Lecture: A Practical and Evidenced-Based Approach To Vision Screening of Children

DR. MOORE: Hi, everyone. My name’s Dr. Bruce Moore. I’m a pediatric optometrist at the New England College of Optometry in Boston in the United States. And welcome. Topic of my talk today is A Practical and Evidence-Based Approach to Vision Screening of Children. First I would like to acknowledge past and continuing support from a variety of grants and organizations and entities. I have been a founding member of the Vision in Preschoolers Study funded by the National Eye Institute in the US for now 30 years. We have been engaged in trying to provide a scientific foundation for vision screening of preschool-age children. And in later years, we went on and looked more closely at relationship between vision problems in preschool-age children 3 to 5 years of age and learning problems. And that’s something I’ll be talking about at length. I’d also like to acknowledge that I have been a faculty member of the New England College of Optometry for the last 25 years. I’m currently a professor emeritus. Partially retired. I have been a founding member of the National Center for Children’s Vision and Eye Health. Part of Prevent Blindness America. Originally funded 15 years ago by the United States Department of Health and Human Services, Federal Government. We were given the responsibility through a multidisciplinary group of pediatric ophthalmologists and optometrists and pediatricians and nurses, educators, epidemiologists, public health people, et cetera, to come up with a systemic approach to vision screening for children across the United States. We have been working on that for 15 years. We’ve published a variety of content over the years. And right now over the next 3 to 6 months, we’ll be publishing three papers that look at in great depth appropriate screening methodologies for three groups of children. First one, birth to 3 years of age. The second, preschool-age kids 3 to 5 years of age, and the third, school age children. A lot of what I’m gonna talk about today has been developed through that group. And represents, to some degree, those collective efforts. And that will be provided in great detail as those papers become published in the next several months. I’ve also been doing some work for Orbis in Mongolia specifically. We have been implementing this vision screening program in large part across the country. Both as part of a public service project through the Ministry of Health and the Ministry of Education. And we’re also doing a more formalized research project to provide in-depth data about the effectiveness of the screening program in both urban and very rural areas of the country of Mongolia. So, thank you for all of that. And finally, I want to give special thanks to my colleagues at Children’s Vision Massachusetts. An organization that has been working to put into effect pediatric vision care programs throughout the Commonwealth of Massachusetts, which is one of the states where Boston is located in the northeast part of the United States. And I especially want to acknowledge my very close collaborative, Paulette Tattersall who much of this work has been done in collaboration with. So, thank you. So, let’s start off by asking question of: Ideally, providing vision care to all children at an early age would be the ideal. The problem, however, is that nowhere on this planet is it possible to provide eye examinations for every single child. Periodically, or even a one-off. So, the only way to provide care to children on a universal basis, at least in concept, is to come up with an effective and efficient system of vision screening which can detect children at increased risk of having important vision problems that can have an adverse effect upon their lives, on their education, frankly on their ability to see. And then funnel those children into a care system. The difficulty is that, again, nowhere on the planet, including in Boston, a city where we have, within a 30-mile radius for medical school, ophthalmology training programs, and two large optometry training programs producing a large number of new practitioners every year in a relatively small state and area. Even in the Boston area, we do not have the capability of providing care to every child. Therefore, we need to establish a system of screening. So, what do we typically screen for when we’re thinking about vision screening of children? Well, the number one issue, historically, has been looking to detect amblyopia and amblyogenic risk factors which are significantly refractive error and strabismus. We have screening programs to try to identify those children. But the most effective programs don’t look at the worst scenario, which is amblyopia and strabismus in children. But more importantly, refractive errors that can complications for a child’s education, for a child’s future. We look at amblyogenic risk factors, we look at refractive errors. And all of this has really put an exclamation point on in the last 10 or 20 years where we have this myopia epidemic that we’re all acutely aware of. So, we know myopia has exploded both in prevalence and in magnitude. Particularly in Asia, but really everywhere around the world. And what we now know in part through a massive document that was published a couple of months ago by the National Academies of Science, Engineering, and Medicine in the mathematics, the NASEM report on myopia. A 400-page report that looked at myopia, in terms of the pathogenesis and the mitigations and what we do from it nowadays. What we know from that, the earlier we detect the presence of myopia, the earlier we have the effective means of mitigation in optical correction, or pharmacologic with atropine or other drugs, the more effective those are likely to be. We have important reasons for detecting vision problems at early ages in children. And then periodically thereafter to, again, identify kids that are developing vision problems at later ages. And finally, this critical element that I’ll come back to a number of times in my discussion. And that is the relationship between vision problems and learning problems. Vision in preschool in study in the later phases looked very closely at this issue of how refractive error, moderate degrees of hyperopia in particular, can have really significant effect on the acquisition of pre-literacy and literacy skills in children as young as 4 and 5 years of age. And we know that children that have significant impediments to seeing clearly and using their eyes in a very efficient manner are the children that are most likely, in many cases, to have problems acquiring a full benefit of their education. Vision in learning is a critical element and one that we need to be mindful of. So, the rationale for modernization of vision screening is based upon a lot of things. Historically, vision screening was almost entirely based upon distance