Epi-LASIK News and Information

When doctors first began performing Epi-LASIK a few years ago, we used to put the epithelial layer back on the eye after the laser treatment. In the past two years many of us have found better results by removing it entirely and letting a fresh new layer of epithelial cells grow in its place.

A study published in last month’s issue (June, 2008) of Investigative Ophthalmology and Visual Science, a professional journal for ophthalmology researchers, shows that there are several advantages to removing the flap:
1. It speeds up the visual recovery after surgery. This means patients can get to their best visual result even faster.
2. It reduces haze. Haze is a potential complication that is most common in patients with higher corrections or those who are exposed to high levels of UV sunlight.
3. It may result in better visual quality under certain conditions, such as driving on a road in the rain or at dusk with headlights coming at you.

Dr. Qin-Mei Wang and his colleagues found no differences in patient comfort or the ultimate visual result between the two techniques. They studied 62 eyes of 31 patients over a three-month period.

In 2007, I did a similar study in my practice and came to almost the same conclusions. For the end result, it doesn’t matter whether you leave the epithelial layer on or off, but my patients’ eyes healed almost twice as fast when I left the epi-flap off. During the first week after surgery they could see better and were able to return to work sooner than they could with the old technique. I also found that patients had less pain. Needless to say, I have shifted to the newer technique for all my patients.

Epi-LASIK is already very safe. The good news for laser vision correction candidates is that we continue to find ways to make Epi-LASIK even more comfortable and easier on the patient, too.

In my experience, there are some patients who prefer Epi-LASIK—and are willing to put up with the longer healing time it requires—even though they may be good candidates for LASIK. Here are some of the reasons people choose Epi-LASIK for themselves:
• They are extremely safety-conscious
• They are very squeamish about having their eye cut
• They are very active in sports or have a profession where they might get hit in the eye

Let’s talk about this last category a little bit. The LASIK flap, even years later when it is well healed, can be knocked off or moved if it is hit very hard in just the right way. Most of us will never get hit like that (let’s hope!) so we don’t consider that a major risk. However, people who are very active in sports like basketball, boxing, soccer, or karate have a higher likelihood of getting hit in the eye with a ball or someone’s hand. A police officer might also have a higher risk of getting hit in the eye. In such situations, a surface ablation procedure like Epi-LASIK, where there is no flap to be dislodged, might be the best option.

Typically, patients are first placed under the excimer laser (used to reshape the cornea and correct the patient’s prescription) to ensure they are in proper position for ablation, or reshaping of the cornea. The surgeon drapes the area around the eye and inserts a small device used to hold eyelids open during surgery. After applying numbing drops (anesthetic), the eye is rinsed with a saline solution followed by one more drop of anesthetic.

Next, the surgeon secures the epi-keratome (a device that gently separates the thin layer of cells that covers the surface of the cornea) onto the eye by using suction. This increases pressure within the eye and stops the blood flow for a moment. When the pupil becomes a little wider, the surgeon typically asks the patient if it is getting dark, which subjectively tells the surgeon that the vacuum pressure is correct.

The epi-keratome creates a flap similar to a traditional LASIK flap. However, unlike LASIK, there is no cutting with sharp blades, lasers, or knives. This process takes about 30-40 seconds. The surgeon releases the vacuum and removes the epi-keratome from the eye.

After the excimer laser gently reshapes the cornea (and corrects the patient’s prescription), the eye is gently rinsed with ice-cold saline solution for several seconds before a bandage contact lens placed on the eye.

Patients may feel a slight pressure while the eyelids are held open during surgery and when the epithelial separation begins. During the laser ablation, some patients may sense light.

Epi-LASIK is not painful or uncomfortable for the patient.

Recovery time for epithelial healing, which includes wearing a bandage contact lens, is between 2 to 4 days. During this time, visual acuity is typically around 20/40. Visual acuity should increase to 20/30 or 20/35 within the first week. Most patients are able to drive and begin working after within 3 to 4 days.

If you’re like a lot of people, the biggest question in your mind is probably, “Is this going to hurt?”. The good news is that we have learned a LOT about how to prevent and manage pain after surface ablation procedures like Epi-LASIK. These days, most Epi-LASIK patients are surprised at how little pain they experience.

The procedure itself doesn’t hurt at all while you’re going through it. At most, you will feel a little pressure on your eye or maybe a little teariness from looking at the bright light.

