Optometric Management

Diminishing Dryness
These pre- and postsurgical strategies combat dry eye throughout the LASIK experience.

Paul M. Karpecki, O.D.: Let's discuss the perioperative strategies you use to diminish the effects of dry eye in your LASIK patients.

Kerry D. Solomon, M.D.: Although the postoperative regimen is important, the perioperative regimen may be even more important. Patients prone to dry eye tend to be much more prone to developing epitheliopathy, epithelial separation, abrasions and so forth during surgery.

I also think physicians tend to overanesthetize the ocular surface during LASIK. At my office, we instill one drop of proparacaine when the patient is in the waiting area, then one drop when he comes in, and no more.

Frank A. Bucci, Jr., M.D.: I delay application of proparacaine until just before the procedure. I also use ocular occluders to sweep the lashes out of the surgical field. This limits the exposure of lid secretions to the ocular surface.

Hinge Position and Dry Eye

In a study presented at the 2001 American Academy of Ophthalmology, Dr. Kerry Solomon and I examined hinge position and dry eye. The results of that study, which looked at pre-existing dry eye, show that a nasal-hinge flap results in less dry eye and better sensation than a superior-hinge flap. That's because you're preserving the nasal arm of the long posterior ciliary nerve with a nasal-hinge flap.

At 6 months, patients with a nasal-hinge flap had the same sensation and dry eye symptoms after LASIK as they did before LASIK. Patients with a superior-hinge flap had very significant dry eye 6 months post-op as compared to their preoperative level.

The trend is that the dry eye does improve, but corneal staining, conjunctival staining, Schirmer's testing and sensation are significantly worse with a superior-hinge flap. In our group of 52 patients (104 eyes), five patients with superior-hinge flaps still had corneal staining at 6 months post LASIK; none with nasal-hinge flaps did.

--Eric D. Donnenfeld, M.D.

Just before the microkeratome pass, I instill one drop of Celluvisc (carboxymethylcellulose 1%) ointment and two drops of Refresh Plus (carboxymethylcellulose 0.5%) artificial tears. I've found that using Celluvisc alone can sometimes damage the Hansatome microkeratome head. I believe lubricating the ocular surface before the microkeratome pass decreases trauma to the epithelium.

Immediately after the procedure, I have the patient sit up and read an eye chart. A typical patient will see 20/60 within 2 minutes after LASIK and is usually thrilled at that time. I tell the patient that I'll be putting a viscous tear in her eye that will blur her vision but enhance healing. The post-op nurse then reviews the patient's instructions. Finally, I check the flap at the slit lamp before the patient puts on her goggles and leaves the laser center.

Paul M. Karpecki, O.D.: What about temporary punctal plugs? Do you use them postoperatively?

Frank A. Bucci, Jr., M.D.: For patients who don't receive silicone punctal plugs preoperatively because of a relatively healthy epithelium, I frequently place collagen plugs in the lower lids immediately following LASIK. For patients who received silicone plugs in the lower lids before surgery, I frequently place collagen plugs in the upper lids immediately after LASIK to supplement the effect of the silicone plugs.

Anecdotally, I've found that these patients do much better in the first week, especially when they comply with our recommendations for using Celluvisc during the first 24 hours and Refresh Tears thereafter. Placing collagen plugs also has the advantage of being cost-effective.

Paul M. Karpecki, O.D.: What tears or drops do you recommend immediately post-op?

Frank A. Bucci, Jr., M.D.: I prefer to use very viscous lubricating drops during the first 24 hours following LASIK. I tell patients that I'm purposely blurring their vision with these drops, but that doing this will improve their outcome.

I prefer Celluvisc, which is a thicker form of carboxymethylcellulose (CMC). I ask patients to use this every hour while awake for the first 24 hours following LASIK. Then I convert them to Refresh Tears and ask them to use these drops four to ten times a day, stressing that more is better. I've reported that patients prefer Refresh Tears over GenTeal Drops during the first month following LASIK.

Significant evidence in the scientific literature and from our study demonstrates that CMC provides a greater benefit to the ocular surface than hydroxypropyl methylcellulose. I've presented this study at numerous meetings, and the results will be published soon.

Kerry D. Solomon, M.D.: Like Dr. Bucci, I have patients use a thicker artificial tear preparation for the first 24 hours postoperatively. This soothes the eye for most patients. I also have them take a nap for the first 4 hours or so at home to help clear the surface.

For the month after surgery, I put them on a much more aggressive regimen, whether they think they need it or not. I instruct them to use the tears initially about six times a day and then four times a day, not as needed. I believe this helps with fluctuating vision and earlier stabilization.

The one complaint I've had with the thicker drops is that they tend to make the lids stick together, especially the next morning. I warn patients about this beforehand and instruct them to separate their lids gently upon awakening. A new gel product, Refresh Liquigel, may represent the compromise that provides optimal protection but isn't so viscous.

Eric D. Donnenfeld, M.D.: Telling patients that they need to use tears, whether their eyes feel dry or not, is important. Often patients don't know that they have dry eye because their corneas are desensitized postoperatively. For this reason, a prescribed therapeutic regimen is very important in patient management.

We also firmly believe in the immediate use of Celluvisc (CMC 1%) in the perioperative and postoperative period. We begin our treatment immediately on the operating table. As soon as the flap is laid down and positioned, we wait about 30 seconds and then put one drop of Celluvisc in the middle of the cornea and let the patient lie there for an additional minute while the flap adheres. That one drop of Celluvisc lubricates the surface, prevents desiccation under the operating microscope and drastically decreases epitheliopathy in the first day postoperatively.