visual acuity. In the United States, there was systems of vision screening that were employed in school settings in many states, beginning in the late 1900s. Those systems all were based upon distance visual acuity only. That is continued until research in the last 20 or 30 years, some of which is provided by the Vision in Preschool study, showed that is not necessarily effective. Systems of vision screening that are being developed even today. An example being the World Health Organization came out with vision screening guidelines a little less than a year ago which employed for children distance visual acuity only. They did not include near visual acuity testing in individuals until presbyopia, in adults. There’s a growing evidence basis that we need to do more. There have been dramatic improvements in the effectiveness of the test. And increased visual acuity testing today than we did before. We’ll go into that in some detail. And we have also been able to improve the testability and the sensitivity of these procedures to do vision screening. Especially in younger children. It was always difficult, and still is difficult, to do visual acuity testing in 3-year-olds. But if we use the right test, designed in the right way, with modifications based upon the abilities of children in that age, we can improve testability to very high levels. In general, we needed to make screening easier, faster, and better for the people doing the screening. Whoever that might be. Whether it’s I care professionals or educators or nurses or laypeople. And also, obviously, for the children. We need to do a better job than what we did before. Too many of the vision screening techniques employed in the past either were not particularly effective, or in some cases were very complex. Had many, many different procedures included in it. And in some cases required eye care professionals, optometrists and ophthalmologists, in order to do the screening procedures. That is not an efficient and effective system that can be disseminated broadly in country around the world. We also, today, have the ability of better balancing under-referrals and over-referrals. Based upon the cut offs that we use. For example, if we had a very high visual acuity cut-off of 20/60, 20/70, then we would be missing many, many children with visual acuity poorer than that. On the other hand, we had an acuity of 20/25, we would be over-referring kids and having children with marginal, at best, deficits which would make it more complicated for children with more complicated, more immediate vision problems having increased difficulty with access to care. We’ve made the test easier, faster, and better. And we’ve modified the cut offs to try to balance sensitivity and specificity as much as possible. Now, the epidemiology of vision problems, and the effect they have on children varies quite dramatically with age. Obviously, in high school kids, 15-year-old kids, it’s all about myopia. We know myopia is the big problem. And we recognize that techniques to detect presence of myopia can frequently be as simple as distance visual acuity. But in younger children, 3-year-olds, there’s very little, if any myopia. that’s not the reason we’re screening children, we’re looking are a amblyopia and amblyopic risk factors. The conditions are different and the tests need to be different. There’s obviously big differences in the cognitive ability of children. A 3-year-old is not able to do the same complex tasks as an older child. So, what that translates to is that if we create multiple age groupings that can better target specific vision problems that are important at each age cohort, we can make those tests more effective. We can increase the efficiency and the effectiveness in detecting the important vision problems of children at those ages. And if we had the same procedure for children of all ages. Obviously, doing a whole chart of distance visual acuity targets to a 3-year-old child is not gonna work very well. So, I’ve already said that distance visual acuity alone is inconsistent in its ability to detect certain vision problems. And that is in particular moderate to high degrees of hyperopia and astigmatism. On a transient basis, a child may be able to easily overcome with accommodative input. Hyperopia of even moderate to high degrees, if looking at a distance visual acuity chart with only a small number of optotypes on it. So, VIP study and other research has determined that in order to properly detect the presence of hyperopia and of astigmatism to varying disagrees, you need to do more. Visual acuity is one way to do that. But thinking about strabismus, a child, for example, with a large-angle exotropia might have excellent vision in each eye. If all you’re doing is distance visual acuity testing, mono-occipitally, you’re not gonna detect the presence of that. You need to do the test that has the ability of requiring the child to effectively and efficiently use both eyes at the same time. Test the binocularity and particularly stereopsis to meet that. And there is a necessity to use a combination of distance and near visual acuity and the binocularity procedure. In this case, we’re gonna be using a stereopsis test. What we’re talking about here, the system I’m going to be presented is a consensus-driven model vision screening with a very strong evidence base to support it that has been developed over the last 30 years in the United States and around the world. It is a procedure that, as I mentioned earlier, was really developed by a lot of research and a lot of consensus opinion by the National Center for Children’s Vision and Eye Health. And the major papers that will be coming out will be providing great detail about that. But what I’m gonna be presenting here in a model that I’m calling the Massachusetts-based vision screening model, will be applicable to children around the world. Now, this particular set of procedures was developed by a group of us from Children’s Vision Massachusetts in collaboration with the Massachusetts Department of Public Health. And has been implemented now for several years across Massachusetts. Both in educational settings, school settings for children 3 to 18 years of age, and in medical home settings. Pediatrician offices and clinics, that are utilizing a very similar system. This follows many of the precepts of the American Academy of Pediatrics, guidelines by the American Academy of Pediatric Ophthalmology and Strabismus, the American Academy of Optometry and the American Academy of Pediatrics and a variety of other organizations have all looked at these consensus approaches and agreed that this is the way the system should be modeled. Now, again, modifications could be made based upon the needs of specific communities. Based upon languages and culture and other issues like that. But this is a model. First I want to mention a few things in particular about visual