Joel Hunter, MD Refractive Surgeon, Hunter Vision Updated 08/14/17 10:07 AM
One of the downsides of spending a lot of years becoming more and more specialized into a small, niche field is losing touch with how weird your very specific job sounds to others. Who among us hasn’t gotten a business card with a job title that says something like, “Chief Escrow Abilitance Officer” or “Vice President of Perennial Commodity Plantification”? I believe, after hearing enough people ask what a refractive surgeon does, that my job might be like that. There are something like…
At this point, I stopped writing and spent 15 minutes that I’ll never get back trying to find out how many refractive surgeons there are in the U.S. All I can say for sure is there aren’t enough for statistics to be available after a frustrating and futile 15-minute search on Google. That tells me it’s worthwhile to explain what refractive surgery is. I need this article to tell me something so I don’t lament that wasted time for the rest of this article.
Surgery is what you’d probably assume it is based on TV shows or just being around long enough to know how to read. It’s the refractive part of refractive surgery that’s less well-known. Refraction has to do with bending and focusing rays of light, and refractive is the adjective form of the word. If a surface focuses light, it is a refractive surface. If a lens focuses an image (which is made of light), it is a refractive lens. If a surgery improves how well someone can focus on images, then it is a refractive surgery. Since eyes are the only place we can do anything with light—actually, that’s not fair to skin’s role in using light for Vitamin D metabolism, so let’s start over. Since eyes are the only place we can do anything with focusing light, refractive surgery is eye surgery that makes eyes see better.
There are several forms of refractive surgery, all of them aimed at making light focus more perfectly to improve image quality. Leaving out the rare stuff that’s rare for a reason (it doesn’t work well), the three main ways to improve focus are reshaping a lens you already have, adding a lens you didn’t have, or replacing a lens that isn’t working. The more common names for these refractive surgeries are, in order: LASIK, Implantable Collamer Lenses (ICL), and cataract surgery or refractive lens exchange.
With LASIK, or it’s equally-able sibling PRK, the lens your eye is already equipped with is reshaped to work better. There are only two lenses in the eye, and LASIK is done on the lens called the cornea. You can’t reshape the lens inside the eye. We’ll get to why in a moment. The cornea can be reshaped really easily, and it’s been done in one form or another for the last 50 years. Refractive surgery existed that far back, but it existed the same way we can say computers existed that far in the past. That’s in the way you’d look at it and say, “Oh okay, I see how you mean that’s a [computer / refractive surgery]. It’s because you’re using a very broad, nay, unrecognizable definition about those [punch card holes / knifed cornea cuts].” Today, refractive surgery uses lasers that track the eye a thousand times per second and can painlessly sculpt the cornea into beautifully focused lenses.
Refractive surgery in the form of adding a lens is necessary when there’s just too much change required for it to be wrought on the cornea. Interestingly, corneal refractive surgery (LASIK and PRK) was done for these patients in the ’90s and early 2000s because there wasn’t a better option. Now, with ICLs a fraction the size of a pinky nail, even a prescription of -14.0 diopters is a breeze to fix. This is despite the fact that the glasses necessary to correct that prescription weigh enough to cause nose damage.
Replacing a lens is the last form of refractive surgery. If your lens is clear, but can’t autofocus up close causing a need for bifocals or reading glasses, this surgery is called refractive lens exchange. If your lens is cloudy, this surgery is called refractive cataract surgery. In a 15-minute surgery, the dysfunctional lens comes out, and a new, permanent, prescription-correcting artificial lens is placed in its stead. I mentioned earlier how we can’t reshape this lens and must replace it entirely. That’s because, in an absurd twist of fate, we’re super allergic to the lens inside our eye and it must be replaced if even the slightest opening is made in the capsule surrounding it. Isn’t that crazy? While it doesn’t have much to do with refractive surgery, that’s so fascinating I felt I should share it. In any event, this final form of refractive surgery is the latest and greatest in the evolution of the field. The reason it deserves that title is that people who couldn’t be helped with LASIK or ICL surgery finally have a way to get out of reading glasses.
Refractive surgery is a field measured in micrometers of tissue and nanometers of different wavelengths of light. Computer technology capable of operating within such precise margins has evolved rapidly in the last 20 years. So rapidly, in fact, that when I was in med school my current job didn’t exist outside of science fiction . The idea of using refractive surgery to change how light is focused in the eye has been around a long time. But the ability to actually get light to refract the way we want it to is so new that I can’t even find out much about my job on Google.