Lecture: Incorporating Low Vision Into Your Practice

This live webinar will discuss clinical and practice management strategies for incorporating low vision into an existing practice. The webinar will also discuss ways to leverage community resources to improve patient access to care and overall outcomes. Lastly, the webinar will include a review of exam techniques and existing technologies that can be of benefit to your patient.

Lecturer: Alexis Malkin, OD, FAAO, Associate Professor of Clinical Optometry, New England College of Optometry (NECO), Massachusetts, USA


DR MALKIN: Good morning, everyone. I wanted to spend a little bit of time this morning or afternoon, depending on where you are, talking about some of the strategies that I recommend for how to incorporate low vision into your practice. Just a brief bit of background on who I am. I’m faculty at the New England College of Optometry in Boston. I’ve been on faculty for five years. Prior to that, I split my time between a low vision private practice, and Johns Hopkins Hospital Low Vision Practice. So I’ve had some experience in a variety of different settings, and have always been thrilled to do some work with Orbis, including a past trip to Bangladesh. So feel free to type any questions into the Q and A. We’ll save those for the end, and we’ll go through the lecture. So there’s gonna be three major topics that we talk about today. First is just making sure that we’re all on the same page about defining what low vision is. Then we’ll talk a bit about who has low vision, the patients you would expect to present for the services. And then I think what most of you are here for is: How do we manage those cases? And what are the ways to not spend 2 to 3 hours doing a low vision exam, but still make sure you’re serving your patients appropriately? So we’ll talk about clinical and practice management strategies for incorporating low vision. I have a few mini-cases to describe some patients that I have managed recently. We’ll talk a bit about how to leverage community resources, to improve access to care, and we’ll go through some basic exam techniques, just as a refresher, or perhaps new information for some of you who haven’t done a low vision exam any time recently. So let’s begin by talking about what low vision is. I think the most important thing that I convey to my students and to my referral sources is that we want to focus on functional limitations. It’s a permanent impairment that causes functional limitations. You can choose to define in terms of acuity or visual field loss, but I think it is much more important to think about the function and not what the number is. And we’ll talk about why that is in a couple of minutes. Low vision can be congenital or acquired, so don’t forget about people who were born with vision impairment, and may not realize that they aren’t functioning to their best capability. Internationally, the categories of low vision are defined as mild, which would be presenting visual acuity worse than 6/12. Or 20/40. Moderate, which is presenting acuity worse than 6/18, which is about 20/60. Severe, which is worse than 6/60 or 20/200. And then the international definition of blindness is 3/60 or 20/400. Similar categories here in the US, though we define legal blindness at 6/60 or 20/200. So I think this again goes to the importance of using the functional definition, because the categories may vary, depending on where you’re practicing. When I think about what is actually included in low vision rehabilitation, it’s managing patients whose vision loss cannot be corrected with medical, surgical, or conventional eyeglass or contact lens treatment. It’s a multidisciplinary approach, and it’s really aimed at improving that function. And that just goes back to why I use that definition. I know I’m gonna say that a lot today. But we aren’t actually trying to improve the visual acuity, though if we can, that’s always a really nice bonus. We’re actually trying to improve the function and help people maintain their independence, to whatever degree they need to. The team members may include a whole host of different rehabilitation specialists, so optometrists, ophthalmologists, low vision therapists, occupational therapists, orientation and mobility specialists, teachers of the visually impaired, at times a geriatrician is involved, psychology or psychiatry can be involved, as well as local agencies. So to kind of get a sense of where everybody is today, what types of professionals do you work with regularly? And this will our first poll. You can choose all that apply. All right. So it looks like the majority work with vision rehabilitation specialists. And I do find that internationally, that seems to be the most common professional involved. Here in the US, we rely quite a bit on occupational therapy. That has to do with the billing structure. In the US, where occupational therapists can be paid for vision rehabilitation, through insurance carriers, whereas vision rehabilitation specialists cannot. And it looks like a smattering of reliance on the other areas as well. So I wanted to emphasize a shift in thinking that has gone on in the United States. We’re still slowly integrating this preferred practice pattern, but it’s nice to see that our leadership in the American Academy of Ophthalmology is encouraging low vision rehabilitation. And they say that you should provide or refer for low vision services if a patient has reduced best corrected vision of 20/40 or 6/12, central scotoma or metamorphopsia, reduced contrast sensitivity, visual field loss, or functional difficulties. So this — the first time that I started to see that the Academy of Ophthalmology really emphasizing something beyond acuity, and also starting at that mild level of acuity loss. When I first started practicing low vision, and obviously I haven’t been practicing that long — I graduated only 12 years ago — the mentality was very much to refer at the level of legal blindness. And we know that patients at 20/40, 20/50, 20/60 really do have functional difficulties, and these are often the easiest problems to solve. So this is something that is nice to see coming out of the Academy of Ophthalmology, and it has really helped me communicate with my referral sources. I like to reference that they have a really nice five-minute video. You can share with referral sources about the impact of low vision rehabilitation early on in a disease process. So here is another poll. Where do you think most cases of low vision occur? At what level of acuity? Mild, moderate, or severe? And just a reminder for those of you not using the 20-foot distance, 20/60 is 6/18, 20/200 is 6/60, and then worse than 6/60 for the severe. Okay. So most people said moderate. I would have said before I started looking at the data — I would have said the same thing. But you’ll see that actually people are presenting at better acuity levels than that, as we go forward. So looking at the prevalence and incidence here in the United States, and the numbers match pretty well when we remove treatable causes of vision loss, when we remove treatable refractive error and cataracts, in other parts of the world. The prevalence of people who are worse than 20/40 but better than 20/60 is by far the highest group of people affected with low vision. The smallest group is those who are worse than 20/200. This isn’t to say that we don’t want to treat those people who are worse than 20/200. It’s just kind of reemphasizing the importance of asking functional questions in the patients who you think maybe would be doing fine at 20/40, 20/50, 20/60. Part of what I think is going on is that these are the patients with the early macular degeneration, they have small scotomas, they have contrast loss, and it’s just enough to be frustrating and to be causing some problems, but not bad enough that most people looking objectively at the numbers would think that they’re having difficulty. And this kind of matches what I see presenting in some of my practice settings. Some are more of the 20/200 or worse. It really depends on kind of where I am and who’s referring the patients. We also know in the US, as well as across the world, that the incidence and prevalence of low vision increases significantly as people get older. This is from a variety of large epidemiological studies that were conducted in the US. And you can see that big uptick past age 80, to where it’s almost 10% of the population has some degree of visual impairment. Another issue we’re dealing with — and I think everyone listening is probably dealing with this in their own communities — but there is a huge shortage of people providing low vision services. So the areas that we have studied in the US and Canada show that at best, we’re serving about one in five patients who could benefit from low vision services. And this is when we included optometry, ophthalmology, occupational therapy, orientation and mobility, and other professionals. So we like to — and obviously in the COVID crisis, I’m not sure that the US has any basis to talk about having a good health care system. But we talk about having good access to care. And