ADVICE ON PATIENT MANAGEMENT AND EDUCATION
LASIK Formulary
Therapeutics before and after surgery can enhance your patients' outcomes.
BY PAUL M. KARPECKI, O.D., Kansas City, Mo.

The formulary for laser-assisted in situ keratomileusis (LASIK) includes relatively few medications, but they're very important. Taken preoperatively, they can prevent problems later. Postoperatively, they can treat complications such as diffuse lamellar keratitis (DLK). Here, I'll tell you what the important drugs are and when to use them.

Address blepharitis before surgery.

Preoperative assessment

During the initial consultation with a patient, you should look for disease that would disqualify him as a LASIK candidate.

Then check on conditions that require treatment before LASIK surgery. Conditions that might be treated therapeutically before surgery and aren't contraindications for LASIK include blepharitis, meibomitis and mild-to-moderate dry eye. If you can't manage these conditions before surgery, your patient shouldn't undergo LASIK.

Blepharitis and meibomitis. Address blepharitis and meibomitis before surgery to prevent bacteria from inoculating the eye and causing an infection during the procedure and to help prevent postsurgical dry eye. Studies have shown that patients with blepharitis or meibomitis are more than twice as likely to have postsurgical dry eye, which may persist for 3 to 6 months.

Fluoroquinolone drops such as ofloxacin 0.3% (Ocuflox), ciprofloxacin 0.3% (Ciloxan) and levofloxacin 0.5% (Quixin), when used as a lid scrub nightly for 2 weeks have been shown to treat blepharitis and meibomitis effectively.

Bacitracin ointment, which is excellent against Gram-positive organisms, is another good choice for treating blepharitis and meibomitis. The patient applies hot compresses to his closed eyes for 10 minutes and then applies bacitracin ointment to the lid margins every night for 10 to 14 days (or until the condition resolves).

Patients who show significant inflammation (erythema and edema) with blepharitis or meibomitis may be best treated with a combination steroid and antibiotic. Dexamethasone 0.1% and tobramycin 0.3% (TobraDex) or sodium sulfacetamide 10% and prednisolone acetate 0.2% (Blephamide) are two such examples. However, both have some disadvantages as treatments for Staphylococcus, the primary pathogen in blepharitis. Tobra-
mycin and dexamethasone are more effective against Gram-negative bacteria, which aren't involved in blepharitis. Also, bacteria are highly resistant to sulfacetamide and prednisolone, which can cause allergic-type reactions.

Acne rosacea and significant blepharitis and meibomitis. When acne rosacea exists along with blepharitis and meibomitis, oral tetracycline is indicated. Tetracycline derivatives such as doxycycline have two properties that make them ideal for lid disease and acne rosacea:

• they accumulate in oil glands, allowing higher concentration at the site of treatment (the meibomian glands and sebaceous glands are examples of the typical oil glands that tetracycline would target)
• they've been shown to have anti-inflammatory properties.
• study by Solomon and Rosenblatt showed doxycycline's ability to inhibit interleukin-1, an inflammatory mediator that's a precursor to T-cell activation.

Recommended dosage is P.O. doxycycline 100 mg b.i.d. x 1 month. Patients may experience phototoxic reactions, so warn them to wear sunscreen or protective clothing. Also tell them that tetracyclines could chelate with dairy products, such as milk and with antacids, and become ineffective.

Some patients can't take tetracyclines due to gastric inflammation. Tetracyclines like doxycycline are contraindicated in children, pregnant women and nursing women due to possible teratogenic effects and teeth and bone deformities in children.

Also prescribe therapeutics before surgery to minimize the possibility of subconjunctival hemorrhages (SCHs). I'll discuss this in more detail in the section on managing postsurgical conditions and complications.

Dry eye. LASIK is contraindicated for patients with severe dry eye from systemic diseases such as rheumatoid arthritis and Sjogren's syndrome. For mild-to-moderate dry eye, however, simply treat it before surgery.

No single artificial tear best serves all dry eye patients. Preservative-free and dissolving-preservative tears and gels are probably better than preserved tears for the short term before surgery. Preservative-free artificial tears include GenTeal, Liquifilm Tears, Moisture Eyes, Refresh Plus and Tears Naturale Free.

We used to advise patients to use artificial tears when their eyes started burning or when symptoms began; now the goal is to prevent the inflammatory cascade that may result when the eyes are irritated. Using drops beforehand serves this goal best. Tell patients to use artificial tears at least every 2 to 4 hours while awake and before any task that's likely to cause dry eye symptoms, such as reading, computer work and outdoor activities.

Patients with significant inferior staining that indicates lagophthalmos should use lubricating ointments at night. Ointments include Duratears Naturale and Refresh PM. Tell mild-to-moderate dry eye patients to begin this regimen 2 weeks before surgery and to continue for at least 3 months after.

Post-op treatment for all

After LASIK, place all patients on antibiotic drops and steroid drops or on a combination medication q.i.d. for 1 week. These drugs include ofloxacin, ciprofloxacin or levofloxacin q.i.d., and fluorometholone 0.1% (FML) q.i.d., or combination medication dexamethasone and tobramycin drops q.i.d.

