SMILE Eye Surgery Offers an All-in-One Alternative to LASIK

Since LASIK is more than two decades old at this point and has several drawbacks despite its proven results, it should not be a surprise that people are always looking for a new alternative procedure. The new candidate is called SMILE surgery, which is short for Small-Incision Lenticule Extraction surgery, and it uses only a femtosecond laser to reshape the cornea.

This procedure hopes to remove flap complications associated with LASIK as well as the risk of dry eyes after the procedure, and maybe give a treatment alternative to many people who cannot benefit from LASIK.

In SMILE surgery, a small incision is made in the surface of the cornea using a femtosecond laser. The femtosecond laser is then used to cut out a lens-shaped section from the interior of the cornea. This section is then extracted using a small tool.

There have been a number of significant studies performed on this procedure. One of the earliest was performed in Germany and the results published in the Journal of Cataract and Refractive Surgery in 2008, using a slightly different version of the procedure called Femtosecond Lenticule Extraction (FLE, sometimes FLEX or reFLEX). This study treated ten myopic eyes, with 90% of them achieving +/- 1.00 D, approximately equivalent to 20/50 vision. The study showed no evidence of higher-order aberrations.

A more recent study published in the British Journal of Ophthalmology looked at 91 eyes of 48 patients. This multi-center 6-month prospective study showed even more positive results, with 95.6% of patients within 1.00 D, and 83.5% of eyes achieved an uncorrected visual acuity (vision without glasses or contacts) of 20/20 at 6 months, comparable to LASIK results. In the follow-up questionnaire, 93.3% of patients were satisfied and would undergo the procedure again.

The SMILE procedure is already being offered in Britain and India, and researchers are recruiting candidates for clinical trials here in the US. It’s hard to say just how long it will be before the procedure will be available.

To learn more about advanced vision correction alternatives, please contact a local ophthalmologist today.

PRK Safer than LASIK for Retreating Radial Keratotomy

For those who need radial keratotomy (RK) re-treatments, it has been reported by the RK Re-treatment Study that PRK is safer than LASIK.

The RK Re-treatment Study group, led by ophthalmologists, looked at 221 procedures over a 12 year period between 1997 and 2010 from six different US surgical centers. All but three LASIK procedures were done conventionally, while two-thirds of the PRK procedures were conventional. The other one-third were wavefront-guided custom PRK. (Wavefront-treatment did not become popular until around 2005.) Refractive errors between PRK and LASIK patients were roughly the same.

Three to six months after eye surgery, both conventional LASIK and wavefront-guided PRK showed better at keeping best-corrected visual acuity in patients than was conventional PRK. Nearly 80% of all patients showed better than 20/40 vision after eye surgery.

However, for patients who needed to be retreated, there were complications in 12% of the custom LASIK patients, while only 4% of PRK patients had complications. Complications included ectasia in the LASIK group, which required penetrating keratoplasty. Two patients in the PRK group required both eyes needing phototherapeutic keratectomy due to “postoperative haze.” Retreatment gave these patients 20/20 and 20/25 vision respectively.

The RK Re-treatment Study recommends further evaluation in this area of laser vision correction. This may be especially important due to the increasing number of people seeking vision correction surgery.

If you are interested in finding out more about PRK or LASIK, please find a doctor in your area through eyes.com today.

The Eye Knows Better Than the Brain What It Has Seen

As the US Supreme Court is hearing arguments that eyewitness testimony is not a reliable category of evidence, researchers are proving that eye witness testimony might actually be the answer.

Police and lawyers have long struggled with the reliability of eyewitness testimony. In 12 Angry Men, the eyewitness testimony that may have served to convict a young man of murder is famously dismissed because of the eyewitness’ myopia, but even without refractive error, eyewitness testimony is unreliable. According to recently released research, about 75% of DNA exonerations come in cases where an eyewitness misidentified the perpetrator.

This is due, in part, to the pliability of memory, which can be altered by an act as simple as retelling what happened. By the time a witness is asked to identify a perpetrator from a line-up, he or she may have been asked to retell the events several times, and each time the memory is accessed, it is also resculpted, and the actual visual memory is lost and replaced more or less with a set of descriptors.

However, it turns out the eyes themselves also have a memory, distinct from the one in the brain, that might be a better way to make eyewitness identifications. According to research to be published in Psychological Science, eye movements more accurately identified a remembered face than conscious identification.