we’re still only serving at best 20% of the patients who have that need. So huge, huge issue here in the US. Similar problems in Canada. And I think even worse in other countries around the world, where low vision is just starting to become a part of optometric and ophthalmologic care. So who are the people who have low vision here? And that we’re seeing in our clinics in the US? This is from a study of about 850 patients who presented for low vision services. And the majority of patients had macular degeneration, or some type of macular disease. We also saw patients affected with diabetic retinopathy, glaucoma, and cataracts. I compared this data to a study out of India. It showed a similar breakdown. A little bit less macular disease, and a little bit more of the other conditions, but still central vision impairment as the primary cause. Different practice settings that I’m in have a different breakdown. But the vast majority, especially as we think about age-related eye diseases, it’s macular degeneration more than others. And from that same study, much like I said, we see that the prevalence and incidence goes up dramatically, as people get older. You can see here, of those 800 patients, the youngest admitted in the study was 18. But the median was 76, and a tail here, with heavily, heavily skewed to people in their 70s, 80s, and 90s. And as we mentioned in the poll earlier, the majority of people were better than 20/200. In this particular study, of who actually presented for services, not who has low vision, about a third were in the 20/20 to 20/60 range. And then another 35% to 40% were in the 20/60 to 20/200. So that covers about 75% of patients who were actually showing up for services. And this is really kind of the answer to what’s going on there. Patients were asked to rate their quality of vision before they came in for that low vision visit. And it didn’t really matter what the level of acuity was. Nobody rated their vision as better than fair. We can say that it shifts more towards poor at the worst levels of acuity. But typically you wouldn’t think that a patient who’s between 20/20 and 20/60 would say that their vision is fair to poor. So this really gets at that very first thing I said, which is: We’ve got to look beyond the acuity to understand what is causing the vision impairment, and how we’re going to manage that vision impairment. And just reemphasizing prevalence rates by age, huge shift as we get to over the age of 70. And we hear a lot — people thinking “Well, it’s just because I’m getting older.” But that’s not necessarily true. You know, it’s still only between 7% and 10% of people over the age of 70. So it’s not a normal part of aging, to start to lose vision. It’s just a more common part of aging. So when I think about how we actually do low vision in our practice, I like to think about it in terms of low vision tiers. And this is something that the American schools, the College of Optometry, are adopting in the US. Where our goal is: Every student graduating from optometry school should be able to, at a minimum, do primary low vision care. And if people want more training, then they can go on to advanced low vision care. So when I think about primary low vision care, that’s what I’m thinking about, for people integrating low vision into their practice. So this is thinking about spectacle solutions. So assessing higher add powers. I know it may sound basic to a lot of you, but considering a switch to single vision glasses. So a higher powered reading glass than what someone might wear in their bifocal or their progressive. Actually pulling out the trial frame and doing a trial frame refraction. That 20/20 or 20/25 patient with a small scotoma will really do better in a trial frame than they will in a phoropter. Early use of magnification. Education about the condition, about lighting, about contrast enhancement. And referrals for those other services, like mobility training or vision rehabilitation training. As many of you mentioned, as services you work with. When we get into the more advanced cases, we’re talking about primary care plus starting to integrate digital magnification. Looking at telescopes. Performing more comprehensive technology assessments, or perhaps referring for those technology assessments. Vocational rehabilitation. And beginning things like sensory substitution. So referring for Braille assessments. For learning to use tactile markings. Those are somewhat more advanced. We’re gonna focus mostly on the primary today. But I will mention some of the advanced techniques. This is the low vision decision tree that was developed by a colleague of mine, Dr. Rich Jamara. And I think it really breaks it down for a new practitioner. The first thing it does is say: Let’s assume the vision is not correctable to 20/20. The next step he asks about is: What is the contrast sensitivity? Then we go into: Are there scotomas or metamorphopsia? Then we go back to that acuity number. So really emphasizing that acuity is one tiny component of the whole picture. And he goes through some initial suggestions for spotting and for fluent reading. And when I joined the NECO faculty, I actually started looking at the decision tree to see if what I had been doing for the seven years of previous practice matched. And it was nice to see that it did. Because this was a new graphic for me, but was clearly showing how I was doing things, based on seven years of experience. But it’s really, really helpful for that new practitioner, as you’re trying to figure out: Am I in the right starting point? I don’t have the time to start really working through a lot of devices. And we’ll talk about some other tips to get you to those reading goals a little bit more easily. So some of the things we’ve been trying to assess here are: Figuring out what are the perceived barriers. Why are we only serving at best one in five patients who need the care we can provide? So we did a study. It was in Optometry and Vision Science in January of this year, where we looked at perceived barriers. And we found that optometrists who did no low vision, self-identified saying that it was not part of their practice, they also didn’t integrate those basic primary low vision strategies like a high add or a low magnification. So some who said they did some low vision did both primary and advanced, and those who did no low vision didn’t do even the most basic strategies. The barriers people reported in the study were the cost of the exam and devices, making an assumption that patients are not interested or wouldn’t go if they were referred. And that it was difficult to stock devices in the office. So cost of exam we can’t really change. Other than providing education here in the US that it is covered by insurance. There are great resources for low cost devices. And I think that shifting away from the mentality of assuming that your patient would not be interested is something we really need to work on. And we’re hoping that through different continuing education talks that we will start to see that shift in practitioners’ thinking, about what they might introduce for their patients, or what referrals they might make. In addition, we are starting to try to address some of the poor referral rates. I’ve been doing a lot of work here in Massachusetts with the Lion’s Club. A similar project has been going on in Maryland and Virginia. And the District of Columbia. Looking at ways to improve that referral rate. So we have to improve what practitioners are doing in their own practice. We have to increase what’s accessible to the patient. But we also have to make patients more aware of this service. So if the referral is made, that they understand what they’re being referred for — so I have worked with Lion’s Clubs to train them, so that they can do community outreach programs. They actually go into their own providers’ offices and talk to them about low vision rehabilitation. They talk about people that their Lion’s Clubs have served, devices they’ve been able to provide, to let practitioners know: You could make this referral. I know some people who could help patients if you ever come across them. They’re also going into retirement communities and senior centers, and providing these same kinds of education programs. I’ve done many of these types of talks myself over time. And I’m finding that having community members present the information is having a better impact than going in as the doctor. Patients seem more willing to approach the community member, to ask about their own concerns, and to ask for help with setting up an appointment. They feel a bit less comfortable coming to the doctor to say: I think your services could help me, but I don’t have transportation. Or: I’m not sure my referring doctor would be comfortable with it. So it’s really nice that we’ve used community members to bridge that gap. And then what we’re doing today, which is to try to train more eyecare primary providers to do this basic vision rehabilitation. My volunteers here in Massachusetts have also helped, as I said, coordinate transportation. They’ve been really good about doing in-home follow-up and support. So