference, which is provided by the vestibular and proprioceptive system. And just like the tripod of a camera, which provides stability to the camera. And we need good cognition and good motor system to use this visual information for meaningful actions. This is, in a sense, the brain processing our vision. So when you look at the child with CVI, we need to look at it from all those angles and try and understand where does the problem exist?
Now, starting with the low functioning CVI, these are the things that we do. Instead of listing them, let us go through them one by one. The first and foremost is a good refraction and assessing the accommodation. Refracting is something that all of us do. But assessing the accommodation in young children is something that is not done very commonly. And a useful technique for that is dynamic retinoscopy. As you see in this video, for this young infant we show a bright illuminated object close to the face. And the examiner is trying to look at the retinoscopy reflects. If the child is accommodating well, the reflex has to have an opposite movement or it should at least neutralize the movement, filling the whole pupil. And pupil should become small.
If these things happen, that means there is accommodation happening. If the reflex changes with movement, then probably there is hypoaccomodation. What if the child does not cooperate for dynamic retinoscopy? One can just put plus glasses on a child’s face. Like in this case, the child does not look at the examiner’s face. But when you put on these plus three glasses, the child becomes more attentive and looks at the examiner’s face.
So this is an indicator that the child has hypoaccommodation and is helped by putting on plus lenses. We keep this plus three, plus four glasses ready in our clinic, and just put it on if the child does not cooperate for retinoscopy and that gives us an idea about the need for any correction for accommodation.
Once we know that the child has a hypoaccommodation, it will be accounted for in their glass prescription. That is if the child is hypo, we give that add. If the child is myope, we reduce that much correction from his myopic glasses. The amount of near correction that you give would depend on child’s age, level of vision, and the kind of vision-related tasks that the child is expected to do. And it is a dynamic process that in a few months’ time, as the child’s visual performance improves, we have to slowly taper, reduce the correction depending on the visual needs of the child. So that is the first, foremost and more important intervention. Good refraction, looking at accommodating as well, and accounting for that accommodation in the child’s glass prescription.
The second most important thing to assess is the facial communication distance. Communication, that is what these children are trying for. They want to communicate, they want to get heard of, they want to understand what people are seeing around them. And the most important thing for that is trying to understand from what distance is the child perceive the examiner’s face.
So we go close to the child and examine his facial expressions, we move away from the child, and try and understand to what distance is the child able to track the examiner’s face? And we tell the family that whenever they interact with the child, make sure that they are within this sphere, so that the child is able to access the caretaker’s face. So that is about the facial recognition distance.
Then comes the visual acuity using preferential looking tests. These are the different tests that can be used. Lea paddles, Teller acuity cards. We prefer Lea paddles because they are cheaper, they are something that you can carry from place to place, easy to administer. Once we have found that a child has visual acuity of 4cpd at 40 centimeters, I’ll use Teller acuity cards to do that it is 20 by 200. What sense does it make to the parents? Not really. And when you try to say that, say 20 by 200 means what a normal person can see from 200 feet, the child would have to come to 20 feet. Fine, scientifically all right. But then, how do the parents use this information for the child’s day to day activities?
So we find this way more informative, that is, we compare the mother’s finger thickness with the line thickness on the Lea paddle that the child could look at. So the child could look at this paddle, and the mother’s index finger matches with the thickness of the dark band here, we say that this is line thickness that the child can appreciate. Over here, it’s almost half the thickness of the index fingers. So this is the thickness of the line that the child can appreciate. And whenever you show the child any object, make sure that the details in the object have this level of line thickness, and the separation between the two lines has to be at least this much line thickness so that the child can appreciate the details.
