Autorefractors: Rise of the Machines


written by: Joel Hunter M.D.
Posted on April 17th, 2014

autorefractor

If you’ve ever been to an eye doctor, put your face in a machine, and been asked to stare straight ahead, chances are it was either an auto refractor that quickly measures your prescription for glasses, or that it blew a puff of air in your eye and made you hate eye doctors forever. If it was the second one, I am sorry. That machine, called a non-contact tonometer, measure the pressure inside the eye and used to terrify me when I was a kid. What’s worse, I found out decades later, it’s not even super accurate! There are much more accurate, less terrifying ways to check eye pressure. The Hunter Vision mission statement is that we will love patients well, and never shoot a surprise jet stream of air at their eye. I think that’s it, anyway. I don’t have the exact wording here with me.

If it was the first machine, the auto refractor, then it was much easier because all you have to do is look at an image of a barn or a hot air balloon, while it measures the prescription using invisible infrared light. It’s amazing technology. It’s even more amazing to me that it’s been around for several decades. And while it is more accurate now, a lot of the key principles of it are pretty much the same. The question is, will there ever be a time when an auto refractor is accurate enough that it can entirely replace the mind-numbing “better one, better two, orrrr….one? or two? orrrr one?…” test, which is called a phoropter.

The short answer is, I’d say no it will never replace it, but in general it is a bad idea to bet against technology. I would have been surprised if someone had told me in high school, “Joel, there will be a day about two decades from now when you will be sitting in a restaurant and actually get annoyed at a handheld device, that you personally own, because it took five seconds instead of two seconds to answer when you asked it, with your voice, ‘How many grams of carbohydrates are there in an avocado?’” So it would be unwise for me to assume that my current perspective is a good indication of future technology in general.

With that caveat, the reason that it will be hard to replace a human-driven phoropter entirely with an auto refractor is that there are variabilities in getting a good prescription that require active, creative thinking on the part of the examiner. To name a few, there are variabilities in people’s tear film (the glassy fluid layer on top of the cornea that actually focuses the light coming in), in people’s focusing muscles (with young people typically over-focusing, even when their eye is relaxed), and variabilities in what some brains want vs. others (one example being hyperopic—farsighted—folks that will hate and never wear a glasses prescription that actually have their full correction). So while a computer does a better job processing huge data sets, it has a harder time evaluating personal preferences for people. That’s a job for us humans.

The reason I do the final prescription check on laser day here isn’t that I’m trying to figure out their prescription, because we already know it in five different ways at that point. It is because I’m measuring what machines can’t; it is the prescription that a person will do best with based on who they are and what they need for their vision. The final check makes people nervous sometimes because they want to “get it right” but even that is part of the process here. Reading people and seeing what they hold most dear about their vision, which is different for a commercial pilot and an accountant, all becomes a part of calculating the best outcome possible. It isn’t a coincidence that very close to 100% of our LASIK patients are really, really happy. As a rule, I won’t bet against technology, but it is difficult to see today how our machines will get that part—the human connection—perfect.

Is LASIK a good name for a pet?


written by: Joel Hunter M.D.
Posted on April 11th, 2014

lassie

When we asked our staff to come up with questions that people might want to see addressed in this blog, someone put this one in. That means we have someone on staff that is either a real animal lover, really dedicated to LASIK, or is really horrible at coming up with questions. I choose to believe the second one. “When given a set of choices in which the correct answer is unknowable or irrelevant, choose the one that delivers to you the most happiness.” For example, Benjamin Franklin said that, and since there’s virtually no way to know if that is true, you can choose to believe me or not, whichever makes you happier.*

In any event, a deal is a deal, and I said I’d answer these questions, so today’s short blog will address this important question.

LASIK is a terrible name for a pet. The only exception I can think of is one of those fish with the huge eyes. It could be acceptable then. It is such a bad name for a dog that (and I swear this is true) Apple’s iOS software autocorrects “LASIK” to “Lassie.” You can verify this if you’re an iPhone user. If it doesn’t change it, then I look like a real liar, which is frustrating since I’ve had to go back and fix it for years now. But at least I can be glad that one of my emails finally made it through to Tim Cook.

So in conclusion, LASIK is a bad name for a pet. Go with something better like Champ, or Mike, or Spartacus, or Jim.

*I tried, but I can’t leave it there. Benjamin Franklin never said that. But it kind of sounds like he did, doesn’t it? Also this quote, “Early to rise and early to bed, makes a man invent bifocals, as I just have in my shed.”

My First Experience Performing LASIK Surgery


written by: Joel Hunter M.D.
Posted on April 10th, 2014

Amazingly, or frighteningly, an ophthalmologist is only required to have a weekend course on LASIK in order to be certified to perform the procedure. There are no boards exams for LASIK. It is part of the reason that the “see how many procedures your surgeon has performed” can be useful advice. Of course, it is still possible to do a bad job thousands of times (I once had a haircut from a lady at Great Clips that made me look startlingly like Hitler even though she probably did a thousand haircuts that week), but it is a lot less likely. The reason I chose to spend a year with Dr. Durrie, is that I wanted to be really, really good at LASIK before I started doing it on my friends and family.

That still means that there was a first patient, though. I remember her very well. Dr. Durrie had a deal where patients could choose to let the fellow in training do their procedure and pay a little less than if he was doing it. It was a good deal because they knew they were at one of the best places in the country, and Durrie would only let good things happen to their eyes. Part of that assurance was that he would only let me do a part of the procedure that I was comfortable with, then do that a bunch of times, before moving on to the next part within my skill set. For that first patient, that meant that I got to “drive the bus.”

