Lecture: Approach to the Patient With Unexplained Visual Loss

Patients will present with visual symptoms and seemingly “normal” eye exams. This webinar will describe an organized, succinct approach to these difficult patients. A variety of neuro-ophthalmic conditions will be discussed in addition to non-organic visual loss. (Level: Beginner and Intermediate)

Lecturer: Dr. Karl Golnik, Ophthalmologist, Barrow Neuroscience Institute, USA


>> Greetings from wherever you are in the world. It’s good to be with you today. I’m Dr. Karl Golnik. I’m a neuro ophthalmologist. For the last 30 years, in Cincinnati, Ohio. I’ve moved to Phoenix. I now live in the desert southwest of the United States. We’re going to talk this morning about approach to the patient with unexplained vision loss. Every neuro ophthalmologist and every ophthalmologist sees in their practice. I see it more or less on a daily basis. I see a lot of patients who are sent in with gee, their eyes look normal, why can’t they see? That is the basis of this talk. I have no financial disclosures recording this topic. My objective is when we’re done, you’ll be able to outline a simple approach to the patient with unexplained vision loss. By that, I mean unexplained where you look at the eyes and things look fairly normal and you can’t find out a cause. So this is the outline basically, this is what I tell patients. As recently as this past Friday, I told a patient with unexplained vision loss, the first thing we have to do when you’re approaching a patient who has what looks like a normal exam is figure out where is the problem? Is it the front of the eye? Refractive. In the eyes or retina or behind the eyes, the optic nerve and visual pathways. And of course, it may be none of these. Some patients who have unexplained vision loss don’t really have vision loss, they have non-organic vision loss and we’ll talk about that in turn. I’m going to start with a case called the case of drinking dentist. A 60 year-old gentleman who complains of gradual bilateral vision loss. He lives a far distance from where I am. He was attending his daughter’s medical school graduation. As long as I’m in town, why don’t I get another opinion about my vision problem. He has high blood pressure that is controlled. He admits to drinking one vodka martini a day and diagnosed with tobacco alcohol amblyopia. It’s not related to tobacco and alcohol but related to not eating the right foods. A nutritional problem. He had been told by his ophthalmologist in town to stop drinking. He was upset because he has friends that drink more than one vodka martini in a day and their vision was fine. He was skeptical that his vision problem, which again, would be usually lack of the right nutrition because patients who drink a lot, sometimes don’t eat the right foods. So he was told to stop drinking. Here is his exam. He was 20/60, 618. J2 at near. Saw 10 of the 10 color plates. I will show those in a bit. The pupils were moderately active. No defects. The visual fields were normal by confrontation. The fundus was normal. The question is, is this compatible, just this little bit of information, is this compatible with a bilateral optic neuropathy where you’ve lost central vision? So, we’ll talk a bit about refractive and media. When I became a neuro ophthalmologist in the United States, we can specialize. And my parents wanted to know which eye I would specialize in. I didn’t think I would see many problems with this. Irregular astigmatism and oil-droplet cataracts. This is like if you had a glass of clear water and you took a drop of clear oil and you put it in the glass of water, you can still see the drop of oil. Why? They’re both clear. The refractive index is different. You can see the drop of oil. And sometimes people can have not necessarily a cloudy yellow cataract but a dense central nucleus. So at least once every couple months I get a referral from a cataract surgeon for unexplained vision loss and they have an oil droplet cataract. Occult corneal disease. Things that aren’t that obvious can cause problems with vision. And the evaluation is simple. These are basic things. Something as simple as a pinhole vision test. Even a patient can understand if their vision improves a lot looking through a pinhole, they probably don’t have a brain tumor or multiple sclerosis. Near vision. If there is a difference between near vision, that is probably a refractory or media problem. We can have retinoscopy or corneal topography. Don’t forget the direct opthalmoscope. When I go to the clinic and ask for that, they look at me like I have two heads. You’re so old. We have better techniques than that. I know that. But that’s the point of slip lamp bio microscopy. It cuts through the media opacities. It’s a great way to judge the media of a patient. If you can’t see in well, they can’t see out well. And then rigid contact lens over-refraction can be done. I don’t do that myself. I would send that to someone who does that. And don’t forget color vision which is a neuro ophthalmologist secret weapons. Shouldn’t be a secret. If you have lost central vision from an optic neuropathy, central vision, you’re going to have decreased color vision. And most other conditions, color vision is not affected by refraction, media, even retinal disease unless the acuity is pretty bad. If the person is hand motion vision, of course you don’t see the color plates no matter what the problem is. If they have vision in a fairly normal to 636 or 672, color vision can be pretty normal. The Hardy-Rand-Rittler plates are a bit more sensitive than the Ishihara color plates. Most people have the Ishihara color plates. I use these interchangeably unless I have someone with pretty good central vision. If they’re 20/20, 20/25. So 66 to 612. I’m going to pituitary the Hardy-Rand-Rittler plates. I have people that do well with Ishihara color plates but not with HRR color plates. There is a question that I see here about a role for automated color vision testing. I don’t use that. I’m not sure I can really answer that question well. I think I don’t see why color vision couldn’t be used but I wouldn’t spend a lot of money to do it. What about our case of the drinking dentist. He was 20/60 or 618. 