Lecture: Community Screening Programs: Identifying Undetected Refractive Error

Vision screening programs have been shown to be very successful in identifying adults and children in the community needing comprehensive visual care. During this Live Webinar the limitations and benefits of vision screening, how to avoid the common pitfalls in screening program design, and the necessary steps to establish or adapt local vision screening programs to include the detection of refractive error are discussed.

Lecturer: Dr. Sarah Wassnig, B.Optom, MPH


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DR. SARAH WASSNIG: Okay. So, thanks for joining me, everyone. My name’s Sarah Wassnig, and I’m an Australian optometrist. We’re just going to cover, today, community screening programs, and why identifying uncorrected refractive error is so important. So, our lecture objectives today. First we’re going to just discuss why refractive error is so important. This is based on data released just this last October. In light of this new data, it’s evident that a larger effort is needed across health care to access global eye care and to get access to communities to individuals who currently don’t have access to glasses. So, we’ll look into why including refractive error in community screenings is so important. And if this is something you’re already doing, we’ll look into going beyond that to identifying the refractive error to see whoever is responsible in your health system for providing eyeglasses. We’ll also cover how to achieve a successful screening. I’ve included some procedures, but I won’t go through them in detail. If you want to look back, you can look over the procedures. And at the end, we’ll discuss the ethical issues around health screening. So why are we testing in refractive error?
I’m going to start off with a question. I’m not sure if there are too many people out there. It is early and the day before Thanksgiving here in the U.S., so I understand if everyone is sleeping in. What condition do you think is responsible for the majority of the world’s visual impairment? We have these options. I’ll give you a few moments to vote, there. Most of you said uncorrected refractive error, which is true, actually. The results released on world sight day this by the international agency for the prevention of blindness. Pointed out that 49% of global visual impairment was refractive error. So 49% of people who are visually impaired are only visually impaired because they don’t have access to a pair of glasses. And a lot of these people are not aware of how to access glasses or that their visual impairment can be solved with a pair of glasses. So 124 million are predicted to have uncorrected refractive error. Each person on the diagram here represents 82 million. We have seen a decrease since 1990. So it is not going unnoticed. 19 million fewer people. But over the last 25 years, two very important dome graphic changes have happened. The global population has increased, and our global population is aging. So there are significantly more people living beyond their 50s, and this is increasing those susceptible. This means rather than a decrease in prevalence, we are seeing an increase. So, this is going to make it more likely to see. This is the time to start ramping up our visual screenings.
Not only is our population aging, but we are on a whole becoming moremyopic, or short sighted. You see the combined prevalence of myopia globally. In 2010, over 28% of the world’s population was affected by myopia. By 2050, it’s predicted that 50% of the world’s population will be myopic. That’s a number of high myops increasing. That’s a huge concern regarding the health risks associated with myopia. As the high myopia increases, we have high risk of degeneration, detachment, cataract or open angle glaucoma. In these cases, it’s not just enough to prescribe a pair of glasses, and that’s why we’re going to discuss throughout our presentation here I’m going to keep reminding you, that once we’ve identified someone with refractive error, we really need to shift them on. We need a referral base in place. So with these children here that are being identified early, and hopefully they are being identified early with myopia. Air care providers need to take measures to slow the progression of refractive error. So what’s the impact of refractive error? Why is it so important to get people into glasses? Financial burden is a really big issue. Burden to communities and countries is a big concern. To have individuals out of work or in limited employment due to lack of vision is not fantastic. There’s a financial burden to individuals who are unable to work. And a depression associated with not being able to contribute to their community to their fullest. As we discussed earlier, high refractive error can result in conditions.