“Drive the bus” is what Durrie called it when you put your foot on the pedal (the laser is fired by pressing a foot pedal with the right foot) and make sure the eye is lined up. The fact that there is an eye tracker that is unbelievably fast and precise means that lining the eye up is equivalent to saying “making sure the eye is underneath the laser.” So basically, as long as the patient doesn’t get up and walk around the room during laser, they’re going to be doing good. But on that first laser procedure, it felt like the type of responsibility that Presidents must feel.

Durrie did every part of the procedure except that one 6-second moment where the pedal was pressed. I switched seats with him, looked at the eye (already perfectly positioned) through the scope, pressed the pedal and watched. I said, “fannnntastic, this looks greeeeat, you’re doing greeeaat…” and in my head I thought, “WOOOAHHH!! AHHH I AM SHOOTING A LASER AT SOMEONE’S EYEEEYAHHHH!” There was a lot of adrenaline involved.

And that’s what goes away sometime between the first procedure and the thousandth. The adrenaline. Alex Honnold, who climbs mountains without a safety harness (and who’s videos make my palms sweat uncontrollably) had a quote in a 60 Minutes interview that was so good that I tried to write it down, but gave up because I couldn’t read what I wrote with it being smeared together with sweat. He said something along the lines of his ability to do what he does well depending on the fact that there is no adrenaline involved. If there is adrenaline, it means something has gone wrong, because everything should be smooth and controlled.

No matter what we do, whether it is a salesman’s first sales call, a singer’s first performance, or a doctor’s first procedure, the transition from good to great happens as we move from adrenalinized focus on the fact that we are doing something new, to controlled focus on the steps involved in doing it well.

What makes someone a non-candidate for LASIK?


written by: Joel Hunter M.D.
Posted on April 4th, 2014

eye_hiding

About once a week I will see a patient who was told that they are a good candidate for LASIK, but actually should probably avoid getting it. Several times a week, however, I’ll see a patient that was told that they wouldn’t be a good LASIK candidate, but is actually a great candidate. Most commonly, the person told they shouldn’t have LASIK was given “astigmatism” as the reason.

In 1998, it was excellent advice to avoid LASIK if you’ve got astigmatism. In 2014, though, even high amounts of astigmatism can be cured with LASIK better than with contacts or glasses. The improvement in technology in 16 years has been enormous.

A simple example of the fact that we can do things now that we couldn’t back then would be the concerned looks you’d get telling the 1998 LASIK researcher they could find the answer by “using their phone to google it.” But many doctors—including eye doctors—stick with guidelines created when LASIK was in its infancy.

So what makes someone a non-candidate for LASIK? There are a lot of special cases that require a consult to address, but the vast majority of non-candidates are advised against LASIK for one or more of three reasons:

  1. The cornea, clear dome on the front of the eye, that is treated by laser is too thin to safely treat with laser.
  2. The cornea has a shape to it that is too steep, too flat, or too lumpy of a dome to have predictable good results.
  3. The lens inside the eye, not the cornea, is too cloudy to justify doing LASIK to fix the prescription.

There are other reasons someone might not be a good LASIK candidate, but all of those reasons combined end up being only a fraction of one of these three. We have a lower candidacy rate at Hunter Vision than other LASIK centers because I’m pretty neurotic about every factor being perfectly aligned for someone to love their vision after LASIK. It means that I probably tell a few people they shouldn’t have LASIK that would have done well with it, but believe me, that is a way, way better situation than being told you were a good candidate when you weren’t.

Why You Shouldn’t Choose LASIK Based on Price


written by: Joel Hunter M.D.
Posted on April 3rd, 2014

gas_prices

The other day, I had a patient that had a lot of questions about price. In general, I try to avoid this discussion because something feels “icky” to me about a doctor talking money with a patient. I’ve done everything I can to avoid the misconception that I ever recommend a treatment because of money. Although it is understandable to consider all angles as a buyer of anything expensive, the truth is the cost of a procedure has 0% to do with the medical side of the practice. An eye is either an amazingly good candidate for LASIK, a candidate with some extra details to discuss (e.g. “you might take an extra day to get to 20/20 afterwards because of such and such”), or not a candidate. My definition of non-candidacy is always the same: “Would I do LASIK on this person if they were a family member?” If the answer is “no” or “hmmm…maybe?” then I tell that person they should not get laser vision correction.

But money is important because we need it to live since the year isn’t 10,000 BC. Then I would say wheat is important. So money questions need to have good answers. And this nice lady had a lot of money questions. In particular, she wanted me specifically to answer why 3D LASIK here at Hunter Vision costs more than most of the other LASIK places she’s looked at. It meant that I had to articulate the reasons in a way that I don’t normally, and it turns out it was helpful for me as well. Sometimes it’s a good exercise to explain something you understand to another person, because it makes you more aware of the details yourself. This is understood by anyone who’s had a 4-year-old ask them why fish can breathe underwater.

The main point, I realized as I talked to her, was helpful enough to both of us that I thought I’d write it out here in a blog. It costs a certain amount to run a business because things like office space and great employees and equipment cost money. Lasers, for instance, have costs measured in hundreds of thousands of dollars, and then measured in thousands of dollars to use each day even after you own them. In order to be able to pay for all of these “fixed costs” (is that the right word? I think it is. I should ask Josh.) the money coming in has to be at least equal to them. Gosh, this is boring me to death. I would have made the worst businessman. Just read this last paragraph and we can move on to better blogs about interesting things like how eyes work.