67.5 or 20/25. Saw 10 of 10 of the HRR color plates. Is this compatible with a bilateral optic neuropathy with central vision loss? If you were live, I would ask for some answers. The answer is, as we just discussed the important points about this, is no. There are two things about this. No. 1, he saw all of the color plates. If you’re 618 with an optic nerve problem causing that, you’re not going to see all of the color plates. And there’s a disparity between the distance and the near vision. These two facts immediately make me think, all right, this is not nerve. Let’s look more closely at the things that help to differentiate the media and refractive properties. Further testing. Of course, I looked with the direct opthalmoscope and the view was not that clear. The potential acuity meter, it’s a little device you can mount on the slit lamp and it shines an eye chart through the media onto the retina. It was developed decades ago to try to predict how good visual acuity would be after contact surgery. He showed 20/20. This has got to be a problem with the media because the acuity reading was so good. And when we looked, we saw these oil-droplet contacts. I think they are, I think it’s fine if you have digitalis color plates. Use them. The other thing to say briefly about color vision testing, sometimes the residents say, you know, they have this peripheral visual problem but their color vision is normal. It must not be an optic nerve problem. The color vision thing is only important if they have abnormal central vision. For instance, glaucoma, a common optic neuropathy. You lose your peripheral vision and late on you lose central. Until you lose central, the color vision is fine: You can have a terrible optic neuropathy. The color vision testing is helpful when the acuity level is down. Here is another case, a case that I call the worried traveler. I was on-call on a Sunday night and got a call from a 65-year-old gentleman who complained of blurred vision. It was like when he had the retinal attachment. It was repaired by one of the retinal surgeons in my practice. I said, let’s take a look. We want to make sure you don’t have another retinal detachment. He said I’m in Chicago, that was 500 miles away from where I live. So the, I said come in tomorrow morning. And sure enough he came back the next day and saw one of our, not me, one of the urgent specialists. And the urgent specialist called me late in the afternoon and said I have this patient, who is 20/20. 6, 6 and 1 in the right eye but he is only counting fingers. There is no pupillary defect. He had a retinal detachment and I said I talked to this guy last night. He said the fundus looks normal. Can you look at him? Sure, be happy to. I said you dilated his pupils? Of courser. I won’t look at him today. I’ll do it tomorrow. No relevant pupillary defect and counts fingers. You can’t have an optic neuropathy in one eye and count fingers and have the other eye be normal. And the next day he came in. My resident saw him first. The resident came out of the room and said it’s funny, the patient, you know, his vision is counting fingers but when he tilts his head things get better. I said how good? He said, well, he goes from counting fingers to 20/40 when he tilts his head. That’s odd. I said what else about the exam? Nothing really. I mean everything looks normal. The media looks clear. In fact, really clear. In fact, there’s a note from the doctor from the day before commenting on how nice and clear the media looks. And I said, well, he is tilting his head. Why don’t you look in the slit lamp and see what happens when he tilts his head. Here he is tilting his head. He has a posterior chamber IOL related to the retinal detachment surgeon and the lens was removed. And IOL is rotated out of position. When he tilts his head, it rotates back up and sees through the edge of it and he is 20/40. This is another media problem with a plus 11 lens he saw pretty well. So of course, I called my interior segment urgent care doc and told him about the case. Just don’t tell him who saw the patient. I see questions in the Q&A. What was the previous diagnosis. An oil-droplet cataract. A dense central cataract that was bending light funny. I sent him for cataract surgery and got a note from him a couple months later and he said thanks so much for the cataract surgery. My vision is great and I have one vodka martini a day. The worried traveler had a lens that shifted out of place and they went in and put the lens and secured it in normal position. So, the summary for median refractive. These are the easy ones but they’re often missed. Don’t forget about the simple things we have. Pinhole tests and retinoscopy, color vision. Some of these are simple and help you sort this out. Say you’ve done this and decided that it’s not media refractive. Let owes move onto retina can choroid. The history is important for retina and choroid. In particular, if patients complain of distortion, vertical lines or horizontal lines are crooked or broken up, these are terms used to describe meta morphopsia. Almost always macular. Neuro problems don’t typically cause meta morphopsia. And tiny central scotomas are often retinal. But this kind of history maybes you suspicious there is something going won the retina. There should be no or small APD if it’s occult retinal. If you have a big retinal attachment, it’s going to be APD but it’s not unexplained. You look and yes, there’s the problem. If it’s occult retinal disease, there is usually no APD. Maybe a small one. The Amsler grid is helpful to sort things out. And, of course, we have tons of ancillary studies and fluoresceins and OCTs and ERGs. This can be the topic of three more webinars. Let’s talk about a couple of cases. This is a woman ho had a colonoscopy and woke up from it and she was kind of seeing stars. And then she checked her vision and said her peripheral vision is not good. Had a history of hypertension and treated. And lung cancer five years previously, also treated. And that was it. Her central vision was pretty good. 20/25. The color vision was normal. Pupils were moderately active with no RAPD. And I thought there was a rare anterior vitreal cell. Her visual fields looked like this. Nonspecific but certainly meeting what she was complaining about. That was