Low Vision Therapy for Optic Neuritis
Sudden loss of vision with accompanying eye pain is not only frightening but also instantly debilitating. And people who have experienced optic neuritis know this first hand. But is there anything you can do to improve optic neuritis? The good news is that you can. A combination of pharmaceutical treatment with low vision therapy for optic neuritis is an effective way to improve your ability to function.
What is Optic Neuritis?
Optic neuritis occurs when swelling (inflammation) damages the optic nerve — a bundle of nerve fibers that transmits visual information from your eye to your brain. Common symptoms of optic neuritis include pain with eye movement and temporary vision loss in one eye. It may be caused by an infection. However, the most common cause is Multiple Sclerosis. But there are several other rarer types of chronic autoimmune diseases that result in optic neuritis as well.
Multiple Sclerosis: The Typical Cause of Optic Neuritis
Multiple Sclerosis (MS) is the most common cause of optic neuritis. Up to 50% of patients with MS will develop optic neuritis at some point, but recovery is usually good with only 3% ending up legally blind with vision of 20/200 or worse.
Typically, onset is sudden, and symptoms include blurred vision and pain in one eye. The pain is usually worse with eye movements. Imaging with MRI is used to confirm the diagnosis and results show inflammation of the optic nerve. IV steroids and given for treatment and, for many, pain resolved immediately with vision slowly improved over months.
Neuromyelitis Optica Spectrum Disorder and Optic Neuritis
Neuromyelitis Optica (NMOSD) is a rare autoimmune disorder that is different than MS. While approximately 400,000 people in the US are diagnosed with MS, less than 15,000 are diagnosed with NMOSD. And before anti-AQP4 antibody testing became available in 2005, up to 54% of people with NMOSD were misdiagnosed with MS.
Optic neuritis with NMOSD has more severe than optic neuritis with MS and up to 50% end up legally blind with vision of 20/200 or worse. Not only that, but sensory and motor impairment are more severe as well. While both conditions can result in lesions along the spinal cord, MS lesions are typically smaller.
Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease and Optic Neuritis
Another rare autoimmune disorder that can cause optic neuritis is Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). It is an inflammatory disorder of the central nervous system characterized by attacks of immune-mediated demyelination. It targets the optic nerves, brain, and spinal cord and is diagnosed with positive fest results for MOGAD antibodies. Less than 4 million people in the US are diagnosed with MOGAD.
Typically people with MOGAD respond immediately to IV steroids but, unlike people with MS and NMOSD, results are steroid dependent and multiple relapses occur when tapering off. People with MOGAD must be on long-term maintenance levels of steroids to prevent reoccurrence.
What Changes with Optic Neuritis?
Although each person’s symptoms and degree of severity is unique, optic neuritis affects the following visual functions:
Decrease Visual Acuity – Visual acuity is defined by how clearly you see images. It is measured with an acuity chart held 20 feet (6 meters) away and is used to determine the smallest letters you can read. Visual acuity is expressed as a fraction: the top number refers to the distance you stand from the chart (usually 20 feet); the bottom number indicates the distance a person with normal eyesight could read the same line. For example, 20/20 is considered normal. 20/40 indicates that the line you correctly read at 20 feet away can be read by a person with normal vision from 40 feet away.
Decreased Visual Fields –Your visual field is how wide of an area your eye can see when you focus on a central point. Visual fields allow you to be aware of your surroundings and can be tested in several ways.
Decreased Visual Contrast - Contrast sensitivity is the ability to tell the difference between two similar colors or shades of gray. It helps you recognize an object as being separate from the background behind it and is important for balance, walking and driving. It is measured by presenting a series of images of decreasing contrast and the recording the level at which the images can no longer be identified.
Uhtoff’s Phenomenon - Uhthoff's Phenomenon or Uhthoff's sign is specific to multiple sclerosis and is the temporary worsening vision caused by an increase in temperature. It is usually applied to optic neuritis but other symptoms that can worsen with heat include fatigue, pain, balance, weakness, bladder issues, cognitive or sensory symptoms.
Pulfrich Phenomenon – Another phenomenon specific to multiple sclerosis is Pulfrich Phenomenon in which there is a delay in conduction in one of the optic pathways. This causes a discrepancy in visual perception between the two eyes and interferes with 3D and depth perception. Objects moving in a 2-D path are perceived to move in 3-D. Neutral density filter on the good eye slows it down slightly and can improve symptoms.
How Does Low Vision Therapy Help Optic Neuritis?
Low vision therapy is for people with significant visual impairment that cannot be corrected fully with glasses, contact lenses, medication or eye surgery. Low vision services include:
Lighting, Contrast and Glare: Low vision therapists assess your lighting needs and help you identify lamps and light sources to optimize your vision. They train you in how to optimize contrast in your home and work environments and provide strategies for how to minimize and avoid glare.
Magnification and Colored Lenses: Low vision therapists assess the effectiveness of magnifiers and colored lenses to optimize your vision and provide training for how to use them most effectively.
Compensatory Scanning Strategies: Low vision therapist teach you compensatory scanning strategies to enable you to have the greatest field of vision possible.
Technology and Adaptive Equipment: Low vision therapists keep up to date with advances in technology and adaptive equipment available to help people compensate for low vision. They recommend devices such as talking books, talking watches, IPads, organizers, apps and more.
Home Safety and Community Mobility: Low vision therapist apply lighting, contrast, lenses, compensatory scanning and adaptive technology to the home and community environments to help you maximize your independence and safety for tasks such as:
- Home or cell phone use
- Seeing appliance dials or controls
- Safely managing steps or curbs
- Crafts or hobbies
- Managing medications
- Managing finances
- Computer use
- Locating household items
Getting Low Vision Therapy for Optic Neuritis
Optic neuritis is an unexpected and unsettling condition that strikes without warning. It leaves people unable to do simple tasks they previously took for granted. But you don’t have to struggle alone - the occupational therapists at Therapy Achievements specialize in low vision therapy and can share their expertise with you. If you or someone you know is interested in receiving Low Vision services, you can ask your optometrist or ophthalmologist to fax a referral to 800-317-4728 or you can call the clinic to request treatment at 256-509-4398.