they will do a follow-up phone call after they’ve brought someone in for an appointment with me. In some places, they’re having volunteers actually do the patient history over the phone ahead of time. And by getting that history ahead of time, the patient has a much better understanding of what they will expect from the visit. And so they’re more likely to show up for their appointment. Because now they’re more sold on that idea. And they understand that they’re not going in for a cure to their vision impairment, but they’re going in to address those specific functional complaints. This also helps reduce the time the patient will spend in the clinic. So if you’re worried about how many patients you can see on a given day, if someone, if a volunteer or if a staff member has been able to get the history ahead of time, you can now really reduce the amount of time you spend with the patient. This is particularly important right now, as we’re trying to maintain social distancing, and not spend a lot of face-to-face time with the patient. Getting this visit history done ahead of time reduces the amount of time you are face-to-face with the patient as well. We’ve started to integrate telemedicine — and I’ll talk about this in a couple of different places in this lecture — for follow-up visits. So again, this has sort of come out of the COVID crisis. But we have found it to be incredibly valuable, and we’ve been doing some research prior to COVID on using telemedicine for low vision follow-up visits. This reduces the burden on the patient for returning to the clinic. And in some cases, we can do it just over the phone. They don’t have to have video capabilities with their cell phone. And we can check in to make sure that the referral went through. That the device is working. And that the patient has been able to meet the particular goals that we addressed. So again, the telehealth can let you get that history over the phone. And it can allow you to even start to get certain referrals in place before the in-person visit. So this week, I did a number of telehealth visits on Wednesday with some patients. And rather than only doing follow-up patients, I did a couple of new patients. And in my phone visits, just out of the patients I called on Wednesday, I had three new patients I was able to register with the Massachusetts Commission for the Blind. And I completed four Talking Books forms for the National Library of Congress Talking Books Program. So this is something where the patients have to wait for their visit with me, but I’ve now started the process of getting them resources. So we’re already making sure they’re getting some rehabilitation services prior to when they come into the clinic. So there is a lot you can do through that chart review process, and through that conversation with the patient ahead of time. And these visits on Wednesday were only over the phone. My patients did not have video capabilities. So that’s kind of who has low vision and defining low vision. And hopefully we’re now all on the same page about those concepts. So where do we start with the actual exam? So I want to talk a bit about the components of the low vision exam. We’ll talk about the basic concepts for prescribing. And about the broad categories of resources and technology that can help. So the low vision exam I break into these six categories. So establishing the goals and performing the low vision history, measuring acuity, refraction, special testing, which can involve mapping scotomas, can involve Goldmann visual fields and other peripheral testing. Device prescription, and then referral for other rehabilitation services. So we’re gonna walk through these different areas, to talk about how you integrate them. So in terms of the low vision history, you want to ask directed questions. You’ll find that if you ask patients in general: How are you doing? How is your vision? Often you’ll get the answer that they give in their medical ophthalmologic visit, which is: I’m doing okay. They think it’s normal. As a part of their disease. To not be seeing so well. And they won’t necessarily know what they can complain about. And what you might be able to address. Now, you will have some patients who tell you all of their problems, but for the majority, you need to ask directed questions. So I specifically ask about medication management. You know, if they have diabetes, can they see their glucometer? Do they use insulin? If they’re using insulin, do they have the pens, where they can use auditory cues, or are they using syringes that they have to visually see and measure? Do they have difficulty identifying faces? This is something people often won’t admit. But once you ask, they will tell you. And we worry about isolation and loneliness, as people start to lose their vision. This difficulty with facial identification can add to that feeling of isolation and loneliness. Many of my patients say that they stopped going to religious services, or to speakers in the community. Because they’re worried that when they get there, they won’t recognize their friends, and they’re embarrassed by that, and they don’t want to look like they don’t care about who their friends are, and so they just stop going out. So asking that question can then help you come up with interventions for that. Ask about seeing television. We know that people with vision impairment watch more television than their age-matched peers. So you want to ask how they’re doing. Can they see it? Do they want to be able to see it? How are they doing managing mail and bills? Do they have a family member who does that for them? Do they just call the bank and try to pay everything over the phone? What is their strategy? And how do they determine what is junk mail and what they really need to deal with? Do they have a computer? Do they use their computer? Do they have a cell phone? If so, what type of cell phone? One of my phone visits this week, the patient has a smartphone she was given through a medical assistance program. She doesn’t know how to use it, other than answering the phone when her paratransit service comes to pick her up. So I set her up with in-home training, as soon as we are allowed to do person to person training again. So that she can actually learn to use her smartphone. Because it’s something that could open up some doors for her in terms of access to information. And if you don’t want to have to remember: What are all the major questions I should be asking? You can think about things in terms of the major functional domains. So the broad categories of types of tasks people will be doing with their vision. So reading, which includes mail and bills. It can include computer and cell phone. Driving, if that’s an issue in your population. I ask everybody if they drive, even if I think that their vision is so impaired there’s no way. Better to get the information out there. Mobility, so in addition to asking how people feel that they’re doing with their mobility, I also like to ask them if they have had any falls in the last year, or two years. And get them to describe the circumstances of the falls. Activities of daily living. Which includes the medication management, and writing, cooking, bathing, dressing, shaving. Those kinds of things are all activities of daily living. And then just general visual information. So glare sensitivity, facial identification, seeing television. Any of the kind of general seeing tasks. Once you have a good history, you want to start to measure acuity. You want to think about the acuity chart that you have in your clinic. Obviously you can make it work with whatever acuity chart you have. But there are some charts that are better than others. So when I’m thinking about going to a new clinic site, I want to know: Can I use the chart at multiple distances, without making the patient stand up and walk closer? Is it something that I can bring to the patient? If they have mobility impairment, I don’t necessarily want to have them get up with their walker to be able to see the chart. How many letters are there on each line on the chart? You can see on the picture on the left I’ve got the Feinbloom or Designs for Vision chart. And on the largest numbers, we only have one per page. Eventually, we get to three, and then we get to six on a line, with multiple lines per page. But the disadvantage, though, is with vision impairment. If they have a scotoma, they have to work a lot harder to find that one number. Something like an ETDRS chart, which is here on the right, has five letters per line, no matter what the level of acuity. And you also want to think about the lowest level of acuity you can measure. So a benefit of the Designs for Vision chart is that you can bring it right up to the patient, to a foot in front of them. So you can measure one over — I believe that biggest number is 800. So you can get a really, really reduced level of acuity measurement, which is better than assuming hand motion, or trying to get a patient to count fingers. And we always tell our students, if they can count fingers, they can see a letter on an acuity chart at some distance. Your fingers are a much harder