PRELEX EYE SURGERY, One Person's Odyssey.
Cal Rice, one of Dr. Knolle's patients, documented his personal experience for his family and friends, and shared it with us. He titled it, "PRELEX EYE SURGERY, One Person's Odyssey."
Dr. Knolle with PRELEX patient, Cal Rice
Preface
Medical Background The surgery is basically identical to current cataract surgery. A small incision allows removal of the natural lens of the eye and it is replaced with an artificial one. The “magic” is that the replacement is an Array Multifocal Lens. This lens is similar to a variable focus lens in a pair of glasses where the focal length varies from top to bottom. In this lens there are five circles, the odd ones being for distant vision and the even ones for close vision. The brain learns to select the appropriate images for the desired distance.
Personal Background
I have always been somewhat farsighted. About 1956, while in college, I began wearing glasses, and went to bifocals about 10 years later. As time went by I lost my “intermediate” distance vision. This was most noticeable when I tried to read the computer screen of a student or playing table games. For instance, it was difficult to read cards lying on the table.
A few years ago I went to trifocal glasses. These were certainly better for general use. Trifocals are made by keeping the upper (distance) vision portion the same and splitting the bifocal (near) portion into two portions. The trifocal portion (in the middle of the lens) is used for medium distance and the bifocal (lower portion of the lens) for close vision. The problems, for me, were the trifocal portion was too narrow for me to see the complete computer screen without having to move my head and, the bifocal portion was so small that I had to hold my head unnaturally high and move it when I was reading. My solution was to have the trifocals for general wear, bifocals for reading, and single vision for computer work
Now, the glasses that I wanted were always at the wrong place! Second, when I was in the office I would be switching glasses when I switched from being on the computer to wanting to read documents at my desk. It was becoming more and more frustrating.
The Odyssey
Pre-operation
My right eye, without glasses, tested 20/40 and my left one tested 20/100. Glasses made it possible for me to live and work in a reasonable manner. I wore glasses from the time I got up until going to bed.
The pre-op doctor visit was the normal eye check plus a number of measurements of the eye and mapping the surface of the cornea.
The video I viewed about the procedure cautioned to set realistic expectations.My biggest concern was that I might set my expectations too high. I told Dr. Knolle my expectations were to be able to see without glasses better than I now see with glasses. He said he did not think that was too high an expectation.
The Operation
I arrived at the outpatient operating center about 10:30 on Wednesday, February 11, 2004 had the right eye dilated (in a major way – more than for a normal eye exam), had the operation around noon (taking 20 minutes or so) and went home around 1:00. A week later the left eye was operated on.
The Excitement
The first Wednesday afternoon I took a nap and generally played lazy. The right eye had some discomfort, similar to putting in a contact lens, but did not hurt. Thursday I woke up at 5:00 a.m. By 5:30 I just had to get up and see what I could see. It was magic! I went to my computer and could read the screen, without glasses. I could read the names of the books on my shelves (4-6 feet away), without glasses. At 8:00 I drove to the Dr. Knolle’s office for the “day after” check. My vision checked out at 20/15 for distance and 20/20 for close work.
On Thursday and Friday I noticed that my eye was sensitive to light. Being in the dark and turning on a room light or a cloudy bright day outside would cause some pain. This may have been due to the effects of the dilation still wearing off. By Saturday I was outside in the sun, without sunglasses, with no problem.
On Monday, I was talking on the phone, leaning back in my chair with my feet up on the computer table. I could read the words under the icons on the screen, very clearly, without glasses. With my left eye I could barely determine whether there was one line or two lines of words under the icon.
The left eye operation was more complex. The left eye had a significant amount of astigmatism which means the cornea is out of round. This can be corrected by making incisions at critical locations in the cornea to release the “out of round” pressure.
The week before had gone so well that instead of being lazy for Wednesday afternoon, I went right to work and spent several hours on the computer. Anyway, Thursday and into Friday, there was discomfort in the left eye but by Saturday it was great.
The Side Effects
The only side effect, which appears to be universal, is seeing “halos” around point sources of light. These appear around car headlights, taillights, streetlights, yard lights, etc. I would describe them more as a star burst rather than a halo. They look something like a fireworks starburst. The farther away the light is the larger the halo. For example, car headlights at a distance have halos large enough to overlap. As the car approaches the halo becomes smaller and (basically) disappears when it is within several car lengths. I am not finding it to be a problem.
Current Experience (February 21, 2004)
I CAN SEE!
- I was reading the newspaper and realized I had no glasses on – for the first time in almost 50 years. To read fine print on containers I need magnifying glasses.
- I was doing some woodworking that required drawing a line about two feet long. I was able to see the whole line at one time, rather than looking through one part of my glasses for the far part of the line and another for the near portion.
- When hammering a nail I could actually see the hammer, rather than having it go through different portions of my glasses during the swing.
- When driving I can see distance and also read the instruments on the dash (like odometer).
- I am working on the computer now with no glasses.
- I have to remember to put on safety glasses, when needed, as my glasses are not always there.
The Future
The general experience is that vision continues to improve for several weeks (or months) as the brain continues to adjust to this new vision system. Dr. Knolle, who has had the procedure himself, says that in three months I will wonder why I thought my vision was so good right after the surgery. I anticipate I may want reading glasses to reduce the eyestrain when I am reading for prolonged periods, but I can read without glasses.
I will never have cataracts, as they grow in the natural lens of the eye. General experience is the halos will become less noticeable as time goes by. At least one patient was disappointed when the halos disappeared; she thought the Christmas lights were so beautiful with the halos (starbursts) around them. |
