During this live webinar, we will review the optic nerve anatomy and its correlation with optic neuritis. We will also discuss the evaluation of the optic nerve head and its function, and review several causes of optic neuritis and its management plan. Questions received from registration and during the webinar will also be discussed.
Lecturer: Dr. Adel Ebraheem, University of Maryland School of Medicine, USA
DR. EBRAHEEM: Good morning, guys. I am Dr. Adel Ebraheem. I’m working on the University of Maryland. Today I’m going to discuss optic neuritis. I have received several questions and I tried to answer most of them. So, the objective of this presentation is to take care of optic nerve anatomy and the correlation with optic neuritis. Evaluation of the optic nerve head, causes of neuritis and its management plan. And at the end, we review some cases. First of all, the optic neuritis, or the classification of primary or second optic nerve atrophy, it depends on the blood supply of the optic nerve. As you see in this picture, it enters the optic nerve like 12 millimeter behind. And if anything happens in front of these blood vessels, it can lead to swelling and ended by atrophy. Which is called secondary optic atrophy. And if it happens in the blood vessels, it can lead to atrophy from the beginning. It’s called primary optic nerve atrophy. And the evaluation of the optic — we like at visual acuity, contrast sensitivity, and saturation and defects. Optic nerve assessment. Field. We use visual field 30-2 or 24-2., and angiography and MRI. The first is visual acuity as entrance exam. We use that denominator, which you have 20/100. We use this 100 divided by 10. This 10, it gives the oma associated with optic neuritis. With optic neuritis, their visual acuity is may way better than contrast sensitivity or color vision. Because normally the primary visual cortex is more sensitive to see this board which we use for VEP. It helps with similarity with short, black and white. The light brightness is diminished light brightness even in presence of normal visual acuity with optic neuritis. Same with contrast sensitivity. It diminished. And it doesn’t — just the normal visual acuity doesn’t give the indication that the optic nerve is healthy. Now, we come to the color vision. At the beginning of our acute optic neuritis with the patient has defects in the blue color. If you see it’s a proportion or there is a percent of the cones, you see the blue-sensing cones is 10%. So, there’s high possibility that this kind of blue-sensing cones are affected first. This is why the patient will have at the beginning of optic neuritis, they have the blue color defect. At the end, it can lead to red-color defect. So, this is — it’s in the diffusing color plate, we recommend to use Hardy-Rand-Rittler plates because it tests blue color. One thing that’s very important to understand is principle of univariance. It means that the cones doesn’t see colors. Just is affected or stimulated by the energy. And each cone has proportion or probability of absorbing certain wavelengths and others. So, this is how cones respond to the color. And the color vision is just actually divided into a hue. Which actually is determined by the wavelengths, brightness, and saturation. Saturation is a percentage of the white that is added to the color. So, like 570, this is the colors that contains the most white. Red desaturation test. We use red desaturation to determine if there’s any optic neuritis signs or symptoms. The healthy eye see more bright. And the non-healthy see more dim. We use red color instead of colors like green for three reasons. Because cones, it’s more dominant. Here, if you see this graph, at 600 and 500, the cones are very sensitive. The threshold is very low. It’s very easy to determine if the cells is not sensitive to red color or can determine if there’s any kind of decrease in the red saturation between the healthy and unhealthy eye. This is a study that’s interesting. And it gives us a indication of the sickness of the nerve fiber layer. The thickness is decreased after 6 months from acute optic neuritis. And we find that the contrast sensitivity and color vision is affected by that. Below this 75, it would be permanent decrease in the contrast and the color vision. Relative afferent pupillary defect is an important test if the optic nerve is only affected in one eye. And this can track the damage between optic nerve to the lateral geniculate nucleus. We conduct 1 second test. And if it’s negative, we duct a 3 second test to see