target to see, actually, than the large 7 on the Designs for Vision chart. So think about what you can do with your chart, and how to leverage those tools to get the best measure of acuity, really so you can educate the patient better about how they see. I really encourage people to integrate contrast sensitivity into what they’re doing in their clinic. You can see I’ve got a picture of the MARS chart here. The MARS charts are not inexpensive. But they’re really portable and really handy to bring with you. And I have the information here about kind of the levels of contrast sensitivity. So what normal is for age 60, and normal for young adults, and then what those levels are. I find MARS is a pretty quick and easy test to do. As long as you have access to it. If you don’t have access, or MARS is only available in English letters right now, so you’re worried about that in your population, there are some other things you can do. So what are questions that you think you could ask, or what are complaints people might come in with, who have contrast sensitivity loss? All right, good. So most people said all of the above. That was what I was hoping. So this is something you can do when you don’t have a contrast chart. You can ask those directed questions, and you can find out: If the acuity is relatively good, but the patient seems pretty unhappy, and these are the issues they’re having trouble with, now you know it might be more of a contrast sensitivity issue than an acuity issue. So that difficulty with facial details is a really big factor with contrast loss. Difficulty with stairs and steps, particularly going down the stairs, tripping on uneven ground, uneven sidewalks, tripping in holes on the grass or on dirt, a lot of my patients with contrast loss describe just an overall haze or fogginess in the vision. They have a hard time kind of saying much more than that. And I actually had a patient bring in a photo for me, of a car with headlights on, driving on a really foggy road, and he said: This is what my vision looks like. How do I fix it? And one other thing we’re seeing a lot with contrast loss is that people have difficulty reading digital displays. So if they have a digital oven or stove or thermostat, that is becoming more difficult than you would expect, based on the size of the print on those displays. So once you’ve figured out what the acuity is, and what the contrast is, I encourage everybody to do a refraction at the next step. If you’ve already refracted the patient yourself, with a trial frame, perhaps you don’t need to do that at every visit. I try to refract my patients at least once a year. And some patients I refract at every visit. If they have conditions that I think need that refraction more frequently. This is probably preaching to the choir. But in my practice, I really like to use retinoscopy as a starting point. I can’t always get a good starting point with an autorefraction or with another measure. Patients have small pupils, or they have trouble positioning at the autorefractor. So I’ll pull out my retinoscope and do retinoscopy over the glasses they’re wearing. This gives me a sense of: How close am I to neutral, or how far off is their prescription? You also want to think about the pathology. So has the patient recently had cataract surgery? This is obviously gonna change the prescription significantly. I have many patients who have had cataract surgery, and for whatever reason, they still think their old glasses are gonna work, and they bring me a whole bag of old glasses, which are clearly not even close to their postcataract surgery prescription. After trabeculectomies, patients have increasing astigmatism. If your patients have corneal irregularity, scleral buckles, or have myopic degeneration, these are patients you really need to refract regularly and very, very carefully. Your macular degeneration patients who are pseudophakic — like I said, if you’ve refracted them once in a year, that’s probably sufficient. If you’ve done a good trial frame refraction. And there can be other reasons to change the prescription, beyond an actual Rx change. So many times, patients with stable visual impairment, or with retinal disease, where the refraction isn’t changing, they’ve got glasses that are falling apart. They’ve had that same pair for five, six, seven years. Because every time they go, people tell them: Your prescription hasn’t changed. So give them a copy, take the time to refract, and allow the patient the opportunity to get a better fitting pair or a better manufactured pair for what they need. I also like to talk to patients about their fall risk, and perhaps if they’ve been in bifocals, they should switch out of bifocals, or maybe for some reason they decided a progressive was a good thing to try, but now they’re feeling less confident walking in their progressive. So you can talk to them about what feels comfortable. Are they dizzy? Are they having trouble? And those can be other reasons to change the prescription. You want to use the principle of a just-noticeable difference, when you’re refracting people with vision loss. So the reason the trial frame is helpful is for a couple of different reasons. First is that the patient can eccentrically view a bit better. They can look around. They can move their eye to be able to find the clearest point. It also lets you do larger lens changes. So if you’re gonna try to change by a diopter in each direction in the phoropter, it’s just a little bit more cumbersome. Whereas if you can pick up a trial lens, it’s much, much easier. You also want bigger differences between lenses when the acuity is more impaired. I love my handheld JCCs. I use a plus/minus a quarter, plus/minus a half, and plus/minus 1 in my clinic frequently, and I get pretty large shifts in astigmatism correction, and can really help the patient refine their axis more comfortably than if I’m only doing the plus/minus a quarter changes in the phoropter. So this may or may not be something people can answer easily, but we will see. But what bracketing lenses do you think you would start with, when you’re refracting a patient who is 20/100, or 6/30? So kind of split between plus/minus a half and plus/minus one. We typically go with plus/minus a half. We’ll walk through that in a second. There’s no major issue with going to a bigger bracket. But the 20/100 would be a JND of 1, which is why a lot of people choose plus/minus 1. So the full difference is 1. So your bracketing would be plus 0.5 and minus 0.5 to give a total of 1. Just like if you had a 20/200 patient, the JND would be 2, so the bracketing lenses would be +1 and -1. If you’re unsure, I always say to err on the side of the larger lens change, because you can always back off and do smaller lens changes as you work through the refraction. If you have a patient who really isn’t giving you good information, jump to larger lens changes and see if that helps. There’s been some studies looking at: What are the differences in who can understand and appreciate which just-noticeable difference? There’s a lot of individual variability, in terms of how much difference people can perceive. So don’t be afraid to jump to those higher lens changes. So now we’ve done our history. We’ve measured acuity. We’ve gotten our contrast. We’ve refracted our patient. And we really get to the meat of what we’re doing in the low vision exam. We get to that reading assessment. So letter acuity at near can be done. In my opinion, it has pretty limited use, unless your patient is only interested in spot reading a number or a letter here and there. If they’re not literate and they don’t have a goal of any kind of fluent reading. Otherwise, I think it’s more important to use some kind of continuous text card. There are many continuous text cards available in a variety of languages. And if you don’t have access to that, you can actually keep a supply of real world reading items in your office. So I like keeping a newspaper, because it has multiple print sizes on it. So I can get a sense — you know, I have the picture of The Globe here. Can the patient read only the title? Can they read the headlines? Can they read the sub-headline, and can they read the copy? Is it a formal continuous text reading card? No. But does it give you a sense of where the patient is, in terms of fluent reading? Perhaps. We keep some paperback books around. We keep large print hard cover books. We keep medicine bottles. So we have a lot of different things available to really assess what that real world reading goal might be for the patient. And this is one of the things that was in the decision tree. But there are a number of methods to determine your starting power or equivalent power needed to read 1M. 1M is often considered the goal size print. That’s standard copy in the newspaper. You may have patients with a goal smaller than that, and you may have patients with a goal larger than that. So you can take an inverse of the distance acuity, Kestenbaum’s formula, you can use inverse of near acuity, acuity reserve, or what we use at NECO, the last good reading. So inverted distance acuity. You take the reciprocal of the best