Now, how can we use this information? One of the routine activities of the child is having milk with a feeding bottle. So while intervening, first we enumerate what are the routines of the child? And one of the most common routine activities is feeding with a bottle. So this bottle is made of plastic, which is transparent, so visually it may not be really accessible. So on this transparent bottle, we can put these shiny, colorful bands of the thickness that the child could appreciate on the Lea paddle. With the same separation between those two bands. And we showed this bottle against a dark cardboard, so that the bottle and the band are enhanced. Further, we put light on it because this paper is shiny and it would be more attractive for the child.
Then we put milk in this, so the milk again gives a contrast against this dark cardboard in the background. There is a movement of the milk, so there is some kind of movement perception that is encouraged. When the child has that milk, you have the taste sensation coming that the child really likes. And this whole experience can become complimented by a song, which is related to this activity. Which is sung in a very slow way.
So now, this routine activity of taking milk with a feeding bottle is made accessible to the child, by means of vision, by using this information from the Lea paddle. We are also complementing the sense of vision with a sense of touch, the child holds the bottle. We complement it with taste, smell, and sound. So feeding is now an intervention. A routine activity that the child does three, four times a day, now also becomes a part of the intervention strategy.
The toys that the parents would choose for the child. This doll is really adorable, but the line thickness is such that the child cannot access it using his vision. But if you have something simple like this, with line thickness that matches with what they saw on the Lea paddle, and the contrast, and the simplicity, is such that the child’s brain can process that information. This kind of a simple toy is much more accessible and enjoyable for the child.
The feeding cup. Again, having the same line thickness. Like Alice in Wonderland, looks nice but it’s not accessible to the child. This simple cup with bold letters with the same line thickness and contrast, is not accessible to the child. So that’s how the objects for use in routine activities can be made accessible.
Food. Food, again, contrasting background. With this kind of food material separated by distance from each other. Makes the food material accessible to the child.
Many of times, we don’t have access to this kind of preferential looking tests. So this puppet faces is also a very useful alternative. The difference between this and the preferential looking is that here we have the same lines but they’re in the form of a face, which is biologically more attractive for a child. It gives us the same information about what is a line thickness and line separation that is required for the child to look at it.
One of the uses of puppet faces that we routinely use is for mapping the visual field. As you see in this video, we have this black cardboard in the center. And we show a puppet face in different directions and try to see if the child can look at it. We showed it from different sides and the child looks at it immediately. But when you show it from the low side, it takes a long time for him to take cognizance of it and this is suggestive of a lower visual field impairment.
So if one doesn’t have puppet faces, you can use any toy that the child appreciates. A favorite toy of the child, and you can show it on different sides with a black cardboard blocking the central visual field.
Lea wand is also helpful for children who may not be responding to the puppet face, because of poor acuity. So this flickering light we move from periphery to the center. And as you see, over here, when we cross the light from left to the right side, near the midline, that is where she starts appreciating the light and she catches it.
Then we repeat it from going down to up, and as it approaches her eye level, going from down to up, that is where she starts appreciating the light. So this means that she has a field impairment on her right and lower side. This is mostly her seeing visual sphere and that needs to be told the parents very clearly.
Now, what if the child has a lower field impairment? Once the children start learning to walk, they need something like this so things on the ground can be alerted to them with the help of this toy. So that they don’t fall off, they lose their confidence, and they lose interest in walking. So this kind of a toy would help such a child as she would grow and learn walking.
When we feed such children, like this child, with lower visual field impairment, when you bring the spoon from different directions up, right, left, the child responds very nicely. But when you put the spoon in the lower field, which is the non-seeing part of the visual field, she starts crying because she doesn’t appreciate that spoon. This demonstrates that the child has lower field impairment. So what is the applied importance of this? When you show a child a new object, make sure that it is in the seeing part of the visual field.
Now, how do we take care of the non-seeing part of the field? How do we try to engage that also in the vision processing? Once the child gets familiar with the object, we can try to bring that object from non-seeing to the seeing part and try to encourage the child to look at it when you’re at the boundary of the seeing and the non-seeing part. This color of the spoon is part attractive, it contains the food that the child likes. So this is an object that child would love to explore.