When Josh and I opened Hunter Vision, there was the choice to have me, as the surgeon, involved in details of helping patients and the general experience here, or to hire people to do all that while I just fire the laser. If you hire people to do that, as is common in most of medicine, you can see way more patients and charge them some percentage less because there are so many of them. But, I want to be there for people. That’s why I became a doctor. So I spend a lot of time with each patient. I’m the one that personally and neurotically checks each measurement that will determine their treatment. I make sure each patient can email me or call my cell phone at any time they need. I sleep less, but sleep better when I —the guy doing the surgery—am crafting every step before, during, and after surgery. And you know what? People see better because of that. There is a level of nuance that can’t be delegated. The only downside to it is that we can help fewer people because I only have 24 hours in a day. But wow, do I feel better about it than having discount prices because we pushed as many LASIK and cataract patients as possible through our clinic.

Do you have any eye surgery day rituals?


written by: Joel Hunter M.D.
Posted on March 28th, 2014

Mismatched Socks

The other day, someone asked if I have any eye surgery day rituals. Well, obviously there’s the one where I have Alpha-Bits cereal for breakfast and eat only the letters J, O, E, and L, but that qualifies as less of a ritual and more as an example of just being prepared.

In all honesty, even though I don’t have a ritual, superstition and excellence at a job are often found in the same person. Pavarotti always kept a bent nail in his pocket when performing. Napoleon had a superstitious fear of cats. Really, to have a complete case of Napoleon Syndrome, you must be short, arrogant, and hate cats.

I used to have a ritual that I would wear mismatched socks on cataract surgery day when I was in residency. That may seem odd to you, as it does to me now, but I remember it was pretty important to me at one point. Then one day, I had a complication (the patient ended up doing great) while wearing them and realized that superstitions aren’t nearly as helpful as knowing what to do.

They say that ideas we hold that were not formed by logic cannot be changed by logic, which is to say, crazy people gonna be crazy. Well, I’m proud to say I proved them wrong because my socks match perfectly today.

What eye technology do you most want to see advanced?


written by: Joel Hunter M.D.
Posted on March 27th, 2014

eye_tech

This question was submitted by Claire Jordan. Claire is our Director of Strategic Partnerships at Hunter Vision.

When given an opportunity to make a new partnership, we ask, “Is this strategic?” And if the answer is yes, then Claire directs it. (When the answer is “no,” we give task of directing it to our Director of Unstrategic Partnerships, who is my four-year-old son. He is currently directing our unstrategic partnerships with his two stuffed animals: Bear Joel and 7-11.)

Claire does a wonderful job in her role because she possesses a rare combination of two gifts: she is ruthlessly organized, but also delightful to be around. She also has a British accent so everything she says sounds important, and probably is.

She asked me the other day if I’d write a blog about what technology in eye medicine I’d most like to see advanced if I could choose it. The answer to that one was pretty easy for me because worldwide, the cause for blindness, by a very wide margin, is plain old simple-to-fix cataracts. Outside of developed countries, it accounts for close to 50% of blindness, while all the other eye problems combined make up the other 50%. But that fact, to me, isn’t the most amazing one.

Most amazing is that there is a procedure that can completely cure blindness from cataracts for less than $20 per eye. It is a different technique than modern phacoemulsification used in developed countries, but has a success rate equivalent to it! This was proven by one of the greatest modern cataract surgeons in the world. David Chang MD is a cataract surgeon of such magnificence that his talks at eye conferences cause mass swooning in a way that would make the footage of his audiences hard to discern from old footage of the young women at Beatles’ concerts.

The Himalayan Cataract Project, which has now spread globally far beyond the Himalayas, has set out to cure preventable blindness from cataracts. The two men at the helm, Sanduk Ruit and Geoff Tabin are both the type of people whose lives would make a fascinating book. Luckily someone else also thought so and Second Suns was written to tell their story. Rather than summarize it poorly here, I’d say you’re better off reading it. If you’re looking for a good book to make you feel encouraged about the world, you’ll like it. It’s not about eyes as much as it is about heroes and hope.

So that’s the answer to the technology I’d like to see advanced the most. It already exists, and in this case the world will be better for it advancing geographically rather than technically. I don’t dream about retirement, but I do dream about Hunter Vision getting big enough that I can spend a lot of time working in these places to help blind people see.

I remember asking God to perform little miracles (“move this ceiling fan”) to bolster my faith when I was younger; what I didn’t realize at the time is that there are miracles happening all around us that my world was too small to see. Ironically, it’s just that we get to be the ones to make them happen if we stop sitting around asking.

About Ortho-K Contacts for Overnight Vision Correction


written by: Joel Hunter M.D.
Posted on March 21st, 2014

woman_sleeping

I get asked about Ortho-K contacts lenses about once a month, so I thought it’d be worth writing a little bit about them in case it helps someone trying to research the idea. Ortho-K contacts are worn at night while you sleep and taken out in the morning, leaving myopic (nearsighted) people with clear distance vision throughout the day. These contacts work by reshaping the thin, clear layer of skin on the surface of the cornea (which is the clear window on the front of your eye). The cornea, like any lens, focuses light based on its shape. The more curved the lens (in this case, the cornea), the more power it will have. Though that seems like a good thing — because knowledge is power, and knowledge is good, therefore power must be good — this is actually not true at all. It is a silly syllogism. Despite every effort to not write this horrible joke, I failed.