constriction of the visual fields. She was convinced that colonoscopy caused her to have this visual problem. And on fundoscopy, he looked like this. Big cups and big nerves. These to me look very much like physiologic cups. Of course, if this were glaucoma, there is a lot of nice and healthy pink rim and you would not see that degree of visual field loss in glaucoma. This is not glaucoma. It’s a baseline visual field. She had an MRI because the doctor seeing her couldn’t find a problem. And the MRI was normal. What’s the next step? The next step, I will let you think about that briefly. While you’re thinking about that, could you summarize the difference between the HRR and Ishihara plates. The HRR plates are a little more sensitive. If someone has 6-9 vision, I would choose the HRR color plates because they’re harder. They’re tougher. If their vision is worse than 6-12 or 20/40, I don’t care which ones use. The next step was an ERG. It was flat. The ERG response was terrible and the diagnosis was cancer-associated retinopathy. This is a paraneoplastic process where the body generates an immune response against the cancer, although she thought she was cured. She wasn’t. Against the cancer and sometimes the response will attack the retina with the anti-recoverin antibodies. People have rapid peripheral field loss before central field loss. Positive visual phenomenon. If you hear the story of flashing lights and constricted fields, ring scotomas can be seen early. This went further than that. You may see a little anterior vitreal cell and the ERG is the test. Cancer-associated retinopathy. A good friend of mine, Andy Lee who did a recent Orbis webinar. His first rule of unexplained visual loss, if it’s referred by a retina, it’s always retinal. That is kidding a little bit. So we talked about retina and choroid. We have lots of tests. When OCT came around it eliminated a lot of my referrals to look at the retina. Now I just get the OCT. Optic nerve and visual pathway. What I thought I would be doing as a neuro ophthalmologist is looking at these types of problems. As a neuro ophthalmologist, of course, I have to emphasize the importance of the relative afferent pupillary defect. Under emphasized in neuro ophthalmology. You don’t need much to test it. You need a darker room. A bright light. Two eyes. Only one pupil that works. And don’t fetor to have the patient fixate at distance. Don’t let them look anywhere. You can see an obvious, this is an obvious right relative afferent pupillary defect. The secret weapon is the color vision testing, HRR or Ishihara. And we have all sorts of ways to test peripheral vision. Goldmann. I have not done Goldmann periphery in 20 years and don’t plan on it. Automated perimetry. These are Humphrey programs. I don’t have any interest in Humphrey in the United States at least. The programs are 24-2, 30-2. Looking at 24 degrees and 30 degrees. The 10-2 looking at the central degrees. And Amsler grid is a form of perimetry. We have all things to use to sort out nerve and visual pathway problems. So let’s look at a couple of cases. Here is the first one. This is a patient, I have never seen this patient. I was called by their ophthalmologist. And they said I have a patient of mine. Did a cataract surgery a while ago. Following her for dry macular degeneration. I saw her for a routine exam and everything is good. She said since yesterday I’m having trouble reading. High blood pressure that is under control. 20/20 or 6-6 at distance and near. Color vision is normal. Visual fields, full confrontation. Slit lamp exam, the same well position. The fundus had the same drusen that we had seen before: I know you want more information than that. And my assistant walked in the room and said doctor so and so just faxed the visual fields. Here are the Humphrey 24-2 visual fields. The question is, what is going on? She can’t read. When someone tells me they can’t read, there is one really important question. The question is, what do you mean you can’t read? I said, I was on the phone with the doctor and said, is the patient there? She is sitting right here. Ask her, ma’am, what do you mean you can’t read? Well, when I look at the words in the book, I can only see part of the word. I don’t see the whole word. Hum. She has a scotoma. A small scotoma. She can’t see part of the word with both eyes open. What does that tell you? That tells you a couple things. No. 1, if she was blind in one eye, she would see the whole word with the other eye. She has to have bilateral small scotomas. And not only that, but if you had a scotoma in one eye in one place and in the other eye in another place, you would still be able to see the whole word. She has a scotoma in both eyes and in exactly the same place in both eyes. Look at the fields. There is no scotoma there near the center. What’s the problem? What do we do? Well, I told him, listen, thanks for doing this automated perimetry but you did the wrong test. You should have done a 10-2. Here is the 10-2. The difference between the 10-2 and the 24 is not just the number of degrees but a 10-2 has a tighter stimulus density. So there’s a point every 2 degrees. Whereas, in a 24-2 it’s every 6. If you have a small scotoma that fits within the density of the shown stimuli you can miss the scotoma. Look at that, she has a scotoma that goes up the center in both eyes in the same place. What did I tell the ophthalmologist, this was sudden. Yesterday. In an elderly woman. I said, she had a stroke. She needs an MRI. This, I would describe as a left superior, or central hemianoptic scotoma. She had a stroke in the back right occipital lobe just below the fissure. He said I will get an MRI. Send me the results because this will be a good case for my talks. Here is her MRI showing that occipital tip stroke just as we expect given the visual fields. There is a question in the box about 30-2 and 24-2. The 30-2 takes longer. So I never do 30-2. Only do 24-2. All right. I’m going to move onto the next case. Let me look at the chat. Photo stress test can help. If you have a retinal problem, the acuity won’t recover. The problem is remember that early or mid way through the cancer, you don’t have a problem with central vision. I suspect the photo stress test is not adequate. Is