Not only does this make the patient feel better, but also it dramatically reduces the risk of flap slippage and striae formation. That's because the cornea's surface is much smoother and the lid will move against a lubricated ocular surface in the immediate postoperative period when flap slippage is most likely, rather than moving against a roughened ocular surface when the cornea has been dried.

J. James Thimons, O.D.: We have our patients take a 30- to 45-minute nap right in the postoperative area. With that nap, I've seen marked improvement in the initial exit quality of the cornea on the operative day. What's more, on the first postoperative day I've seen a great improvement in the general quality of the ocular surface.

Paul M. Karpecki, O.D.: Are preserved artificial tears indicated at a certain point?

J. James Thimons, O.D.: I don't recommend them during the first week. I don't like having any preservatives in the system when they're not required. Some patients find these drops on their own. But if they have a problem, I remove the preservatives from the regimen and take them back to a non-preserved system until the cornea clears.

After the first week, if a patient has good healing characteristics, I don't have a major concern about a dissolving preserved drop. But I don't want patients to use a true preserved system any time during the first month or so because the cornea is fairly fragile. After a month, most patients can choose whichever drop they prefer.

Dry Eye and Steroid Use

Some newer theories on dry eye continue to support the inflammatory nature of this condition. A study by Marsh and Pflugfelder of Bascom Palmer Eye Institute showed that a short-term steroid "pulse" treatment was very effective in treating keratoconjunctivitis sicca in Sjögren's patients. But the disease's chronic nature and the long-term complications of steroid drops, such as increased intraocular pressure (IOP), raised concerns that this treatment might not be warranted.

Steroids can provide effective therapy in Sjögren's keratoconjunctivitis sicca, as these pre-steroid (top)
and post-steroid (bottom) photos illustrate.

Soft steroids, such as loteprednol etabonate 0.2% (Alrex) and loteprednol etabonate 0.5% (Lotemax), may be the solution. Although a 2-week regimen is still recommended, these drops have shown a significant reduction in inflammatory signs and symptoms with a safety profile equal to that of placebo, according to a study published by Stewart et al. in 1998.

A study by Shulman et al. in 1999 showed that loteprednol etabonate 0.2% for seasonal allergic conjunctivitis had an extremely high resolution rate over 2 weeks compared to placebo. Only two patients experienced IOP rise, one of those in the placebo group. For this reason, loteprednol etabonate 0.2% may be a suitable medication for dry eye therapy including post-LASIK neurotrophic epitheliopathy.

--Paul M. Karpecki, O.D.

Avoiding Erosion

In the perioperative phase, you want to avoid an erosion or an epithelial defect. During your preoperative assessment, look for epithelial basement membrane dystrophy (EBMD), which will predispose the eye to an epithelial erosion or defect. If you have a clear case, you have to worry about it. If you closely examine the corneal epithelial surface, you'll often find subtle irregularities that are diagnostic even in asymptomatic patients. The prevalence increases in patients over age 50. We probably all underdiagnose EBMD, and that's one more reason to be careful to protect the ocular surface during LASIK.

A few weeks after surgery, patients start to feel better and want to stop using lubricant drops. You have to be vigilant and tell them to continue using the drops for at least a month. If they stop prematurely, they'll be prone to epitheliopathy with an associated decline in visual acuity.

--John R. Bierly, M.D.

Epithelial basement membrane dystrophy showing map dot fingerprint lines in two eyes in the same patient.

Beware of Toxicity

J. James Thimons, O.D.: Most refractive surgeons are acutely aware how the procedure changes the quality of the corneal surface. But one element that many tend to overlook is the impact of the surgery itself.

Following surgery, even minor insults (such as preservatives in tears or within the antibiotic system and anti-inflammatories) are more than sufficient to make the patient much more symptomatic. Before surgery, those insults probably wouldn't have affected the cornea.

One key involves discontinuing topical postoperative therapeutic systems fairly quickly. In my experience, even a four-times-a-day regimen of topical fluoroquinolone taken 7 to 10 days in a postsurgical eye can be toxic to the cornea. The patient can have induced dryness and induced ocular surface disorder secondary to postoperative treatment versus the surgery itself.

Eric D. Donnenfeld, M.D.: In the perioperative period, I try to stay with transiently preserved or non-preserved drops whenever possible. I use non-preserved ketorolac tromethamine (Acular) when I want a non-steroidal, and when I want an antibiotic, I avoid the more toxic antibiotics, particularly the aminoglycosides that cause surface disruption. When I use the fluoroquinolones, I prefer ofloxacin (Ocuflox) over ciprofloxacin (Ciloxan), not only for its antibacterial coverage but also because the ciprofloxacin product has twice as many preservatives as ofloxacin.

Extra Ammunition in a Gel

Paul M. Karpecki, O.D.: Gel products are popular with patients because they're less viscous than ointments, don't cause blurred vision and have somewhat longer staying time. Is there a need for a gel product after LASIK?

John R. Bierly, M.D.: I understand Refresh Liquigel has the same concentration of carboxymethylcellulose as Celluvisc. However, the molecules have shorter chains, so it's less viscous. I could see using this product on the first postoperative day instead of Celluvisc.

Eric D. Donnenfeld, M.D.: A gel fits the niche between conventional drops and ointments, so that you increase your treatment armamentarium. The patient who was unhappy with ointments now has a treatment that can make him a little bit happier. And you now have extra ammunition for the patient who wasn't getting enough therapy from drops but for whom you didn't want to prescribe an ointment.