Diane Ferguson

Cortical Vision Impairment (CVI)


Metrolina Association for the Blind and My Journey from 20/300 to 20/25

My name is Diane Ferguson and I have waited several months for today. A referral to Metrolina Association for the Blind, (MAB) has been a driving goal of mine for months, ever since I learned about the organization in the hospital. I walk carefully across the uneven parking lot -- and even more carefully, step up the curb with my husband’s help -- into the low vision clinic at MAB.

I’m very hopeful about this visit, but also a little anxious. Would this be like my experience at other clinics?One clinic told me they could help with rehabilitation, but had a months-long waiting list for services.I didn’t think I had time to wait.I felt an internal clock constantly ticking as the weeks passed from my initial trauma.I believed the early weeks and months after my trauma were the period when rehabilitative therapy for my vision loss might make the most powerful gains.

At another clinic the doctor looked puzzled and said, “You should see better than you do.” Yes.There’s nothing wrong with my eyes or optic nerve.For people with cortical vision impairment (CVI), the problem is in the brain.None of us really “see” something until our brains recognize a meaningful pattern.

And at another clinic I was devastated, left in tears, without answers or hope. I zeroed out on every vision test they tried, since they made no allowance for the effects of my CVI.The doctor would only say, “You have a profound vision loss.I’m afraid there’s nothing I can do for you.”At least he was honest.

Now the MAB optometrist comes out to meet us and introduces herself. We walk back to her office and I sit in the examining chair. She reviews my history.

“You had multiple cardiac arrests?”

“Yes,” I say, “I know I’m lucky to even be alive.” I tell her about my catastrophic health crisis – two pulmonary embolisms, three cardiac arrests, severe shock, my body temperature reduced to protect brain function, and all the rest. I tell her about my work as a speech pathologist with clients who have significant neurological impairments -- which helped me in the hospital to diagnose myself as having visual field loss and CVI.

A person with CVI might also have damage in their eyes or optic nerve, but often not. There are several different recognized CVI effects. These include visual field loss, complexity (difficulty seeing and recognizing complex patterns, or objects in a busy background), latency (slower visual processing speed), reduced acuity, loss of depth perception, difficulty with color vision (easier to see red, or blue, or yellow, for example), difficulty recognizing novel objects, or objects out of context, difficulty with visual memory, difficulty with hand-eye coordination, double vision, difficulty with spatial relationships, difficulty with glare, and more.Any individual with CVI may experience all or only some of these effects.Each effect can vary in severity.

For days after I coded in the ER, I was unconscious, in a medically induced coma. When I regained consciousness, I immediately knew I had a vision loss.Everything looked pixelated, like a digital TV screen frozen over signal loss.Over the next few weeks several more strange vision effects would appear.

But at first I couldn’t tell anyone.I spent weeks lying in silence, on a ventilator, unable to speak.My husband devised an eye blink communication system, but that could only answer Yes/No questions that someone thought to ask me.I couldn’t discuss my very strange vision experiences with anyone.My professional background helped me understand that I wasn’t hallucinating, that I was experiencing the results of neurological damage. But still, my strange vision was very disorienting.

Of course, besides my vision I had a few other things to think about while lying in bed.My life was saved in the emergency room, but now, after surviving profound physiological shock, my body needed total rehabilitation.I had to learn to walk again.I had to relearn many daily living tasks, like tying my shoes.The hospital rehabilitation staff was right on top of all of that.But what I really wanted was rehabilitation for my vision loss.For that, no one in the hospital had any resources.But they did mention MAB, and it became my goal to get there.

Aside from generally pixelated vision, I remember the first CVI problem I experienced.My husband was leaning over me in the ICU -- and I could only see him from the nose up. No mouth. No chin. No torso. This half-apparition made me a bit scared and confused, but I was relieved to see him all the same, because my breathing tube really needed to be suctioned. A gunky breathing tube makes you feel like you’re drowning.Suctioning really hurts, but it beats feeling like you’re drowning.

After suctioning me, my husband walked across the room, and I got an even greater shock.He disappeared! As he crossed my visual midline, he became invisible for a moment.

Whoa!Did that really happen? Am I going crazy? For a moment my husband looked like he was in a Star Trek transporter, being beamed up by Scotty.What is going on?

On my back, in an unresponsive body, I had weeks to think. I begin to realize that these weird visual effects were living examples of visual field loss. Something must have blinked out in the occipital lobe of my brain. When I studied CVI professionally, long before my own trauma, no one told me how really weird visual field loss could look from the inside.I began, almost desperately, to tell myself, “It’s not light’s out. It’s not light’s out. You still have lots of usable vision and you are going to use it.It’s not lights out.”

I realized I had become my caseload.

Still more weird visual effects were waiting to show up.I didn’t see any written text in the hospital until I got out of ICU and went to in-patient rehab.There I discovered that I had acquired some serious dyslexia (in CVI lingo, an aspect of complexity).I recognized text as text, but plain English looked like letters of some unknown foreign alphabet I could not read.Actually, it looked like Russian to me.Helpful people tried printing messages in larger fonts, but that only made it Big Russian:

And later I discovered what latency (slower visual processing speed) could look like.After three months in the hospital, I finally went home.And got to see stop action cars.My husband drove us away from the hospital.We came to the first stop light.It was red and traffic flowed in front of us.Instead of seeing cars moving through the intersection in continuous motion, I saw stuttered snapshots of a car -- on the right -- snap -- in the center -- snap -- on the left.Cars were moving through the intersection too fast for my brain to process their motion, so they became intermittently invisible to me.Yeah, it was weird.