Once you have encouraged the object in the seeing part, from next time, you try to bring it from below up and encourage the child to look at it and that is what makes the child aware of the non-seeing part of the field. And instead of being away from the non-seeing part, it’s helpful if we are in the boundary between the seeing and non-seeing, so that the child is encouraged and then slowly move onto the non-seeing part. So that is how using the day to day activities and objects that the child likes, we map the visual field and then try to work on expanding the visual field and the non-seeing part.
Contrast sensitivity is something that is not assessed in children routinely, but if a child has brain damage, it is very, very important to make this assessment. And for that we use this Hiding Heidi test, which is again, very similar to the other preferential looking tests. We’re trying to understand what is the level of the contrast of the face that is required for the child to look at it.
What do we do with this information? If it is known that the child has no contrast sensitivity, one of the aspects of child functioning is one that gets affected is the facial communication. Because human face is a low contrast object. The facial expressions, the way the skin moves, all those are in such low contrast with each other, that the child is going to find it very hard to identify a face or facial expressions using vision.
So for such a child, we advise the mother to enhance the contrast on the face by using some facial makeup. This is a very traditional way that women would put up this color on their forehead, then lipstick, and some lash liners. If we can match the thickness of these lines, as for the Lea paddles, so that it is accessible to the child. And what would child maybe seeing with this kind of a vision contrast? This is the face without any enhanced facial makeup and this is the face with enhanced facial makeup, and if the child has poor acuity and poor contrast, this is how child would appreciate at least some details on the parent’s face, compared to this one. So that would help the child to get engaged with their caregiver’s face. So that’s how we translate this assessment of contrast sensitivity into day to day activities.
Color preference is something that is seen in a few children. And I don’t think there’s any particular color that they’re attracted to. But we all have colors that we like, for reasons that we don’t know. I like sky blue. Now, why do I like sky blue? I really don’t know. But whenever I buy a shirt, or I buy anything, blue attracts me. Similarly children with CVI, also may have preference for a particular color. I don’t think it’s a characteristic of a CVI, but it is something that is common in all of us. How do we really assess that?
We show the child illuminated walls of different color. And as you see here, when we showed red, the child’s responses are much more encouraging. It looks as if the child likes red. Now, we put blue again, and we don’t see the child as engaged as earlier. Then we put yellow, this is again, something the child likes. We go back to blue, and the child doesn’t give a similar response. It looks like red and yellow are the colors that excite the child more than other colors. So we can use this color more often in the child’s routines for whatever objects that they play with, that are used for feeding, brushing, whatever, all those things. We can use this color more often to make the information more attractive for the child.
Now once we have found all these parameters, we must ensure that the mother, or the caregiver, understands these thresholds very well. It is very important to make them understand how big an object should be, at what distance it should be held, in which part of the visual field, at what level of contrast, or which color? And for how long you need to hold the object for the child to take recognizes of it? And how long can it sustain his attention on that object? These are a few critical questions that should be answered with our assessment and we need to explain that to the child’s mother.
Now, coming into some common misconceptions about vision interventions. That if a child has poor vision, don’t make any sound, don’t use any touch, just try to stimulate vision in a dark room using some brightly illuminated objects. That is to stimulate vision alone. But this is ill founded because if you look at the way brain functions, all these senses are so interconnected, it is for our understanding that we say that this part processes sound, this part processes vision, that part processes touch. But if you really see how these parts function, they are so closely interconnected. And when one sense doesn’t work well, the other senses try to compensate for it. Because the brain has to get its job done.
So if we try to stimulate vision in isolation, we are taking away these opportunities of the brain to heal itself and this opportunity of neuroplasticity is taken away if we just try to work on vision in isolation. So that is something that should not be done. There is a very nice review about this intervention strategies which clearly states that stimulation, which refers to watching passively high-contrast visual stimuli in a dark room is something that you would discourage.