Instruct all patients to use artificial tears after LASIK. Carboxymethylcellulose products appear to be effective. Tell patients to sleep for 2 to 4 hours after surgery then use 1% carboxy-methylcellulose (Celluvisc) q1h for 24 hours. Use of true preservative-free drops such as 0.5% carboxymethylcellulose sodium (Refresh Plus) q2h for the first 2 weeks appear to be effective. Patients should use artificial tears every 2 to 4 hours and before tasks that may cause dry eye symptoms such as computer work and reading.

After the 2 weeks, consider starting your patient on dissolving-preservative tears such as 0.5% carboxymethylcellulose sodium (Refresh Tears), 0.3% hydroxypropyl methylcellulose (GenTeal) or 0.25% sodium carboxymethylcellulose (Thera Tears), which are convenient and inexpensive. Patients should use these for 3 months (the expected post-LASIK dry eye interval as indicated by studies).

Managing postsurgical conditions and complications

Below are some conditions and complications that can occur after LASIK and how you can deal with them.

Subconjunctival hemorrhages (SCHs). Although SCHs are asymptomatic findings that resolve in 2 to 3 weeks, using brimonidine tartrate 0.2% (Alphagan) just prior to LASIK surgery decreases the incidence of this problem, quiets the eye and produces a cosmetically appealing "whiter" eye after surgery. Surgeons must be careful about using this drop, however, because it can cause flap slippage and decreased adherence if certain techniques aren't followed.

Loose epithelium and epithelial abrasions. Loose epithelium after LASIK is essentially a large corneal abrasion. Apply a bandage contact lens if the patient is in extreme discomfort. Remove the bandage lens by the third day, or when the cornea has re-epithelialized.

Therapeutic management involves antibiotic drops and maintaining an anti-inflammatory such as a mild steroid (fluorometholone 0.1%, for example). Although it's not typical to place a patient on a steroid drop to treat a corneal abrasion, post-LASIK patients who experience trauma or an abrasion seem to be more susceptible to DLK, and a steroid drop may prevent this.

If a patient has delayed healing or a prolonged epithelial defect, discontinue the steroid drop to promote re-epithelialization.

Once he's epithelialized, monitor the patient for DLK and, if significant corneal edema exists, consider maintaining steroid drops for 1 to 2 more weeks.

Halos and glare. Pilocar-pine nitrate 0.5% (Pilagan) has been suggested for patients who experience significant halos and glare at night following LASIK surgery. Pilocarpine has significant drawbacks, however, which make using it to shrink pupil size and prevent the patient from seeing the "knee" of the surgical ablation zone questionable.

One drawback is that most patients who experience halos and glare were high myopes before surgery. They have an increased risk of retinal detachment, and because pilocarpine constricts the pupil, it could cause retinal traction and precipitate detachment. Younger LASIK patients may experience a "brow ache" from the miotic effects of this medication. Some doctors suggest brimonidine tartate, which has an effect on pupil size, as a possible treatment that doesn't have the side effects of pilocarpine.

DLK ("Sands of the Sahara"). DLK may occur after LASIK, causing inflammatory cells to migrate to the flap interface. The following are possible causes of DLK:

• bacterial exotoxins found on the microkeratome blade or other equipment
• the oils in the keratome
• solutions
• temperature, or the simple trauma of the procedure.

Therapeutic treatment depends on the severity of the condition. Mild DLK means "dusting" of inflammatory cells with mild edema, no cell coagulation and vision correctable to 20/20. Regardless of severity, treat this condition aggressively. Use prednisolone acetate 1.0% (Pred Forte or Econopred Plus) drops every 1 to 2 hours and dexamethasone and tobramycin ointment at night.

Moderate DLK, which means more white blood cells or polymorphonuclear leukocytes (inflammatory cells) and edema, with vision decreased to 20/25 or 20/30, may require a surgeon to lift the flap and irrigate the inflammatory cells from the interface. Follow this with prednisolone drops every 1 to 2 hours and dexamethasone and tobramycin ointment at night.

Scott MacRae of the University of Rochester suggests using oral steroids to treat DLK. He placed four patients with moderate-to-severe DLK on topical medications and four others on oral medications. The four on oral prednisolone had complete resolution of their DLK. Use a Medrol dose pack for the oral prednisolone regimen.

Severe DLK, with aggregations of white blood cells, significant inflammatory cells and edema that reduce best corrected visual acuity to 20/40 or worse probably requires that the surgeon to irrigate the cells and prescribe oral steroids.

Forewarned is forearmed

Know what conditions to address before scheduling LASIK and how to treat problems that might arise afterward. And, of course, learn to recognize patients who aren't good candidates in the first place. Making LASIK safe and comfortable is vital not only to your patients' sight, but also to your word-of-mouth referrals and bottom line. Therefore, it's also imperative for you to know which drugs to turn to when treating ocular conditions both pre- and postoperatively.

Dr. Karpecki is clinical director of Cornea and Refractive Surgery at Hunkeler Eye Centers in Kansas City and is a national director for NovaMed Eyecare Management. He has lectured internationally on refractive surgery, ocular emergencies, new technology and anterior segment disease.A SAMPLING OF ARTIFICIAL TEARS AND OINTMENTS