Hyperopia can result in sight threatening conditions as well. Lastly, uncorrected refractive error in adult and children has a large impact on the educational potential of our children. This happens in two facets. Often children will stay home to care for a visually impaired family member. Or if they’re visually impaired themselves, they will start to fall behind school and work. The latest study in preschool suggested that early reading skills were significantly reduced in 4 to 5 year olds if they had moderate hyperopia. So, another reason to get kids into screening programs really early. I love this picture that comes from vision spring. It was reported in the world weekend this woman is a potter, and with her reading glasses, she was able to increase her production from two pieces a day to ten pieces a day. This is a fantastic example of someone with a pair of reading glasses, it really changing their lives with them being able to contribute to their community in a significant way. Which population should we be screening? presbyopes. We see so many over-the-counter readers. It’s mind-boggling that many people are not utilizing the cheap production of glasses, and sending readers out to people. But 1 billion people without access to near glasses. Taking those individuals out of work early. So, like that Bangladeshi potter, if she didn’t have the glasses, her production would decrease. And she would end up working a lot less as a result. Sometimes this is a condition that the individual is unaware of, they are unaware that it can be solved by glasses. They’re unaware that they can lose their vision and they’re not sure that glasses can make all the difference.
So, education in the community is important in improving the rates of presbyopes that are uncorrected. That’s educating community leaders and helping them disseminate the message throughout the community. Women, globally for every man who is visually impaired, there are 1.07 women who are visually impaired. So, they’re more likely. Life expectancy of women is a lot longer. In the case of refractive error, we’re having a lot more presbyopic women out there. And coupled with that, we have a higher risk of sight-threatening eye conditions. Women are greater risk, and in some countries, women are disadvantaged to accessing health care. So, making sure when you add in screening in communities that you’re not only seeing the people who are working, but you’re also seeing the people in their homes and working from home. Lastly, a really important group is children. As we mentioned earlier, refractive error limits educational potential and work.
Also, children are less able to identify themselves as visually impaired. So, they do recommend a yearly screening of children between 3 and 6. The reason is, I know I can compare, I can discuss with other adults what my vision looks like, and what I can see. Whereas children have less of an idea of what everybody is able to see. They don’t know anything different. They assume that everyone can see as well or as worse as they can. Even if kids say they’re seeing pretty well, make sure that kids are being seen.
So, lastly, why do we need screening in communities? Why doesn’t everybody go to the hospital? The big city? A lot of remote communities have limited access to big city hospitals where most people in most countries are working in health care. Either due to limited transportation or not be being able to take the time off work to get to hospital. This is a big concern that limits their access. If we can get out there, then we can solve that problem. It’s also difficult to self identify if you don’t have the education or the facts about what eye conditions there are out there, then you don’t know that you need to go and get your eyes checked and get a pair of glasses. So, let’s establish a community screening through refractive error. Let’s find out what we do first. We need to start off identifying and speaking with local leaders in the community about the importance of screening for refractive error and gaining trust with community leaders. Once it’s supported in the community, we need to get the word out for the visit. We need to write a list and collect necessary equipment, including children and adults. You’ll see how this lady is holding up a child specific eye chart so you need to make sure you have the materials necessary for testing children and adults.
Before we get out there, we need to establish a clear referral criteria. This will depend on the hospital. Or on your group who is looking into sending people out for community screening, but it’s a good idea that anyone out there screening in the field understands who needs to be referred, and who are happy to stay at home. Lastly, there needs to be a referral process in place. Once we’ve identified the people with visual impairment, we need to know how they’re going to get their glasses. Will there be someone on site with frames and picking lenses? A lot of people are out there with ready made lenses and frames, once we identify what the refractive error is, they can grab lenses and frames and click it in. We have some people out there in community screening who have glasses that they can change the thickness of the lens, and they can snap off that piece that’s changing the thickness of the lens. So, we’ve got a lot of different ways of supplying lenses on site. Another way is maybe the person will be sent to hospital, particularly if you find something other than refractive error causing low vision. And so maybe the person needs to go to hospital to collect their glasses or have an extended examination. If that’s the case, how are you going to get those people there? Are you going take them straight away? Are you going to come back and pick them up? And you need to think about how long they need to be there, and bring them back again to their community. Another option is, are you going to take away the results? Make sure if you are doing that, you’re recording people’s names correctly. Are you going to take away the results, make up the glasses, and then bring them back in maybe a month or two months’ time. It doesn’t matter what your plan is, as long as you have a feasible plan in place. You must decide what the referral criteria is, and what you’re going to do with the patients on the spot is never a good plan. One of the biggest concerns is there’s not enough available ophthalmologists available. The people we need to call upon are allied health care providers. Optometrists, nurses, etc.