And vision intervention should be encouraged, which is a dynamic and interactive approach where the instructor chooses the stimulus as per the assessment. Looking at the way the child reacts. And as for that, the instructor makes adjustments and continues to engage the child. So it makes use of vision in a more refined and applied way.
Now, what are we trying to achieve by intervention planning? To make the child learn something. How do we learn something? By stirring his memory. And then recalling it when it is required later. That is learning. This is my cup of feeding, or this is milk, or this is ball.
How do you train a child to identify that this is a ball if his vision is poor? You need to enhance that ball, which takes into consideration the visual thresholds of the child. And vision is very poor, so you will need help from other senses to come in and then make it a wholesome experience. And then the child is going to recall this experience later that this is a ball, that is what intervention’s about. So how can we make a lasting memory with just one sense which is not working very well?
Now we want to teach this child what ball is because that’s something that the child is going to look at every day. So we choose a color that is favorite for the child. We make it high contrast by making the room dark and putting a light on the ball so it becomes enhanced. We put child’s hands on the ball to make him understand that this smooth, curved surface is ball. And why she feels that the examiner is pronouncing the world ball in a very slow way that the child can get it. And while one says that, the hands of the child are rolled over the examiner’s face and lips so that the child understands where’s the sound coming from. And how does the child’s sound really get produced? And that is what engages the child. So this is multi-sensory learning to teach the child what is a ball in a more interactive way so that the child has a lasting memory of it. Instead of just showing this bright ball in a dark room, which doesn’t make any sense to the child.
Now, similarly, for different kinds of visual skills, there are different activities which have been described very well in this book. And it is basically meant for children with just ocular impairment but we can make a few adaptations to it for a child with brain damage. So that is how we can have an individual intervention plan for each child.
Now it is important that we connect this information about vision with other therapies as well. Because physiotherapy, speech therapy, all those therapies they all are vision based. The child is supposed to see and do those things. If they don’t know how well the child sees, the therapies are not going to be optimally effective. So it’s very important that we work closely with these therapists and make them understand how does the child see, so that they can incorporate this component into their strategies.
So that was about connecting assessment to interventions for a child who is really low functioning. Now coming to a child who is high functioning, that means his visual acuity is reasonably good. But that doesn’t explain the difficulties that the child has. Say a child has visual acuity of 20/30, 20/40 but he can’t recognize his parents when they’re in a group. Or a child who has a good visual acuity but seems to be very clumsy while doing his day to day activities. He just can’t write on a line on the page. So possibly, some children have difficulty in using that visual information and we call it high functioning CVI.
Now, the diagnosis of high functioning CVI is basically made by history. A very good history taking. Because the clinical tools meant for diagnosis of high functioning CVI are still getting developed. We have little experience of using some of these tools and I will share those with you. But cornerstone of diagnosis is still a very good history taking by using an inventory so that you don’t miss out on any part of the visual processing. And the one that we use and find very useful is the one by Professor Gordon Dutton called Insight.
Now coming to the clinical tests, these are the tests that are helpful, we’ll go through them one by one. Crowding ratio, that is ratio of best corrected visual acuity with linear optotype divided by visual acuity with single optotype. So you make the child read a few letters in a line and then you show the same letters one by one. And check which one is better, and take a ratio. If this ratio is more than two, it is suggestive of dorsal stream dysfunction. That means the posterior parietal lobes are unable to process too much information at the same time.
So take an example of line acuity was 20/125 and with single optotype it improved to 20/30. You take the ratio of the two, it is four. So that is called crowding ratio of four, it means that the child has significant difficulty using the information when there are too many things close together. That is called simultanagnosia, the inability to process multiple stimuli at the same time.