Afterwards, most people experience discomfort but not actually pain. This discomfort may include:
• Grittiness
• Dry or tired feeling in your eyes
• Light sensitivity
• Feeling like there is an eyelash or dust in your eye

Some of this discomfort is from the surgery itself and some is from the bandage contact lenses we put on the eyes to help them heal. It will last for a few days. You will probably feel OK on the first day, a little worse on day 2, and then your comfort level should rapidly improve by day 3-4.

Follow your doctor’s instructions for resting your eyes and taking your medications. Your doctor will probably give you some optional eye drops or pain pills to take if you need them. Today we have medications that nearly eliminate the post-op pain. And most patients don’t even need them! Your doctor should also give you an emergency contact number to call in case the medications don’t seem to help.

Dry eye is a common symptom after LASIK. It is typically mild and goes away after a few weeks, especially if you use artificial tears regularly, as your doctor will likely recommend. But in a very small percentage of the population, post-LASIK dry eye can be longer-lasting and more severe.

Patients who have dry eyes before surgery (and many do) may want to consider Epi-LASIK. Epi-LASIK is less likely to cause or worsen dry eye because it doesn’t sever the peripheral nerves of the cornea. These nerves send signals to blink and to produce the healthy tears that are needed to protect the eye and give you clear, comfortable vision.

Here are some indications that you might have dry eye:
• You are female and post-menopausal (or currently going through menopause)
• You used to wear contact lenses successfully but stopped because they were no longer comfortable
• Your eyes frequently feel tired, gritty, achy or dry in the late afternoon and evening
• Wind and air conditioning bother your eyes

If any of these symptoms sound familiar, be sure to ask your eye doctor whether you have dry eye, whether you should consider Epi-LASIK, and what other steps you can take to maintain a healthy tear film for the best quality vision.

After any refractive surgical procedure patients may experience some discomfort. The good news is that Epi-LASIK patients tend to experience minimal discomfort (and side effects) following surgery. In fact, only 5 to 10 percent of my patients experience any pain after surgery.

Be sure to ask your surgeon how he/she manages postoperative discomfort. No two patients are alike and aftercare plans are typically based upon the needs of each patient. Discuss any concerns that you may have about certain medications and potential interactions, or side effects.

Usually, patients who achieve the best outcomes closely follow their doctor’s instructions. I’ve noticed that patients who are fully compliant with instructions generally have little or no discomfort and enjoy rapid visual recovery. Not following instructions may lead to greater discomfort and a slower healing process. For example, I’ve observed that patients who don’t use tears as frequently as they should may take up to five days to fully recover.

Preoperative and postoperative regimens vary from surgeon to surgeon. Our surgical plan includes the following medications for epi-LASIK. Please keep in mind that no one plan is “correct” – this is simply what has worked best for our practice and patients.

Preoperative
• Only patients’ usual medications

Postoperative
Day of Surgery and 2-3 Days After Surgery
• Gabapentin, 300 mg three times per day
• Imitrex, 100 mg once a day (day 1 and sometimes on day 2)
• Artificial tears (Bion Tears) – every 15 – 30 minutes during the day
• Steroid and antibiotic (Maxidex and Vigamox) – 3 times during the day (every six hours)
• Oral NSAID (Advil) – Take 2 tablets every four hours during the day
• Vitamin C – Take 1 gm per day

After contact lens removal: Day 3 or 4
• Steroid drops (Maxidex) twice daily for a month
• Artificial tears as needed for comfort

What is the ideal location or depth for laser vision correction? This was a hotly debated topic at the recent meeting of the American Society of Cataract and Refractive Surgery, in Chicago. I spoke at this meeting, and heard some interesting perspectives from other speakers as well. One of those was Dr. James Lewis, who showed high-resolution images of the different layers of the cornea.

As one gets deeper into the cornea, the layers get rougher, because the collagen fibers are more tightly packed in the deeper layers. LASIK is performed at about 130-160 microns (a micron is one millionth of a meter, which is smaller than the width of a human hair). You can see that this layer looks rougher than the other two in the picture. Some surgeons are now performing thin-flap LASIK at a depth of 90-110 microns. Epi-LASIK, is done essentially on the surface, after removing about 50 microns of cells covering the cornea.

Dr. Lewis asked his audience, “If you were going to project an image onto a surface, which one do you think would provide the best quality image?” That’s exactly why the nice, smooth Epi-LASIK surface is my choice for laser reshaping of the cornea.