Whoever you have that providing glasses in your community or health system. Another way is reach out to community leaders and have these professionals train community leaders whilst they’re there as well. This comes from the most recent day release from IAPB. There’s a link at the bottom where you can access the visual atlas. There are a significant number of ophthalmologists working in countries that have a lower incidence of uncorrected refractive error. That is significantly less in countries that have a higher instance of uncorrected refractive error. On the top, we have high income countries, and ophthalmologists are circled. There’s quite a few per million population. The countries in blue, green, orange, and yellow down there, you can see have a significantly less number of ophthalmologists. Ophthalmology is already very stretched when it comes to providing services to the community. You can see here if we compare the number of optometrists or allied ophthalmic personnel, we can see that the countries that have a lower instance have a larger number of supporting staff. People helping identify people with refractive error, with eye concerns, eye conditions, identifying them and dealing with those who don’t need to be sent to ophthalmologist so we need to work on building the number of ophthalmic personnel. A study was done in 2009, and they compared train nurses to trained lay people and their ability to administer screening tools successfully. I do want to stress, this is in children. They found that both groups were able to correctly identify up to 80% of children with at least one vision disorder. That’s quite high. They did this with auto refractors and visual acuity charts. Let’s consider that adults are maybe a little easier to test than pre verbal or newly verbal children. We can see that this would also be quite successful in adult screening as well. So we need to start increasing our supporting personnel by increasing the training of lay people as well as those supporting ophthalmology through allied health. So allied health professionals getting out there and training community leaders, teachers, government officials, the people really setting an example in communities. In 2004, the vision preschoolers group looked into the most successful tools for assessing refractive error. For trained licensed allied health professionals and ophthalmologists, retinoscopy is the most effective. I want you to keep in mind, again that this was over a decade ago. So, there has been a lot of changes when it comes to auto refractors. Based on this study here, our most successful tools are auto refractors, and charts.
We have other tests that you can include, distance cover test and near cover test, which is going to help you identify aphoria or atropia, extraocular muscle testing, which will help you identify a muscle or nerve palsy. Bruckner is something that we will go into in a little bit of depth. Near point of convergence will give you an idea about binocular vision concerns. We also have color vision and pupil response. The other tests either require equipment that is more advanced or requires training that is a little more advanced. But these can be taught to lay people, but you need to make sure they understand what the test is for and they practice a lot. And in the beginning, being soup vised by the allied health professional. What equipment do we need to take if we’re doing visual acuity and refractive error. We need to take a visual acuity chart. You can use ETDRS letters or LEA symbols. Preferably a logMAR chart and a tape measure. Also a near visual acuity chart an occluder if you don’t trust that people won’t look around their hand. If you’re an advanced trained professional, then your diagnostic kit is valuable. Bringing your retinoscope or retinoscopy, and your direct ophthalmoscope and transilluminator. If your examiners are less trained than an auto refractor is necessary. We want to start by asking the patient important health and visual questions. We will ask if they have had or owned glasses. If they have worn or wear contact lenses. If they have concerns about their vision. If they have anyone in their family with vision history. If their general health is pretty good. Looking out for big ticket items like high blood pressure. Diabetes. A really good idea is ask about someone’s occupation and their daily tasks. It’s one thing getting someone a pair of glasses, but if they don’t know what the person does on a day to day basis, we haven’t addressed the patient’s concerns at all. As a child, do they like reading? Do they need to use their finger when reading? Do the words move on the page? Ask them what their favorite subject is. That might give you some idea about what’s holding them back in school and also helps you bond with the child. And can you see the board at school, whether that’s a white board or black board, or in some cases an electronic board.