The researchers gave students a set of 36 faces to study. These faces were also subtly morphed to create slightly different faces that were not seen by the students. Then students were shown 36 3-face displays and identify a face they had seen, if there was one. If there was not a face they had seen before in the display, they were to pick any face and verbally say whether the face they were looking for was there or not. Eye tracking was used to look at the movement of their eyes as they were making their identifications.

The research showed that eye movements disproportionally moved to the previously seen face even before an identification was made. However, this memory is not immune to rewriting. Once the person had identified a face as having been seen before, the eyes kept moving to the “known” face as if it had been seen before, whether it had or not. In the words of researchers, “pre-response viewing seems to reflect actual experience, and post-response viewing seems to reflect the decision making process,” which leads the eye to “endorse” the face the brain has decided is the right one.

This research is in its early stages, but perhaps it will in the future allow for more reliable eyewitness reports and fewer wrongful convictions.

Also helpful in being a reliable eyewitness is having your refractive error corrected. To learn more about LASIK, please talk to a local ophthalmologist today.

FDA Asks LASIK Providers to Ensure Advertising Includes Risks

This Week, the FDA sent out a Letter to Eye Care Professionals stressing that all advertising of procedures performed with FDA-approved technology must comply with the agency’s labeling guidelines. In its letter, it made pointed reference to the lasers used for LASIK procedures. Essential to complying with guidelines, the FDA stressed, is ensuring that all advertising includes information about a device’s limitations and risks.

As part of the communication, the FDA said that it was giving doctors 90 days to bring advertising into compliance with the Food, Drug, & Cosmetic Act or face enforcement activities. These enforcement activities may include: warning letters, product seizures, injunctions, and civil money penalty proceedings.

At eyes.com, we are concerned that you understand the benefits and risks of all types of eye surgery, including LASIK. As a result, we include not one, but two pages on risks associated with the procedure.

On our LASIK side effects page, you will read about some of the more common minor side effects many people experience associated with LASIK, including dry eyes, light sensitivity, night vision problems, and temporary loss of visual clarity.

On our LASIK complications page, you will read about some of the more serious but thankfully less common adverse events that people sometimes experience after LASIK surgery, including irregular astigmatism, diffuse lamellar keratitis (DLK), ectasia, over- or under-correction, and severe dry eyes. These complications are serious enough that many have their own pages detailing them so you can fully understand each. Just follow the links on the complications page to read additional information.

We also invite you to look at the FDA’s own pages on LASIK to get the agency’s perspective on risks and complications associated with the procedure.

LASIK is among the most remarkable advances in medical science, giving us the ability to restore vision in people who were previously forced to wear glasses or contacts for life. But it is not without risks, and understanding those risks is essential to making an informed decision about the procedure.

If you have additional information about the benefits and risks of LASIK, please contact a local ophthalmologist to discuss the procedure in person.

Refractive Surgery for Ocular Herpes Patients: Proceed with Caution

Undergoing refractive surgery can carry serious risks if you have ocular herpes. Any corneal trauma or ultraviolet light exposure caused by the laser can result in a flare-up of your herpes condition, leading to an assortment of other eye issues. If a dormant case of ocular herpes gets reactivated during your refractive procedure, it can lead to the following complications:

While these risks are very serious, there are still ophthalmologists who will move forward with refractive surgery on herpes patients. That being said, not all ocular herpes patients will be deemed candidates for refractive surgery. Your ophthalmologist will have to make that determination based on a variety of factors associated with your condition.

In many cases, your ability to undergo refractive surgery will depend on how long it has been since you have had a flare-up of herpes. “If I had a patient with a herpes episode 10 years ago and it went away and never came back and the cornea looked perfect – zero haze, zero scar – I think it’s reasonable, with proper informed consent, to do refractive surgery,” said Dr. Christopher Rapuano, the co-director of Cornea Service and Refractive Surgery Department at Wills Eye Institute in Philadelphia.

Unfortunately, it is not always easy to diagnose whether a potential refractive surgery patient has ocular herpes or determine when their last episode occurred. Often, patients can be unaware that they even have ocular herpes. Symptoms can be as minor as a red eye, leading patients to believe they just experienced a mild case of conjunctivitis. Additionally, testing for ocular herpes is not effective since such a large percentage of people have been exposed to the virus in some form, creating a considerable number of false positives.

As a precaution, ophthalmologists should always check patients’ corneal sensitivity and look for signs of scarring, thinning, or neovascularization when determining candidacy for refractive surgery. This can prevent many unnecessary complications down the road.