Our Q & A today is with Dr. Jonathan Carr who is an Ophthalmologist with Emory Vision and a Clinical Assistant Professor in the department of Ophthalmology at Emory University School of Medicine in Atlanta.

Q: Many people are interested in Lasiks how does one pick a procedure or do they all go by Lasiks?

JC: Theirs lasik and lasak. The difference between the two is lasik your making a flap and treating with a laser beneath the flap, lasak is a surface variation of that were you don't create a flap in the lasik way.

Q: Is that the two basic kinds?

JC: Principally, there are a variety of things that we have available.

Q: Emory has Interwave, is that an Emory only service?

JC: Interwave is what's called a wave front sensor. In simple terms it's a way of performing a 3 minute test on the eye, giving us quantitative information about the quality of vision, not only in day time but at night when the pupil is bigger. So we can be in the position were if a patient were to say "I see great at night" we can show them the results of the Interwave test and say "Oh no you don't". So it's a great tool that allows us to understand when a patient is having a problem, and they don't have to relay on their lay terminology to articulate it to us. We have a way of getting past that limitation and really understand what quality of vision were dealing with. So it's been a tremendous aid to us, and it not only allows us understand how patients are having issues at various lighting conditions, whether or not they've had surgery before. It also allows us to understand what laser platform might be appropriate to treat them and what laser platform might not?

Q: So is Interwave done before, during or after surgery?

JC: Interwave is a gate keeper test. It's done at the initial examination it's also done after a primary surgery if for example we are considering doing an enhancement procedure, which statistically is a 20% likely hood for our treatment population. It's a reflection of the fact that the cornea is living tissue and some people heal more than others, and there is a little bit of variability in the outcome. So some people need enhancements. Interwave allows us to make smart planning adjustments for any enhancement just as it does for any surgery as well.

Q: Is Interwave available outside of Emory?

JC: Let's understand what Interwave is doing. If we think of Interwave as a wave front sensor. Wave front sensors are digital cameras by analogy and lasers are printers. For the longest time we were always told the digital cameras haven't beaten 35 mm film yet. And then we moved past that to the point were we didn't have printers that could print with a high enough resolution to justify us spending all that money to get a high resolution digital camera. And now we have 1 mega pixel cameras and 5 mega pixel cameras and a whole range in between. So the wave front sensor is the camera type image or information, and the laser is the printer. Interwave is one version of the wave front sensor in my analogy, and its different from the others that are available and made by laser manufacturers in association with whatever laser platform they have in their stable, but its an interactive one. Now that may or may not be a critical issue, we believe it is. The alternative technology is called Hartman - Shack technology, and that is not a patient interactive test, but rather it's like a snap shot determination of what the eye is seeing under different pupil sizes and different lighting conditions. Hartman - Shack wave front sensors are not all created equal, and my analogy of the digital camera becomes helpful here, there are 1 mega pixel Hartman - Shack sensors and 5 mega pixel Hartman - Shack sensors. It's good to know that there are a variety of tools that we have under the umbrella of wave front sensors that allow doctors to truly understand in a way that they've never been able to understand before how well patients see in daytime but especially under dim illumination conditions dusk and night.

Q: Explain to us what you tell your patient is going to happen the day of surgery?

JC: What I tell patients on the day of surgery, they've already met me and had a thorough examination, is were going to do a lot of checking before we start. Both of the assembly of the flap making equipment and the data entered into the computer for the laser. At that point were on our way. I'll be placing a lid separator or lid speculum to keep the eye lids open, it stretches but it should not be painful. If the patient would beg to differ on that point, I'll empower them to speak up because we can make any discomfort go away. Next thing the patient will experience is a pressure sensation for 20 to 30 seconds, its pressure not pain. During the pressure the light in the eye that we are working on fades towards darkness, that's not such a bad thing because while the light is out the surgeon will make the flap and with the lights out I would warn the patient that their will be a couple seconds of buzzing, After which the flap is made, the pressure drops to normal and the lights come back on. At that point the laser system comes into play after the surgeon lifts the flap to align the laser treatment. The laser treatment itself is a painless process involving a snapping sensation and I'll often clap my hands to give them an idea of what to expect. Most laser treatments are accomplished in less than a minute and the majority infact in less than 30 seconds. Upon finishing the laser treatment the flap is put back down, the surface is arrogated with saline, and that basically is it.

Q: What is the expected recovery time?

