In the spring of 2015, shortly after Brian Dawson landed his dream job as deputy secretary for libraries for the Commonwealth of Pennsylvania, he experienced a series of ailments, starting with a persistent, severe cold.
After attributing his symptoms to stress and trying to power through for about two weeks, Dawson went to an urgent care center, where he was diagnosed with bronchitis and pneumonia and prescribed antibiotics. “After a couple of days, I still wasn't feeling any better, and I also had noticed that I was starting to have pain in my left eye,” he recalls. He returned to urgent care, where they changed the antibiotics and suggested that the eye pain was caused by sinus pressure.
Three days later, he was extremely weak and fatigued and noticing dark spots in his field of vision. When he got up from a restless sleep on the sofa, he could barely stand. “I went to the emergency department, and within five hours of getting there, I was in the intensive care unit, completely blind and paralyzed from the chest down,” he says.
After two weeks in the hospital, he was diagnosed with optic neuritis—inflammation of the optic nerve. He was then discharged to an inpatient rehabilitation facility, where he was told he had neuromyelitis optica spectrum disorder (NMOSD), a rare condition in which the immune system attacks the spine and optic nerve.
Dawson, who was 42 at the time, was told that he could go permanently blind within five years, and that the disorder could even be fatal. He continued to have episodes of impaired vision and problems with balance, which were treated with high-dose steroids.
About a year and a half later, Dawson saw a new specialist, who conducted more extensive blood work and diagnosed him with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), a condition related to NMOSD. In this autoimmune disorder, myelin oligodendrocyte glycoprotein—a protein that helps build the protective myelin sheath around the optic nerves, spinal cord, and brain—is attacked by the immune system. The doctor prescribed the immunosuppressant medication mycophenolate mofetil (CellCept), which stabilized Dawson's vision.
Bill Bonesteel, 75, of Mechanicsville, VA, was diagnosed with myasthenia gravis, a neuromuscular autoimmune disorder, in 2006 after several years of progressively more troublesome visual symptoms. “It started with droopy eyelids,” says the retired accountant and boat sales and service dealership owner. “It got to the point where I had to hold my eyelids open when I drove.” His eyesight steadily worsened until one day he woke up with double vision.
His doctors tested for thyroid eye disease and several other possible conditions. Then his ophthalmologist, who was monitoring possible vision changes related to his diabetes, told him it could be myasthenia gravis. “That doctor had me follow a pencil with my eyes all the way up and hold my gaze for 90 seconds,” Bonesteel says. “After that, he recommended I visit my primary care physician and ask for a myasthenia gravis test.” His blood work tested positive for myasthenia gravis–related antibodies AChR and MuSK.
Visual disturbances like the ones Dawson and Bonesteel describe are common not only with neuro-inflammatory diseases such as MOGAD, multiple sclerosis (MS), and NMOSD but also with other neurologic conditions, including migraine, stroke, intracranial hypertension, myasthenia gravis, and brain tumors. Some vision disturbances—such as migraine aura, where people may see sparklers, floaters, or flashing lights—can be transient and reversible. Vision loss or difficulty with eye movements that can occur after a stroke can potentially be permanent.
“Vision symptoms can be the first sign of an underlying neurologic problem,” says Nancy J. Newman, MD, FAAN, director of neuro-ophthalmology at Emory University in Atlanta. It's important for people to seek treatment quickly if they experience symptoms such as uncontrolled eye movement, eye pain, or sudden partial or total loss of vision in one or both eyes. “Prompt treatment can indeed restore vision in some cases,” Dr. Newman says.
Since early treatment may prevent further impairment or blindness, a winding road to an accurate diagnosis like Dawson's can be concerning. During his two weeks in the hospital, Dawson had an MRI that showed areas of damage in his spinal cord. He was prescribed steroids to treat the optic neuritis and physical therapy.
A few days after the diagnosis, a neurology resident told Dawson his eye pain and vision loss were not due to MS but were caused by the neuro-inflammatory condition NMOSD. Both MS and NMOSD can cause sudden and acute optic neuritis and spinal cord attacks—involving weakness, numbness, pain, and bladder problems—but the flare-ups are typically more severe in NMOSD, and recovery from them is often poorer. This can lead to permanent disability relatively early in the course of the disease. People with NMOSD and MOGAD have specific antibodies not seen in people with MS.
Dawson returned to work once he was discharged from the hospital, but he experienced frequent relapses. “It would always start with my eyes,” he says. “If I looked up, I'd feel the pain, and within 24 hours I'd start seeing dark or hazy spots, and then finally my vision would dim and go black. Every time that happened, I'd have to take high-dose steroids. For about 18 months, my life was extremely grim. I expected to lose my vision permanently at any time.”
