Writing for the New York Times, David Kaplan details his experience navigating a medical mystery that caused his vision to suddenly become "wobbly" during a cross-country drive.
When driving from New York to Lake Tahoe with his wife, Kaplan noticed that the lines on the road suddenly seemed to be "bouncing around." "Sometimes the melding of lanes occurred late in the day, sometimes early. Sometimes in blinding sun, sometimes in fog. If I closed one eye, the lanes became separate again," Kaplan writes.
Notably, Kaplan had worn glasses for nearsightedness since he was in fifth grade. He had seen his eye doctor recently and had a current prescription.
When they reached their destination, Kaplan visited an optometrist. The doctor did not find any problems with his eyes, but suggested he get an MRI to rule out a brain bleed or a tumor—a few days later, the test ruled out both conditions.
However, the doctor also told him to visit a neuro-ophthalmologist—a rare subspecialty made up of only about 600 clinicians in the United States. And since many of them do academic research or have general ophthalmic practices, only 250 of them are full-time clinicians.
Fortunately, Kaplan's brother, a surgeon at Stanford Medical Center, helped him get an appointment the following week with Heather Moss, a neuro-ophthalmologist at Stanford. During the 90-minute examination, Moss took measurements of Kaplan's eyes, including the degree to which they were properly centered.
When Moss positioned a bar of triangular plastic in front of either eye, the bouncing in Kaplan's vision would stop.
Ultimately, Moss diagnosed Kaplan with a condition known as esotropia, which means inward turning of one or both eyes.
Esotropia can cause the eyes to turn outward, upward, or downward. All variations of the condition are forms of strabismus, and double vision is the primary symptom among adults whose brains typically receive two slightly differing images. An individual with symptomatic strabismus will still receive the two images—but they are distorted because the eyes are misaligned.
Typically, the condition is congenital, and most often diagnosed in children whose symptoms present as a "lazy eye," largely because the brain will suppress images from the weak eye.
According to Ophthamology, around 4% of adults have been diagnosed with the condition, but it often goes undiagnosed, and people unwittingly live with imperfect vision. "Most regular ophthalmologists are just looking at the eyes—not eye movement," said Marc Dinkin, a neuro-ophthalmologist at Weill Cornell Medicine.
While surgery is sometimes used to remedy this misalignment in adults, prisms are a more common treatment. In fact, prisms can be permanently ground into lenses to displace light and change the position of the image the eye receives, effectively tricking the brain into correctly interpreting images from both eyes.
For Kaplan's treatment, Moss first recommended temporary Fresnel press-on vinyl lenses, which are one-millimeter-thick lenses that allow patients to try different strengths. However, they often fall off, and the etched plastic isn't as clear as ground-in prisms.
Initially, Kaplan tried a one-diopter lens, then a two-diopter, before settling on three-diopters for the next three months. Immediately, he noticed that "[d]riving was no longer harrowing," but his vision was still nowhere near perfect, and actually seemed to be getting worse.
The 'perils of getting older'
When Kaplan returned to the East Coast, Dinkin took over his care. During an exam, a large "A" was displayed on the wall, and Kaplan removed his Fresnel lens and saw two A's instead of one.
"When I looked through his hand-held prism, the A's magically merged," Kaplan writes. "What I had described as bouncing images on Interstate 80 were really separate images that my brain was trying to fuse. I didn't think it was double vision at the time because the middle driving lane looked pretty much the same as the left lane. In fact, I was seeing two left lanes."
As a result, Dinkin increased the strength of Kaplan's prism to 10 diopters and divided them into lenses for both eyes. Soon after, Dinkin told him they would add the correction in a pair of permanent lenses.
Although his new glasses initially worked well, the thicker lenses distorted his vision, producing the effect of a fun house mirror. So, they adjusted his lenses down to four diopters in each eye. "I'm trying to use those most of the time, reserving the 5-and-5 glasses for driving or when I otherwise need a vision boost," Kaplan writes.
Kaplan credits his "vision misadventure" as one of the "perils of getting older." (Kaplan, New York Times, 2/26)