JC: On the day of surgery you'll walk into surgery and then out 20 minutes later on average. You'll have underwater vision which is slowly clearing on an hourly basis and the vision by night time if you've had surgery in the morning has cleared substantially. However it's a little bit soft around the edges, so we really know were we are at the 24 hour visit. The over whelming percentage of patients meet the driving standard after 24 hours that's the 20/40 driving standard. Most people in the United States are chomping at the idea of getting back to work at the 24 hour visit, a little bit of common sense might allow some patients to have the first day off, but from our prospective its totally safe for a patient to return to work the day after.

Q: Do the results hold or are they prone to drifting back to the original state of the eye before surgery?

I've treated a lot of military and federal law enforcement personnel and I've learned a lot about the initial days after surgery from those guys and they say it very well even better than I, and ask me to pass it on their colleagues. For the first week or two they are less comfortable seeing who or what is in the back of a car they stop at night. It dramatically improves in the 2nd week and that's an important thing to be aware of due to the nature of their work. Beyond that because we are operating on living tissue there is a healing process that allows some people to regress a little bit and in near sightedness we are with a laser flattening the corneal mountain and there is a limited ability for the cornea to steepened a little bit in the first 3 months typically. That leads to a 10 to 20% retreatment rate or enhancement and not everyone does it, so that would be another reason for some change in the initial 3 months. The average patient has a relatively stable retraction at 6 weeks but because out lying patients can take 3 months to stabilize we have to wait for that 3 month gate. So theirs a short term subtle change that is on going into the 2 week for every patient and beyond that the other reason why their would be changes in the vision is that healing process which requires around 20% of patients to have the retreatment process to sharpen things up.

Q: So the results will be maintained through out your life?

JC: To the extent that I've indicated a small amount of regression. Were talking about achieving 20/20 immediately after the first surgery and over about 3 months dropping back to about 20/40. You would not be expected to regress all the way back to your pre-surgery state.

Q: Can any problem be fixed with laser surgery, be it near sited, far sited, stigmatisms?

JC: You need to have a noncandacy rate wherever you are. I think those patients who are seen in a high volume price competitive situation should expect to hear that perhaps every 7th patient is a noncandidate statistically. At Emory because we have people who might perceive themselves to have more complex issues, self select, hop on a plane and come see us. We should have a higher rejection rate, and indeed we do we reject between 1 in 4 and 1 in 5 people through the door and that's just normal for us. The take home message for us in terms of simple numbers is, and there are 4 of them 1. Is the far sightedness or near sightedness in the treatment eligibility window for that laser according to the FDA labeling. 2. Is the stigmatism present within the FDA window? 3. Is the cornea adequately thick enough to allow the surgeon make a flap, remove trivial micron amounts of tissue, and leave enough tissue beneath flap for mechanical integrity through the patient's life and also keep a little tissue up one sleeve if there is that chance of an enhancement which statistically is in the 10 to 20% range? 4. What's the pupil size in dim light, and that's generally measured with an infrared camera. In other words you can't just stick a ruler in and turn the lights down its not accurate enough. The reason for the pupil is we need to be sure we encompass the night time pupil diameter and have a larger treatment diameter with the laser to prevent any mismatch of bigger pupil and smaller laser diameter. That is were some night hallowing has occurred.

Q: How does one pick a clinic or surgeon for this type of procedure?

JC: I think the first thing is to identify a practice that truly monitors its out comes and can tell you how safe they are as well as how successful they are with respect to surgery. There are many objective online sources and various organizations The American Academy of Ophthalmology, The International Society for Refractive Surgery and we at Emory have a mail out or guide for patients who are geographically miles away from us. One of our missions is to be some what of an oricall because of who the personal are here, and we feel the need to empower the public a little bit. That's one of the reasons we have partnered with SurgicalEyes.com. Beyond that the FDA's website is very good theirs a link to lasik surgery on their website at FDA.gov. Basically theirs is a lot of convergence in the guidance which lets us find out what the true complication rate is for the surgeon your in front of, how many times does the surgeon get into difficulty were he or she may not be able to deliver laser treatment on the day of surgery and if so, what has the remedy been for that surgeons patients, did they turn out fine or not. Then learn what the likelihood of 20/20 uncorrected vision would be at your given prescription, make sure that you have a normal eye exam and that your are truly a candidate for surgery. Board certification is a relatively poor discriminator for the purposes of refractive surgery, its not mandatory from my prospective that a surgeon be a cornea specialist but for the purposes of second and third opinions and dealing with problems its pretty much mandatory and my colleagues here are cornea specialist.

Q: What are the statistics for errors or complications?