Dawson was eventually referred to Michael Levy, MD, PhD, FAAN, who was director of the Neuromyelitis Optica Clinic at Johns Hopkins Hospital in Baltimore. Dr. Levy informed Dawson that he had MOGAD.
Neuro-inflammatory Conditions
“One of the earliest signs of optic neuritis due to MOGAD is pain when you move your eyes. It hurts like someone punched you in the eye,” says Dr. Levy, who is now research director of the division of neuro-immunology and neuro-infectious diseases at Massachusetts General Hospital in Boston. “Typically, vision loss begins about two to three days after the pain starts. It can start with a gray or cloudy spot in your vision called a scotoma. You may see color in the periphery of your vision, but not in the scotoma. As the disease progresses, vision can sometimes deteriorate to the point of [having] no light perception at all.”
The long-term recovery of vision varies. “People with MOGAD will typically recover most of their high-contrast vision, although they may still find it hard to see gray on white,” says Brian G. Weinshenker, MD, FAAN, professor of neurology at the University of Virginia in Charlottesville.
“Within the past several years, blood tests have become readily available that help distinguish between MS and antibody-mediated conditions such as NMOSD and MOGAD,” says Dr. Weinshenker, whose research at Mayo Clinic has been critical to understanding the distinctions between these overlapping disorders. “Those with MS typically recover to 20/30 or 20/40 vision. People with MOGAD tend to recover better and have less severe or lasting visual loss than those with NMOSD. People with NMOSD who have no light perception may only recover to about 20/200,” which is considered legally blind.
Other visual disturbances that can be caused by neuro-inflammatory disease include blurred vision, double vision, or “jumping vision” (oscillopsia), in which stationary objects appear to move.
For Bonesteel, his vision problems persist. In early 2022, he began taking efgartigimod (Vyvgart), a newly approved myasthenia gravis treatment, which has dramatically improved most of his symptoms—except the eye problems. “When you take this drug, they track your symptoms around eight functional areas like talking, chewing, swallowing, and so on. I'm doing very well on all of them except the visual ones, like eyelid droop and double vision, which affects my balance,” he says.
He's adapted in various ways. “Reading can be tough and very tiring, so I shift the book a little closer to me or further away. When I need to look close up, I may have to close one eye in order to have single vision,” he says. “I've learned to compensate enough that I can still drive.” He says he can't do all the things he used to, but he manages his expectations and looks for something positive. “I consider myself very fortunate,” Bonesteel says.
Blood-Flow Problems
Vision problems also may be caused by an abrupt loss of blood flow to an area of the brain, such as with a stroke. “We can pinpoint where the stroke occurred by what type of visual field loss the person has,” says Marc J. Dinkin, MD, associate professor of ophthalmology at Weill Cornell Medicine in New York. “For example, if the patient has acutely lost vision in the right upper quadrant of both eyes, typically that is related to a stroke in the left temporal lobe.”
Sudden, painless loss of vision in one eye may be the result of a blood clot involving the central retinal artery, which supplies blood to the retina, the nervous tissue lining the back of the eye. Called central retinal artery occlusion (CRAO), this condition typically leads to severe loss of vision in the affected eye. Intravenous medication to dissolve blood clots may be used to treat CRAO within four and a half hours if an ophthalmological examination rules out underlying eye conditions. Strokes also can cause other eye problems, such as double vision due to difficulty with eye movements.
Vision loss can be caused by giant cell arteritis, an inflammatory vascular disease affecting blood vessels, typically in older people, that also presents with headaches and jaw pain with chewing. “When we suspect this disease, immediate treatment with corticosteroids is needed to prevent further vision loss,” Dr. Dinkin says.
No matter what causes eye problems, early treatment may prevent further vision damage, although whether damaged vision can be partially or fully restored depends on the condition. “If there is a tumor compressing the visual pathway,” Dr. Newman offers as an example, “and it's resected before the damage is irreversible, patients may get most of their vision back. With optic neuritis, especially NMOSD or MOGAD, treating with immunotherapy and corticosteroids early may give the best chance of minimizing permanent damage to the optic nerve.”
Similarly, vision loss related to a stroke has a greater chance of being reversed if it's treated quickly. “We say that with a stroke, time is brain, and that goes for the visual centers of the brain, too,” Dr. Dinkin says. “Early treatment with clot busters helps restore blood flow to brain regions affected by a stroke and may reduce the number of brain cells that die because of the initial stroke.”
