More Vision Tests: the ERG and LKC

While I’m sure some think I took the day off from work yesterday because of my wedding anniversary, the primary reason I was off was to have more vision tests performed.

Yesterday was my third trip to the Dean McGee Eye Institute. On my first visit I was diagnosed with profoundly advanced macular degeneration in my left eye, and on my second visit, with additional tests (including one where yellow dye was injected for the purposes of studying the blood vessels in my eye more closely) I was diagnosed with Stargardt’s Disease, a genetic condition that causes early macular degeneration and inevitably leads to blindness. On yesterday’s visit, my third to the institute, I was administered an ElectroRetinaGram, or ERG test.

Prior to that test, I repeated the tests I’ve performed during my other visits. First up was a standard vision test. I scored 20/25 in my good eye, and 20/2000 in my bad eye although I was able to increase that number to a whopping 20/125 by using my peripheral vision. Next up was a new test, the Ishihara Color Blindness Test. You’ve probably seen this test on the internet before; it consists of picking out numbers written with circles of one color presented on top of a background of circles of another color. Apparently, color blindness goes hand-in-hand with Stargardt’s. I had no trouble with the color test, a good sign for now. After these tests were performed, my eyes were dilated and then after receiving a few numbing drops, some rubber thing poked my eyeballs a few times.

Next, the ERG.

The ERG is performed in a small office with barely enough room for two people. Spouses get to wait in the waiting room for the duration of the test; fortunately for Susan, Dean McGee has a steady stream of Gilligan’s Island, Three’s Company and Green Acres reruns playing in rotation out there. No such luck back in the ERG testing room. Instead of old reruns, I was treated to multiple rounds of eye numbing drops. Every couple of minutes while making small talk with the gentleman who administers the test I received another round of eye drops.

After fifteen or twenty minutes and with my eyeballs now both numb and dilated, custom contact lenses were inserted into my eyes. I’ve never worn contacts before so the sensation of having someone else insert something into my eye felt odd. Fortunately by this time my eyes were so numb I couldn’t feel anything. The lenses further distorted my vision, thanks in part to the wires connected directly to them. After the lenses were inserted, another dozen or so monitor wires were connected to my face and ears.

I found a picture on the internet of a women with one of the lenses installed, preparing for the test.

By the way, if you’re wondering how a person blinks with bulky contacts (with wires protruding from them) inserted into their eyes, the answer is, you can’t. For the next 10-15 minutes I was unable to blink. Again due to the numbness of my eyes this wasn’t as physically uncomfortable as it was psychologically disturbing. That scene toward the end of A Clockwork Orange came to mind.

With negotiations performed, it was time to dance. The first of two tests required me to stare into a small screen with my eyes focused on a small red dot. Although I was assured the dot was small, to me it looked like the sun. Then, while staring at the light, different flashes of light appeared. I was told that these flashes of very specific wavelengths of light were being used to stimulate the rods and cones in my eye. I thought about the poor inner workings of my eyes who were no doubt trying to make sense of this odd exposure to flashing lights in the darkness. The final exposure, proceeded by a nonchalant “You’re not epileptic, are you?” was a 10-15 second barrage of quickly flashing lights. Even without having one’s eyes dilated and forced open staring directly into a quickly flashing strobe light would be uncomfortable; having a hundred flashes of light going off in a matter of seconds in a dark room left me seeing stars for a minute or two.

The next test was I believe what was called an LKC Test, although I also believe LKC to be the company that devised the test. For this test a large, high-resolution computer monitor was placed directly in front of me. The picture on the monitor consisted of a grid of hexagons alternately colored black and white, with a large red “X” laid over the top of the picture. Each time the doctor clicked a button, the hexagons alternated rapidly, randomly flashing between black and white for roughly ten seconds. This was done approximately twenty times. Again this test was more headache-inducing than physically painful.

This is a picture from LKC’s website showing the pattern, although this specific picture appears to show some sort of magnification lens in front of the monitor. My test had no such lens.

After this test was performed, the lenses were finally removed. The doctor said my eyes might feel “goopy” for a while. I asked him if this was an official medical term and he confirmed it was. The final round of eye drops consisted of water to flush the eyes. Throughout the entirety of my visit I think I received somewhere between ten and twelve eye drops per eye.

Next I was sent back to the waiting room where, after a short wait, I was called back to see the doctor who reviewed my results. Unfortunately, the test confirmed the previous diagnosis. After again mentioning “I can’t believe you can still see so well out of your right eye,” the doctor reminded me that this will not be the case forever, and down the road I will definitely be making some life adjustments as my Stargardts worsens with time. Each time I tell the doctor I cannot make out the vision test or his face with my left eye, he reminds me my good eye will be the same in another decade or so.

While the test was over by noon, I spent the rest of the day with blurry vision and a minor headache. Even with (2x) reading glasses, it was nearly impossible to read anything on my phone or a restaurant menu. Several hours later, after resting my eyes and taking a short nap, my vision had mostly returned to normal.

My normal, anyhow.

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