corrected Snellen acuity at distance. That gives you your initial diopters. Not x, but diopters. Required to read 1M. What I find with inverted distance acuity is that that is nowhere near the end power you’re going to prescribe for the patient. So I don’t like to use that method, because I find it takes me a lot more time to get to the endpoint. Distance and near acuity are not all that well correlated, when you start to add in things like scotomas and metamorphopsia and contrast loss. But here’s an example, in case that’s the only thing you have access to, is a distance chart. It gets you somewhere to start. So if your best corrected acuity is 20/100 or 6/30, then you can divide your 100 over 20 or your 30 over 6, and you get 5 diopters. So that would be your initial equivalent power required to read 1M print. I don’t find that that holds true. But it gets you somewhere to start which is higher than your standard add power. An inverted near acuity is obviously a little bit better. If you have access to any kind of near chart. Because now you’re at least at the same distance where the patient is going to do the task. So you ask the patient to read the smallest line possible. You want to use an appropriate add power. And the equivalent power is the letter size over the viewing distance, and that gives you your add required. So if our patient read 2.5M, which is this HVORK, you can see the 2.5M there, at 40 centimeters, that’s 0.4/2.5M. You flip it. Now you’ve got an equivalent power of 6.25 diopters to start with. So that’s your tentative add. And that’s probably a better starting point than from a distance acuity. The acuity reserve method was developed by a number of different researchers in low vision. And they say it’s — excuse me. The acuity reserve is the relationship between the reading conditions for a task and the patient’s threshold. The thought is that you need at least two times the acuity reserve for peak reading efficiency. So you would need 2X Kestenbaum’s rule to achieve an appropriate acuity reserve. So you would want to aim for something like 0.5M print, rather than 1M print, if your goal is to get to fluency at 1M. And this makes sense. Nobody wants to read at their threshold. I can read pretty small print. I’m a myope. I don’t have my Kindle set to the smallest print available. I have it set to bigger than that, because it’s much more comfortable for me to read a little bit above my threshold. So the same principle applies to your low vision patients. You want to go past their goal print, to make sure that they can read for extended periods of time. So as I mentioned, there are some limitations to the previous methods. We know that letter acuity doesn’t correlate to word or reading acuity. Continuous reading ability can be affected by scotomas and contrast and other factors. And so we need to really consider those things as we go forward with what we’re prescribing for the patient. So I love the MNREAD card. Like I said, there’s many different ways to do continuous text. The MNREAD is currently available in English, Spanish, French, Italian, and Portuguese. There are other continuous text cards available in Arabic, in Hebrew, in other languages. The MNREAD card goes from 8M on the front all the way to 0.13M on the back. Your super high myopes will love to show off that they can get to very small print. It’s selected for third grade reading material, so it’s not appropriate for all patients. It is available through iTunes, if you’re using an iPad on your clinic, to try to have fewer charts and to be more portable. And we use what we call the last good reading, or critical print size. So it’s the smallest print at which the patient can read at their maximum reading speed. So the principle is that you would have the patient start all the way at the top here. My father takes me to school every day in his big green car, and would read all the way down to where it fades out. So maybe they would say kind of three of my friends, I’ve never been to the circus before today, and the print gets kind of small here. My grandfather has a large garden with fruits and vegetables. So you can notice that change in pace. Your critical print size, your last good reading, would be here. So the step-by-step — this was developed by Flom, and Ross helped modify it. It’s been a very useful tool for our students. So first you want to know what spectacle correction the patient is wearing, allow the patient to hold the card at its best focus point, ask the patient to start reading from the lowest print, note the maximum reading speed generally. Are they slow at all print sizes, fast at all print sizes, and note the critical print size. You can time them on every line. You can listen to them. You can note when they slow down. One of my tricks, if I’m really short on time, is just to say to the patient: If I could give you every printed material, in a particular size, what size do you like best? And they can point to a line. I have never had a patient point to the biggest line by default. They typically are able to point out and say: This is what’s most comfortable. I could read things comfortably if it looked like this. And then you note that threshold. So you note your best fluent reading. And then you make a note of how far they can go for spot reading. So usually it’s a line or two past where their fluency slows down. So an example is that a patient is wearing a +3 add over their refraction. They hold the card at 30 centimeters, which is where we would want them to. Their last good reading, they slowed down at 2M print, but they could push themselves to get to 1.6, so they could get to one line further. So their equivalent power, their starting power, is that 2M last good reading, divided by the distance, which is 0.3M, and that gets us a 6 diopter starting power. And then we figure out what device we use, and we figure out if we need to go up from there in the power. So this gets you a pretty good starting point, and it helps shift away from trial and error. So you don’t just grab devices off a shelf. You have a starting point that should be pretty close to where you end up. Usually I’ll maybe go up one power from where I started. So how do you pick the right device? So you really need those specific goals from your patient that goes back to why the history is so important. Is the patient trying to do things at near? At intermediate? At distance? Do they need to be monocular or binocular, based on how their vision functions? Do they need to be hands-free, or can they hold a device in their hand? How important is lighting? Is their contrast really reduced, so they need that good lighting? Or are they doing pretty well with contrast and a non-illuminated device would be okay? And do you need to add contrast enhancements to the device that you prescribe? So remember the decision tree. I’m not gonna walk through it again. But it goes through kind of all the different options at these different powers. And what you would do for those patients, depending on whether their goals are spotting or fluency. And now we’ll go through some mini-cases, to try to kind of emphasize what I’ve already been saying. So in this case, this was a 66-year-old I saw. He’s a musician. He has macular degeneration in both eyes. It is wet in the right. It’s dry in the left. And his complaint was that he’s having a hard time seeing fine detail on sheet music. He’s tried enlarging it, but he finds that that’s not sufficient. It ends up being the big pages on the piano — it becomes too complicated and he’s still just not comfortable. His acuities were 2 over 12.5 or 21/25 in the right eye, and 2/5 or 20/50 in the left, and he has a scotoma just to the right of fixation in both eyes. Because he had an intermediate goal and he needed his hands to be free, I went to a spectacle mounted telescope. It’s a fixed focus telescope, and it has a reading cap for his working distance. Based on a 20/50 acuity, I didn’t think I would need a lot of magnification, but his sheet music is very, very small. So we’re talking about probably 20/20 to 20/25 near needs. And so we looked at a 1.7x and a 2.2x telescope. And he really liked the 2.2. He was able to visualize the finger positions for his music, and also see the piano music with that higher power. The +2 reading cap gave him an appropriate working distance and good clear focus. He was pretty happy with his general reading. He could enlarge. He was using an iPad, and the rest of his tasks were working well, so we were able to solve that specific intermediate goal pretty quickly based on these principles we’ve already talked about. This is the patient, 59-year-old, with proliferative retinopathy in each eye. He’s monocular. 