if there’s any subtle effect. Optic disc assessment. It’s an important part. We see normal optic disc with optic neuritis. Elevation of the nerve head in any quadrant. Blurring disc margins. Perry papillary, it can happen in diseases like optic nerve glaucoma, meningioma. And retinal venous dilation tortuosity. And neuritis. So, the visual field test, we can do it — see the test because it shortens the time and gives, you know, a good picture about serum. We use global indices to see if there’s any improvement from the first visit to the full op. And we use ND to determine the natural density filter. We put a gray filter in front of the healthy eye until they have similarity in the pupillary constriction. We use a visual field, ND, to determine the number of the filters that we used. Visual field defect. There’s different kinds of scotoma. centrocecal is very common, central, and 360 degree depression, complete depression in like optic neuritis. Optical coherence tomography. This is a good test during the first visit and follow-up visits. But it’s not necessarily gives an indication if there’s any optic nerve swelling. There might be some swelling in the optic nerve. But it can not be detected by the OCT. However, long-term, if there’s any optic atrophy, we can see the atrophy of the nerve fiber layers. Visual evoked potential. There’s increase in latency in the P100s. It may be like P130, 125. This happens in optic neuritis. The amplitude is decreased in case of like compressive optic, toxic optic neuropathy. Just like in optic neuritis, it can lead to increased latency only. Angiographic leakage can differentiate a truly swollen optic nerve from pseudoedema of the disc. This can be edema or other cause of optic neuritis. We can use T1 with operation to see any white lesion in multiple sclerosis. T2 is similar, but it appears hypo-intense. It gives the lesion around the ventricles more distinct. Here as we explained before, that as the entrance of the blood supply to the optic nerve determine if there’s any swelling or there is no swelling from the beginning. In case of primary optic neuropathy, like inherited, toxic or retrobulbar optic neuritis, there is no swelling. You can find sometimes some swelling, but this is the general idea. Secondary optic neuropathy, there’s swelling precedes, like in papillitis or peptic edema. With optic neuropathy, any sick optic nerve we call optic neuropathy. Due to optic neuritis or other causes like infiltrative, autoimmune, compressive. And we say demyelinating. Infectious like syphilis or Lyme disease. Neuroretinitis, technique happen with macular nerve or edema or the layers. Parainfectious. It comes after the infection. It is in filamentary edema. It doesn’t cause exactly by the virus or bacteria. But because of the immune response to the pathogen. Optic neuritis is inflammatory disorder of the optic nerve associated with visual loss. And we divide optic neuritis according to anatomy. Papillitis, and retrobulbar, this is the most general term for optic neuritis. However, there are other categories or classifications. It’s called the neuroretinitis, which affects the optic nerve. And then later on, maybe after like 1.5 to 2 we cans. And perioptic neuritis. So, what’s a perioptic neuritis? It’s mostly idiopathic. If it affects the surrounding of the optic nerve. The primary target. It’s different than optic neuritis in the prognosis and the treatment. And the picture should be the same. You cannot distinguish when you look at the fundus if this is perioptic neuritis or optic neuritis, because it’s the same swelling. However, if you ask the patient about the pain, the pain is out of proportion in the perioptic neuritis compared to optic neuritis. It can be primary, idiopathic, or secondary due to sarcoidosis or syphilis. As you can see here, the pathophysiology is immune-mediated, and affects the nerve sheathe. Once it affects the action, then it can cause decreased version, affects of color vision and other degrees of effect. You see here in perioptic neuritis, optic disc edema. And MRI shows enhancement of meninges, which is different from optic neuritis. Exophthalmos. And you can see in the picture, the MRI shows perioptic enhancement around the optic nerve sheathe. However, we do this test regarding if it’s perioptic neuritis, optic neuritis, typical or atypical. This is a primary test that you should do. Then we do a lumbar puncture to rule out malignancy or infection. We do blood tests for syphilis. The treatment is high dose steroid. 