At the recent meeting of the American Society of Cataract and Refractive Surgery, Dr. Jose Pitarque shared his unique experience as a laser surgeon in Quito, Ecuador. Quito is located high in the mountains of South America, nearly 10,000 feet above sea level. People who live there are exposed to about 30% more ultraviolet radiation from sunlight than those of us at lower elevations. They also have to deal with dust, wind, low oxygen, and pollution, so this is a challenging environment.

To make matters worse, 80% of Dr. Pitarque’s patients have dry eyes and about 10% have a genetic condition known as keratoconus, which is a contraindication for laser vision correction because it causes the cornea to weaken. People with an early stage of keratoconus called “form fruste keratoconus” are prone to ectasia, a weakening and thinning of the cornea like keratoconus itself. Unusual astigmatism and thin corneas can also indicate that someone might be at risk for this condition, so we look for those signs preoperatively to avoid performing surgery on patients with form fruste keratoconus.

Dr. Pitarque said he wanted a procedure that was safe, had a lower risk of ectasia and that wouldn’t worsen his patients’ dry eye. He still turns away a lot of candidates, but when he agrees to perform vision correction surgery it is almost always Epi-LASIK.

When I recommend Epi-LASIK, there are basically two things I need to explain. First of all, why would somebody want to have a surface ablation procedure instead of LASIK? And secondly, why this surface ablation procedure (Epi-LASIK)?

Let’s deal with each of these questions in turn.

Why surface ablation?
Epi-LASIK is a surface ablation procedure. Compared to LASIK, it takes a little longer for vision to fully recover and there may be a little bit more discomfort. So why would you want that?

For starters, not everyone is a candidate for LASIK. Surface ablation is a good option for some patients who otherwise wouldn’t qualify for laser vision correction at all. It’s also a great choice for someone who is really safety-conscious. Epi-LASIK preserves the structural integrity of the cornea because we don’t have to cut into the deeper layers of the cornea to make a flap. In addition, LASIK complications are quite rare, but when they happen, they are usually related to the corneal flap. If you want to reduce the chance of this type of complication, surface ablation is worth considering.

Why Epi-LASIK?
Compared to older surface ablation options like PRK, Epi-LASIK has several advantages:
• More advanced technique
• No “scraping”, no toxic alcohol on the eye
• Faster re-growth of epithelial cells that cover the eye
• Easier healing phase, with less discomfort after surgery
• Faster visual recovery
• Patients return to work sooner

I perform Epi-LASIK on Thursdays and most patients are back at work on Monday, so they only have to take one or two days off. In a recent survey I did among my own patients, most rated their pain level after the surgery at only about a 2 on a scale of 1 to 10. I used to see a lot more discomfort with PRK and other surface procedures.

I think Epi-LASIK really combines the advantages of PRK and LASIK and eliminates most of their disadvantages.

By Dr. Robert Mitchell

What about the new “blade-free” LASIK procedure? Isn’t that safer?
Bladeless LASIK uses a laser to cut a flap under the corneal surface much the same way that a physical blade does. LASIK (whether the flap is cut with a blade or with a laser) has potentially 17 different postoperative complications including corneal ectasia, flap wrinkling, debris under the flap, etc. Nearly all of these complications are a result of the cut, and not the laser itself.

In comparison, Epi-LASIK is the only true “blade-free” refractive surgery – no flap is cut. There are only two potential complications with Epi-LASIK. These are early infection and early delayed healing; both of which are easily treatable. Once the surface has healed, these will not occur. The only other potential problems with Epi-LASIK are optical (e.g. halos, regression, etc.) and are shared with all other corneal laser refractive surgical procedures.

Dr. Mitchell, why are you one of the few doctors who exclusively performs Epi-LASIK? Are you some sort of renegade surgeon?
Many years ago, I was one of the first surgeons to start performing LASIK (with the cut) because of the problems my patients were encountering with early PRK.

It was many years before the majority of other surgeons adopted LASIK. Four years ago, I heard Dr. Ioannis Pallikaris – the father of LASIK surgery – explain why he had stopped performing LASIK surgery. I re-evaluated what was available and decided to adopt Epi-LASIK because I believe that it is so much safer than LASIK and yielded better long-term results. Many surgeons internationally are switching from traditional LASIK to Epi-LASIK and I ultimately predict that LASIK will disappear because the alternative – Epi-LASIK is so much safer and better.

Our patients have enjoyed terrific results with Epi-LASIK. Although the healing process is slightly longer, the outcomes are better and safer and my patients are more than willing to trade off a few days of blurred vision for safety and an optimal outcome.