If the device based screening is chosen, so you have community leaders mainly doing the screening, then we need to choose an auto refractor. We have the retinomax and sure sight vision screener. They were really identified by the VIP study as superior devices for identifying refractive error in children, specifically. We also have the new one on the market, the Welch Allyn spot. We also have the PlusOptix vision screening device, which has been labeled as acceptable at this stage. Also, interestingly enough, there is a lot of cell phone technology coming about. So, watch this space. Everyone we know has a cell phone, and so if we can utilize this technology and include it in auto refraction, that would be fantastic. On the bottom, this lady is using a virtual reality headset, and the phone is being provided there to find out what her refractive error is. There’s a lot of technologies out there. They’re not as they’re probably not up to scratch as much as we would like, but it’s definitely something that is worth keeping an eye on. There’s a lot of advantages and disadvantages to using auto refractors. The advantages is, it’s quick. You can get through a lot of people in a short amount of time. It requires minimal cooperation from the patient. It really does require a lot less training for the person administering the test. It’s portable. And it’s great for preverbal or pre literate children. If you can’t get the visual acuity response, it gives you a starting point of what this child’s refractive error is. Disadvantages is it’s a limited ability to detect a strabismus and higher hyperopia. There are studies saying that they haven’t been quite as accurate. The cost of the instrument, they can cost quite a bit. They require electricity or batteries to work. You need to make sure that you have a generator or a charge, or enough batteries for the time when you’re out where you are if they don’t have electricity. And it may be less reliable in children. This is due to active accommodation, and also perhaps a less stable fixation. They’re more inclined to look around, and so that would contribute to an odd result or unreliable result.
Thinking about auto refractors and thinking about refractive error, obviously as your referral criteria becomes tighter, it’s going to increase the number of patients that you send off, which means that you will increase the number of patients that you correctly identify as needing to be referred or needing glasses. But it will increase the number of patients you have sent off that were unnecessary. So that’s something to consider when you’re thinking about your referral criteria. Okay. Just so I can have a little bit of a break and a drink here, we’re going to add a question to the audience. Who do we refer? We have a question here. What is the expected refractive error for a 1.5 year old toddler? It is less than — it’s easier to identify in adults. Children are a bit more complicated. They’re expected to have a small refractive error from a young age. Let’s see if I can move on. There we go. This is just a little table giving you an idea of the refractive error that we would be looking for. Notice at the bottom, an isometropia at less than one. We want to make sure there’s less than a one difference between the two eyes. When kids are born, they start off relatively hyperopic, and as they get older, it decreases. So, you need to understand, or your screeners need to understand if they see a 4 year old and they’re 1.5 diopters of hyperopia, and it’s even in both eyes, we’re just going to leave them be. However, if you have a 45 year old with 1.5 diopters, you might find that their vision in the distance starts to decrease. And so, you need to explain to those who are screening that there are different standards and different referral criteria. And a little bit of hyperopia is absolutely fine.
Children, as we mentioned, they’re a little bit more complicated. They’re at a higher risk of ambiopia. That limits that eye’s visual potential. So we need to look for concerns regarding amblyopia. One of the concerns is, is the refraction normal? If this chart is four months, is it above 350? We also want to look to see if the vision and refractive error is equal. So again, referring back to thatanisometropia, the left eye is a plus six, that’s not fantastic. That plus six. The eye is going to start drifting away and turning off. And sending less signals to the brain. We need to make sure that we correct the child and equal signals are going to the brain. One thing that you’ll find both with receipt retinoscopy, this is for both children and adults. In adults, we’re probably mostly looking for cataract, but in children you’ll be able to see if the media is clear, if you’ve got a cataract. You may also observe if the eyes are misaligned. If you’re not doing any test that specifically address the misalignment of eyes, then having that still on your piece of paper that the examiner can tick off and say, Yes, I’ve noticed that the right eye isn’t looking straight ahead isn’t a good idea. Sometimes they might find during the refraction that one eye isn’t looking at them, and they can see that. So, we’ve gone over hand held auto refractors and retinoscopy.