acuity methods that have been widely used in the past that have now been discontinued in Massachusetts and are not recommended for use in the US and elsewhere. The top of the page, you can see tumbling E chart. Now, I know many of you around the world routinely use tumbling E charts. Long history of usage. Can be very effective. But there is a real problem with it in children, and particularly in younger children. Children under the age of 7 in particular. But in many cases, even older children. And that is, as a developmental attribute, laterality, the determination of left or right, is not complete in many children until a little bit later on. So, if you present a tumbling E chart to a 3 or 4-year-old child and ask them to do this or this, you’re gonna run into a problem, because many of those children are not able as effectively to do left and right as they are up and down. So, it’s been a lot of research done on that. It’s been shown that this issue of laterality is a real complication. So, in the US, this chart is not widely used and not recommended. The Landolt C on the bottom left, a basis of a lot of acuity testing over the last 40 or 50 years. There’s a lot of strong scientific basis for the use of that. However, on a practical basis, it’s a difficult test for children to do. And we have not used that test in the United States. So, tumbling E and the Landolt C which are widely used approved and have good scientific basis in older individuals are not useful, in our view, in children. There are any number of picture charts represented on the bottom of this page that have been used for a very long period of time. The second from the left on this page is the Allen cards, widely used. Devised by a pediatric ophthalmologist, Henry Allen, probably 40, 50 years ago. The difficulty with that, you can simply look at those optotypes and you can tell that there are difference in the shapes that go way down towards threshold. And you can still tell, even below threshold, different shapes preferentially. The chart next to it with that horse on top, or the one next to that with the sailboat on top are particularly egregious examples of badly-designs charts. You look at the sailboat, for example, and you look at O or the plus just below that. Even way below threshold, it’s easy to tell the difference. Same with the horse on top and the dinosaur just below that. The giraffe. Not effective. On the far right, you have an old style Snellen chart. The problem with that is not necessarily the letters. The problem with that is that it is not a log mark configuration. Not gonna go into all that have. Most of you, I’m sure, are very familiar with the concept of logMAR visual acuity. So, it is imperative, we believe, that charts that are used be able to conform to logMAR design. So, there are many types of visual acuity charts that have been in use for a long time that we believe should not continue to be used. What is approved? I’ll go through these one-by-one. On the top left, it’s called the Eye Check. That test is done at a meter and a half. This is based upon research from the VIP study that showed that in 3 and 4-year-old children, closer distances beyond the 3 meters, or closer than the 3 meters that is typical for use in children, enhances the testability quite dramatically. Another design element is the use of the single surrounded, reassembled optotype. Now, we recognize that if you don’t use an entire chart, as on the bottom, then you’re not getting the full benefit of a crowding effect. We know that if you put various crowding bars or detailed surrounding either a single optotype or as on the right side on the top, the Sight Line, where you have five optotypes next to each other with a crowding box surrounding it. You do get improved elements of crowding, although you do not reach full crowding benefit. The Eye Check, meter and a half chart, is designed for use in the youngers children where the testability is the biggest issue. Getting the child to actually do the test is really difficult. So, you need to provide some design element that enhance that. Going to the crowded optotype and a closer distance, and using the symbols is a way of enhancing testability. Studies have shown that you can get over 95% of most 3-year-old children to be able to do effective visual screening with a design of that sort. Notice, also, there is a cord that is held by the child to their eye down over here. The cord extended out to where the screener is holding the cards. And presenting it to the child. And that maintains the distance. Maintaining the careful distance is absolutely essential. Now, going to a meter and a half has the deficit of missing some children with low degrees of myopia. However, in the younger children, low degrees of myopia are not an important problem to detect. So, we’re willing to forego that enhanced detection of low degrees of myopia to improve testability. Now, a couple of comment about the LEA SYMBOLS. As many of you know, the LEA SYMBOLS were designed by the with ophthalmologist from Finland, Lea Hyvarinen. She designed that to have universality in able to be utilized by children around the world. And she and many others have shown that it is relatively culturally neutral. That children can use a matching paradigm to not necessarily have to name those symbols, but can simply match it with a lap card as shown on the top right on the sight line. Child can hold that card with the four symbols and can point to the one that looks the same as being presented bit screener. The LEA SYMBOLS have one really important benefit over all others. And that is they have equal blur. Dr. Hyvarinen traded the actual size and dimensions of those symbols so that at threshold and below threshold, those symbols all have equal blur. Unlike the kindergarten chart with the horse on top on the previous slide, it’s relatively easy to make a determination based on differences in shape and contour, you can’t do that with the LEA SYMBOLS. So, there are some really major advantages of that. In the US, we also use the letters H, O, T, and V. But in the designs that we’ve utilized in this series, we’re not using HOTV. We’re using LEA SYMBOLS instead. So, again, Eye Check on the top left, meter and a half. Sight Line on the top right, 3 meters, standard testing difference. And again, uses five LEA SYMBOLS with a crowding box around it. Can be used as a matching. There’s a cord to maintain distance. The charts below that are for the older children. Sloan Letters, the ten letters that were designed that have particular characteristics. Presented in a logMAR fashion is probably the best approach to visual acuity testing. We can also use the LEA SYMBOLS on a whole chart. But an important point, and I’m gonna make this again, is that we do not do threshold visual acuity testing. In other words, we do not start at the top and go line-by-line down to the bottom until a child misses at least three of those. And ends at that point. We go to a critical line. So, we have determined a specific line the child must pass. We go directly to that line.