I wanted rehabilitative vision therapy, and to the extent I could, I acted as my own first therapist.Lying in that hospital bed, there were opportunities.As with everything else involving muscle movement, my speech was affected by neurological shock, so I did speech therapy on myself.I had no training in vision therapy, but I certainly understood general therapy principals, so I did what I could about my vision.Visual field loss issues seemed like the easiest targets.Whenever someone entered my hospital room, I focused intently on tracking their movements, trying to extend the time they were not in “transporter” mode.At this time my brain was likely still healing, so I can’t be sure that my efforts made a difference.Still, the “Scotty” effect resolved by the time I left the ICU, after seven weeks, to go to inpatient rehab.

And now I’m actually at MAB.We move on from my medical history to conducting a vision exam. The doctor who said he couldn’t do anything for me had tried to administer several standard vision tests without adjusting for my CVI deficits.As a speech pathologist, I knew that different assessment techniques are often needed when working with severe, profound and unusual cases.I wanted someone who could “think outside the box” enough to help me.Now it’s testing time again.I am hopeful, but definitely a little nervous.

First, the optometrist tries me on a standard eye chart with letters.I can’t see anything. I see no letters to name. “OK, no problem,” she says.“Let’s try numbers.” No joy. I can’t see numbers either.I feel my heart rate pick up.“All right, no problem. Let’s see how you do with these shapes.”

Ah ha! I see a black and white drawing of a house. Inside, I sigh with relief. I knew I could see something, and I’m so happy she figured out what it was. I see some other shapes, an apple, an umbrella. It’s a start.

My initial vision assessment at MAB shows I have overall vision at 20/300. I will be certified as legally blind.I’ve presented several features of CVI, most notably visual field loss, complexity and latency.Finally, I’ve received an overall assessment of my CVI from a competent professional.So, was there a competent therapist who could guide my efforts to rehabilitate my vision?

Yes!A MAB occupational therapist devised many different activities for me to practice to address my various problems. She stressed that vision exercises should address two or three problems at once. For example, I played a game similar to “Pong” to work on visual field loss, hand eye coordination, and latency.My husband and I played flash light tag in the evenings to work on latency, tracking and fixation. I looked at simple photographs of common objects and had to name them.Over time, the photographs became progressively smaller and more detailed, addressing complexity. And we also worked on complexity and visual field loss by playing Scrabble on a jumbo sized board.That game was one of many exercises by which I learned to read again.

I didn’t know it at the time, but I was an unusual case for the MAB staff.Most of the published literature and clinical work previously done with neural re-patterning therapy to address CVI had been done with children.There was no professional training, literature or materials on how to do this with adults.But instead of saying, “We haven’t had a case like yours before and we’re not sure what to do,” they smiled and said, “Let’s try something and see how it works.”That positive approach meant everything to me.

Over the months that I was still on medical leave, my vision rehabilitation exercises began to show results.Objects and details began to “pop” into my vision.One day something might appear as an abstract meaningless pattern, and then, suddenly, I could see it! Very usefully, one day I could suddenly see a toilet paper roll in the bathroom. I would recognize the pattern and see a meaningful, three dimensional object or scene.I saw curb cuts in 3-D!I saw denomination numbers on money!I could see numbers on lottery tickets again!

MAB turned out to be the organization responsive to ALL of my rehabilitation needs.To return to work I had to learn to use a computer no matter how bad my vision might be at the moment.MAB offered me computer retraining, and I learned to use JAWS (Job Access With Speech, a program to control a computer with keyboard commands and text-to-speech feedback). An MAB Orientation and Mobility (O&M) specialist helped me learn to navigate independently and safely in the city.

Today, my vision has improved from 20/300 to 20/25.I was officially de-listed as legally blind. When it was time to renew my driver’s license, I passed the vision test at the DMV! Not that I actually try to drive. I’m not that crazy – if nothing else, the latency aspect of my CVI doesn’t make it safe.

I am not “cured” -- not by a long shot. My near vision is fine all day long, but my distance vision seldom remains 20/25 as the day wears on, or for more than 10 to 20 feet, for familiar and predictable people and objects.It can take me up to 15 seconds to recognize an object, say, a screwdriver, out of context.While I can read visually again, it can be slow as I continue to have significant dyslexia.I still use computers with assistive technology.

Compared to those early days in the hospital, “significantly improved but still flaky” sums up my vision.I’m grateful for every scrap of it.

Was MAB any different from other service providers?They’ve made all the difference in the world! MAB gave me the accurate diagnostics to identify my specific vision deficits. They provided strategies to improve the vision that I have. MAB retrained me to use a computer as productively as I did before my trauma. They gave me O&M, so I could independently navigate in the city.

For my part, I did the work. I worked my rehabilitation with as much effort as I would a job. Often I practiced exercises until my brain just wouldn’t process anymore. Typically, I did rehabilitation work up to six hours a day – vision and reading exercises, computer retraining, occupational and physical therapy.And it all paid off!I’ve successfully returned to my work, full-time.I continue working with clients who have neurological problems -- many of whom have CVI.But now, I’ve seen the world they see.I’ve walked in their shoes, rolled with their wheels.My difficult gift allows me to advocate for and serve them better now than I did before my own trauma.It’s a life worth living, and I welcome each day.


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