Now, this Lea puzzle is something that is quite popular. And it is useful to assess some of these high visual processing issues. We give child this red circle and she has to put it in its right slot. Now, she knows where is the slot, but she has so much difficulty in placing it exactly where it should go. So that is because of the visual spatial difficulty. Her posterior parietal lobe doesn’t map it so well, so that is the reason why her hands are not able to precisely reach where that circle should go using vision. But when we put touch into use and that touch gives her additional clues as to where it should go, she takes her own time to figure it out. And finally, she is able to place it.
So finally yes, she could figure it out and place it. So what does it mean? It means that the child’s visually guided hand movements will not be precise because of the less accurate mapping of the visual world by the posterior parietal lobes. So she needs additional help and with the help of touch to complete the puzzle. This test demonstrates what is her difficulty, what is the reason for it, and how intervention should be planned. The intervention for this is using touch as an additional tool to understand her damage to the map.
Lea mail box test. Here, the child has to post this white card through the slit. And as the examiner holds the card in the air, child finds it extremely hard to grasp it. Although the card is right in front of her, so close to her, look at the way she searches for it. She just can’t understand the three dimensional position of the object in space, in relation to her and her hands. Then we make the child make the object two dimensional by keeping it on the surface of the table and then she can catch it. She is unable to understand the reorientation of this line, the slit, and orient the card as for the orientation of the line and pass it.
Yeah, so this is called optic ataxia. This test demonstrates the visual spatial difficulties of the child. That is the issue with posterior parietal lobes.
So in the object sorting test, we put a few objects in a basket. Make sure that the child is aware of those objects, familiar with those objects. And then we ask the child to pick up one of those which is not difficult to find. Like over here, we have asked the child to pick up a green colored kitten which is right there, but she is unable to find it. She has to pick up things one by one, make sure what it is, and then tries to explore one by one. And it takes awhile for her to find the object that we have asked for. So this test is about simultanagnosia, that is the inability to process multiple objects at the same time.
But if we keep fewer objects, then it becomes easier for the child. So this way we demonstrate to the parents as to why the child has difficulty in finding his own things at home when there are a lot together, like say finding one clothes from a pile of clothes, or finding a toy from a bunch of toys. So that is because the child cannot process too many things at the same time. But if you give a few objects, the child picks it up with no difficulty, and even close to the object becomes either. This demonstrates as to what is their difficulty, what is the reason for it, and what is a strategy to intervene. That is declutter the surrounding and the child is likely to be much more comfortable.
This is a simple test, a Pepi test for assessing the motion perceptions. Here we have a central red lines which is the fixation target. And on pressing the key on the keyboard, we have a dog which moves from one corner to the other. And we check if the child is able to track the movement of the dog. So that tells us about the biological motion perception.
So here the child is just not able to track the dog, even if you, from the child using finger as to which way it is going. So that is marker of dyskinetopsia that is poor motion perception. And if this is found we should make sure that whenever the child is engaged with some vision-related activity, the object and the child both should not move. The more still they are the more likely that the child is going to register that information. The Pepi test. It was developed by Professor Lea Hyvarinen and that software is available on request. It is simple to use and install in any computer.
If one doesn’t have access to that, we can use this finger motion test, described by Profession Gordon Dutton. We start with still hand, and ask the child to count the fingers. And you see she is able to count. But the moment you set the hand in motion, she feels lost and she’s unable to count the fingers. Until we again make the hand still and she’s able to count again. All right? It suggests that the child is not able to process moving objects very well. So that was about the connecting assessment to interventions for a child with high functioning CVI.
Sorry if I have rushed too much. But then for the time limit, I thought we should have enough time for discussion as well.
[Adedayo] Somebody in the audience is asking the difference between CVI and functional visual impairment. The difference between CVI and functional visual impairment.
[Niranjan] I think functional visual impairment it refers to an inability to use the vision for day to day activities. So that is functional visual impairment. So it means that the child or the adult may have good acuity, good field, but he is unable to use it to perform the tasks of daily living. That is functional visual impairment. Maybe it is something similar to the high functioning CVI. It may not be just because of the higher processing of vision, but even because of low contrast, one may have functional impairment of vision.