para flee owe plastic syndrome more common. Yes. It’s the more common, small cell lung cancer. Let’s move onto another case. This is also an older, 71-year-old gentleman that complains of difficulty reading but for four months. Not yesterday, four months. Comes in with his wife and he is seeing three doctors. Has a brown paper bag and he dumps it on my table and there are five pairs of doctors. I have seen all these doctors and all these pairs of glasses and not one of them helps me read. Is there anything else going on? The wife says he seems more clumsy. On the exam, 6-6 at near distance. I often scoot my chair over to the family members and say he just read that line at the bottom and they look at the near card and say I can’t read that card. He had a 24-2 and 10-2 that would you describe normal. For those who are listening to the presentation, the first question I asked when someone says I can’t read, why not. I don’t really know. I can see the letters and everything. I can see the words. And I said, well, I gave him a magazine. And said read and he started to read. He read the first sentence and started the second sentence and stopped. And then he looked at me and went back and started reading at the beginning again. And then he read more and skipped a sentence. I think I know what is going on here. I’m not sure anyone else in the audience knows. Let’s try one other test. And I showed him this. This is readily available online. You have an 8 and a half by 11 sheet of paper with this on it. You give it to the patient and say what do you see on this picture. And he said I see a woman washing a dish. I said okay. Anything else? Nope. You don’t see anything else? Nope. With my finger I pointed over here at the sink and he said, yes, that sink, it’s overflowing onto the floor. Yes. Anything else? No. Nothing else. What about — oh, there’s a kid taking a cookie. So the point is he was only seeing one thing in this picture. We call that simultagnosia and the visual variant of Alzheimer’s disease. Posterior cortical atrophy. This is a problem of visual processing. Once you start talking to the family about this is not a seeing problem, this is a processing problem, and the family is all shaking their heads. Yes, that makes sense there. Are other things. His memory is maybe not quite as good. Other things are going on. They usually quickly grasp what is happening. That is, there is some degree of early dementia that happens to be affecting vision and vision processing more than memory. So reading difficulties. 90 percent of these parents have reading difficulties. About 2/3 have simultanagnosia. And spatial disorientation, yes, when reaching for the water glass, he will bump it and knock it over. It’s one of the few things that cause homonomous VF defects with relatively normal MRIs. They will present with field defects that look homonomous and the MRI looks normal and they come to me for that reason. Unexplained vision loss. Brain or optic nerve. Did you miss a relative afferent pupillary defect. Is the color vision normal. Did I do the correct visual field or is there a diffuse cerebral dysfunction? You have done your exam. You said I don’t think it’s refractive media. I looked at the retina and choroid. I have looked for the APD, color vision, fields. I don’t think it’s optic nerve or visual pathway. What is left? Unfortunately, not all patients with vision loss or vision problems have quote unquote real visual loss. That is where this term non-organic comes in. So let’s start with a patient, 28 year-old woman. Has poor vision last night in — sorry, poor vision in the left eye since being kicked in the eye in a bar fight. She was in a fight the night before and called one of my partners whose patient she was. And her past ocular history. He was following her for HLAB27 uveitis. She is 20/40 or 612 and that’s the baseline over the last year or so. And that’s where she was. She called him in the morning and said I got kicked last night and can’t see out of the left eye. The right eye was baseline. But the left eye is counting fingers. He said, well, he came down the hallway to talk to me in his scrubs because he was going to the OR. I have this patient and she is counting fingers in one eye and other eye is baseline but no relative pupillary defect. I didn’t dilate her. I looked at the fundus and had a clear view and can see the macula and the maculas looked like they did two months ago when I saw her for chronic mild macular edema. I said, well, what do you think? Let me grab something and I’ll take a look at her. The question I will ask later is, what did I take from my office? That’s the case. We’ll come back to this case in a bit. Non-organic is a term a prefer. Malingering or faking or, what’s the other word that people use? Functional. I don’t like those words. Malingering is a psychiatric diagnosis. Someone is faking vision loss on purpose to get something. The majority of my patients with non-organic vision loss are malingering. I’m not a psychiatrist. There are Munchausens. This is intentional because the patient likes medical attention. I know. That’s weird. Conversion disorder. This is where for instance a soldier at war has a flesh wound in the shoulder but they can’t walk. And they’re not really doing it on purpose. Their subconscious does not want to go back to war. That’s a conversion disorder. And hypochondriac. Non-organic encompasses all of these. There are different presentations of non-organic. I’m going to talk briefly about four. Unilateral or asymmetric visual acuity loss. This is the most common type I see. Unilateral or asymmetric. Bilateral visual acuity loss. Tunnel vision, they can see centrally but not to the sides. And unilateral temporal hem field is not very common. Unilateral vision loss. You can start with tiny letters. Patients don’t know how big they are if you have an electronic visual acuity chart this is easier. My technician that is cynical shows them the 20/15 and 6-4.5 and then 6-6. When she is up to 7.5. She showed them six lines and the patient thinks they’re getting big. There is the DKR that takes so long either you die or they die. Gradual fogging in the phoropter. If the patient is with it, they can close one eye or the other and they will understand what