JC: There are published documented complications regarding lasik, and the FDA in its guidance to those that manufacture lasers who want to embark upon clinical trials, have documented the complications that they should know about. It boils down to this; the lasers themselves are very seldom the cause for any adverse outcomes for patients. It really all revolves around making the flap safely, that has been shown by my colleagues and I at Emory to be an experience related task. There is a learning curve, no matter how good you might be before embarking upon lasik in your career. The key issue is how many times as I said earlier does the doctor in question if you're a patient have a flap complication, whether the flap is incomplete, its to short, or if their were a flap button hole. Anything that would lead the surgeon to say to the patient we can't deliver the laser treatment today because I'm not happy with the flap that we made. That is the question that you need to know and we need to educate the public. But it is meaningless and a false conclusion to say that the surgeon who did 10,000 lasik procedures is surely twice as good as the surgeon who did 5,000 procedures. Any baseball enthusiast would know to the contrary, we need the batting statistics. You need to know how many flap complications as a percentage of the total number of lasik procedures done. If you look in the literature for guidance, the highest that number gets is 2% or 1 in 50 and at the quality end of the spectrum you have people encountering flap problems less than 1 in a 1,000 times, and that would be the case for all of my 9 colleagues here. We know this because we have quality assurance system in place that I sit on with one of my colleagues. So the range would be 1 in 50 to even better than 1 in 1,000, and that's something that patients need to get from other patients and carry that message with them into other aspects of medicine. There are measured complication rates that are related to surgeon experience in corroded vascular surgery in the neck for example and we could go on, so it's a good thing that patients would be empowered beyond refractive surgery once they learn what to ask. So it all hinges on the creation of the flap, the lasers themselves once FDA approved are documented safe and affective, and I would say 5 to 10% of the time there are cases were I will say I can't treat you with this laser but with that laser I can. That's why we like having a suite of lasers, but its nice to say no no no we have to treat you with this laser, and it prevents me from being dissengenuice, I can choose the right laser for the right situation and Interwave dove tails into that decision making process because it guides me further.

Hopefully there are some very firm lines in the sand and the FDA gives strong guidance to surgeons as to what's the most you can treat with a laser. The candacie variability lies less in the laser wiggle room and more in the other numbers we talked about, the thickness in the cornea, the pupil size; those are the things that if not respected humbly by the surgeon can lead to unhappy patients. We will on occasion have patients come to us and I'll say your not a candidate and they'll say that's interesting two other surgeons said they'd treat me. I have to dig my heals in and say we'll your not going to be treated in this building, at that point we'll typically prevail upon the patient to explore other options. I do know cases were those patients have gone else where to be treated and they'll either have a problem or they won't. And if they come back to me and say see, I did fine I'm happy. More power to that patient, but they are missing the point which is I do not want to add measurably to the percentage chance of a risk or complication given that its elective surgery. The fact that the patient swung the bat and hit one out of the park doesn't reassure me and make me look back and think well maybe I should have treated that patient.

Q: Its sounds like many problems lead back to poor decision making

JC: Its true. There are two areas where things happen that lead to patient problems. And they are; Poor decision making in the preoperative examining room and that's a candacie thing; and subsequently and literally some surgeons are just not as skilled as other surgeons.

Q: After surgery is their any pain or discomfort and if so at what time should a patient be concerned?

JC: Contact lense type of irritation is a normal type of discomfort after lasik; it will normally come on about 1 hour after surgery if at all. Patients will say it generally last about 3 hours and is typically during a time when they would be sleeping. Standard non steroidal anti inflammatory drugs or Tylenol are sufficient for most and one out of ten will take the stronger medication that we make available to them. Beyond that initial 3 or 4 hours the eye settles down. The eye feels dry through the remainder of the first day and lubrication is the standard remedy for that. That would be a standard post operative course for patients.

Q: Are their warning sign following surgery that would indicate problems or infection?

JC: Well the infection rate for laser surgery is in the range of 1 and 10,000 and to make that mean something to your readers, the infection rate for cataract surgery is in the range of 1 and 1,000. Beyond that potential problems rear their head early and are generally caught with rare exception at the 24 hour visit, that's why we have a 24 hour visit. Most surgeons in the country will have another visit in the range of 7 to 14 days, because they recognize that there are rare things that might be picked up at that point. So infections are generally early problems, and other things that people should know about were the surgeon may need to intervene, such as flap slips in the first 24 to 48 hours the patient are generally able to determine that the vision was clear and then I rubbed my eye or my child poked me in the eye in the first 24 hours, that's happened to two patients of mine, they know to call and we'll reposition the flap. Common sense for 7 days is really the only advice one needs in terms of looking after your eyes. The take home message is that any potential problems are recognized by both surgeon and patient very early on and are pretty much caught within the first 24 hour and/or the 2 week visit. We routinely give antibiotics for 7 days after the procedure and that's really a preventative measure.

