LASIK/PRK, part 1.
Just got my eyes fixed at Scott Hyver’s Daly City location south of San Francisco. Figured I’d provide a little bit of detail on the process, since most of the summaries I found while researching were either positive (and very short) or negative (and very long). In the case of the negative reviews, many of the entries provide a lot of whiny details but not a lot of medical background, sometimes even without a date.
Maybe this story will help out a little bit. Here’s my background - I’m 31, and had myopia with about a -7.5 diopter prescription. (Roughly 20/1100) My prescription hadn’t changed in nearly 4 years, although my glasses had started to feel a little bit underpowered. A stable prescription overall.
I’ll give a little background then some terminology. This has been of interest for about 10 years, but I was too cheap to pay for it. In the summer of 2006, I decided to seriously investigate LASIK (with wavefront in particular) at Coleman Vision in Albuquerque. I was approved, but didn’t quite go for it. Then Wind River came in and I ended up in the bay area.
After settling in, I went to Pacific Vision in San Francisco, and got turned down. The rumor is that if you’re not a really ideal candidate, you can be turned down by offices to keep their success rates up. I don’t know if this was the case, but I did get an elitist feel (from a technology perspective) at Pacific Vision.
As an aside, I was told at Pacific Vision that my corneas were thick enough, but too flat, and could result in halos. Instead, they wanted me to go with ICL as a replacement for LASIK.
Next, I went to Scott Hyver’s location in Daly City, on December 27, 2007. They approved me, particularly for PRK. And they could fit me in for surgery December 28. (I had reviewed a lot about Scott before going in, it really wasn’t an uninformed jump.)
Before I go into the details of the surgery, here are some terms:
LASIK (easy one) - the process of using an excimer laser to reshape the cornea to correct vision. A key part of normal LASIK is that a ‘knife’ is used to slice the cornea so it can be hinged back for the laser to do the work.
LASIK/PRK - (photorefractive keratectomy) this is the same as above, but instead of cutting a flap, the epithelium (special layer on the surface of the cornea) is scraped off, and the laser works from there.
ICL - This is a relatively new procedure (and currently twice as expensive) that is similar to cataract surgery. A slice is cut in the eye and pressure is maintained while a new (rolled up) lens is inserted. It unrolls in place and acts as a new lens, correcting vision internally.
Wavefront - A variation on the normal correction procedure. Rather than just taking off X microns of the cornea to get back to 20/20, Wavefront analysis takes a high resolution map of the cornea and accounts for the specific shape of the cornea. This lets the surgery correct for any local aberrations, correcting for minor irregularities in the cornea.
I have a slight abnormality in my cornea shape that made me a little better fit for PRK, according to Scott. All 3 locations indicated my cornea was thick enough to account for my prescription. (The higher the prescription, the more that has to come off to bring vision back to 20/20.)
I was comfortable with PRK - it has some significant differences from normal LASIK:
- A longer recovery time. Normal LASIK gives almost 20/20 vision immediately, once the flap is back. PRK leaves you with an open wound that has to heal, and for my prescription, takes months to heal.
- A longer track history. PRK is actually one of the older procedures (oldest?) still in use. It’s got almost 30 years of history, and the technology is well known with a low failure rate.
- PRK does not leave a flap that has to heal - instead, the epithelium grows back naturally (but slowly). Flaps always have a risk of being ripped open, and while rare, still a possibility.
- PRK actually _can_ provide better results, in theory. Since the wavefront corrections are at the surface, the epithelium grows in properly around them, whereas with a flap, the flap may not fit back as naturally as it would have without the corrections.
That’s the overview - next I’ll cover the actual procedure.