If an eye has more power than it needs (because the cornea is too steep of a dome), then objects are really clear up close, but very blurry far away. That’s what myopia, or nearsightedness is, an eye with too much power. So, ortho-K lenses basically flatten down the clear skin (epithelium) on the surface of the cornea to make the dome less steep, and therefore less powerful, and viola! Distance vision becomes clear.

They work best for people who are mildly nearsighted, generally in the -2.00 to -4.00 range and without astigmatism. And there are a lot of people who like them. I’ve found that the people who tend to get the most benefit out of them are young athletic folks who don’t want to wear contacts while they’re swimming or doing other sports games (is that what we call them? I am not an athlete). The risk of Ortho-K is relatively low if you take good care of the contacts, but like any other contact lens, the risk of infection leading to vision loss increases if you don’t clean them well and follow the rules on wearing them. Probably the biggest downsides to them are that you sleep with a piece of plastic in your eye, and there’s chance of an infection if you’re not careful.

Oh, since this is a blog on a laser vision correction website, I guess I should mention that people who use Ortho-K contacts can still be candidates for LASIK. Actually, with the demographic that tends to wear them, they are usually really good candidates.

Night Vision: Why cats see more in the dark than you.


written by: Joel Hunter M.D.
Posted on March 20th, 2014

Glowing Cat Eyes

I guess I should put a disclaimer at the beginning of this to say I am not a “cat person.” But honestly, I feel like it is more accurate to say every cat I’ve met is not a “person cat.” If you love cats, then please know that I respect cats, and even more, I respect you. If you’re a “cat person” it means that you have self-confidence in abundance, and that unlike me you’ve never let a cat make you wonder “why am I so uninteresting and stupid?”

If cats could talk, they would probably use that ability as a another way to ignore you by not talking to you, only on purpose. But if they did talk to us, I imagine the conversation would be mostly about how much better cats are than people. And in one area, they would be 100% correct. Cats have night vision that is far superior to ours. They hunt at night and have no need for artificial light to do it. They see prey in the dark that we could never see without a flashlight. Owls have the same ability to an even greater degree, but they are less smug about it. Probably because of their wisdom.

For an eye to see something, enough light has to hit the retina (which lines the inside of the eye) to activate its photoreceptors, called rods and cones. For humans, the quality and sharpness of vision is a much bigger deal than night vision, so our photoreceptors sit on a dark, pigmented layer that absorbs extra light which could otherwise bounce around inside the eye and blur vision. But for animals that need to see in the dark, the eye is adapted to increase night vision even if it means a decrease in sharpness of vision.

Nocturnal animals’ eyes have a retina that sits on a layer called the tapetum lucidum, and it is basically a built-in reflector. This reflecting layer bounces light that has passed through the retina’s photoreceptors back into the eye so that every little bit of light will provide the most vision possible. It lets them “see in the dark,” but that only encompasses what looks dark to us but isn’t. Have ever been outside at night and looked up and seen the moon, and then looked around you and seen only darkness? The same light from the moon that your eye focused on your retina when you looked at it is also shining on everything around you, you just can’t see it. Cats, with their tapetum lucidum, are able to look at that same scene and see the details of it bathed in moonlight.

So if you’ve ever seen a photo where the flash turns the people’s eyes red, and a cat’s eyes into glowing orbs, now you know the reason. You were looking at retinas that absorb light next to one that reflects light. Or that cat was possessed.

How did you choose the name “Hunter Vision”?


written by: Joel Hunter M.D.
Posted on March 15th, 2014

Hunter Vision Door

Kaila is one of our ophthalmic technicians, and she just may be among the best ophthalmic techs on Earth. She’s going to medical school this year, and it makes me happy for humanity and sad for Hunter Vision. It’s probably about 60/40 happy to sad. She was kind enough to write a list of questions that might be good subjects for blogs on LASIK and cataract surgery. One of the them was, “How did you guys arrive at the name Hunter Vision for the practice?”

My brother Josh and I started actively planning out the details of this place about eight years ago, and without really deciding to, we just referred to it as Hunter LASIK. We still have a 30-page Word document entitled “Hunter LASIK Manifesto” that was written over emails back and forth over the course of a year while I was in Virginia completing my internship. We realized that it’d be better not to pigeon-hole ourselves with the name of just one procedure in the title of the company. At some point, you can’t just keep adding services to the title or it becomes unwieldy to put a sign out front that says, ‘Hunter LASIK & Cataract & Glaucoma & Bionic Eyes & Eye Color Changing & Personal Robot Eye Repair.”

We thought about Hunter Eye Clinic, but felt like people don’t love the idea of going to a “clinic” and we wanted the place to feel homier and more peaceful than a clinic anyway. The first version of Hunter Vision was actually Hunter Precision Vision. Then one day we shortened it in a conversation to its acronym and realized that “the new HPV place in town” didn’t generate the right kind of buzz we were looking for. But we still liked Vision. And we wanted Hunter in the name since it was our last name and since our dad, also Joel Hunter, had done us the favor of making Hunter a likable name by being a genuinely good man who helped people in Orlando for 30 years. Boy, do I like my father. That’s a whole different blog.

So there it was, Hunter Vision became the name. Just like naming your kid, it is hard a few years in to imagine the name being anything else. I speak from experience because my son is also named Hunter Vision.

