Bottom Line: My experience getting a kind of vision correction surgery called PRK, part 1.
First off, please read my disclaimer. Basically, none of this is intended as medical advice, just a description of my experience and the thought process behind my decisions.
On Thursday (April 18, 2013), I had bilateral photorefractive keratectomy (PRK). It’s a vision correction surgery like LASIK but different in a few ways. In layman’s terms, with either surgery, the goal is to expose a relatively superficial layer of the eye called the cornea, so that a laser can zap it into a shape that will result in a sharper image formed on the retina (in the back of the eye). The major difference between PRK and LASIK is how you expose the cornea.
With LASIK, you can use either a laser or a blade (a microkeratome) to make a superficial cut in the frontal / coronal plane, leaving a small portion of tissue intact at either the middle or the side. This basically makes a little flap of tissue with the hinge. You can open up this flap, laser the cornea into an optimal shape, then flop the flap back over like a band-aid. Several of my loved ones and friends have had LASIK, and most of them have felt nearly good as new the following morning.
With PRK, instead of making a flap, you chemically and/or mechanically abrade the surface epithelium over the cornea — you just scrub it off. You can then proceed to reshape the cornea with the laser, and afterwards a temporary “bandage contact” is placed where the epithelium used to be. This bandage contact is removed in about a week, when the epithelium has had a change to regrow. There are a few days of burning, stinging pain and a few weeks of blurry, distorted vision as the healing continues. Full results may not be apparent for 6 months or even a full year.
At the one year point, there are generally no statistically significant differences between LASIK and PRK in terms of visual acuity. Why then would I ever choose to have PRK over LASIK? Well, PRK is often slightly more affordable… but the ophthalmologist (note the h after the p — tricky spelling) I went to charges the same for either procedure, so I didn’t even have that.
Instead, it’s because of the flap. Apparently, the flap made during LASIK doesn’t heal quite the way it was before the surgery, possibly ever. While the risk of delayed flap complications seems to be extremely, extremely rare (perhaps 1 in 10,000? Lower? Please leave a comment if you have a better figure for this.), there are a number of case reports in the medical literature of traumatic flap dislocations even decades after having LASIK if someone is hit in the eye or what have you. Now even if this occurs, most of these cases end up fine — the doctors are able to reposition the flap and get the person back to pretty darn good vision (often 20/20) within a few days. However, in the worst cases, they may need a corneal transplant. Because the eyes are pretty wall protected against the immune system, some patients might not even need immunosuppression after a cornea transplant. However, it’s still a big deal.
PRK has risks as well. One of the more best known complications is “corneal haze.” You can think of this like a scar that occurs when the abraded epithelium is healing. It’s tough to say what the true risk of haze is because it varies quite a bit depending on the surgical technique and the demographics of the patient, but it’s definitely there — pretty much every study talks about it. Because I’m a young and a male, both of which are risk factors for haze, my ophthalmologist and I elected to use intraoperative mitomycin c (MMC). MMC is a chemotherapeutic agent that has been shown in numerous studies to help reduce the risk of haze. After the laser is done reshaping the cornea, MMC is placed onto the cornea for a few seconds and subsequently washed off, followed eventually by the placement of the bandage contact.
There is a whole lot more to the decision between LASIK and PRK, and both have risks. The drastically shorter and less painful recovery for LASIK is really an important point to consider. I almost couldn’t have PRK because the recovery time can be so long… I couldn’t find a time where I have three weeks of being visually handicapped. However, I’m glad I was able to squeeze it in. Honestly, the deciding factor for me was less about the surgery and more about me. Knowing myself, even though the risk of a traumatic flap dislocation is so extremely low, I would probably be paranoid about it… maybe for the rest of my life. I can’t imagine waking up and rubbing my sleepy eyes 10, 15, 20 years from now and still having my heart rate jump up a few beats as I wonder if I’ve messed up my eyes. I realize this is pretty irrational (I have close friends that are much more active than me — firefighters, military special forces, and one busybody mother-of-five — and none of them have had any issues after LASIK), but it was a deal-breaker for me.
One last piece of information that belongs in the introduction is an explanation of why I’m having vision correction surgery at all. My refractive error is -3.0 diopters OU (bilaterally). I’m 28, and it’s been -3.0 for a long time… perhaps a decade? I wore contacts happily and without any complaints whatsoever for many years. However, about two years ago, during my surgery rotation in the third year of medical school, I suddenly started having intolerable burning and tearing of my right eye after wearing contacts for more than a few hours. I tried changing contacts, contact brands, brand of contact fluid, cases… everything. I saw an optometrist and an ophthalmologist, neither of which noticed anything too remarkable about the eye, I tried steroid drops for a while, I tried “resting” my eyes for even a couple months between attempts at wearing contacts… but no matter what, each time I tried, my right eye got bright red and painful after only a few hours. I got a new set of glasses that looked pretty good, but I’d still put in my contacts to ride my bike, each time hoping they would somehow remain comfortable all day, like before.
Like biking, a few other situations were often problematic for glasses. I got a decent set of prescription sunglasses, but I hated having to remember to bring both with me on outings and road trips. I’d go flyfishing and have to trade out which I was wearing every time a cloud passed overhead. Some of the less trivial occasions were in the hospital — when you’re “scrubbed in” or doing a sterile procedure, you can’t adjust your glasses (because they’re not sterile). While therapeutic hypothermia has its place, patients often fare better when warm. Given a warm room and a technical procedure, I often get a little trickle of sweat down my forehead… which often ends up either on my glasses, obscuring my vision, or helping my glasses slide down my nose, where they’re useless to me. Then I have to ask someone who isn’t sterile to push them back up. If nobody is around… I have to figure something out quick. Having recently matched into emergency medicine, I can imagine a day sometime soon when sweaty glasses will be a complicating factor making a (potentially life-saving) procedure all the more difficult. No thanks.
Okay, well I think that’s all for this post. My next post should be up momentarily, since I wrote this all as one big post but decided to split it up. To find other posts in this series, scroll to the top and hit the PRK tag under the post title.
- Cui, M., Chen, X.-M., & Lu, P. (2008). Comparison of laser epithelial keratomileusis and photorefractive keratectomy for the correction of myopia: a meta-analysis. Chinese medical journal, 121(22), 2331-2335.
- Franklin, Q. J., & Tanzer, D. J. (2004). Late traumatic flap displacement after laser in situ keratomileuisis. Military medicine, 169(4), 334-336.
- Lee, D. H., Chung, H. S., Jeon, Y. C., Boo, S. D., Yoon, Y. D., & Kim, J. G. (2005). Photorefractive keratectomy with intraoperative mitomycin-C application. Journal of cataract and refractive surgery, 31(12), 2293-2298. doi:10.1016/j.jcrs.2005.05.027
- Shortt, A. J., Allan, B. D. S., & Evans, J. R. (2013). Laser-assisted in-situ keratomileusis (LASIK) versus photorefractive keratectomy (PRK) for myopia. Cochrane database of systematic reviews (Online), 1, CD005135. doi:10.1002/14651858.CD005135.pub3
- Solomon, K. D., Fernandez de Castro, L. E., Sandoval, H. P., Biber, J. M., Groat, B., Neff, K. D., Ying, M. S., et al. (2009). LASIK world literature review: quality of life and patient satisfaction. Ophthalmology, 116(4), 691-701. doi:10.1016/j.ophtha.2008.12.037
- Sutton, G. L., & Kim, P. (2010). Laser in situ keratomileusis in 2010 — a review. Clinical & Experimental Ophthalmology, 38(2), 192-210. doi:10.1111/j.1442-9071.2010.02227.x