you’re doing. Stereopsis is okay if you have good vision in both eyes. By far my favorite is the vertical prism test. If you get one thing out of this entire webinar, this is worth it’s weight in gold. Here is the vertical prism test. You check their best corrected vision. And you then put up a letter that is bigger than their best corrected vision in the good eye. If they’re 6-6 or 20/20, you put up a 6-12 single letter and hold the prism vertically in front of the good eye. The patient is thinking, what am I going to say when he holds it in front of the bad eye. But you hold it in front of the good eye. What does the patient see when you do that? If their vision is really bad, they will see this. The good eye they will see one clear letter. With a bad eye they see nothing depending on how bad the vision is or see some blurry thing below or above it. Depending on which way you hold the prism. If they’re non-organic, they will see two, one above the other. They don’t get that. They don’t get that. So this is a really simple and quick test. If they — so I put up the prism and say what do you see? Do you see two? Yes. I see two. Is one above the other? Yes. One above the other. The critical question is, are they about the same clarity? Yes. What did they just tell you? My vision is the same in each eye. They don’t understand they’re seeing one of the letters with the good eye and one with the bad eye. And sometimes you take the prism away and they say aren’t you going to check the other eye? Not today. If they see two letters, you got them, it’s non-organic. If they see one letter, now, I’m a believer. And there are patients that I see that I think are non-organic and I do this test and they give the correct response. Really? You see only one? I really have to look hard for the reason they can’t see. What about our patient? 20/40 and counting fingers. What did I grab when I went to the office, a 4 diopter vision prism. If the vision is bad in one eye, they will see this. If it’s good in both eyes, they see this. She saw two letters of the same clarity. Any colleague said I to me I know that means something. Let’s go out in the hallway and talked. And we reassured and said you’ll get better and sent her on her way. Here is another patient with asymmetric vision loss. She was 20/60 or 6-18. 6-72 in the other eye. The retinal specialist who referred said this guy has unexplained vision loss and no APD, slit lamp, the fundus is normal. When he made the appointment with you he pulled out his pocket calendar and made the appointment so he must be faking. Let’s look. The visual field looked like that. That is interesting. That is usually not what I see in someone who is non-organic. It’s black or really constricted although they have central loss of vision. What do we do with this guy? He has seen a retina specialist, that’s a hint. I said something is going on. We did a vertical prism test. Indeed, he said one letter. So he was not, it was real. We did a multifocal ERG. I’m sure many of you don’t have the ability to obtain this. But it should have a nice peak in the fovea like this. And neither of his multifocal ERGs had that peak. This was a form of cone dystrophy. And I sent him right back to the retina specialist. Vertical prism test. Super simple. What about bilateral visual acuity? That is tougher depending how bad the vision is. You can observe ambulation or obstacle course. Sunglasses are a red flag. This QR code takes you to a site where if a person come on with sunglasses in a darkroom, there is a high probability they are non-organic. An OKN drum can be used. There is phone apps with OKN drums or strips. Just spin it slow. Not fast like this. You have to spin it slow and watch their eyes move. It’s hard for them not to move their eyes when the stripes go by. This doesn’t tell you the vision is normal, just that they can see the stripes. The question is, can you see black and white stripes. If they say yes, put it away. You can start with tiny letters and do the DKR. Electrophysiology. We have a test VEP that can tell us about what your vision is. We can measure it. There are other things to do for bilateral vision loss. Tunnel vision, the classic woman, I can only see straight ahead and my vision is fine straight ahead but constricted. And on APD, she looks like this with both eyes. It’s the tunnel versus funnel field. If they have a constricted field, if you’re twice as far away from them, the field is twice as big. It doesn’t do this. Normal vision, no matter how constricted the field, it expands as the distance is farther away: I check the confrontation fields at one meter and then scoot my chair across the room and check at 2 or 3 meters. Here is a tangent screen. 1 meter it’s this big. At 2 mooters it should double. At 3, it’s non-organic. Unilateral temporal hemifield. This was a patient with an injury at work. Had a problem with vision in the right eye. Couldn’t see off to the right. He had an ophthalmologist. The exam was normal. Got an MRI, it was normal. Sent the patient to me. We repeated the fields. They looked like this. That is odd. I’m sorry, I just want to do this test one more time. Because I think this is non-organic. Wait a minute, that’s good. He is right up and down the midline. Anything can do that. You r I said we’re going to do one more test. Just bear with me. I tell my technician, leave both eyes open and center him right on the nose instead of on the pupil. And here is what he did. When he was blind in the right eye, we put a patch on the eye to do this eye, he had a normal field. Leave both eyes open and does this. He is purposely not beeping. Has to be. Then the last case is this 60-year-old gentleman who complains of poor vision since childhood. No changes noted. Hypertension. Social history, recently released from prison after 25 years in prison. He was hand motion in both eyes. The pupils were briskly reactive and no APD. Could see motion in all quadrants and referred by a retinal specialist. He was sent to the retinal specialist because of the problem. He had an ERG that was normal. And the retinal specialist said look at this patient. Gee, do you think maybe he is faking? And he said, no, no, he has a cane. Okay. What do we do? Well, he is hand motion. We quickly just