20/200 in the right eye, no light perception in the left. With MNREAD, with +3 add, he read 0.3/0.3.2M. So it’s 10.67. But the patient was already using a 16 diopter hand magnifier. So his predicted FEQ was 10 to 11 diopters, but he’s not doing well even with a 16 diopter. So we did a bit more of an extended near assessment with this patient, and to get him to his spot reading goal, we had to go up to a 20 diopter hand magnifier. I do find in diabetes I have to go slightly higher power than the formulas would predict. There are lots of patchy areas of ischemia, and you don’t want to use a hard and fast rule from the formulas. You want to use those as your starting point. In this case, I did calculate the Feq, but I used the starting point of what the patient was already using that wasn’t working. I didn’t go back in power. Although sometimes patients overpower themselves. But I had prescribed the 16 and felt pretty good with that. Here is an 82-year-old with dry macular degeneration. She has a hand magnifier and fatigues using it. She doesn’t like having to hold a device all the time. She’s 20/125 and 20/400, and her MNREAD, her critical print, last good reading, she got to 1.6M. So that is 1.6/0.3 gives us 5.33 diopters. So she doesn’t need a lot of power. To get to where she needs to go. So we started with the lowest power stand magnifier that we had. 8 diopters is where those typically start. And this allowed her to get good fluency, reduced the fatigue of having to hold a hand magnifier, and she loved the field of view. This is part of the stand magnifier. It has an illumination source that connects in, that you need to use with it. So those are just some of the examples of the more basic tools you can integrate. It would be a whole other lecture to talk about technology, but you can really get into video magnification, the accessibility on smartphones and tablets is making huge, huge changes for our patients, you can add on apps that can magnify, convert text-to-speech, connect to visual interpreters, and even assist with activities of daily living, like currency readers. Patients use Kindles and other e-readers to enlarge and access books for pleasure reading. And a lot of people are starting to inquire about head-mounted displays. I use head-mounted displays somewhat often in my clinic, but for more specific goals. I try to start with the basic tools. The hand magnifier optical solutions if I can. And I try to jump to head-mounted displays for patients who can’t meet their goals with more standard optical devices. In the last couple of minutes, don’t forget about your activities of daily living and your non-optical aids. Not everything has to be an expensive device or even a high-tech pair of glasses. Patients can get large print watches, talking watches, banks can provide large print checks. You can see it’s much, much easier to see the one on the bottom here. Large button phones, signature templates, needle threaders. These can all make a big difference for activities of daily living. Talking to the patients about modifying their lighting, the pattern, the contrast, putting a white plate on a black placemat. If they’re eating darker food or vice versa. High contrast cutting boards. Long arm oven mitts for the kitchen. These are all really important recommendations you can make. Or recommendations that your vision rehabilitation specialist can make, if you refer out for those services. Encouraging patients to explore sensory substitution, thinking about tactile and Braille labeling, computer modifications, and cell phone accessibility. These really get into — some are more advanced features, and some are kind of basic. Things that you can do for people with vision impairment. Don’t forget about patient safety. We talked a bit about asking about medication management. Does the patient have an emergency plan? What is their fall risk? Do you need to have a mobility specialist or physical therapist involved in the care of the patient as well? So these are kind of my go-to starting devices, which is a range of hand and stand magnifiers. Some prism half eyes. Some telescopes and some filters. And I like to have at least one portable video magnifier in whatever clinic I’m working in. Use your community volunteers. Use the outreach services that are available. And really help your patients and your referring doctors to understand what you can do for patients with vision impairment. So in the last couple minutes, your take homes are: Remember what the Academy of Ophthalmology here says. Provide or refer for low vision services. If the patient has reduced best corrected vision of 20/40 or worse, central scotomas, reduced contrast or visual field loss, and most importantly, functional difficulties that they complain about. Access to low vision care is a challenge. There’s increasing incidence and prevalence. But just doing some of these basics that we talked about can really improve how your patients are seeing, and can help you get them connected to services before they need that most advanced low vision care. So think about the quality of life and independence, and try to integrate that as best as you can. And thank you to some of my colleagues for their support. And we’ll go to questions. Because it looks like a number have come through in the chat. All right. So I’m gonna start with — it looks like — okay. Some of them have been answered. One of them was answered. The first question is: How do we define low vision in pediatric age group? And is that setup dependent or not? So I think that you’re gonna define it the same way you do for older adults in a pediatric age group. You’re still going to look at that level of acuity, as well as that function. And then you can go from there. I think there’s also a question about what a low vision clinic should have at a minimum, so I answered that kind of towards the end of some range of devices in different areas. So that is, I think, for pediatrics, it’s different rehab strategies, but same levels of acuity you would use. There is a question about orthoptists’ roles in low vision. So in the US, they’re permitted to practice, but they’re typically working on binocular vision issues, and not low vision. So that is something that — there is a different role for orthoptists here. In some practices, they may train them to do some of the low vision rehabilitation, but for the most part, they’re dealing more with vision therapy diplopia management, and not so much for low vision in most practices here. And so questions about prevalence of ARMD. And why is it still increasing, even with better diet and those kinds of things. I think that diet is only one component of what’s going on with macular degeneration. So we can’t overcome the genetic components and people’s history of smoking, and those types of things. So diet does seem to play some role. But I think the other factors are just really more critical to the development of the condition. At what age do you stop helping low vision patients? Is it worth it to help bedridden low vision patients? I do not have an age cutoff. My current oldest patient is 107. We prescribed a portable video magnifier for her. She has significant reading goals, and was really thrilled to be able to use that device. I have made prescriptions for people who are bedridden. I think quality of life is still really important in those situations. So perhaps using telescopes to see a television more easily, educating the team caring for that patient, to make sure they announce their name when they walk into the room, to make sure that patient has good glare control. We still want to have some role in improving quality of life in that situation. So I don’t personally have a cutoff. Anyone who is having a functional complaint, I will try to help. So what are exercises according to diagnosis at home, that patients can do? So this is a bit trickier. So a bit of what we’re doing with the telemedicine is getting an assessment of the vision impairment. And then we’re still working with ways to prescribe new devices when the patient is home. Rather than bringing them into the clinic, but a lot of what we’re doing is kind of education about resources, discussion around lighting, education about the devices they currently have, rather than doing new prescribing, because the patients just don’t have access to that. So that’s one we’re still working on. And then what are different types of magnification for near aids and distance aids? So I think that got answered through the lecture. Vocational rehabilitation. So that is a specific service that is looking at helping people either maintain the job that they have, or become trained to do a new job. So it’s assessing their skills and looking at how their vision will function in those different areas. So a vocational rehabilitation specialist will often go to a job site to help figure out what the patient needs. So I have a patient who works in a food processing plant, and kind of needed to only work at one particular station, and needed the computer set at a certain distance. So the vocational rehabilitation specialist went in and helped the team with the measurements that were needed there. We have good protection here in the US with the Americans with Disabilities Act. And so we’re able to make those recommendations to workplaces for our patients. There was a question about getting a copy of the low vision decision tree in the mail. I will check with Dr. Jamara and make sure he is comfortable. And then I can coordinate with Orbis about getting it sent out to people who registered. Presenting VA and best