60 to 80 milligram per day. If we use low dose, there’s high possibility of relapse. Which is different than optic neuritis. The response to treatment is very good comparing to optic neuritis. It can be self-limited. There is a case here that I would like to share with you. A 53-year-old male came for an acute visit for blurry vision in the right eye. He went to the urgent care. Complained of crusts and blurry vision. But they didn’t address his complaint. The right high is — sorry. Is line hand motion. Count the finger. And left eye is 20/70. The pressure is within normal. And the confrontation visual field is restricted in the right eye. As you see here in the optic nerve, it’s swollen. Hyperemic. It’s optic neuritis versus — we can see looking at the picture. Here is just a visual field in the right eye. You see 360-degree scleroderma. In the right eye, you see severe swelling and layers compared to the left eye. This is the day of the visit. Here we order this MRI. As you see, there is no enhancement of that — of the meninges around the optic nerve. This can determine this is not perioptic neuritis. It just is optic neuritis. We order blood work for him. And we find that it has reactive FAT-ABS and positive RPR. So, this indicates that he has neurosyphilis. The MRI in the brain show two nonspecific subcentimeter enhances lesions in the white matter. Unfortunately, because of the delay in the management, his primary care doctor prescribed for him doxycycline. Saying he has sensitivity to penicillin. We contacted primary care to do desensitization and administer penicillin. We came later on with visual acuity like 3 feet and OCT optic nerve thinning in the temporal sphere. And it ended with a bad prognosis of complete optic atrophy. And that neuroretinitis, inflammatory disorder of the optic nerve includes the ma cue lea and papillomacular bundles. And this gives like a star shape because of the layer and the anatomical structure. It can be idiopathic or due to some infectious diseases like cat scratch fever. We do for cat scratch, appears in the client. We can use it. Syphilis, we do RPR, GRL to see if there’s any active inflammation. And the tests. If the R P is positive and the other tests are negative, that means false positive. Both should be positive so we can start the penicillin. If that RPR is negative and the VR is negative, however the other test is positive, the vision should show that they had penicillin before or we start penicillin. Lyme disease is two tests. It’s ELISA for the first test. And then the second test to confirm if there’s Lyme disease positive or not. Then we do sarcoidosis. And as you can see in the pathophysiology, inflammation in the optic disc vasculature with the exudation of the fluid by the papillary retina. It’s swollen and has signs of variable degrees of vision. Constriction of the field and swelling of the OCT nerve fibers. We do the blood work for infectious like FTA-ABS, RPR and VDRL. And we do the blood analyzer for Lyme disease. In this kind of neuroretinitis, because there’s edema, there will be a retinal detachment. And the treatment is we just treat the underlying cause. Papillitis and retrobulbar optic neuritis, there’s typical optic neuritis and atypical. The typical one is one, and the atypical is not related to multiple sclerosis. In case of multiple sclerosis, 75%, Yu New York lateral vision loss. 75% retrobulbar. No swelling when you look to the optic nerve. The definition of multiple sclerosis should be remission and relapse separated in space and time. Acute loss of vision. There’s associated with eye movement. Less painful than optic perineuritis. And optic perineuritis is out of proportion. There’s diplopia. Uhthoff phenomenon after exercise or shower. It’s vision loss or numbness. The Lhermitte sign, after, there’s a sensation like electrical shock. Normal appearance of the optic disc or papillitis. And in case it’s — or in papillitis, inflammation of the head. And can be associated with intermediate uveitis. And in the MRI, we see these lesions. The visual field. Diminished sensitivity is the most common in multiple sclerosis. There might with central or centrocecal scotoma. Altitudinal defect. Thinning by more than 6 microns. This takes 6 months and thing of the nerve fiber layer by at least 9 microns. And the CSF is the oligoclonal band. And the VEP is the latency. And the treatment, we use methylprednisolone, 250 milligram every 6 hours, and then start again. Relapse is very common and bad prognosis. Neuromyelitis optical, and inflammatory and in the nervous system and