[Adedayo] One other question that we might want to ask. Starting with someone from, somebody called Salome, she asked, “How are the practical results? What practical skills have you reached by this visual trainings?” So if you would want to answer that?
[Niranjan] Well there’s a wide range of improvements. Like the child that I showed at the end. She started functioning like any other normal child over a period of a year or so. It took a year for her to get back to her schooling and other routine activities. I think a lot depends upon the primary cause, whether it was congenital, acquired, what was the level of the insult, which parts of the brain are affected. So we cannot say as to any generalized statement about how much improvement happens in which areas of functioning. There are variable factors.
But I’m yet to come across a child who has not experienced any improvement. Most of the children, at least 80-90% of them experience some form of improvement. And one of the most important factors in this improvement is the parental understanding of the issue and the accommodations that are made based on that understanding in the child’s environment. That is the most crucial factor than anything else.
[Adedayo] Many of the parents they want a quick fix, they want it to happen very fast, they are often disappointed that this takes quite a while for some changes to happen. But when we explain, like you have said, you explain to the patient or the parents, that this is exactly the process, how to go about it, and this is what you do so that you don’t get frustrated easily by this challenge. Many of them are quite intelligent children, it’s just to be able to channel and help them use the little vision they have to be able to take care of themselves and to be able to attend school.
It’s been a very interesting discussion. But one other question that is important. What other household modifications can we employ to improve the quality of life? Household modifications? What other ones can we employ aside of using color, using makeup for the parents, some parents we also tell them to grow a beard. Telling the father to grow the beard so it will increase the use of touch, to be able to identify who is there, for those who have facia. So what other modifications can we use? Can we employ?
[Niranjan] That’s a great question. I think that is something that is likely different from a child who has a purely ocular impairment version a child with cerebral vision impairment. That the environmental modifications have a bigger role in CVI compared to just ocular impairment. And one of the most important environmental modifications needed at home is decluttering. Which sounds so simple, but it can work miracle for a child with brain damage. Because of the posterior parietal lobe damage, which is so common, children are not able to register too many things at the same time using their vision. But if they are exposed to one or two objects at the same time, they tend to function much better.
Not keeping things that you don’t need outside, try to put them behind a curtain, or inside a cupboard, so that it’s out of sight. Try to have simpler patterns, like say for curtain, the bedsheets, the pillow covers, less of the design the better. Of course, enhanced contrast definitely helps.
Having the sound level at home in general, which is low, so that there is no competition between the senses of hearing and seeing. These kinds of environmental modifications are likely to help the child.
Some of them have topographic agnosia, because of temporal lobe damage. They tend to forget things. Putting labels at home until the time they get accustomed to the map of the home in their heads. And when possible, try to put in the tactile touch as a supplemental sense for them to understand the object that they are looking at. I think these are the environmental modifications at home which I use far most with children with brain damage.
[Adedayo] Great. One of the things that I do is to also ask them to do a brain MRI so that you can see exactly where some of the issues may be. The process of trying to explain connecting the defects of the brain to the parents, there’s some form of information, so that you can tell whether this kind of person would be a high functioning or will be a low functioning. What do you want us to tell parents when you see just a very thin cerebral mantle, you see ventricles all filled up with fluid, there’s hardly any brain tissue. What do you want to tell parents, in terms of the future for this child?
And many of them, especially those who don’t have any particular lesions that you see, they say brain is normal, but you can see the child is having problems connecting vision with function. For low functioning, that is the question. What do you tell the parents for those who have children that are low functioning? And what do you tell parents that have children who are high functioning in terms of the future of this child?