We’ll go into that in a moment. Child needs to get four out of five correct on that in order to pass for the right eye. And four out of five correct on the left eye. And that can be done either with the Sloan Letters, or it could be done with the LEA SYMBOLS. For near visual acuity that we use in ages 3 years of age up to third grade. Roughly age 8 years. We also include near visual acuity. Near visual acuity, again, because only in the younger children reason are the LEA SYMBOLS. We use a line with near visual acuity. We do OU only. Both together in order to enhance the speed and efficiency. And again, there is a cord attached to that to maintain that critical distance. Your approved stereo test is a simplified version of the pass test. Pediatric assist of stereo vision. Sometimes also called a Stereo Smile test. This was devised by one of my colleagues in the VIP study, Lynn Cyert. And we are using 120 seconds of arc as the test plate. This test has three cards. One is a blank. Someone a demo card that has a picture of a smile face printed on it as you can see here. The third plate is the test plate that has a random dot stereo gram at 120 seconds of arc. VIP study showed that in 4 and 5-year-old children, those children that were unable to get this plate at 120 seconds of arc had a deficit in terms of amblyopia or near visual acuity. So, we feel it is important to include a stereo test to be able to detect presence of strabismus and amblyopia. There are variations of other stereo tests that could potentially in other countries be used in lieu of this. Not gonna go into that. But keep in mind that all of the tests that I’ve shown on the last couple of slides can all be substituted for other tests of equal scientific value in other countries for a variety of reasons. Now, I’m gonna show three charts that go into specific detail about the Massachusetts Vision Screening Guidelines. And as I said, this has now been employed in the schools and in the pediatrician offices across Massachusetts. This system has been in place for several years. It’s been used relatively efficiently and effectively without a whole lot of difficulty. The uptake on it has been quite good. We have not had very many complications or problems as a result of it. So, we’re quite confident that this is a system that can be used in a wide public health basis. So, there are three charts here that I’m gonna be showing. The first one on this side, on this screen, rather, shows the custom for the pre-K. 3 to 5 years of age. Below that for kindergarten children. And it includes the details. And for the youngest children, we can use either the eye check or the sight line. Again, either the meter and a half or the 3 meter test. Using crowded LEA SYMBOLS in a variety of ways. We use a distance visual acuity. We use the near visual acuity. We do not, however, for 3 to 5-year-olds use the stereo test. And the reason we do not use the stereo test in these young children is that the testability in children 3 and 4 years of age is reduced in terms of being able to actually accomplish effective testing with the stereo path’s OneOhio version. And that means we would get too many referrals. At this point in time, we are not using stereo test in the youngest children. There is an alternative to using distance visual acuity. And we could use influence-based children in 3 to 5, or 3 to 6-year-old children including the kindergarten kids in the chart below. Using the spot or the plus optics, it’s widely used in the United States and around the world today. Very fast, very patient. However, there are some issues. And those issues are that photo screeners have a technical problem with the ability of detecting accurately the presence of moderate to high degrees of hyperopia. In studies that we and others have done, we have shown that the system tends to break down with children having over three, three and half diopters of myopia. It misses many of these children and doesn’t provide an accurate measure. That provides concern on my part. Nonetheless, because of the improved testability in some of these 3-year-old and younger children, it is widely used it is approved by the American Academy of Pediatrics. So, in our guidelines, we do allow for the use of that. However, because of its difficulty with detecting hyperopia, we do want near visual acuity to be used in addition to the photo screener. So, whether you use distance VA with a meter and a half or three meter test of LEA SYMBOLS or you use a photo screener, you need to do the near visual acuity in addition. The kindergarten children, we add the stereo test because at that age the testability is high enough. And again, for visual acuity, you need four out of five correct on the sight line, on the eye check. The more simplified version, three out of four is required on each eye. On this next table here we have grades 1 through 3 on top. Grades 4 through 5 on the bottom. Grades 1 through 3 we continue the requirement of the distance and near visual acuity along with the stereo. We are still interested in detecting amblyopia at this age. This is really when myopia begins kicking in. And we know in some Asian countries, myopia starts kicking in earlier than it does in some western countries. Again with the reasons why, still up for discussion. But we include all three of those tests. Once we get to the 4-year-old children, we’re really now concerned with myopia really alone. And we now use only the distance visual acuity procedures for children grades 4 on up through high school. And this table here shows grades 6 through 8 and 9 through 12. And again, we do that. Now, the frequency of the test in the earlier grades we do it every year. So, between preschool and third grade, we do screening every year. What’s important about that is that even if we miss child with important vision problems at an earlier age, hopefully it will capture that child the next year. So, doing it each year, we believe, is important in the younger grades. When we get to the older grades and talking about myopia and increasing levels of myopia, these children who are already detected as having myopia are already in the vision care system, hopefully, so, we’ll leave it up to the vision care system to be the primary means of follow-up care. But we will repeat the screening once in middle school and once in high school in Massachusetts. We’ve reduced the frequency so that we allow the people doing the screening in the schools in Massachusetts. We have a system of school nurses that are present in all schools. We have the burden of effort on those school nurses to do the screening in the younger children where it’s more critical to pick it up. To pick up amblyopia and amblyogenic risk factors