causes demyelination of the optic nerve. It’s different than multiple sclerosis. In the necrosis of the white and gray matter. The IgG antibody against the astrocytic with a porin. It’s different than in multimillion sclerosis. It affects the optic nerve. Area postrema. This is important for the vision. And the spinal cord is important to ask if their vision has sphincter dysfunction. Symptoms or signs of paresthesia. And optic disc swelling is severe. As a diagnosis, one core clinical characteristic and positive AQP4 and IgG. Or at least two core clinical characteristics and negative AQP4-IgG. We look and see if there’s any further blood work we have to do. And the MRI optic nerve, relatively long lesion, increase in T2 signal. The MRI in the brain, you see necrosis of the white and gray matter. Not just the white matter as in multiple sclerosis. The treatment is methylprednisolone of 500 to 1,000 for longer days, 5 so 20 days. Which is different than with multiple sclerosis, it’s just for three days. We can use after that plasma pheresis or globulin. And myelin oligodendrocyte glycoprotein optic neuritis. It is different and affects. It can happen in young age, old age or any ethnicity. Which is different than African and Asian in neuromyelitis optica. They have rapid and progressive severe vision loss. Bilateral disc edema, and seizures. And there is still the current gold standard, MOG-Ab. We look at the enhancement of the optic nerve. This can read as enhancement to the optic as well. There’s a case here that I would lake to share with you. A 14 years old young lady. She came for an exam. Her vision was 20/20, color vision normal. Red cap test, dimmer in the left eye. And RAPD, negative. You can see here there’s a swelling. We can’t determine if this is optic neuritis or perioptic neuritis. The OCT, as I said at the beginning, it sometimes is misleading if you just look at this OCT. Because there is no swelling and it is normal development. Same with the left eye. And the visual field is completely normal. We order MRI for the patient. And the patient show pineal cyst with thin mural enhancement. It was suspicious. But after consultation and we ordered the cerebral spinal fluid. The HCG was normal. The culture was normal, and the CSF was normal. Not even hypertension. However in the bacterial culture, it becomes gram-positive and negative. The glucose protein was within normal. This contraindicate — or contradiction of meningitis. This is because of contamination. We order blood work and it comes with Vitamin B12. You know, 366. So, because she’s a child and it mentions in the record that between 200 and 400 may experience psychiatric and hematologic abnormalities. Another case. This is 28 years old African American. And he came in complaining of series vision. To weeks before he came to the clinic, he was discharged from the hospital. Suspected HIV positive. Enter the exam room using a walker. He has moderate to severe decreased vision. Getting worse over 4 weeks. Moderate eye ache. As you see, this is his vision. It has — if he was to diffuse in both eyes, cells. And there are cells in the vitreous as well. The pressure like that. The fundus in the right eye was poor view, left eye, it looks like that. So, it looks — this is a picture of the pruritus. And what’s the management plan? So, if you would like to share your opinion about this case. >> Thank you, Dr. Ebraheem. We have some Q&A questions if you want to open up the Q&A box on your side. DR. EBRAHEEM: Sure. Let’s discuss this case and then we will go with these questions. So, what is the differential diagnosis of this case? Can you answer? Do you have any opinion? Yes. It’s exactly. It’s syphilis. We order RPR and the patient has syphilis. When I asked — I did very quick neurological exam. He has cells. This is optic neuritis. Neurosyphilis associated. So, the first question, what would you like if there’s no cause of optic neuritis? It’s idiopathic. We strive with steroid. We want to make sure there’s no malignancy or lymphoma or any kind of cancer. The second question. What is your frank opinion of the findings of a study showing three days IV. If we just use the oral. The prognosis is very bad and the relapse is very common. Yeah. It’s important to repeat this visual field. Because vision, you know, managed with the steroid after optic neuritis, there will be improvement in their visual field. Color vision can be, you know, declined. But there will be some improvement in the visual field. Unfortunately, this patient who had uveitis, because