The most successful tool for assessing visual acuity is a visual acuity chart. There’s a couple of things that we’re looking for in visual acuity charts. Here we have a few pictures. So, at the top here, we have a LEA chart, so LEA symbols. There is a box around them. So making sure that if you are showing a single line acuity chart, that they have crowding or crowding bars. And that box is referred to as crowding bars. You can see the two charts there, the tumbling E and the ETDRS chart there, both have the full chart. They’ve got other symbols all the way around them. And again, it allows us to introduce that crowding. The reason that crowding is really important is we want to give a more realistic idea of visual acuity. And that would include visual attention in our environment. There’s a lot of things competing for our visual attention. If we have something on our chart that is competing for our visual attention, it gives a more realistic measure of visual acuity. And that’s more particularly the case in ambiopia. You notice here, the chart at the top where the LEA symbols are being shown, it’s calibrated for five or ten feet. So, you want to be able to move that chart back and forth, just to get an idea of what the visual acuity is. If they can’t see anything on the chart, you can move closer and do the calculation to work out what the visual acuity is. So, when we’re taking visual acuity, first we will ask the examiner we will ask the patient to cover one eye. If you’re going to use an occluder, that’s fine. If You’re going to use the patient’s hand, make sure they don’t peek through the hand. So, they will point to the letter or LEA symbol or the tumbling E. You need to make sure you’re not covering the symbol or the symbols around it. You will start at the top of the chart and ask the patient to identify the first symbol. If they easily identify it, move one line below. If the patient is squinting, leaning forward, or starting to get incorrect answers, then you want to test the entire line above it.
We might start from the top, and they tell us that’s an E. Move one down, they say it’s a D. It’s correct. If they go down one and they’re a little hesitant, then we’re going to go up and test the whole line that they got right previously, the line with a D in it. They will continue moving down the chart until the patient reads about three or more incorrectly. And that’s your end point there, that’s your visual acuity. One big thing is maintain a positive attitude when someone gets a symbol wrong, going oh, not so good. It’s not a great way to build their confidence. This is really important in children to keep them engaged, just so they’ll play the game and they’ll correctly identify the symbols. So, some pearls of wisdom for visual acuity testing. It’s a good idea to confirm that they understand what the test is. So, if you’ve got a tumbling E, that they understand that you want to point in the direction that the E is facing. If you have a Roman alphabet chart, that you want to make sure that they are literate. They understand the Roman alphabet and can identify them. And if you are using LEA symbols, that the children can name each of the symbols. They can name them whatever they like. If they think the house looks like a triangle, roll with that. This is not your time to teach what a house or a triangle looks like. Whatever they name them is fine. And continue moving on. You want to continue building confidence there. You don’t want to say oh, no, that’s not a square. Keep building their confidence. Whatever they name the symbol is fine.
You want to observe the patient, not the chart. We find the students are watching the chart and getting the answers right, but they miss the patient leaning forward or squinting or peeking around the occluder. You want to make sure the patient is not doing that, to sit back, relax. Stop squinting. You can replace their occluder. Maybe it gives you an idea of where their limit of visual acuity is. Also, they have fantastic glasses from good light here. This allows one screener with a child to have the child wear a pair of glasses with an occluder allows the examiner to be at the other end pointing to the symbols, and not worrying too much about the child looking around their occluder. So, these are from good lite.com. You test one eye and then the other. But you might start binocularly in children or adults who are hesitant, and give them larger letters and symbols to start off with. And you want to test with the patient’s glasses on first. If they are wearing glasses and they pass, then they’re fine. They’re fantastic. They don’t necessarily need to update their glasses for that distance. But if they’re failing, we have a good idea about how much we might need to change that prescription.
So, what’s an acceptable visual acuity for a 4 year old? I’m going to post the question to the audience. Where it says ten, it should say five. This one’s a tricky one. I like that we got 50/50. So, with adults, it’s easier.
Maybe even a lot better than that. But 20/25 should be someone who doesn’t have any refractive concerns. They should be at least be able to achieve that. But in 3 to 4 year olds, you’re looking for about 20/50. If they get less than 20/50 at five feet away, or a difference between the two eyes, then we want to start thinking about referring the child off. When we go up a line, improving by a line at the five foot mark. And then older kids, we should be expecting them to get about 20/30 minus two or so at about 10 feet away. We can afford to start moving back a bit with the 6 year olds. Notice with children, looking for the two-line difference between the two eyes. If there is a two line difference, that should set off warning bells that maybe this child is suffering from amblyopia, and maybe we need to refer the child.