I have a lazy eye. Will LASIK fix it?


written by: Joel Hunter M.D.
Posted on March 14th, 2014

Lazy Eye (So to Speak)

Having one eye that is weaker or “lazy” is not uncommon. In the world of ophthalmology there are shelves of textbooks dedicated to this single subject. While there are many causes for eyes that do not track together all of them have one thing in common: your brain wants information from both of your eyes to build the best possible visual picture. If one of your eyes is consistently not looking in the direction that your brain thinks it should, or is much blurrier than the other, then it will discard the data from that eye so that you don’t get a confusing image. It’s actually pretty incredible that we are built to have that happen automatically! This is only true in childhood, by the way, once adulthood is reached, you can have a blurry eye for years and it will still be able to see well when corrected, as any LASIK patient will tell you, often without you even asking them.

The medical word for this is amblyopia. Amblyopia just means that one of your eyes wasn’t sending enough good data to the brain and has therefore been more or less turned off by your brain. While there are many fixes for a “lazy eye”, there are very few things that can help it to see better once it has become amblyopic. Most young children can be helped early on if a lazy eye is detected and the lazy eye can be encouraged to strengthen by patches, corrective surgery, or a host of therapies that can help to make it track better before the brain decides it doesn’t want the data from that eye any longer. These therapies generally need to occur before age 9.

Interestingly, new research has shown that a program called Revital Vision can help amblyopia even in adulthood. No one (in eye world) would have believed it before the data came out, but it can improve amblyopic vision on average about 2.5 lines on the eye chart. That is the equivalent of a 20/50-ish eye becoming 20/30. It’s fun when scientists create stuff with their brains that help other people’s brains. I’m getting dangerously close to saying the word “brains” enough that it loses all meaning to me for a time.

And now for the short answer to a long blog: amblyopia cannot be fixed by LASIK for most people. There are certain cases in very young children where laser surgery may be an option as part of the solution, but for adults we do not currently have a laser solution. I see patients with great regularity that have an issue like this one and I really look forward to the day when laser technology can help. We’re not there yet, but great minds are making progress every day! Thanks for your brainy interest in brains to read a brain blog brain about brains. Yep, the word has lost all meaning.

Why do I have to get dilated at a LASIK consultation?


written by: Joel Hunter M.D.
Posted on March 13th, 2014

Dilated Pupil for LASIK Consultation

You know what people hate? Getting their eyes dilated. They hate it with a passion that is usually reserved for toe stubbing or political advertisements. I understand that. Spending several hours with blurry vision and having the sun feel like it was turned up to supernova setting is not fun. If it wasn’t really important, I’d skip the whole thing for people coming in to see if they are a good candidate for 3D LASIK. There are two big reasons, however, that it really matters.

First, it is important to see that, as I put it in clinic, “everything is where it should be inside your eye.” Dilation opens the pupil up to usually around 6 mm to 8 mm, and although that sounds like a small window to look into the eye, it is a huge difference when compared to a 2 mm pupil. A 6 mm window isn’t a window that’s 3 times as big as a 2 mm, it is 9 times as big. That’s because the area of a circle is 2 x pi x the radius squared. That’s probably not important to get the point across, but I figure since we were all forced to memorize that at some point, it’s nice to find places where we can mention it.

But concerning your eye, the truth is there’s almost never a problem inside that surprises us during a LASIK consultation. It does happen though, and if you’re that 1 in 100 that it happens for, that really matters. But it is rare. Most of the time, if something isn’t right inside the eye, you’re the first to know. You’ll think something like, “Well then, there wasn’t a big gray cloud blocking the lower half of my vision in just the right eye yesterday, but now there is.” Then we can find the cause by looking inside the eye after it has been dilated.

The second reason that dilation is really important for a LASIK consultation is the more important one for almost everyone. Dilation makes the focusing muscle inside the eye relax. It is amazingly common that people are “over-focused.” It’s so common that I see it several times a day. What’s it look like when that happens? It means your prescription is higher than it should be. You may be in -3.00 contacts, but your true prescription is only -2.50. And if you’re younger than 45, there’s no reliable way to know that unless you get dilated. If you get LASIK and fix a prescription based on one that is too strong and “over-focused,” you’ve just doomed someone to needing reading glasses years before they would have otherwise.

There are a lot of LASIK surgeries that have been performed without a dilation before surgery. Sometimes it even works out okay for those folks. But when we’re talking about your eyes, it is always best to do the safest, most reliable diagnostic workup possible. And it is important to look ahead and make sure you’re not giving someone bad reading vision tomorrow to give them good distance vision today. Overall, it is worth the bummer of dilation and the consequent few hours of blurry vision to make sure of that.

Why remove my contacts for a LASIK consultation?


written by: Joel Hunter M.D.
Posted on March 8th, 2014

Contacts

LASIK takes eyes that do a bad job of focusing and makes them do a good job of focusing. It is able to do that because it can reshape the natural lens on the front of the eye called the cornea. What’s interesting about the cornea (honestly, what’s not interesting about the cornea?!) is that it has a thin layer of skin called epithelium that is constantly being replaced and remodeled. Contacts warp that layer of epithelium. It is the microscopic equivalent of taking your thumb and pressing it into modeling clay.

When we take the pictures and measurements of the cornea that will tell the laser how to reshape the cornea so that it will focus light correctly, we want it to be based on the cornea’s natural shape. If the treatment with laser is decided based on the shape of a warped cornea: (1) it won’t be accurate, and (2) it probably won’t be a candidate for laser in the first place. Many times, I’ll think, “The 3D images of this cornea make it look just crazy”* and then 72 hours after contact lenses have been taken out, it will look perfect. That’s why contacts bugger up LASIK evaluations.

*Every now and then, I guess it would be good to clarify that there is more science to some of this than the descriptions I give. In this case, “crazy” would mean irregular, non-orthogonal astigmatism or an inferior to superior difference in curvature of greater than 1.8 when measuring 1.5 mm above and below the corneal vertex.