earlier. When we get to the older children, we drop down the frequency. Now, I’ve talked at some length about the idea of using critical line as opposed to threshold. This is perhaps a point of contention among some. Now, very often, historically screening systems use threshold visual acuity and there isn’t much question that that is more effective way of measuring visual acuity. No question. However, it takes much longer to do. And when we’re trying to think about screening an entire school full of children, we need to find efficiencies where we can. So, this is one of the accommodations that we’ve made of going to a critical line. And that concept of critical line is really very widely used and has been for a long time in screening systems in the United States. Perhaps less so internationally. For the youngest children, our critical line is 20/50. Children a bit older, 4 and 5-year-olds, it is 20/40. And for the older children, it’s 20/32. Now, again, you may argue why 20/32. Aren’t we interested in picking up kids with lower levels of visual acuity than that? More reduced levels of visual acuity? Sure. But again, we’re looking at overall efficiency. Child that has 20/32 is still capable of performing quite well at distance. Perhaps not perfectly. And if we look at guidelines for visual acuity requirements for people doing examinations for eligibility for driver’s licenses and maintaining driver’s licenses, pretty universally 20/40 is the level. So, we feel that 20/32 is a reasonable compromise. Again, we are extremely mindful of not over-loading a scarce availability of access to care of individuals needing eye care to get to an eye doctor who will be able to examine a child. We don’t want to overload the system. So, we’ve made some accommodations. For all but the eye check, again, for the very youngest of the children, four out of five symbols correct at that passing line for both the right eye and the left eye is required at distance. For near, it’s OU. Four out of five correct on that near chart. Child does not get four out of five correct. It is a refer. We talk a bit more about instrument screening. There’s no question that this is the technology that is being embraced everywhere. Everyone likes the idea of the speed. Of the fact that it does not require a whole lot of experience in terms of doing the test itself. Of pressing the button on the spot of the plus optics. As long as you have the right environment. Reduced illumination. You have the child at the right distance. You don’t have a lot of noise going on in the room and a lot of movement going on in the room. You can do a lot of children in a very short period of time using instrument-based screening. Instrument-based screening has been improved by the American Academy of Pediatrics up until 6 years of age. And it is a reasonable approach, particularly for the younger children. The concern that many of us have, as I pointed out earlier, is that there are technical limitations in the ability of these technologies to be able to accurately measure moderate degrees of hyperopia over about 3.5 diopters. It misses many of those. That’s the single most important group of younger children you want to detect the presence of. So, until a technology improves, until the companies improve their technology or their hardware or software, we’re kind of stuck with this. It is useful, of course, in young children who are shy, non-communicative. You can get a measure as long as a child will look at the instrument. But, again, there are concerns about it. And you think until the technology gets better, many of us are not completely comfortable with it. Now, this is something I think that is very, very important. We recognize that screening, for any health condition, is intended to identify individuals at increased risk of having that disorder. Whatever that disorder might be. In terms of vision screening, a child with neurodevelopmental delays. An example would be Down’s syndrome or cerebral palsy or hearing impairment, autism, many other concerns. These children already have conditions that put them at high risk. An example would be Down’s syndrome or cerebral palsy. The majority, probably the vast majority of those children, have important vision problems. So, you already know they’re on a high risk population. Those children need a comprehensive eye examination. So, it’s fine for social purposes to screen that child along with their classmates. If you bring a whole classroom of kids down to an auditorium and screen every child, don’t leave out the child with cerebral palsy or any other form of neurodevelopmental delays. Screen that child as well. You don’t want to separate them from the other kids. But that child needs a comprehensive examination because of their high risk of having vision problems. The definition of neurodevelopmental delay is very much a moving target. So, when we first came up with this requirement 20 years ago, there were definitions by pediatricians of who that included. But that’s changed over time. Is the understanding of these conditions have changed. So, we’ll leave it up to the pediatricians and others to decide who has a neurodevelopmental delay. And in other environments, in other countries, the definitions may be different than in the US. But be clear about this: Any child that is already at high risk for co-existing conditions, whatever those might be — physical, emotional, educational — those kids need an eye examination. Not a screening. So, who should automatically be referred? Well, again, these children with neurodevelopmental delays. But any recognizable eye abnormality like strabismus necrosis. If the screener sees a bad eye that’s visible even a to a layperson, the child needs an examination, not a screening. Any child with a systemic disease that has known ocular complications. Examples, diabetes, juvenile rheumatoid arthritis, where there are absolutely significantly elevated risk of all kinds of other eye development, those kids need to be part of the vision care system. And to be under the care of people on a continuing basis. Individual that has medication that’s known to cause eye disorders or complications like scopolamine, for example. A child born to a mother who at the time of pregnancy or delivery was using or abusing tobacco or illicit drugs or alcohol, any of those kinds of conditions, needs to have a comprehensive examination. We now know the link between smoking, for example, and increased risk of strabismus and amblyopia is real. These kids need to be examined. Obviously, a child who falls into the category of retinopathy or prematurity risk, premature birth under 32 weeks, low birth weight, et cetera, obviously needs to be under the care. In addition, a child with a first degree relative with strabismus or amblyopia or simply very high refractive error should also have at least an examination initially. And then if nothing shows up, then