Q: Does it totally eliminate glasses?

JC: In the cornea you can't have your cake and eat it if your in your forty's or older, you'll need reading glasses. So if you're a near sited person and you are 25 you are hopefully eliminating your need for glasses (please come back to the word eliminate), and you are exchanging them for reading glasses on that rainy day when you are forty something. I you are already forty something; and our average patient is forty something, you are in affect getting rid of your distance glasses and exchanging them for reading glasses. A lot of good people are doing a lot of thinking and early work now on trying to see if we can reliably impose a bifocal type shape to the cornea. Its very easy to say it, its another thing to do it, which is a reflection of the fact that the cornea is living tissue. Its not that the lasers couldn't technically achieve what we need, and if our eyes were made of plastic indeed we could do it. With regard to reading glasses, monovision is something that patients with contact lenses in their forty's or older try, were the dominate eye the eye you aim a camera with is the distance eye and the non dominate fellow eye is deliberately under corrected slightly, its left a little bit near sited so that it can read out at arms length.

Q: Does that affect your depth perception?

JC: Exactly so. And so 60% of people like monovision and adapt to that slight reduction in depth perception but 40% don't. And the adaptation period is short generally about 2 to 3 weeks based on published data in the contact lenses literature. You can imagine some people would not make good candidates for monovision, such as law enforcement people who are firing weapons, but the person who is working on a shop floor screaming at employees while looking back at a clip board might be a post child for it. People try it and I'm surprised that people can accomplish office work in large numbers and enjoy monovision. So its something to consider.

Q: You had ask me to come back to the word eliminate.

JC: I think that its important for the readers of your site to know that anytime someone says they will eliminate glasses. I would take issue with that and I would hope the FTC would also, in that it would be fairer to say we will reduce your dependency on glasses no matter how bullish we might be about the procedure. Because some people for a variety of different situations might like to have glasses for something. They might be happy for 90% of their life but would like to have distance glasses for driving at night. So I like to tell people we'll reduce your dependence on glasses in the distance and I thing the Federal Trade Commission is in agreement with me on that one. Anyone that guarantees elimination, I tell people to get in the car and leave.

Q: What does the future hold for this technology?

JC: Well were approaching the plateau in what can be brought in terms of laser technology. Initially in the mid to early 90's the lasers were in the form of a broad beam 6 to 61/2 millimeters wide and any laser engineer knows that its very hard if not impossible to maintain a uniform energy distribution across such a beam. So laser manufacturers became smart and did a variety of things. Lasers now deliver energy to cornea in the form of a slit that scans over the surface of the cornea to produce a smoother result, while others employ a spot of light and treats the cornea. As the delivery size of the laser light on the cornea has diminished the treatment time would go up. So with that decrease in the delivery footprint of the laser pulse, we have a higher repetition rate, more laser pulse per second so that we can do the same job in the same length of time. Because time is an issue taken to its extreme, we wouldn't want to have a flap up and spend an hour lasering when its best accomplished in the order of seconds & minutes. Were now at the point were lasers are treating the cornea 30 to 50 times a second for FDA approved lasers and were exploring whether higher repetition rates in range of 200 to 250 pulses per second might be further additive to the quality of the result. Were also exploring whether instead of having a very sophisticated laser plan for every patient, and I give the analogy of off the rack Armani type vision correction, the FDA has approved for certain people a made to measure vision correction. In other words your right eye would have a unique correction plan on a floppy disk. Not everyone benefits from that, and the public is going to be bombarded by laser manufacturers giving them the impression that everyone should benefit from that. Even though on a population basis you can show that the made measure customized type of vision correction is better, its not better for everyone. I give the analogy to patients; If we cloned you and you got the made to order customized type of platform and we treated your clone with the time honored FDA approved standard treatment, you'd both be wowing about the results at 3 months in broad daylight and at dusk your clone with the customized treatment might say wow this is pretty awesome and you would say this is pretty good; Theirs the difference. To date Alcon's Ladar Wave platform and VIS X's custom platform and others will follow. The Candidate whose best equipped for custom treatment or who might get the most benefit would be a person with a larger than average pupil at night and would have a good corneal thickness because such customized treatments are a little more expensive in terms of tissue utilization so it behooves us to be somewhat conservative and identify a patient with thicker than normal cornea's.

Dr. Carr thank you for your time.

Emory Vision
4170 Ashford Dunwoody Rd.
Suite 300
Atlanta, GA 30319

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