So, visual acuity conditions, adopted from the American academy of pediatrics. You want to take a measuring tape or something like that to mark where ten foot is, or five foot. That’s three meters and one and a half meters on the floor. You need a clean chart with a white background. Make sure the chart is stored in an area, in a box that is nice and clean as well, just so you have really good contrast. Want to place the chart at eye level. So, if someone’s holding it, make sure it’s eye level with the patient. If you pin or tape it up, you want to make sure it’s eye level. So, minimize the conditions around the chart. Near visual acuity in adults, ask the patient to hold the chart at their reading distance. This is a little more realistic. You can assume that most adults over 50 will have some difficulties at near with the exception of low myopes.
The prescriptions that I’ve listed there for each age group, it’s a good starting point to, if you want to start prescribing over the counter readers. That would be a good starting point for that patient there. That is based off of the expected level of accommodation. So, a few other tests that we could check to see, so if we have low visual acuity, if we want to make sure that the low visual acuity is due to refractive error, one of the things we can do is pinhole, Bruckner test, and retinoscopy, we will leave that for a later presentation. So, tune in for that.
So, an occluder is an opaque disk. You can see this one on the left hand side is held up like a pair of glasses. The one on the right hand side is held up like an occluder. And there’s a small hole where the patient can look. It’s sort of like a pinhole camera, and it temporarily removes the effects of refractive error. If you have refractive error and you’re seeing a little blurry, you should be able to look through that pinhole and see a little clearer. If your vision is improving, you know it’s a refractive error concern. If you hold that occluder in front and your vision isn’t improving, then you know this is a different type of concern. We’re thinking more ocular disease now. So, we need to make sure that patient is being referred before looking into a pair of glasses. So, we have Bruckner here. This is a procedure done with your direct ophthalmoscope. You hold it about 50 centimeters to a meter. It has transilluminator, but it should say direct ophthalmoscope. You’re dialing in your plus one into it. You look through the hole to observe, and you’re going to observe the patient’s red reflex. If the patient is an emmetrope, you will see bright red. If they are hyperope, you will see the crescent. You can identify what type of refractive error it is, and also see if there is a bit of asymmetry between the eyes. And also, you’ll be able to identify if there’s any strabismus or media opacity.
So, we did have some questions in here, but for the sake of time, I’m going to go through some of these for you. You can see here that this child is myopic. Minus 2.25 in the right and minus 1.25 in the left. You can see a big difference there. I wanted to pop this one, because you can see there’s quite a bit of asymmetry between the two eyes, but you can’t really tell what kind of refractive concern this is, because the refractive error is so high. So, this is a minus 11 in the right eye and minus 13 in the left eye. Here we can see our hyperopia. We have plus 3 in the right eye and plus 4.5 in the left eye. You can see they’re fairly similar. Maybe the left one is a little larger. With this young lady here, you can see that the right eye is deviating, and in fact, this patient here has a 30 deviation. So, you can see you get this nice, red in one eye the eye that’s looking at you. And the eye that’s turning away, you can see that that eye gives a nice white sheen to it. You can tell that it’s not focusing and looking at you. This little one here, both eyes are straight, but you still get that white screen. And the reason we’re getting that white sheen is because we’ve got a bigger concern that maybe this child has some sort of opacity in their media. Maybe a cataract or a tumor. So, the light is hitting that opacity and coming back to us white. You can tell this is more of an opacity issue, because you can see that the child is looking relatively straight.