just periodically thereafter. And a child who failed vision screening or any kind of a child that has observable eye abnormalities needs to be followed up and examined. Recommended if a parent or a caregiver or a teacher has concerns about a particular child, even if that child passes the screening, child should have an examination. I can’t tell you how many times we’ve gone in and done screenings in schools. We ask a teacher when they bring the child down to the auditorium, they bring the class down to the auditorium, do you have any particular concerns about any one of your kids in your class? You have any young child who won’t sit still at circle time? Who runs all over the place? Who has difficulty holding objects at a reading distance? Regardless of whether that child passes the screening or not, that child should have an examination. Any child not reaching developmental milestones in an appropriate fashion should have an examination. In the US, we have an elaborate system of early intervention. So, pediatricians make note of a child having any kind of developmental abnormalities of any kind at all. Can refer that child into a system of providing remediation and diagnostic workups. Those children should have comprehensive examination. The child that has significant difficulty learning to read or educationally, a child that’s in special education. A child where parents have concerns about a child’s education should obviously find out if a child’s got a vision problem or not. If they do, that may be the entire cause of the difficulty of learning. So, those kids need to be screened. And then examined. Child that’s difficult to screen, who just doesn’t pay attention or is untestable or a child that you can’t get a result on a photo-screener needs to have a comprehensive examination. So, we’ll stop here for a moment and present some questions. Read the first question to you: Important considerations in determining the most appropriate approaches to vision screening must include which of the following? We’ll let you guys read it. Give you a couple of minutes to provide an answer. And hope everybody is scribbling down your answers. Okay. And the answer is all of the above. You think about the epidemiology, you think about the cognitive ability of a child. And you also need to have efficiency and effectiveness in the technique. So, all of the above. Very good. Next question: Which of the following is not an important issue devised in a system of vision screening for children? Again, let you guys read it. Okay. And correct answer is employing the latest technology. You don’t care about the technology so much. As I pointed out, the photo-screeners are the latest technology. And frankly, they’re not as effective as the manufacturers would like us to think. Next question, which of the following is the most effective technique of vision screening to detect the presence of strabismus? And the correct answer is Stereopsis. You could argue all of the above. But I think stereopsis is the one I was looking for. Remember, I gave the example of exotropia. You can have perfectly good vision in each eye, and yesterday no stereopsis. Distance and near acuity will not necessarily tell you that. Which of the following is not true? A little bit more complicated. Okay. And the correct answer is the photo-screeners are not so effective at detecting the presence of significant hyperopia. I should point out that screening is never 100% sensitive in specific — screening for any condition at all. You’ll never get perfection. And children with neurodevelopmental delays should absolutely have comprehensive examinations. And using the critical line for visual acuity is effective and efficient. Perhaps it’s not quite as accurate as threshold. But in the context of screening, it is effective. All right. So, this chart here. Signs of possible vision problems in children as presented by Prevent Blindness America. This is, I think, a very useful chart. And Prevent Blindness has lots and lots and lots of downloadable educational content available both in English and in Spanish. And anyone is welcome to translate any of this into their own language it is they like. There is a huge amount of content available that I think all of you will find very useful in systems within your own countries. So, by all means, take a look at the page there. Preventblindness.org. And you will find lots of stuff that I think will be quite useful for all of you. There’s a bunch of additional slides here that I’m not gonna have time to go through. But I’ve included them to help any of you in terms of actually establishing a system of vision screening. Whether you employ the recommendations of what I presented here today in great detail. What I’m gonna show you on the rest of these slides is a lot of useful information on the practical aspects of establishing systems of vision screening. So, I’ll just really quickly go through it. How to set up a screening room. How important distance is. Screening steps. Doing visual acuity testing. All the details of that. And a lot of this was put together by my colleague Paulette Tattersall I want to give enormous credit to for putting all of this together. Lots of information here about acuity, about stereo testing. And again, these on this slide are all sources of information that anyone can download, can look at. Can use to help them come up with systems. And finally, some things to remember. Vision disorders are the most prevalent disabling condition of childhood. Put together by the Centers for Disease Control in the US. No child is too young to have or develop a vision problem. Most childhood vision disorders are treatable. Amblyopia in concept is detectable at an early age and in most individuals treatable in many if you capture it early enough. Same is true for myopia mitigation. Get it early, you can be more effective than if you capture it late. Vision screen willing never detect all problems. If in doubt, refer to somebody who knows what they’re doing. And glasses are a treatment and should not be considered optional. Finally, I want to thank everyone for their attention. And we have some time for questions. So I am gonna stop sharing. And I think I may already have stopped sharing. I have. So, some questions. All right. All right. First question from Grace. Dr. Moore: When I ask if students can be trained to carry out vision screening in schools and communities? And the answer to that is absolutely yes. It’s my view that schools are probably the best environment to do vision screening at. Those extra slides that I just mentioned, went through super-quickly were there to help you provide information about how to go about actually establishing a system. Okay. Next question from Monica from Colombia: Is the Lang II Stereotest accept football for stereopsis? The answer is yes. And the Ohio test, some technical reasons why we use that in Massachusetts. There