PRK is an older procedure. Rather than making a corneal flap, the surgeon removes the entire epithelium layer, does the laser correction, then applies a contact lens which stays on for five days while the epithelium heals and regrows. The downside of PRK is that recovery is considerably longer. LASIK patients achieve their stable corrected vision very quickly. PRK patients can take months. PRK also generally takes several days to achieve even acceptable vision for day-to-day activities. The tech at the office I went to said some people are driving within a day or two, most within five days. But I've also read some recovery stories where people really weren't comfortable driving for a week or even two. Also, the first few days of recovery can be fairly uncomfortable, and some people report rather serious pain. The standard line is that you'll regret getting PRK over LASIK for a couple of months, then be glad about your choice after that.
All of that naturally has me concerned. I'd very much like to get back to work as soon as possible (my job consists entirely of work on a computer), and to be able to drive so as to relieve my wife of the burden of driving me and our daughter everywhere we have to go. Nor am I more enthusiastic about pain than anyone else, of course.
I had the surgery about an hour and a half ago. I'm getting what's called monovision, where my left eye is left about 1.5 diopters short of full correction, so it will be the reading eye. My right eye will be fully corrected and take care of distance. I've sort of been doing that anyway with my glasses prescription, though not by plan. Apparently about 60% of patients are just fine with monovision. Their brains unconsciously adapt to both needs. It drives other people crazy however. In a test before we decided on it, I adapted quickly and easily to it, so I'm hopeful that it will work out fine for me.
The procedure itself does not take long, no more than ten minutes from the time I first lay down on the chair. There was some prep time first of course, where I got various eye drops which numb the eye, protect from infection, etc. The reading eye gets a slightly different procedure than the distance eye, and requires the doctor to mark on the cornea to align the equipment. This more or less involved him writing on my left eye with some sort of pen. With the numbing drops, it didn't hurt at all, though it is of course something of a strange sensation. Then I was told to lie down on the chair and was given a silly stuffed animal to hold on to with both hands. I suppose it gives the patients something to do with their hands. Squeezing an animal rather than flailing would produce much less movement of the head.
To start the procedure, the lids are propped open. Alcohol is applied to the eye for twelve seconds, which they count down. There's a slight burning sensation with that. Next is by far the least pleasant part of PRK, the removal of the epithelium with some sort of scraping tool. The right eye was done first, and it was just a strange pressure sensation, but not at all painful. Psychologically it's a problem for some people. I knew what was happening, and while I didn't enjoy it, I was OK. It ends with a cold water wash, which is a bit startling.
Next is the laser correction itself. You focus on a light, and the laser does its work with very short pulses. It is removing some of the cornea and thereby altering the focusing properties of your eye. You have about 0.5 millimeters of cornea (500 microns) and they don't want to make it any thinner than 300. The worse your pre-surgery prescription, the more they have to remove. I don't remember my exact numbers, but I started out with something like 530 microns and wasn't really going to approach any danger zone. PRK also requires a bit less cornea removal than LASIK. During the procedure, you just focus on a given light. The laser has a tracker to account for any movements of your eye, so you don't have to paranoid about screwing it up. If you accidentally track your focus off the light, the laser stops. I think overall this part took less than a minute. The pulses are audible as very short little cracks. Other people have reported a burning smell as a result of the laser vaporizing the corneal flesh, but I didn't notice it.
Another cold water wash is performed, then the bandage contact lens is applied. Then it's on to the next eye for a repeat performance. My doctor says it's very common that people experience more pain on the second eye than the first. Such was the case with me. Both the alcohol and the epithelial scraping caused some pain. Not excruciating, but noticeable. I don't know if it's a psychological effect or just the numbing drops starting to wear off. If it were the latter, you'd think there would be a way of applying the drops to the second eye a little later, but I'm just speculating.
Afterward I was taken to a normal exam room where a tech checked the placement of the contact lenses. They were fine and I was sent on my way. My vision is currently well off my glasses prescription, but way better than I was uncorrected before. I *could* have driven home, but it wouldn't really have been advisable. I'm able to use the computer, though I have it on low resolution, it's a little blurry, and I can tell there's a bit of strain going on. So after finishing this I'll rest for awhile.
I have multiple drops to apply multiple times a day for awhile. I also have plastic eye shields to wear when sleeping, to avoid any unintentional eye rubbing which could disrupt the lens. Which I'm told, you really, really don't want to do, as the pain of an unhealed epithelium exposed to air is extreme.
Hours 12-36 are supposed to be the painful hours for those people who have pain. We will see. I have checkup appointments tomorrow, Friday, and Monday when the lenses come off. Some people report another small degradation of vision after that.
I have picked as a vision target a piece of sheet music on the piano. Currently I can read the title of the music reasonably quickly and without squinting, at a distance of 4 feet, 6 inches.
Comfort: Eyes sting a bit, and the lenses give a small foreign-body feel.
Photosensitivity: not really
Target distance: 54 inches
Closeup vision: computer use on low resolution is possible but a bit tiring
Driving: not yet
Working: not yet
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