throw up the OKN drum and his eyes moved. That doesn’t prove he is normal. You can be legally blind and have a positive OKN response. Clearly, he is not really being truthful. Because his vision, if he was hand motion, he would not be able to see those stripes going by. I said, is this, first of all, is this exam possible? Can you be hand motion in both eyes with brisk pupils. No APD and a normal eye exam? The answer is, yes. You can. If I remove or severely damage both occipital lobes, you’ll have brisk pupils. You’ll have terrible vision in both eyes. You need an MRI to be sure nothing is going on in the brain. I had an MRI in prism. We need it. We had him sign a record release. No, you need a special records release from us. We will fax it to you. We had to call the patient to come in and sign the prison record release. And he came back in and while he was there, my assistant, the cynical one, watched him. And watched him leave the building from the second floor window and he walked with the cane and his girlfriend to the car. Put the cane in the pocket and got in the driver’s seat and drove away. Dr. Golnik is going to get this guy. Why was his in prison for 25 years and her neighbor was a policeman and he said you can find out. It’s public record. Go to this website and she did. First degree murder, second degree murder and got worried. She said, wait a minute, maybe he’s not happy being out of prison and wants to go back. What are you going to do? I said, well, what does he want? He wants a handicap parking sticker that allows people to park in special places near the stores. I said done and I never saw him again. That was it for him. In summary for unexplained vision loss, the first question is, I tell my patients this, we have to figure out where is the problem. Use common tools. Color vision and direct opthalmoscopy. Get the correct visual field test. You want to prove it’s non-organic. You need to prove it. And the vertical prism test, asymmetric or unilateral loss of vision is a great way to do it. With that, I’m going — I had a couple other slides here. I’m going to briefly mention them. There is a new international group called the ophthalmology foundation. I’m the director of education for this group. It’s to help ophthalmologists become better teachers and better training opportunities through fellowships. Most of the old ICO fellowships — we have 100 fellowships slash observerships a year. 100. These are for people in general under the age of 40. Young ophthalmologists and they’re available all over the world. You have to apply for them. The other thing is faculty development. Improving the training of educators. This is a new group. This is an international group. I’m the director for education. There’s a website that is ophthalmology foundation.org if you’re interested in learning more. That is what I have to say about unexplained vision loss. I’m going to look back through the Q&A if there are questions you can put them in the Q&A. I have answered some of these. Someone commented, subclinical keratoconus. Very true. Keratoconus in my limited refractive role ..(audio blipped).. astigmatism that you can’t correct early on. And posterior lent conus. There is someone that said HCQ question. Not sure what that means. Is there a role of medication and chemotherapy in accelerating vision loss. The answer is hopefully not. Hopefully that will help. You want to find the cancer if you think it’s paraneoplastic. You want to find the cancer and treat it. Can we diagnosis through direct opthalmoscope? I’m not sure which type of drusen you mean. But ocular drusen. If you have buried disk drusen, it can be, it may not be able to be diagnosed with a direct opthalmoscope. You might need auto fluorescence. OCT can look at drusen. Is CRAOH have any rule? I don’t know what CRAOH is. Seeing problem versus processing. That means the visual, if it’s a processing problem, primarily, the visual pathways are intact. It’s a question of, it’s a lot more than just seeing something. You have to be able to see it and understand what it is. And reading is a very complex task. It’s not just I see that letter. You have to make the letters into a word, the word into a sentence. You have to remember what you just read and follow your place on the page. That’s the difference. Sorry, SLE. Slit lamp examination. I’ll remember that. How is the patient counseled after interpretation. What do you tell patients with non-organic vision loss? It depends on the situation. The first thing I tell them and the more family members in the room the better. I said great news, your exam is normal and the testing I’ve done indicates this is clearly not a permanent problem. In fact, you could be better tomorrow or in the next few days or a week even. But I know this is going to get better. And the family says thank goodness, we’re at the specialist. What can the patient say, no I’m not. That’s what I tell them. Now, if in the United States, they say that is fine, I can’t see now. Here is my disability paperwork or my lawyer’s information because this happened when I got hit in the head with a box or something. Then I show them how I busted them. Here is what I did. I have proved without a shadow of a doubt that your vision is fine in that eye. Your brain might be playing tricks on your eyes and we can have you see a psychiatrist. Not because you’re crazy but this can be a subconscious problem. The type of doctor that deals with subconscious problems is a psychiatrist. I give them that option. Consistent eyelid twitching. Not sure if that is a question or not. I have never seen someone non-organic with consistent eyelid twitching. Consistent eyelid twitching can be benign or hemifacial spasm if it’s only one sided. Can you please give a little briefer about AMD? Macular degeneration? I’m not a retina specialist and I don’t take care of that. That is one or two webinar’s worth of information. Kindly brief — for contrast. The question is, for MRIs, I never — I won’t say never — I extremely rarely order an MRI without contrast. A brain MRI. I always order it with and without contrast unless there’s a contraindication to the contrast. Always. Because you will miss things. I see patients where their family doctor orders an MRI without contrast. Normal. We’re looking for inflammation and optic neuritis and a small brain tumor. You’re not going to see it unless you give contrast. I virtually never order MRI without contrast. Does the OCT — have a role in your clinic? Yes. An increasing role. I’m an old neuro ophthalmologist and a dine sour in the world of OCT. I think they can be helpful. A ganglion cell layer can be helpful and it surprises me how normal the rest of the eye exam is. The classic example in the United States is in a patient with multiple sclerosis who maybe had some visual blurring a while ago. Now the vision is normal. You don’t find much. Low and behold the ganglion cell layer is thin. That is a really sensitive test. I think there are issues with artifacts. Am I really sure about the result of the OCT when I get it. ..