are many other stereo tests that are useful. The important point in that is that research has shown that a child that is able to obtain at least 100 seconds of arc on a stereo test is unlikely to have amblyopia or strabismus. Did does not mean they won’t have amblyopia or strabismus, but it’s highly unlikely that they will. So, you can utilize other tests that are available to you in the environments that you’re in. And feel free to substitute. And the same is true for the visual acuity charts that I showed. Really they’re just examples of what is — what we find through good science is useful and acceptable. But you can use alternatives. I think in particular about languages like Arabic or Hebrew or Mandarin or Thai, take your pick of any language that does not use Roman letters. Visual acuity of those languages are something that has not been really studied very thoroughly in many cases. But obviously for children in those countries, you’ll need to make accommodations. So, there are options available. All right. Amblyopia is not well treated at age of 8. Well, as we know, amblyopia in concept can be effectively treated even at much later ages. The new techniques that are being developed, these binocular techniques appear to have much more efficacy of their ability to treat at later ages. But from a practical perspective, you really want to find amblyopia and amblyogenic risk factors at early ages because your compliance is invariably going to be better at younger ages than it is at older ages. And everything about treating amblyopia is about compliance. Okay. In the UK we have a two tiered system. Vision only, no strabismus or photo-screen. Scotland has a different system. Yes, Scotland does have a different system than England. Are either of these public health measures effectively equal? Well, I mean, this is something I think that you’re gonna have to figure out how effective your systems are. So, ideally, you need to do a large population-based studies of different methods of vision screening to find out what works within your systems of healthcare, within your cultures, within your systems. What I presented is applicable, particularly in the United States. Other countries, different systems. The idea of screening periodically and front loading screening particularly heavily on a yearly basis in the younger ages I think is absolutely essential. I think at older ages where you’re looking for myopia and we know, or at least we think we know, that kids who are myopic tend to be kids who do better in school. Kids with amblyopia and high refractive areas at earlier ages are more likely to not do as well in school. So, it seems to me, given the connection we now understand between vision and learning, front load your systems to provide the most aggressive efforts at detecting vision problems in the younger kids. But again, it depends upon the level of resources and many of the western countries, US and the UK. We’ve got a lot more resources available than in countries than, say, Africa. Sub-Saharan Africa. These are things that need to be individually considered. Okay. Dr. Moore, with an already overloaded clinical staffing situation, how have you managed to go around the extra man hours to required for comprehensive regular screening program? Secondly, any comments on applicability in resource-limited settings? So, I do believe that vision screening can and should be done in school settings. What we’re doing in Mongolia, a country of very, very sparse population density. A massive country with relatively sparse resources, particularly out in the countryside. We are using school systems and teachers to do screening. We are pretty convinced that we can teach teachers to do adequate screening in a very methodical way. One of the great advantages of teachers doing screening is that I believe that teachers are in a better position to work effectively with their students. They know those kids. They know the communities. The communities trust those teachers. The children work well with those teachers. Frankly, the children and the parents work better with the teachers than they frequently do with the healthcare system. And I think that you train teachers to do the right test, done in the right way, I think that is the most effective system. Teachers also are in the best position to convince the parents how important it is to get those kids to care. So, those teachers are in a better position to manage the follow-up, to get to an eye care professional. So, I think particularly in low resource countries, the most effective way of doing universal vision screening is not initially through the healthcare system, but through the education system. Obviously, those two need to work together. And you need to establish the referral basis and the referral methodology so that kids get to care. Difficulty is that if the care is not available in a rural community, how do you get kids to go from that rural community into a more urban setting where the care might be available? 20 or 50 kilometers away. That’s difficult. And that is really the essence of what I think needs to be developed. Okay. So, a question from Ghana. I like the fact that the charts can detect myriad vision problems during screening, but has this test chart demonstrated good sensitivity in children across various demographics? The answer is yes. So, the LEA cards, the LEA visual acuity system has been used everywhere around the world. Dr. Hyvarinen was particularly interested in ensuring that that was a culturally-neutral way of assessing visual acuity in children living in rural communities and low resource countries. So, I do believe that that is an effective way of going about it. Using the letters, as I pointed out, in Roman letters in nations that don’t use a Roman alphabet. Arabic for arguments safe or Thai. LEA SYMBOLS have enormous efficacy and something that can be done by children of all ages. What is the normal range of good stereoopsis for a 4 or 5-year-old child? There have been a lot of studies that have looked at the development of stereoopsis. We know that stereoopsis begins developing at around six months, eight months of age, probably earlier than that. When does it reach adult levels? Certainly by 3, 4, 5 years of age. A hundred seconds of arc is definitely within the range. Probably much, much better than that. Probably down to 40 or 60 seconds of arc in 3 and 4-year-old children. VIP study did threshold testing down to 40 seconds of arc and we were able to do that in a high percentage. You can get good stereopsis in 4 and 5-year-old children. We have picked 100 seconds of arc, specifically the test plate of 120, because that seems to be an effective cut-off for yes or no in terms of amblyopia and strabismus. Okay. How do vision screenings address children with neurodevelopmental disorders such as autism or ADHD who may not respond well to traditional