[Niranjan] Adio, I think there are two things that you asked. One is, how do we use the MRI? And second is what do you tell the parents of a child who is really, really low functioning? I use MRI or CT scan to get a hang of what could child’s visual world be? Depending on which areas of the brain are damaged. If you have the right occipital and parietal lobes are damaged, then it gives me a clue that probably the child’s left side would be the non-seeing side. Child would have issues with attention, would have issues with visual/spatial orientation on the left side. But his right eye should be better off.
If the child has both occipital lobes being severely affected by an infarct, then this is quite closer to an ocular impairment in terms of poor acuity, poor contrast, poor field. So scan definitely helps you to have a mental picture of the child’s visual world. But depending on the age at when the incident happened, it may not correlate. Because earlier things that happened, more is the opportunity for the neuroplasticity, so what you expect on examination may be different from what you see on the scan. But nevertheless, a scan is useful as a starting point to understand what to expect during the examination.
Having said that, if the scan is not available, it is not a handicap at all. We can go by what we see on just examination and that is enough to design an intervention plan. Neural imagining is not a must for diagnosis or developing an intervention plan.
Then coming to counseling parent of a child who are really low functioning, one of the things that I tell them is a large part of the brain, different books say different figures, something like 30% to 80% brain is devoted for visual processing. And there is no brain disorder that can knock off all of this 50% or 80% of brain which is devoted for vision. So there is some part of the brain which is always processing vision in some way. It is for us to find out how does the child process and use that vision? And then tailor our day to day duties as for their vision. That is what we’re supposed to do. In contrast to an ocular impairment, like say a child has optic atrophy. Or say leber congenital amaurosis, where the end organ that is the eyes, are completely damaged and now there is nothing that you can expect. No improvement apart from getting the child into a good rehabilitation program.
But CVI, it is impossible that the child is completely blind. But we need to get into a process of understanding and using that vision in a meaningful way. Most of the children experience some improvement over a period of time. It’s a fact. And that is largely related to the brain’s capacity to mold itself. But this capacity is largely dependent on the environment. So it is for us to provide the right environment so that the brain can compensate for the functions that are lost.
[Adedayo] Intentionally teaching. Intentionally teaching the child using the assessments that you have made.
[Niranjan] Yes, absolutely.
[Adedayo] So how much time do you need to put into all these sessions? And how long do we expect to go on before we can see any sort of improvement?
[Niranjan] I think sessions for assessment can go for-
[Adedayo] And interventions. Like we know that these children can’t be assessed just once, right? You may have to see them more than once to be able to get the full picture, because they easily get tired, easily get cranky and all that. So you have to get the best out of them.
[Niranjan] That’s true. So to get a more complete picture it may take a long time, it make take one month, two months, multiple visits. But it is important that we get reliable information out of each visit. And use that information. So that’s about the assessment.
About intervention, there is no number that would say that okay, you can expect maximum improvement at this time. But I feel that four to six months is a critical period. Because that is a time when parents are maximum motivation and they would do whatever you say. First six months are important. If one does not see much change even beyond six months, then it is less likely that we can expect a dramatic change. But this doesn’t mean that we stop intervention. Because there are a lot of children who could not show improvement in the initial few months, but they pick up much better later. I have seen children who have experienced improvement in their teenage or are late teenage and we really don’t know the reason. But it may be that their intellectual capacity has grown to using information that we were already receiving. And now we see that change that they’re doing better.
I think we should give every child an opportunity of intervention. But as we said during the lecture, that intervention should be routine-based. It should be embedded into the child’s routines. Only then it is likely to be carried forward. If it is something that they have to come to the center and get it done or they have to buy an equipment at home and do it, it is less likely to continue.
[Adedayo] So if a child is low functioning and has very, the MRI shows really terrible features and all that. Would you tell the parents, okay, keep this child? Or course you can’t say keep this child in a home, maybe they aren’t walking and all that. What would you explain to the parents about the future. The child cannot even look, he’s not looking at light. You said the child will improve over time. But the child cannot see, the child cannot move, cannot do anything, what do you say to parents of such people? Because these kinds of questions come up very practically in the clinic. The child has a small head, microcephaly, the child cannot walk, cannot look at objects, maybe constantly gazing at lights, what do you say to parents like that, practically?