(audio blipped).. sorry. SLE I mentioned, slit lamp exam and POH is past ocular history. Dr. Killing refraction? I’m kidding. The refraction is so long and takes so much time that you feel like dying or the patient will give up and maybe cooperate. That’s what I mean. It’s supposed to be a joke. What about conversion spasm and agnosopsia. That is not relevant to this topic. People get conversion spasm. That’s another topic. If we’re suspecting neurological causes what do we go for? I do a 24-2. If the patient has a small central field problem, I’m going to get a 10-2. If the patient has, no, it’s way outside my peripheral vision, then a 60-4. I virtually never get a 30-2. The only time is if the patient has previous 30-2s from other doctors and I want to make a direct comparison that I’m concerned about something changing over time. How to rule out malingering? The whole last part of my talk was about that. That was the last 15 or 20 minutes of this webinar is how to rule out malingerer. If you mean malingering versus a different psychiatric diagnosis, I send them to a psychiatrist. Non-organic means there is nothing wrong with the visual system. No organic problem. Organic means there is something going on. And most of the things that we talked about today where doctors referred patients saying I don’t see anything wrong. We find organic things. An oil droplet cataract. Irregular astigmatism. Alzheimer’s disease. Those are organic. There is something wrong with the visual system. Non-organic means there isn’t. It’s another entity. Malingering, conversion disorder, et cetera. Can someone on medication complain of unexplained vision loss. Anything in the world can complain of unexplained vision loss no matter who they are. I at times when the resident says, this patient, I don’t think they would be faking. I don’t care what their age, socioeconomic class is, I don’t care. I see people where I think I don’t know why they’re non-organic but they are. Patient with unilateral hemianopia — oops. Truly have a non-organic issue? Yes. How does the expansion of the temporal field allow us to rule out a non-organic issue? The thing about the test — think about it. When you do automated perimetry, you cover each eye in turn. In that patient when we did automated perimetry with the bad eye closed, patched, there was a normal visual field. When we closed the, patched the good eye and just do the bad eye, you see this temporal defect. Then with both eyes open, the patient also produces a temporal defect. Wait a minute, with that eye blind he didn’t have a temporal defect. The patient doesn’t understand the visual fields overlap. And so when you do the field with both eyes open and the person is blind in the right eye, the field should look normal. That is what it did look like. We blinded the right eye with a patch and the field was normal. Now both eyes are open and there is a temporal field? Only if the patient is purposely not beeping. Lawyers don’t get that usually. I tell them, trust me, they’re faking. I have a patient with keratoconus and nerve bruising. That is tough. We gave a course years ago on how to sort glaucoma from nerve things. There is no way to sort that out. What do you do? If you have glaucoma and drusen, well, you’re probably not going to see increased cupping because the drusen are filling in the space. I think you have to treat them for glaucoma as best you can without harming them and hope their fields don’t get worse. The problem with drusen, drusen can cause gradual peripheral field loss as does glaucoma. It’s a tough question and all I can say is there in no treatment for drusen. There is treat for glaucoma, lower the pressure. Field associated migraine. The answer to that is during the migraine it’s organic. Something is going on in the brain. But when the migraine is over, the vast majority, it’s rare to see a permanent field defect from migraine. It amounts to a stroke. Then it’s organic. Amaurosis fugax. It’s a retinal emboli. That is organic. Of course, its means fleeting loss of vision. Theoretically they will have a normal exam. But I wouldn’t call it non-organic. It’s typically a retinal emboli. Contrast is very helpful. T1 fat saturated post contrast axial and corneal are the best views. I would say that is true. Do you do perimetry routinely for bilateral disk swelling. Yes. In my world, idiopathic intracranial hypertension is the most common condition I see. And in general every patient gets a visual field every time I see them until we have fixed their papilledema. Once we have gotten rid of the papilledema, they are no longer as risk and I don’t get visual fields any longer. Until their swelling is gone, they get a visual field when I see them. The patient with CAR post colonoscopy. Could it be a perioperative ischemic optic neuropathy. That’s an interesting question. Sure, we see people after procedures, typically not something like, of course, you would check, is this an uncomplicated colonoscopy. It can be extremely rare but the person can have a cardiac arrhythmia. If the patient was, we had to resuscitate this patient because of arrhythmia during colonoscopy, that’s another story. But that would be tough. I think the flashing lights and of course ultimately the ERG will tell you the difference between the two. But I think I see a fair amount of preoperative or post procedural problems from the procedure. I just saw a brother of one of our senior retina specialists who had a coronary