tests? Yes. Absolutely. That’s the problem. There is no way of doing a screening on children with autism. You can’t do it. It’s not effective. I think for many of us who work with kids with special needs, work with kids with autism, I’ve had 50 years of clinical experience. I can tell you, it’s hard for me in many cases to do a good examination on a child with autism. You can’t do screening on these children. That’s why these children must have a comprehensive eye examination. Many of these individuals, they depend to a much greater degree on their visual system for their learning, for their dealing with their environment. For their day-to-day tasks than typical children. So, ensuring that they have the best vision possible to allow them to perform to the maximum level is critical. I would go as far as saying that national vision care systems should put the emphasis on these children with medical, social, educational problems over all others. These ready kids that it’s most important to get through. Provide examinations for those children. In your experience, why and how can teachers will empowered as allies to optometrists to communicate the importance of screening and vision care to parents and tutors? Well, this is something that I think is really critically important. So, not only optometrists or ophthalmologists, but all of us in the healthcare system need to understand how important vision is — how important healthcare is — for children to reach their full potential. So, we, as eye doctors, can’t look at vision care as being separate from everything else. It’s not. We need to work with the communities. We need to work with the parents. We need to work with the educational systems. We need to work with governments to get them to understand that providing vision care to children and detecting vision problems that can be complications for children obtaining all that they can and should in life and in education, is something that is worth putting resources into. So, it’s critically important for us as eye doctors to work to educate national systems of healthcare, national systems of education of the critical impact of vision problems on learning. And only through a concerted effort of working together can we implement vision care that does provide enhancements to a child’s education. So, it needs to be a full blown effort. Optometrist, ophthalmologists can not work in isolation as they too often have. We can’t simply think as eye doctors how important it is to find eye problems in children. We need to be thinking in terms of ensuring that children’s vision systems are as finely-tuned as possible to allow them to reach the full capabilities. Next question about color vision testing. We looked at that in the VIP study at the very beginning 30 years ago. I have a code 10 color deficiency. I can say from my own experience how it has impacted my life. And the answer is only when I took organic chemistry in university could not see the color changes did it really have an impact when I failed the lab. The problem with color vision testing is that we do not have good methods of screening for color vision deficiency. To do color vision testing properly, you must have the right illumination system. I’m sure all of you remember learning about illuminant-C, the right color requirements for color vision testing. How many of you actually have illuminant-C in your offices? The answer is probably very few. So, screening for that is simply not gonna work. All right. I did not mention retinoscopy. And the reasons I did not mention retinoscopy is that it’s an eye doctor procedure. And I don’t believe that vision screening should be done by eye doctors. Vision screening should be done by others. Eye doctors should be working to pick up the children who have already been detected or known to have vision problems. They ought to be spending their time doing that. Screenings should be done by other people. Of course, retinoscopy is the best technique for detecting refractive error. But it’s not a procedure that can be done by anybody other than eye doctors. So, I don’t think it’s something we ought to be thinking about. What are your considerations for very young infants with high refractive error? Well, that’s a whole different story. We don’t have good systems of vision screening for children under the age of 3 years now except for photo-screeners. Photo-screeners are probably the only way we have now. There’s the other technology called Blink. Devised by David Hunter, head of ophthalmology at Boston Children’s Hospital that is an amblyopia detector. It is actually a strabismus detector. That might be the best approach. It’s been commercially available. But I think the use of it is still in development. People are figuring out how to utilize it. Bottom line: We do not have at this point in time good methods of vision screening of younger children beyond photo-screening. I wish we had better technology. At some point hopefully will. What are the considerations during refraction of a child under general anesthesia? Don’t do it. Reason being, I had a lot of experience in my earlier days, working with kids with congenital cataracts and trying to facility lenses under anesthesia. Anesthesia drops interocular pressure and collapses the interior chamber. The refractive error under general anesthesia has no bearing whatsoever to not under anesthesia. Do not measure refractive error under general anesthesia. Can strabismus develop in older children? Yes, of course. For a whole variety of reasons. Kind of goes beyond what we’ve got here today available. And I’m running out of time. I think I have time for one more question. Last one being: What is the appropriate device for checking distance visual acuity and near visual acuity, stereo acuity in children age 4 years and above. Well, I did present that in the system that I presented, the Massachusetts system. It is really all there. All right. We have run out of time. I would like to thank you all for your attention. You can find me hopefully my email will be available. It’s Brucemoore49 @gmail.com. If you have questions, get in touch with me. What I do hope, for some of you, we may be able to work in the future through Orbis and develop approaches for vision screening for your countries as we are doing now in Mongolia. So, I will leave you with that. Again, thank you for your attention. And I hope you all have learned something useful. Most importantly, take what we’ve learned here today. Try to think about how to utilize that within your own communities. Begin discussions with other people within your eye care and healthcare systems. Talk with educators. Talk with the public health people. Get systems of effective vision screening that are evidence-based into play in your communities. And you will have an impact on the visual health of the children and the future of your countries. Thank you, again. And have a good day.