[Niranjan] During our first session of counseling we tell the parents about what to expect out of our interaction. The aim of interaction is not to make the child see the way you and me see, but to help the child use his vision so that he is on his own. For a kind of child like you describe, with microcephaly and several motor disabilities, who was even immobile, I think the goal for such a child would be to at least engage in some meaningful communication so that the child can convey what he or she requires, what he or she doesn’t like, that he’s hungry. So as we said during the lecture, most of the children are trying to communicate. If we can make them communicate somehow, using vision or other senses, I think that’s a big achievement. Many families are grateful to start intervention there.
Can the child engage in something which is meaningful? Rather than just looking at the light, can we use our ability to make the child explore an object more meaningfully? Like if he has a tendency to look at a bright light, can we use that as an intervention strategy where we show a brightly illuminated object with some detail on it. And that becomes a child’s object that he uses in his routine activities. Many parents are happy if the child is engaged in something meaningful and interactive, so that is where at least we should be able to take the child is what I feel, for the kind of children that you said. And it is possible in most of it.
[Adedayo] Fantastic. Okay, great. This had been a very informative session. I think that last question will be why don’t they like white coats? They don’t like people wearing white coats, these children.
[Niranjan] White coats?
[Adedayo] They like to see. White coats, they don’t like people wearing white. Why do you have to wear black gloves, black clothing? I know Linda is always wearing black clothing. Dr. Dutton is always doing that also when he’s evaluating these children. Also Lea, also. Why do they like black? Why is it they prefer that?
[Niranjan] Yeah, you have seen in one of my videos where I was wearing black gloves. I think it is to do with, again, reducing the simultanagnosia. And enhancing the contrast. We wear black. It is much more soothing, there is less information to process and the object that you’re showing becomes more enhanced against this background. So I think that’s why a black coat or black gloves, those kinds of things, definitely help. Even for us, decluttering is important, even for so-called normal seeing people. I find it personally very comforting to work against a wall which is black. Because then I can put my whole attention into the task that I’m doing. I think this has more to do with processing less visual information rather than the color that you use.
[Adedayo] Thank you very much, Dr. Niranjan Pehere, for being with us, for talking to us, all our viewers, they are very happy with us. All the comments they’ve made, some of them are saying it’s been a very practical session. It’s been very informative. We’ve broken it down to the level where people can get more interest and possibly include all this also into their field, maybe their expertise, what they already offer to the public in terms of their pediatric ophthalmic care. Thank you very much, we are so grateful.
And we believe that God will keep you safe there in Liberia, and be with your family also. For sacrificing and coming all the way to Africa to come and help us here. Thank you so much!
Our viewers, you have heard it all, now you can do what you can. Listen to this over again, over and over again, it will help in your practice. Now you don’t have to do it yourself, but because you may be so busy, but you can train someone, you can play this video for someone, explain it to them. And while your staff are there with you, you can talk to them, explain all these things that Dr. Niranjan has talked about, so that this group of patients they are no longer marginalized. We have gone beyond the level of just taking care of cataract, and glaucoma, and refractive errors alone. Even these children may have these problems and we have to do our best to make sure that they are taken care of also, as pediatric ophthalmologists and general ophthalmologists. Thank you very much for being with us.
In the next few months, you’ll see us again with another very, very important person speaking to us on another important topic that is of benefit to us as practitioners in pediatric ophthalmology. Thank you very much for being with us. Thank you, Cybersight! Thank you, Niranjan! Bye bye, enjoy the weekend.
[Niranjan] Thank you, everyone, and be safe.
September 6, 2020
2 thoughts on “Lecture: CVI: Connecting Assessments with Interventions”
Thank you very much for nice presentation.
Thank you, Dr Sardar