he came with neurosyphilis, it’s very bad. Even after treatment. Because this is life threatening. We treat him with IV penicillin. But the prognosis was very bad because it’s — it came with end stage. The treatment of idiopathic optic neuritis. We do it steroid. IV steroid. Most of the neuro enteritis is infectious. We have to make sure there’s no infection underlying or disease before we say it’s idiopathic. Most neuritis is infectious. The management of the nutritional and toxic neuritis, depends on the cause of nutrition like a Vitamin B12 deficiency. We supplement the patient with Vitamin B12. Toxic neuritis. It can lead to impairment and optic atrophy if it’s not stopped. We should start the IV immediately to confirm if the patient has optic neuritis due to multiple sclerosis or atypical optical neuritis. But we have to rule out infection first. Yeah. Optic neuritis, ensures it’s mostly atypical. And you do dendrocyte antibody. This is treated by IV for 10 to 15 days. No, actually, I haven’t seen any case with meningitis. It might be, but I haven’t seen a case of cryptococcal meningitis like that. Any more questions? There’s a complication, it can lead to optic atrophy if not treated and it will be irreversible. Why does color vision take longer to recover compared to vision? Actually, it’s not complete recovery of the color vision. Because the color vision, it persists through the pathway and they have the same myelin sheathe. And so, it’s a different distribution of the cone cells. The SL and M. So, it’s optic neuritis, affects the color vision and the visual acuity as I explained before. We don’t used non-steroid medication in optic neuritis. Yeah. How to differentiate between optic neuritis and optic neuropathy. There are two or three differences. The optic neuritis, if we speak about the typical one, it appears in the middle age, female. Between 30 and 50. Optic — and all the age — there’s totally different pictures. And the nerve is not very shocking white. Which is different from optic neuritis. It’s red and edematous. The visual prognosis for optic neuritis can be sight-threatening. And we have to help them immediately. Comparing to optical neuritis which is self-limited. The classical symptoms of the optical neuritis. Explains the vision. And the pain and the eye movement. Decreased color, increased sensitivity, affecting the color vision. Yeah, it can result in optical neuritis. Typical or atypical if it receives treatment in the appropriate time. But in case of the optic neuritis, you want to disclose this, the outcome is the same after 2 years regardless if we start the treatment or not. But in the atypical cases, treatment makes a big difference in separate prognosis. The difference between the 1 second and 3 second affect, you know we move the flash light just to spend 1 second between both eyes to determine very quickly the defect. The 3 seconds to see if there’s any subtle afferent effects. Which is a very important test to do. The gold standard for evaluation and macular — is to do MRI T1 with and without contrast with the orbit. And with separation. And according to the result, we order our blood work. Of course, the patient age and symptoms, past medical history to determine the blood work. We can’t do all the blood work. It just would be very expensive and time consuming. But depending on the MRI result, we direct our blood work testing. Especially in the — countries. You said how long should we give depending if it’s typical or atypical? As I said in typical, we used IV for three days. And then we go with the oral. In atypical, we use for 10 to 15 days. The interferon, we use it in multiple sclerosis. But if we use it in, you know, typical, it has a bad prognosis. We have to differentiate between typical and atypical before we start. And hypertension doesn’t lead to optic neuritis. It’s two different resolutions. Is there a place of biological treatment for multiple sclerosis. I don’t understand this question. For the treatment of neuritis, just replace with Vitamins for nutritional neuritis. Any toxic, you have to stop the toxicity first. You mentioned risk factor of optic neuritis. What exactly do you mean risk factor? Demographic or history of infectious — that depends. Your question is not quite clear. That which clinical sign is more reliable in optic neuritis. Optic nerve is swelling. Or optic neuropathy symptoms and sign. But this is very broad. As I mentioned, if it’s easier to discuss, ask you a question about just multiple sclerosis or typical optic neuritis, 75% it would be retrobulbar. So, there’s no clinical feature of high pain or swelling. 