So, after we’ve done our acuity and refractive error, this is a good list to start, particularly in children. If you want to add some additional tests apart from the pinhole and the Bruckner. We’ve got Hirschburg. This is about half a meter away. You’re going to compare the corneal reflex position of the focusing eyes. If there’s one eye that isn’t focusing, then you’ll see that the corneal reflex is not in the center. In this case you use your transilluminator. This is a schematic of what it looks like. So normal. You’ve got the two central corneal reflexes. You’ve got your exotropia at the top right hand side. You can see that little reflex there is no longer in the center of the pupil, but a little more nasal. And Esotropia and hypertropia gets more towards the center of the pupil. So, again, for the sake of time I think we have a little time. What do you think this is? Yeah, beautiful. It’s an Esotropia. It’s pretty dramatic. You can see the Hirschberg off to the temple side of the pupil. What about this one here? What does everyone think is going on here? Beautiful. I I love that we have a split there. It’s harder to tell. So, our fixating eye is this eye here. This is our eye looking at us. Sorry about that. And then you can see that this little reflex is just off to the nasal side of the center of the pupil there. So it does get a little bit hard tore tell an Exo from an Eso. But this is a good way of helping out there.
Also, some general observations. Like I mentioned before, having a spot with your examiners can write down if they see some shaking of the eyes. If they see one lid drooping. If their head posture is to the side. If there’s any discharge. If there’s any corneal clouding. If there’s a red eye. Lumps or bumps that look unusual. If the person wears glasses, it would be great to have that on your piece of paper to note that down. And if there is any behavior that someone is concerned about. Maybe the child is not developing how the parents expected. Include in the observations, include pupils to a small extent, if the examiner is just a lay person who has been trained. You don’t want to put too much pressure on them. If you can ask if the color between the two are the same. You can ask if the size is about the same. If they are positioned centrally. Or if they have noticed a response to direct light. That’s a little more advanced, and you don’t want to put too much pressure on people who are not trained to identify certain conditions. But this is something that you can start introducing as your screening process goes on.
So, this is going to be our last slide here. I’m not going to go through it. I wanted to make a point here that I’ve put in cover test, and near point of convergence. I’m not going to go through these tests, but I have outlined the procedures for each of them. Just to get you started on reading up on the procedure. We hope to be uploading instructional videos on the test. And along with that, have written instructions over the coming months on Cybersight. So, keep an eye out over the courses of refractive error. There are a couple of manuals out there. Keep an eye out there. We’re hoping to increase our impact on Cybersight as well. So, we’ve just got some instructional slides here. I’m just going to finish up here as we’re winding up. If you have any questions, you can start sending them in.
But I just want to quickly pose to the group, there are a lot of benefits to screenings. I have spent the last 50 minutes convincing you that heading out there for refractive error is important. There are limitations to screening that you should be aware of. There is often the cost to patient and to the government or the hospital if they need to supply equipment. That’s something that you need to consider as well. What equipment do you need? What’s the minimum equipment that you need? Also to the parent or patient, that needs to then be referred to the hospital, what kind of cost are we looking at for that parent or patient? We need to take into consideration language and culture. You need to make sure that you are entering a region that either you have a very clear understanding of the cultural background, or you are with someone who does understand the cultural background, and someone who can understand the language. Screening goes a lot smoother if you can speak the same language.
And also think, you will end up referring a lot of people who didn’t need to be referred. That will be an additional cost to that parent or patient that with us unnecessary. And you will end up not referring a few people who did need to be referred. There will be some people who are missed, and some who are sent unnecessarily. We can’t really do a lot about that. Although we can try to train our personnel as best as possible. And very clear referral criteria. Keep that in mind, that there will be both times where you ear unnecessarily referring, or you’re or we have missed someone. To avoid the number of people that you’re missing with refractive error, going back to the same area every year, year and a half is a good way of addressing that. So that comes to the end of our lecture today. I hope it was informative and that everyone’s enjoyed it. If you have any questions, please feel free to send them through. I’m not quite sure if I can… if I can see that. I think I can.
>> MODERATOR: Thank you. We don’t have any questions yet. But we have about five minutes if anyone wants to type those in. Do you have about five minutes?
>> DR. SARAH WASSNIG: Absolutely. I hope it’s a lot nicer weather wherever everyone else is than it is here. It’s pouring rain and quite cold. It looks like it’s going to be a wet Thanksgiving, everyone.
>> MODERATOR: So I don’t see any questions coming in. I can share my screen if you want to go through the other ones that came in before.