corrected vision is creating confusion in defining visual impairment and estimating prevalence. We need to kind of fix the definition. I think that’s a really, really good point. A lot of the epidemiological studies either don’t specify whether or not it’s best corrected vision, or perhaps it’s not a good refraction that was performed. I think there are a lot of people working with the World Health Organization in other areas to figure out: How do we get more consistency there? So I think the best thing that we can do is: As each of us are seeing our patients, and as we’re publishing data, that we really try to report that difference between presenting VA and best corrected visual acuity, and emphasize that there is a really big difference between what could go on there. But that is a work in progress. Do we have a structured course for the primary eyecare/vision centers to screen low vision patients and low vision aids? So we don’t have a structured course to start screening. There are a couple of groups working on having a flag in an electronic medical record system. That if a patient has a certain diagnosis or a certain level of acuity, that it will prompt the treating physician to make a referral. But unfortunately there isn’t any kind of standard screening right now. It’s more education to talk about the potential for those referrals. A question about the main barriers for people to visit optometry or ophthalmology for low vision. That is a very loaded question. I don’t think we necessarily know what the patients define as their main barrier. We know that transportation is sometimes an issue. We know sometimes it’s a denial about the vision impairment. We know that sometimes it’s a fear of cost. There’s a lot of different things which seem to be playing a role, and we’re still trying to really flesh out what is that main barrier from the patient’s perspective. And I’ll answer a few more questions, and then I probably will try to answer some just by typing the answers later, and we’ll send those out to you. Because there’s lots more coming in. How do you do screening for senior communities, in order to provide low vision services earlier? Do you treat them as early as possible, or do you wait to allow medical treatment first? So I encourage ophthalmologists to refer patients early. I do encourage — even if they’re getting their very first anti-VEGF injection, I still think it’s worth it to get the patient in for low vision. For a couple of reasons. One is that I have a really long wait to get in to see me. So they might as well make the referral. And then I can make the assessment as to whether or not the patient needs to start using devices, or if they can wait until they’ve had 3 or 4 or 5 injections, to see where things go. But we do know that even with anti-VEGF injections, when the acuity is maintained, patients still lose contrast sensitivity. And so they will likely still need lighting, they will likely need that trial frame refraction. And so I think it’s worth it to at least educate the patient and allow them to make that choice, as to whether or not they should go to that visit. What kinds of devices can be prescribed through telehealth? And how can you assess best corrected vision? So we have actually been doing a couple of different things. We’ve been mailing patients charts ahead of time. With specific distances measured out for them with a piece of string. They have a short string and a long string for 1 meter and 2 meters. And we actually ask the patient to hang that up on the wall in their home. You know, is it as good as testing them in the clinic? No. It’s not backlit. It’s not perfect. But we’ve been mailing out — my colleague, Nicole Ross, made a logarithmic acuity chart, and we send it out, and we actually can get a vision. We can’t get a best corrected vision. We’re still sort of sorting through how we could eventually do a refraction remotely. But we can get a starting point for patients and for our follow-up patients, we can know if their vision is stable or if it has changed. We’re also experimenting with some kind of kit that we can send to the patient. We’re trying to figure out if patients are going to be willing to pay for shipping of — here’s the three magnifiers that seem like they will be appropriate, based on that reading assessment I did over telehealth. They’ll get the magnifiers. We’ll do another video visit. We’ll assess. And then they’ll put the two that don’t work back in the package and send them back to us. That is — hopefully we’re gonna start doing that later this summer. But we’re open to ideas, and I think there should be some dialogue about how we can really do this for people who can’t come into the clinic. There is a question for what tests to carry out when evaluating a patient to reduce chair time due to COVID. So I think that — I did mention that a little bit. But getting the history ahead of time, if possible. Shortening your reading assessment perhaps to just asking the patient: What is your most comfortable reading line? Rather than having them read the entire chart. You know, maybe doing some more binocular assessments of things like contrast, rather than each eye, if you don’t feel you really need each eye done separately. Doing a lot of the education over the phone or over video from a separate room, to reduce that chair time as well. These are all strategies we’re looking at. When do you decide to treat for ARMD or RP? Can we do it in the first visit? I think with macular degeneration, if the patient is not receiving anti-VEGF, you can definitely start making recommendations and prescribing devices in the first visit. If they are receiving anti-VEGF, you typically want to wait at least 3 to 4 injections or 3 to 4 months after the first injection, if they only get one. To see where things stabilize. So you want to be a little bit more cautious in treatment at that point. RP definitely you can start early. If they’re being treated for macular edema, you just want to keep that in mind. As you’re looking at prescribing. What is the difference between low vision and functional low vision? And how do we define it globally? So I think that we have to just explain to the patient about that functional impairment, and help them understand why, although perhaps the World Health Organization’s definition says they have mild low vision, their function is more on the level of a severe impairment, I think that to define it globally, we really need to start seeing contrast sensitivity and scotomas and integrate it into the definition. I think we really need to have a shift away from just looking at acuity. There is a question about pediatric cases. That’s a whole separate lecture. Which I would be happy to do or have one of my colleagues do it another time. I think it’s a similar approach in some ways. Different approach in some ways. So I’m gonna hold off on getting into that. If you don’t have a MARS chart or a Pelli Robson chart, what kind of contrast chart would I recommend? So there are some charts available on an iPad. You can also just ask those questions I mentioned to try to get a sense. Precision Vision has produced a chart that has — I believe they call it the CamBlobs or the Spot Test. It’s just a sheet of paper, and the patient can point to where the circles start to fade. So that’s a really easy one to use. And you can integrate that if you’re not able to have a MARS or a Pelli Robson. Because I know MARS and Pelli Robson can be cost prohibitive for people. There’s a question about the Skerik Gray Scale Test. I would need to look at the data validating that, compared to the MARS. I don’t know that one off the top of my head. So I think that if we can defer that question, I will answer it by email or by message board. Is establishing the diagnosis not an essential part in a low vision clinic? Besides for the purpose of data, do you really need to know the diagnosis as much as the functional loss? I think it depends on where you’re practicing. So for me, most of my patients come in with a diagnosis. So I don’t have to spend the time to figure out what’s causing the vision loss. I can really focus on the function. But I think if you are somewhere where the patient does not already have a diagnosis, you do need to understand, because if it is something treatable, you obviously want to start that treatment before you get just into the functional low vision. So it really depends on where you’re practicing, and what setting you’re in. What is JCC? So JCC is the Jackson Cross Cylinder that’s used to determine the astigmatism correction. In which particular pathologies or conditions should we repeat trial frame refraction? What’s the recommended interval? So this is gonna be kind of patient-dependent, and dependent on your own comfort level. So for the more stable conditions, especially in people who have had cataract surgery, once a year is sufficient for me, with my comfort level of my initial refraction. For people with myopic degeneration, I refract at least twice a year. Sometimes more. I also kind of gauge by how much I’m seeing change. So if I’ve refracted, and then I see them again for three months, and I