What do eagles see that we don’t?


written by: Joel Hunter M.D.
Posted on March 7th, 2014

Eagle Vision

Katie is the Director of Hunter Vision’s Community Outreach. If you think that role hasn’t played an influence in your life, well, you may be right; you also may be wrong, though, and the way to tell the difference is if you’ve ever seen a Hunter Vision booth in your life. Many times a week, and at some points, many times a day, there are kind people from Hunter Vision handing out bananas, or snow cones, or coffee at different community events in Orlando and answering people’s questions about 3D LASIK or laser vision correction in general. She’s wonderful. But that’s not the point of this blog. The point is to answer a question that her husband Joe asked me. He is also a fine example of a human being, but I’d better move on to talking about vision before this blog hits a critical level of digression.

Joe asked why it is that eagles have the ability to see so much better than humans. It’s a great question. You may have heard a factoid at some point that eagles have 20/2 vision (that’s not a typo), and that it correlates to something similar to reading the date on a quarter from across a football field. You may have heard it from me, at a party we were at, right before you found a polite excuse to end our conversation so that you could go talk to someone interesting. Either way, the truth is that eagles, and birds of prey in general, have among the most impressive eyes on earth. There are two main reasons for this, and one of them actually has something to do with 3D LASIK.

The eye is like a camera, and because of that, two of the biggest influences on sharpness of vision are the quality of the lens and the quality of the film on which the image is focused (See? Just like a camera!). The “film” inside the eye, whether in an eagle or a human, is called the retina. How small or fine an image may still be discernible is determined by how close together the light sensors (cells called photoreceptors) are packed. In an analogous way, it’s a lot like what determines how high the definition or how sharp the image is on an iPhone screen, or TV screen. The more tiny pixels that are covering the same amount of space, the better the image will be. In this analogy, an eagle’s retina would be like an iPhone’s Retina display (well, that analogy worked out better than expected) and our human retina would be like the display on one of those old indestructible Nokia phones that only had one game, that was called “Snake.”

The other reason has to do with the quality of the lens. The lens on the front of the eye is called the cornea. When a cornea is flat in the center (a 3D geometric shape called “oblate”), it has poor fine focus. When a cornea is steeper in the center (this is called “prolate”) it offers higher resolution. Eagle corneas are hyper-prolate. They were built to see a very tiny zone of very high definition. When you hear about vision side effects of LASIK from 10 years ago, almost always it has to do with the laser making the cornea more flat in the center than it should be. A flat, oblate cornea will have a much higher chance of bad night vision, poor contrast sensitivity, and regression toward it’s old glasses prescription. Part of 3D LASIK is that we use a Wavelight laser that was specifically designed by some very smart German engineers to better keep the natural prolate, steeper-in-the-center, shape of the cornea.

So while eagles see better than we do because they have a better retina, they’ve never built a laser that can shape the cornea to correct vision like humans have. So we’ve got that going for us, which is nice.

How long will I be out of work after LASIK?


written by: Joel Hunter M.D.
Posted on February 28th, 2014
It says a lot about people that one of the most frequently asked questions I get during LASIK consultations is about how long they will need to take off work to get LASIK. It seems like a waving American flag should appear behind them and it makes me proud. There are 20 questions about how early they can get back to their job for every 1 request for a “get out of work” note. As my brother Josh would say: ‘Murica. Well put, brother. ‘Murica, indeed. 

The answer is easy. Almost 100% of the time, people can have the LASIK procedure on an afternoon and be back to work the next morning after a quick one-day post-op check to make sure the eyes look good. There are a few times a year where someone will poke their eye (usually an accident and not Munchausen syndrome) and I have to do an easy fix that morning. I’ve never had a patient that didn’t do great after that, but it pushes the timeline back a day.

So if someone is getting married at 9:00 AM the next day, maybe get LASIK the week before or after, so you don’t tempt fate to make you the one in a million that accidentally pokes yourself in the eye with a chopstick. Otherwise, people that have LASIK on Friday can plan for a normal weekend.

What are those spots I see floating in my vision?


written by: Joel Hunter M.D.
Posted on February 27th, 2014

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Chances are if you’ve ever looked up at a cloudless blue sky, you’ve seen little spots floating around in your vision. Since the general public usually comes up with better names for scientific phenomena than scientists, these floating spots are known as “floaters” to most people and as “vitreous syneresis” to scientists. Another example of a good, descriptive name vs. an obscure, scientific name is a “housefly,” which biology majors spend years learning to call “drosophila melanogaster.” It can sometimes take years for a scientist to unlearn the useless name of objects, and lead to frustrating situations. “Harriet, bring me the drosophila swatter! No, no! This is the orthoptera spray! Gahhh!”

Back to the floating spots in your vision, which can come in all shapes and sizes. The are tangled up pieces of protein and gel inside the eye. The whole eye holds about 5 milliliters of fluid, and over 4 of those milliliters are a gel that you’re born with called “vitreous humor.” As a kid, the vitreous is the consistency of jello. As 100-year-old, that same vitreous is the consistency of water. Between those two ages, the vitreous is liquifying unevenly and forming little water pockets. What happens to those big (on microscopic terms) strands of proteins and other molecules where the water pocket forms? They bundle up into little tangles that then get stuck in the surrounding gel. And there they sit, suspended like pineapple chunks in jello. Only they annoy people even more than pineapple chunks in jello.