>> DR. SARAH WASSNIG: Absolutely.
>> MODERATOR: Can you see my screen?
>> MODERATOR: So if you want to talk through these, that would be good.
>> DR. SARAH WASSNIG: So blurry vision on one side of the eye, that is something that you want to refer. I think we’re talking a visual field concern. So, including confrontation fields is a great way to address visual field concerns. In our actually it prompts me to make sure that we pop up confrontations and instructions on confrontational fields and facial fields on Cybersight cap 1. So we’ll pop up instructional videos on both procedures. But that’s definitely something to refer to ophthalmology. Again, that’s going to be something to refer, or depending on the country you’re working within, you might refer to your nurse or optometrist to deal with. Once you have addressed the redness and itching concern, you can look to see maybe if visual acuity improves once the itching has died down.
How far is the refractive error reliable for school screening because of accommodation in the younger group? That’s an issue. We try to get them to look as far away as they possibly can. They have something really interesting at the other end. I usually get my students jumping up and down. I get them to juggle. The worse they juggle, the more entertaining they are. That helps relax the accommodation. You can introduce a fogging lens if you are a bit concerned. If their pupils are small, I would think there’s a lot of accommodation happening there. And I would be thinking about hyperopia, and warning bells would be going off. The pupils are so small that I think this child is accommodating quite a lot to see clearly in the distance. So that would send warning bells off. Unfortunately, with smaller pupils and your auto refractors, I think some of them have less reliability when a child has small pupils. So that’s something that you want to consider with your auto refractor. And also with your auto refractor, this might be one of those moments where you’re not sending off as many kids as you need to. If they have very high accommodation, you might not catch that really high hyperopia with an auto refractor. Practicality of using cycloplegics in an outreach program. I think if you have someone on site, that’s a possibility. What you need to make sure, though, is that you’re doing a thorough test of the angles. You don’t want to pop in and find that you get yourself into a bit of a pickle with the angle closing. So, you just don’t you don’t want that to happen because you’re in a situation that you don’t have immediate access to the care that you need to reverse that, or to alleviate that. So, that is something that you’d want to consider. But if you particularly if you have a had held foot lamp or doing a pin torchlight test from this eye, and you can see that the angles are clearly open, then I think that this is something that you can definitely incorporate, if you have somebody trained in the administering of drops.
An acceptable alternative? Look, I think if you are thinking about in terms of kids, again, like I was saying, you could fog the chart a little bit. Make sure it’s on a frame and make sure that their accommodation is relaxed using plus lenses or a plus over their current prescription. In terms of dilating for looking at eye health, then that’s something that you want to sort of consult with your ophthalmologist on. Hopefully you have one ophthalmologist on site doing visual screening as well. But if that’s not the case, then you need to get those patients off to ophthalmology, Somehow.
>> MODERATOR: We have one final question. That should probably be it.
>> DR. SARAH WASSNIG: Yeah, stereopsis is interesting. You it may not be a major concern in screening. So, I think it’s a good idea to have a clear set of objectives. So, I want to identify anyone with refractive error, anyone who has strabismus, and you may or may not include binocular vision. It’s not always very reliable, but it maybe gives you a clue as to how well both eyes are working together. You would be better off looking into or adding tests like your near point of convergence or your cover test to assess binocular vision, and if their eyes are aligned and if they’re working well together at distance and near. You can also add into that a word for dot test, which would test for vision. You can get the red green glasses for the child. We include on Cybersight over the next coming months, all of those procedures and instructional videos. So, we’ve convinced our students to act as patients for you. And we will show you how we administer those tests. So, keep an eye out for those tests. But if you’re looking for binocular vision and in stereopsis, adding cover testing is a great start.
>> MODERATOR: Great. Thank you so much.
>> DR. SARAH WASSNIG: Thanks for having me. I want to point out that we’ve got a lot of optometry webinars coming out. And keep an eye on Cybersight for instructional videos as months go on, as we get into 2018.
>> MODERATOR: Have a good day, everyone.

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November 22, 2017

Last Updated: October 31, 2022

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