You move your eyes more often than your heart beats. Vision problems are one of the mysterious, unexplained symptoms people are plagued with long before their doctor knows what is wrong. While not as frequent as sensorineural hearing loss or balance issues a large percentage will suffer from some vision disturbance.
Anisocoria, diplopia, nystagmus, dry eyes, or phantom images in your peripheral vision should all sound an alarm. An experienced ophthalmologist will recognize you may be exhibiting an early symptom of a neurodegenerative disorder and suggest neurology consults.
Superficial Siderosis patients may have at least one of these symptoms, or they can be an overachiever like Gary. At one time he was experiencing every vision problem we just listed. Years earlier Gary’s optometrist had diagnosed early dry macular degeneration in one eye, so he always has regular screenings. I see an ophthalmologist, so I mentioned his vision problems during my appointment.
In the beginning
First were his complaints of double vision and problems with depth perception. He would see things out of the side of his eye, moving or stationary, that wasn’t there. Driving our backroad after an errand Gary was forced to pull off the road. His vision had gone black for a few moments. When he made it home, I noticed his pupils were both the size of pinpoints. Eventually, if you looked carefully at his pupils, you would see one was slightly larger than the other. We decided it was time for him to visit my ophthalmologist.
His initial consult with his neurologist also happened during this time. The two doctors ordered a joint MRI, and while it confirmed there was cerebellar atrophy, the ophthalmologist ruled out optic neuropathy. Between the two physicians, Gary learned he was experiencing nystagmus, diplopia, anisocoria, phantom objects, dry eyes and to top it off his eyes were starting not to track together. Within six months both doctors were recommending he voluntarily discontinue driving.
The ophthalmologist suggested an over-the-counter treatment for his dry eye. He uses either an artificial tears substitute or a glycol based eye lubricant during the day. Overnight he uses a gel mixture of mineral oil and white petroleum.
Diplopia is the strange sounding medical term for double vision. Gary now has prism lenses in his eyeglass prescription. These lenses are intended to help with both diplopia and positional problems like tracking or nystagmus. Standard lenses work to correct focal distance (near or far-sightedness) or cornea curving (astigmatism). A prism feature in your lense will try to fix positional abnormalities by encouraging your eyes to work together.
Anisocoria is a condition where your pupils are uneven in size. It’s one of the few symptoms that, while it is odd, really won’t have any effect on your health or ability to see. Harmless. It’s the one symptom Gary had early on that seems to have disappeared for now.
One of the oddest symptoms, Gary sees “Shadow” people or animals in his peripheral vision all the time. Sometimes just a movement or a full body silhouette, but enough to make him think something is there. No one has been clear if this is a vision problem caused by a vestibular disturbance or if it is psychological. He only knows that sometimes things are not there.
Nystagmus is by far the most disruptive vision disturbance. Caused by the dysfunction of your vestibular nerve, the vestibular nucleus of the brainstem, or the parts of your cerebellum that transmit signals to your brainstem, it is a vision condition in which your eyes make repeated jerking, uncontrollable movement. The result is difficulty reading, focusing and depth perception problems. It is a frequent symptom of superficial siderosis.
Gary has been diagnosed with horizontal nystagmus by his current ophthalmologist and vertical downbeat nystagmus by his new neurological team. It is confusing, but his eyes seem to have a mind of their own.
Vertical downbeat nystagmus causes the most trouble when he tries to read either his tablet or the close-caption on TV. Words are in a constant scrolling movement downward. Web pages with moving backgrounds or animations are very hard for him to read. The continuous motion of his eyes contributes to trip hazards and balance issues.
Ophthalmologists are now recommending specialized weighted contact lens for some nystagmus patients. Gary has not been successful with contacts in the past, so he prefers glasses.
Making concessions for safety
Fighting neurodegenerative vision problems can range from annoying to dangerous. Gary wasn’t happy when he followed the advice of his doctors to stop driving. He was willingly losing an essential part of his independence besides also being forced to leave a job that required a lot of road time. When you’re fighting a rare disease, it becomes clear there are situations where your safety and the safety of others has to come first.
Identifying vision problems is one more step your healthcare providers can use in determining where your areas of most significant concern are and just maybe put a name to an unknown diagnosis.