The wiggling and dancing that floaters do at the edge of the vision is a result of the natural, darting movements of the eye, called “saccades.” Those saccades are usually used to find objects in our peripheral vision and lock onto them. But it’s impossible to do that when the speck you’re trying to see is inside the eye because it moves when your eye moves! Even if you slow your eye down and try to “follow” the floater, it will slowly move along with your eye, just outside your central vision. It’s no wonder they annoy people. It’d be like trying to locate the pebble in your shoe, and after shifting your socks and readjusting your shoe, realizing it is inside your foot. Everybody gets floaters, because everyone gets liquified eye gel called vitreous syneresis. I used to think that knowing what causes them would make them less irritating to people, but I’ve found out over time that isn’t true. Which makes sense when I think about it, since in light of the previous metaphor, it’s equivalent to me saying, “Ha! Good news! I know exactly what the problem is, you’ve got a pebble inside your foot! But don’t worry, it’s natural.”

One last point: if the tiny specks you are seeing when you look at a blue sky are moving with a purpose and not related to your eye movement (almost like ants marching by), that entopic phenomena is caused by white blood cells squeezing one by one through the capillaries on your retina. Neat, right? Eyes are neat.

The 5 Best LASIK Surgeons in the U.S.


written by: Joel Hunter M.D.
Posted on February 26th, 2014

Sometimes, patients will ask me, “If you were getting LASIK, who would you go to?” and my answer is always the same, “I did have LASIK, and I did my own, using a complicated system of mirrors.” Every once in a while someone won’t realize I’m joking and then I’ll feel bad because I have to immediately confess that I was just trying to say something entertaining, but I don’t want them to feel silly for believing me. It’s the same reason I would make a terrible magician. “Sorry everyone, you see, my assistant just scrunched her legs up into this first box and I never cut her in half with this big saw. This saw isn’t even a real saw. I apologize for deceiving you.”
The truth is, there are several LASIK surgeons who are incredible at their job and I wouldn’t hesitate to let operate on someone I care about. Lewis Groden MD, who operates in Tampa, FL, is the man who did my LASIK, and he is one of those people. He was my mentor through residency and was the one who built the foundations for my understanding of refractive surgery. And since I get the question a fair amount, and I thought maybe it could be helpful for people living other places in the country, here’s a “Top 5″ list (of refractive surgeons):

1. Dan Durrie MD

He’s the founder of Durrie Vision in Overland Park, KS. I did my fellowship with him. I quickly realized a few weeks in that I was right to have so desperately wanted to learn from him that I moved my family to Kansas. I realized it when all of the doctors that write articles in ophthalmology magazines, and speak at the big conferences, were coming to see Dr. Durrie to learn from him. This happened every week. Part of my job would there was to give some refractive surgery big wigs a tour or an explanation of the new technology we had.

2. Stephen Slade MD

His clinic is in Houston, TX and he was the co-writer of the study (with Dr. Durrie) that coined the term Sub-Bowman’s Keratomileusis (SBK) for the new, improved LASIK technique done entirely with laser. He is also very kind and has a voice that could be, and is, regularly used to make the most anxious patient feel like they are entering into hypnosis-level relaxation. Almost every new laser or technology goes to his clinic first for him to put it through the paces.

3. Vance Thompson MD

Many people south of the Mason Dixon line may never have heard of this great man without reading this blog, and that alone would make writing it worth it. He founded a practice in Souix Falls, SD that is one of the most amazing I’ve ever seen. Even the building itself is a masterpiece with huge, 3-story, floor-to-ceiling windows offering vistas for miles across the plains. But much more important, Dr. Thompson is a surgeon so brilliant and prolific surgeon that many patients drive hundreds of miles just to have him as a doctor. Also, he is the nicest guy I’ve ever known. I mean that literally. I may someday meet someone nicer, but I will only believe it after I verify that it is not him in a disguise.

4. Karl Stonecipher MD

He is the winner every year of the Coolest Name in Ophthalmology Award. His practice is in Greensboro, NC and he’s been involved in a lot of studies to advance LASIK technology. It’s also exceptionally rare to find a doctor who is a great researcher that is also a really talented public speaker. Most speakers in ophthalmology make you think, “Yes. Clearly this is a man who prefers math to speaking with people.”

5. Marguerite McDonald MD

She also practices in New York, but she was in New Orleans for years before that. She was the first in the U.S. to perform excimer laser on a person. Lasers have gotten a lot better since the late 80s and she has been there for all of it. Dr. McDonald also a world leader in dry eye treatment. While out at dinner with her once, she saw a picture of my son and said that he was very handsome. It was around that time that I objectively realized that she was not only a great surgeon, but also a delightful person.
There are a lot of other great LASIK surgeons in the country. They all have the same two things in common. They are very smart, and they care as much about your eyes as much as they would care about their best friend’s eyes. If those two qualities are there, everything else will generally fall into place.

Can I get LASIK if I hurt my eye as a kid?


written by: Joel Hunter M.D.
Posted on February 21st, 2014

I’d like to start by telling you a story about a boy named John. John was a strong young man who lived in the backwoods of the midwest. He spent his days working the cattle and maintaining the family farm. One day, at the age of 6, John was mowing the back pasture and not using his eye protection as was advised by his eye doctor and his tractor’s user manual. John was hit in the eye with a small projectile from the mower. The shrapnel hit just outside the limbus. For those not familiar with eye anatomy, the limbus is right at Schwalbe’s line. What’s that? Near the palisades of Vogt? Well then nevermind; the point is the injury didn’t have any effect on his chances of LASIK later in life. The clinical details really took the punch out of the surprise ending I had: “He went on to get LASIK on his 18th birthday.” So, in order to rescue the wow factor for this story… that boy went on to become John Adams, second President of the United States.