Quick intervention for people experiencing eye-related symptoms can improve their prognosis for the neurologic disorder causing the symptoms. “If optic neuritis is the first clinically isolated syndrome in someone whose MRI shows high risk for subsequently developing MS, those patients usually do better if they are started on disease-modifying treatments sooner,” says Dr. Newman.
Brain Tumors
Tumors are another disorder of the brain and central nervous system that can affect vision. “This can happen at any level of visual processing, all the way from the retina to the occipital cortex, the seat of vision at the back of the brain,” says Dr. Dinkin.
An adenoma, a common type of tumor in the pituitary gland, can affect the functioning of optic nerves if it grows into the optic chiasm. In this area of the brain—under which the pituitary gland sits—optic nerves that take visual information back to the brain cross and exchange information. A person affected by an adenoma would lose vision on the right side of the right eye and the left side of the left eye, says Dr. Dinkin. “Meningiomas—tumors affecting the outer layers of tissue between the skull and the brain—also can compress the optic nerve and cause vision loss in one eye,” he adds.
Removing the adenoma or meningioma is essential to preventing further vision loss and can sometimes restore some vision. “I have seen patients with these kinds of tumors get a majority of their vision back a few weeks after surgery,” Dr. Dinkin says. “But that depends on how long the nerve or chiasm has been compressed.”
Vision also could be disrupted by brain tumors, such as glioblastoma, the most common aggressive brain tumor in adults, if the tumor originates in or invades the cortical regions responsible for vision. Metastatic tumors that spread to the brain from, say, breast or lung cancer also may cause vision problems, depending on their location.
Long-Term Prognosis
Some people experience permanently damaged vision. For those who become sensitive to light, glasses with special lenses that block out blue light can help, says Dr. Levy. Glasses with prisms may correct double vision. Physicians and therapists also can work with patients on other adaptive strategies, such as learning to look around and move their eyes more. “For example, if patients can't see in their left periphery, we train them to turn their heads or move their eyes to the left more frequently when walking,” says Dr. Dinkin.
That is one of Brian Dawson's approaches to dealing with his disease. “My central field of vision is undamaged, and I'm still able to drive, but I have to be more vigilant,” he says. “My head is a lot more on a swivel than it used to be, although backup cameras and blind-spot alerts [in the vehicle] have really lowered my stress. I also have to make sure there are clear paths around the house or I'm certain to trip over something.” He continues to take the medication that Dr. Levy prescribed and has had no relapses since 2017, but he has permanent peripheral vision loss of about 30 percent.
Dawson stayed in the Harrisburg-based state library job until 2018. In 2019, he became director of the Mount Pleasant Free Public Library in his hometown in Pennsylvania. “I got my first library card from there, and it was a wonderful way of coming full circle,” he says. He retired from that position during the pandemic, and in 2022 joined the staff of the Sumaira Foundation, which works to raise awareness of NMOSD and MOGAD. “It has been a challenging eight years,” he says, “but things are going well now.”
New Technologies for Diagnosing Vision Loss
The innermost layer of the eye, the retina, is the only extension of the brain that can be viewed noninvasively. In many neurologic diseases, looking at the retina and the optic nerve, which carries messages from the retina to the brain, can provide essential information to help with a diagnosis.
Advanced imaging tools are expanding neurologists’ ability to analyze the fine details of what is happening with the retina and the optic nerve. One such technology is optical coherence tomography, which uses a harmless and painless light-based technique to scan all 10 layers of the retina in a few seconds at almost microscopic resolution.
“This noninvasive instrument allows for fairly precise measurement of how healthy the optic nerve is, and it can detect retinal conditions that may be the cause of visual loss,” says Steven Galetta, MD, FAAN, chair of neurology at the NYU Grossman School of Medicine in New York. “It is an important diagnostic tool in multiple sclerosis (MS) and other neuro-inflammatory conditions and is also being studied in the diagnosis of neurodegenerative conditions like Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis (ALS).”
Another tool is the tabletop ocular fundus camera, which allows doctors to look at the back of the eye without using eye drops to dilate the pupils. “As these technologies become less expensive, neurologists can include them in regular physical exams, sometimes with the aid of artificial intelligence (AI) software to improve diagnosis,” says Nancy J. Newman, MD, FAAN, director of neuro-ophthalmology at Emory University in Atlanta. For example, the U.S. Food and Drug Administration has approved three types of AI software for use with these cameras to identify diabetic retinopathy. Retinal changes also may occur in several neurologic diseases, including neuro-inflammatory disorders like MS, Parkinson's disease, Alzheimer's disease, and ALS.
“Without being able to see the back of the eye, you can miss some pretty important findings, such as hypertensive disease or swollen optic nerves,” says Dr. Galetta.
Read More
