The Efficient Ophthalmologist

LASIK: A Lesson in a Shared Experience

Hard-won knowledge exemplifies ophthalmology’s ‘learning community.’

By Steven M. Silverstein MD, FACS

One of the most stimulating and enjoyable privileges in medicine is the opportunity to exchange ideas and share cases, techniques and innovations. It makes us better, more efficient physicians, improves patient safety and outcomes, and leads to new directions in research and technology.

LASIK is a perfect example of ophthalmologists acting as a “learning community” to advance our specialty. LASIK began as a totally new (and not without risk) technology. In these last two decades, thanks to the contributions of many skilled surgeons, it has enjoyed truly remarkable advancements in technology, nomograms and technique.

Here, I will describe my personal learning experience with LASIK and the technique this has helped me develop over the years. I’m sure others who perform the procedure have had similar experiences.

Learning LASIK

I am 52, so I have enjoyed being part of the refractive surgery revolution, learning radial keratotomy (RK) directly from Charles Casebeer, MD, and corroborating on cases with Michael Dietz, MD, who brought RK to the United States in the late 1970s from its father in the Soviet Union, Dr. Sviatoslav Feoderov. I had the opportunity to participate in the early FDA trials, which led to the approval of excimer laser treatment, and have witnessed (and sometimes suffered) the consequences of our early learning curve.

From flap complications and corneal ectasia to central islands, induced dysphotopsias of every description, glare and halos and significant dry eyes, I have experienced the sleepless nights that many of you had as early adopters. The good news is that if we pursue new techniques and technology, we learn so much about tissue physiology (and pathophysiology), the biomechanical mechanism of our successes and failures, and in the end, become better, more effective and competent physicians.

I would like to now share my current LASIK procedure (always subject to improvement) — the result of tens of thousands of cases — with the hope that it is likewise helpful to you and, ideally, encourages an exchange of your ideas and experiences.

The Procedure: First Steps

Preoperatively, we administer the patient three rounds of a flouroquinolone antibiotic, and a drop of Alphagan P (brimonidine tartrate, Allergan), which significantly reduces hyperemia and punctate subconjunctival hemorrhages associated with the procedure and vacuum ring pressure. We also offer diazepam, dose-dependent on body weight, in the holding area, where soft music is playing.

I prefer to drape the patient myself (after the circulating nurse performs the sterile prep), to sequester the lashes thoroughly and ensure the speculum does not create any undue pressure on, or distortion of, the lids or adnexa. We prefer to use a Lieberman speculum because it controls the unwanted problems that may arise due to significant lid squeezing (such as loss of vacuum) more reliably than a flexible speculum.

Creating the Flap

As the patient is positioned under the microscope, we apply one final anesthetic drop and thoroughly dry the cornea and conjunctiva with a Weck-cell sponge (Beaver Visitec), so that the ink of the corneal marker may be applied, and the vacuum ring of either a microkeratome or femtosecond laser is able to make an optimal connection with the globe. Once I confirm appropriate pressure, I create the flap. In recent years, the femtosecond laser has become the flap-creator of choice, but some LASIK surgeons still use a microkeratome.

I consider providing what I call “continuous verbal anesthesia” a major priority, so that the patient knows what to expect and remains calm throughout the procedure.

I then lift the flap and taco-fold it back in a preferred axis (that can be superior, nasal, etc), and quickly dry the bed with a Weck cell sponge. Exposure time is important from the point when the flap is lifted, as prolonged evaporation will have an influence on the final outcome, particularly in higher myopes where treatment time is typically longer and the hydration or dehydration of the stromal bed comes into play.

Engaging the Laser

The eye tracker is then engaged. During laser ablation, I keep my hands on the patient’s head and face like a four-point gentle vice, to make adjustments to head position throughout the procedure as needed to make every laser pulse count.

Following ablation, I reposition the flap with an irrigating cannula atop a BSS bottle, guided by the inked marks placed earlier with an eight-line RK marker. I then smooth down the flap with a saturated Weck cell sponge, followed by a dry sponge.

The moisture beneath the flap is further squeegeed using the Johnston flap applanator, followed again by a dry Weck cell sponge. I then use oxygen to deterge the gutter, achieving the “shrink wrapped” appearance, but without over dehydrating, which may lead to slipped flaps postoperatively due to misalignment. I use one final dry Weck cell sponge to confirm proper flap position before I apply antibiotic drops and a vial of lubricating drops.

Eliminating Slipped Flaps

Despite meticulous drying, careful patient education and caution about eye rubbing, and a one-hour postoperative slit-lamp exam, I still saw the occasional slipped flap day one postoperatively. The most significant recent change to my routine was the placement of what I call a “Comfort Lens” (a standard bandage contact lens) at the end of the procedure.

I tell patients this will lessen the scratchiness of the first night of healing (which they appreciate) and instruct them that we will remove the lens in the office the following day. Since instituting this change, we have not experienced any slipped flaps or flap wrinkles or crinkles.

This $3-per-eye investment in a comfort lens has made for notably more comfortable, happier patients, and the elimination of performing the occasional flap refloat. In addition, a bandage contact lens used in patients who undergo a lift-flap procedure for enhancement decreases the incidence of epithelial ingrowth, which is higher in this particular scenario than in a primary LASIK procedure.

We also monitor the humidity carefully in the OR, as we have learned over time that significant seasonal variation in humidity (ideally maintained between 40% and 50%) had contributed to the occasional slipped flap and some unexpected over-corrections in particularly dry operating environments.

Following the Procedure

We do not routinely give patients a prescription for narcotic analgesics following surgery, except for those undergoing PRK (who have always received a bandage contact lens at the end of surgery). Because we perform same-day bilateral PRK, these patients are appreciative of the pain medication provided for the first few days after surgery.

Postoperatively, our LASIK patients are treated with a flouroquinolone and a mild steroid QID for one week, and non-preserved artificial tears every two hours and as needed.

This describes my personal LASIK technique. I always appreciate hearing your pearls. Please let me know about them. I am hopeful that the results of my learning curve are helpful to you. OM

Steven M. Silverstein, MD, FACS, is a cornea-trained comprehensive ophthalmologist in practice at Silverstein Eye Centers in Kansas City, Mo. He invites comments. His e-mail is ssilverstein@silversteineyecenters.com.