The moral of this story (with minor details changed for illustrative purposes) is that LASIK is often still an option for those that have experienced an eye injury in the past. We look at everything while you are here for your consult and make sure that we have a thorough history of your eye health. There are times when a past corneal scar (located where the laser treats the eye) can make or break the decision for whether or not LASIK is the best procedure for you. However, it is far more common that a past eye injury which you remember vividly (they are hard to forget!) will have little to no influence on your chance at getting perfect vision without glasses.

If you are wondering if you are a candidate, but aren’t sure if a previous eye injury would allow you to have the procedure, you can dig for more information on this website and then come and see us when you are comfortable with letting me look at your eyes. We purposefully make the consult free for everyone because we want everyone to get trustworthy advice on their options for seeing the world better. Honestly, sometimes the best gift we can offer someone is a genuine bit of advice to not let anyone ever laser their eyes.

So if you want to see better, but always assumed you couldn’t, you can always stop by here to figure it out. A lot of times the answer is “yes.”

Can computer screens compromise my eye health?


written by: Joel Hunter M.D.
Posted on February 19th, 2014

Z88.3 asked me to come to the station and talk about whether or not looking at computer screens all day can damage your eyes. There was an article in USA Today that implied eye health could be compromised by the screen light. Ironically, I didn’t see the email or the article because I can’t read a thing on my computer screen because I have three layers of protective screen shields on my monitor. Plus, I  wear very heavy glass goggles and lead blankets, like the ones they put on you during X-rays at the dentist, when facing a computer. Once a co-worker told me about the email, I did some research and found that I had overestimated the amount of dangerous radiation coming from computer monitors. By no less than 100%! I was relieved. Then I thought I should learn to be less sarcastic before going on air at Z88.

If you’re reading this from some other state than Florida, Z88.3 is our local “Positive Hits” station. It’s the most popular station in Orlando because people like to know they can listen to it with their kids in the car and not worry about what they’ll hear, and because people like to be happy and encouraged. And that’s what the Z genuinely offers listeners. It’s a wonderful thing. Part of the reason that I was pumped about a chance to talk about “Computer Vision Syndrome,”* is that I might be able to give people one less thing to worry about. If you wonder why I put that in quotes, I wrote a little bit about why people shouldn’t stress over looking at computers at the end of this blog.

jdh_z88

Overall, the experience of going to a radio station to be on the radio was not as stressful as it seems like it should be. Most of that was because Tyler and Tracy (Ellis was out) are two of the nicest people I’ve ever met. As they interviewed me about eyes, they just had a conversation with me as if there weren’t giant microphones in front of us. Knowing that this conversation was being broadcast to more people than I talk to in a year, however, is still pretty hard to forget. I talk about vision around 12 hours a day, so that part was fun and felt natural. But also there was a different part of my brain shouting, “What is happening?! Why are we ignoring these huge microphones?! Oh man, these microphones are huge and your voice is weird!” Once I listened to it later and heard that I didn’t say any of those things out loud, I felt good about the whole thing.

*Computer Vision Syndrome is a somewhat made-up name for the natural eye fatigue caused by concentrating on something up close for a long period of time. You blink less and your eyes get dry when you concentrate. You also use eye muscles to focus up close and those muscles get (temporarily) tired. Using high-quality artificial tears, and taking a break to look across the room for a minute every now and then can eradicate Computer Vision Syndrome globally. If you’re 40 or older, a pair of reading glasses might help make the computer screen a little less of a strain, but this is because you are reading, not because it’s a screen. Everything we see is because photons of light are flying into our eyes from the objects we are seeing, whether that is a computer screen or moonlit walk on the beach. The amount and intensity of photons needed to cause damage to the eyes is huge, and we usually see it from arc welding or people who stare at the sun through binoculars. UV light (which everyone who has been outside has been exposed to) is high energy light that can cause longterm eye problems. Since we know long-term damage like macular degeneration increases with age, it is good to wear sunglasses when you’re outside to block UV light. But the amount of UV light emitted from a computer screen is 0%. That’s not rounding down from 0.0001% or something, it is actually 0%.

Can Cataracts Grow Back?


written by: Joel Hunter M.D.
Posted on February 14th, 2014

Since eyes almost always get worse over the decades starting at age 40, people rightfully assume that they will have to get new glasses every couple of years. It is part of the inexorable decline in vision. So when people ask if their eyes will continue to get worse after cataract surgery, or if cataracts can grow back, it is a good question. The answer is that if the eye stays healthy then then the vision will stabilize permanently after cataract surgery. And cataracts never grow back.

The key to the answer is that almost always the cataract — the cloudy lens inside the eye — is the cause of the decline in vision. The lens loses focusing power and clarity and so the glasses have to be continually changed to compensate for that. Once the cloudy lens is replaced by a perfectly clear artificial lens (made of acrylic or silicone), it will not change. The one thing that has been getting worse is now not only completely better, but it will stay that way.

When I say “cataracts never grow back” I should clarify one thing. The new, non-changing lens that is put in the eye is placed specifically in a capsule in the eye that held the old cloudy lens. We do that so that the new lens will sit right where the old one did. In about 50% of cases, if you look close enough, you can find a little bit of cloudiness to that capsule at some point between 3 months and 30 years after the surgery. This is cleared by a 30 second laser procedure that is covered by insurance. People refer to it as “second cataracts” which is incorrect and confusing, but either way it is easily fixed one time and then never has to be fixed again.