artery tier owe gram. Coronary catheterization and the procedure was uncomplicated and he was changing back into his clothes and realized he couldn’t see well to the left. He had an occipital stroke from a coronary catheterization. Weird things can happen. If this was an uncomplicated colonoscopy, then you know, ischemic optic neuropathy would not be on my list of possibilities. It would be pretty rare. I see lots of ischemic optic neuropathies that have bilateral symmetric constriction of the visual field. How long should we observe delayed visual maturation? I’m not sure. I’m not a pediatric ophthalmologist. Is central retinal artery occlusion play a role? If it’s acute, you should see a central retinal artery picture. If they have an old occlusion, the retina might look okay, but the nerve should be pale. There should be a relative pupillary defect and it would be unexplained in a sense and you can then do an ERG to prove whether it’s retina or whether it’s a primary optic nerve problem. In general, if we see optic atrophy. You can have optic atrophy from nerve damage or from a bad retinal problem, too. We wrote a paper some years ago now, Dr. Lee was one of the coauthors on unexplained optic atrophy. We had 97 patients in the paper. They all got imaged. These are people that didn’t have any obvious reason to have optic nerve damage and more than 25 percent had tumors pushing on the optic nerve. If there is no definite answer, they get an MRI with and without contrast. At what stage do you operate on oil droplet cataract? As soon as the vision is bad enough. That depends on the patient. Young boy coming in with excessive blinking with no obvious visual problems. Can this be non-organic, yes. Thank you from one dinosaur to another. I have seen lots of kids that wanted glasses and they all has tunnel vision. Sometimes kids want glasses. I don’t know why. I never wanted glasses as a kid. I don’t know why. But you’re right. Some kids just want glasses. And they do that sort of thing. Interesting point. For malingering patients, knowledgeable ones, what single test is recommended? It depends. What are they malingering. Most patients in my patients malinger bad vision in one eye. The vertical prism test is beautiful. It’s so simple and quick. In that setting, the vertical prism is. What could cause a patient to become photophobic and flashes after dilation. The fundus appears slightly swollen. I don’t know that I can answer that one. Fundus appears slightly swollen. I’m not sure if you mean the optic nerve or nerves appear slightly swollen. I don’t know. I’m not sure of the answer to that question. Photophobia, presumably they’re not in angle closure glaucoma. I’m not sure about that. Please, what is DRG? I’m not sure what DRG is. I said ERG, but I’m not sure about DRG. Is sectorial optic nerve atrophy always caused by a vascular problem? If I see sectoral, superior or inferior optic nerve atrophy, I think old vascular. If there is a history, documented by an eye doctor of swelling of the nerve and they send me the patient and the — is gone and they is sectorial swelling, assume it was anterior ischemic optic neuropathy. If they just come in with sectorial optic atrophy, MRI with and without to look for something pushing on the nerve. I have seen it with compression lesions. Is cortical and occipital stroke always associated with retinal thinning? Not always. In fact, when I was in training and for decades until OCT came out, it was thought to never be associated with retinal thinning. But when OCT came out, because to get retinal thinning, you have to have trans-synaptic degeneration. We used to think that only could occur sort of in utero. And once you’re born, you don’t get trans-synaptic degeneration. But OCT has shown you can have trans-synaptic degeneration. Never say never. Never say always. The answer is you can see it with cortical and occipital damage whether it’s a stroke or anything else. For elder patients sudden blurring, significant vision loss but nerve looks normal. Work up showed elevated sed rates and normal brain scan. Manage with steroids? The answer is, I think the answer is yes. Certainly if they have significant visual loss in one eye and a relative afferent pupillary defect, then they have by definition a posterior optic neuropathy or retro bulbar optic neuropathy. If they have significant loss of vision in one eye and a normal nerve and exam, and no relative afferent pupillary defect, I would pull out the vertical prism. Because it’s impossible. The answer is, yes, I probably would. If I couldn’t do a biopsy, the MRI is normal. Have an APD. By definition a retro bulbar optic neuropathy, I would be tempted to treat them. You want to know about other symptoms but giant cell arteritis can have no other symptoms. That’s the end of my questions. I know that some people did have questions in the pre, the registration standpoint. I eliminated a lot of the questions that were not relevant to this topic. They’re all good questions but could be part of many other webinars. So I was going to just look at what I’ve got. One question is Diff rating between hysteria and cortical blindness. Cortical blindness, an MRI is going to be the test that tells. Does an RAPD ..(audio blipped).. in a patient with normal visual acuity? Sure. If they have bad peripheral vision in one eye and a normal eye the other. The RAPD has nothing to do with acuity but asymmetric optic nerve damage. I didn’t include patients with amblyopia in this discussion. Certainly they could have unexplained vision lost but there is a history of amblyopia. I didn’t include that. Are all sudden vision loss emergencies? Yes. That’s about it for those questions. I think those are the most relevant to the topic that we’re talking about today. So I think with that, thank you all for participating on this Orbis webinar. I do a lot of traveling and a lot of speaking around the world. If you see me, please say hello and tell me what you thought about the webinar and let Orbis and Cybersight know about other ophthalmology topics you want to hear about in the future. I wish you all a great rest of the day no matter what time of day that might be for you.

Last Updated: January 8, 2024

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