25% would be papillitis. But you evaluate the functions of the optical. This is how you first take into consideration. The visual acuity, contrast, sensitivity, color vision. Red test, you have to do these tests first to determine if there’s any dysfunctions of the optic nerve. The macular — or more common in optic neuritis? It can be due to as I mentioned infectious diseases like syphilis or Lyme disease or due to diabetic changes. Hypertension. There’s multiple causes of macular star . You mentioned what other treatment option do we have as the vision cannot be destroyed. What do you mean? If they’re diabetic, for example? We use, you know, interferon for in the case of multiple sclerosis as well. It’s totally different between neuritis and — there are two different pathologies. The differentiation between the — and optical neuritis. Multiple sclerosis can lead to optical neuritis and neuritis, you can take this in. It can lead to manifestation of optic nerve neurology. And optic neurology. And part of one of the cranial nerves. So, the vision was double vision. And optic neuropathy. So, you ask about the acute optic neuritis in the first trimester of pregnancy. I explained, you have to determine the cause of the optic neuritis. If it’s multiple sclerosis, as I mentioned, it’s self — if it’s due to atypical, we have to start steroids. Because it’s a sight threatening. We mentioned white — does not improve visual outcome. This is done after a clinical trial of optic neuritis treatment trial done. And they found that the oral — we just start oral prednisolone without the IV steroid, the reoccurrence is very high. Yeah. We give interferon for multiple sclerosis. We use it. Here is a treatment of recurrent optical neuritis, a report. It is standard to determine the cause. If there’s any optic — before you determine if it’s idiopathic. Because like I say it, optic neuritis has a similar picture of optical neuritis. And sometimes we need to take a biopsy. If there’s any reoccurrence. And as a patient doesn’t respond to steroids. Yeah. Atypical optic neuritis. If it can affect any age. We see multiple sclerosis in all the ages. It’s common during the middle age. But it can affect the older age as well. In case of bilateral optic neuritis in a child. As I said, you have to determine if it’s typical or atypical. Mostly typical. And you have to do blood work for just… yeah. I think as a MRI is most definitely the standard for risks. If you see the white lesions, multiple lesions in the brain, ventricular. That is definite diagnosis of multiple sclerosis. The clonal gland is additional test. Of course, it can be part of the disease prognosis. Your question, if you speak about multiple sclerosis, it’s more common in white, Caucasian people. Which is different than, you know, myelitis optical, which is very common in African and Asian. But it can happen in any ethnicity. Yes, nutrition, it can be one of the causes of optic neuropathy. And the result of optic neuritis. It can be resolved if you use — if you manage it at the appropriate time. You cannot stop what’s destroyed after IV for 2 to 5 days. You have to continue. It will not affect ultimately in the prognosis after 2 years. But it is helping to prevent a reoccurrence. Okay. No, there’s no difference between optic neuritis and intracranial pressure — that’s two different. If you discuss — your question means a lesion or intracranial hypertension. Neuritis can be caused by infectious or Lyme disease. But it’s mostly infectious. You know, optic neuropathy is a very broad term. So, you have to be very termed when you say multiple sclerosis is, optic neuropathy. It’s a very broad term. With the optical neuropathy, as I said, it’s… it would depend on the clinical feature, the age of the patient. It’s above 65. They complain of intermittent claudication, temporary headaches. Pain when they do mastication. And it’s cause — its main cause is because of joint arthritis. Papillitis is usually unilateral over edema. As part of the edema, it’s increased intracranial pressure. Bilateral optic disc swelling. And the patient has symptoms like nausea, vomiting. Severe headaches which increase during the laying down position. And there is different grades of papilledemas that we use it. I hope that I answered most of the questions. >> Perfect. Thank you, Dr. Ebraheem. We are at the hour so we appreciate your time. DR. EBRAHEEM: Thank you. >> And thank you, everyone, for joining. DR. EBRAHEEM: Thank you.