refract again and I find a change, and then I will refract again in another three months. So I really try to look at what’s happening with the patient. I think in our keratoconics, in our patients who have had trabeculectomy, you may want to refract a little bit more, until you get comfortable kind of knowing that there isn’t a change, or that you can wait another six months to do it. So there’s a question about near contrast sensitivity. So you can actually use distance or near contrast. So the Pelli Robson is more at a moderate distance. It’s kind of intermediate. And the MARS is at near. They correlate really well, so you don’t need to measure contrast multiple times. Should I test with white on black background and a reading chart or phone background? If a patient reports that it is better? Yeah, I think it’s worth it to look at that difference with the patient. I do find that with reduced contrast, patients prefer a black background with white letters. I try to do the acuity on the standard chart, white background, black letters, just so I can compare to known measures. But if they’re more comfortable reading, then this is where the digital devices and incorporating things like an iPad or an Android Tablet could be really helpful, so you can give them that contrast enhancement with the reverse polarity. JCC is done with a subjective response. So how can a low vision patient do this? And what distance? So you want to use the distance you’re using for your acuity chart. Typically, I’m doing things mostly at 2 meters. But sometimes I will bring the chart to 1 meter. I want to make sure the patient actually can see enough letters to make a decision. And that’s where you want to use that just noticeable difference principle, so a bigger JCC bracketing choice than what you normally would do. So maybe it’s that plus/minus 0.5 or plus/minus 1. And you’ll find that low vision patients typically can respond and let you know which is clearer for them. Scotomas and hemianopia for reading. This is one that I think we should defer to another talk as well. There’s a lot that can be done with eccentric viewing and hemianopic training. So I think that’s one I’m not gonna get into here. If we prescribe binocular telescopes to a child going to school, how can the child manage their near work, like writing in a textbook, along with the distance viewing? So I really like to use a bioptic design for that. That way, the student can go in and out of the telescope pretty easily. It keeps their hands free and lets them have their reading ability. So I try not to use a full field telescope for school aged children, if they’re gonna be using it in the classroom, to also be able to do their handwriting. And someone else answered that as well. They sometimes will give either a full field telescope for one eye, and they can use the other eye for near. That’s also a good potential solution. Do you manage low vision patients with nystagmus? Yeah, I manage them just like I do all of my other patients. So I go by acuity and contrast and reading ability. I don’t actually find that nystagmus patients have particularly more difficulty than others. And often they do a bit better, because it’s typically congenital, so they’re well adapted to their nystagmus, and we can use the exact same principles we use throughout. So someone wants a little bit more clarification on the acuity reserve. So the acuity reserve would be if you take the near acuity, you invert it, and then you double it. So you want to give the patient double their threshold reading ability when you’re prescribing. So whatever your starting power is, from converting to get your starting diopters, you just want to double that before you actually start with the patient. And then there’s the 2/12.5, so that was a 2 meter distance. So you just convert it to a 20 acuity, multiplying by 10, or convert it to 6 by multiplying by 3. 20/125 and 20/50 were those acuities. Most low vision rehabilitation services are magnification dependent. Can we talk about enhancing mobility? This is one where I rely a lot on orientation and mobility specialists. So I refer, so they can talk about using their mobility skills to accomplish the tasks they want to accomplish. I also use filters for glare control, telescopes for field enhancement, minification devices, prisms, things like that. But again, I consider that a bit more advanced, so we can talk about that — we’ve got lots of ideas for future lectures. Do I have a PDF or reading material or book we can recommend? So there is a book that has been written by the faculty at the American Schools and Colleges of Optometry. It is available for download. I believe it’s $9.99. It’s only electronic. But it’s an excellent resource that goes through all of these principles, and kind of walks you through all the parts of low vision. So I believe if you just go into the iTunes Store, you can find it. I will double check if it’s now available not on Apple devices. They were working on that. And I can share that link. That’s something we can send out for you as well. Lots of questions about getting the decision tree. My email was on the very first slide, and I believe the slides will be posted on the Orbis website. So you should be able to access my email that way. Or Lawrence can send it out to everyone who registered. Online courses. There are a number in development. I think through these different webinars, you’ll be able to attend more online courses. We’ve talked a bit about the nystagmus. The inherited conditions. We can — you really want to go by the same principles. You really want to go by the history, the function, and what the visual measures are. You don’t necessarily need to manage them differently. So having a cone dystrophy — they may have different complaints than someone with macular degeneration. But you’re gonna ask the same questions. So you’re still gonna use the same principles and just go from there. That was kind of what I try to use, especially with my students, that the diagnosis only sort of matters. Because you just really want to know how they’re functioning with that particular diagnosis. Devices for one eye with large scotomas — again, you’re really gonna go back to that principle of: What are they trying to do? Are they trying to spot read? Are they trying to see television? Are they trying to see the computer? You’re gonna go by what the goal is, when you’re trying to figure out which device is most appropriate. We’ve talked a bit about vision therapy and orthoptists already. Keratoconus. If you’re not using contact lenses, it becomes a bit trickier. Because there’s so much distortion. So depending on the severity of the keratoconus, I will look at using speech output, because the distortion can be so significant that magnification isn’t very helpful. If you’re magnifying through distorted media, it’s not very functional for the patient. So you want to really look at glare control. And then: Can they benefit from magnification? Or do you really need to shift to sensory substitution? Depending on the amount of distortion. If they can’t wear contact lenses. And then I have a question in Spanish. And my Spanish is… Good enough to maybe answer that? So it is asking a little bit about the definition of low vision. In the European Council. I don’t know the specific European Council’s definition. Here in the US, that visual function category was added. But I don’t believe that it has been added in other places. We do include a visual field definition here. And I think that that is included in the European definition as well. But typically what I have found is that the field level is 20 degrees in diameter. Which — we see that patients have a lot more trouble earlier than a 20-degree field. So I think there’s a lot of work to still be done on defining visual field and how that impacts function. So I think I’m going to stop there. I got through almost half the questions. But we can perhaps do a follow-up webinar, and I will talk to Orbis about how to address the other questions that weren’t answered yet. I don’t know if I type the answers, if that will show up for you, or if we need to email those out, but I will coordinate that. And thank you again for your time. And I will wrap up here.

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May 18, 2020

Last Updated: October 31, 2022

6 thoughts on “Lecture: Incorporating Low Vision Into Your Practice”

  1. 1) nice talk, definitely a much required one, also wanted to intergrate – VIRTUAL REALITY tools for the low vision aid both for mobility and also for their reading . currently working on .
    2) Affiliating to organisations who can help in job opportunities, or teaching jobs for the low vision which can built their moral confidence

    • Hola Liliana. Puedes cambiar el idioma en la parte inferior de cada página en Cybersight al español, que traducirá la transcripción. Envíenos un correo electrónico a [email protected] con cualquier problema.

  2. Thank you so much. It’s really an informative session for Optoms as well as for all eye Care professionals. Want to hear from you ahead.


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