During residency training, it was drummed into our heads that topical anesthetic should not be prescribed to treat corneal surface problems. The reasons were that (1) the frequent use of such drops can mask an infection by reducing pain and retarding epithelial healing and (2) prolonged use by the patient, without the knowledge and supervision of the treating ophthalmologist, can cause severe corneal opacity that necessitates a penetrating keratoplasty.

For more than 1 year now, I have routinely given a small bottle of tetracaine to keratorefractive patients who are apprehensive about surgery or have sustained a significant epithelial defect during LASIK. I prescribe the medication postoperatively q.i.d. for the patient to use while awake if severe pain occurs. I ask post-LASIK patients to return the bottle the next morning and ask PRK patients to return it after 4 days when their contact lens is removed. None of my patients has experienced a problem of any kind when following this regimen. Equally important, all patients were thankful for the topical anesthesia medication and said that it rendered their postoperative courses relatively benign.

I present my experience with postoperative tetracaine because this well-known medication has a new indication: the relief of pain immediately following laser keratorefractive surgery. The fact that this medication is contraindicated for long-term use should not disqualify its short-term application if the medication provides a clinical benefit. The practice of medicine forces conscientious physicians to consider using medications off-label in order to provide better care for their patients. For example, aspirin can be detrimental to the gastric mucosa if taken long term in high doses. In long-term small doses, however, aspirin's platelet antiadhesion effect is useful in preventing strokes, and physicians recommend this medication to millions of elderly patients.

I do not believe there should be a single standard of care proclaimed for any medication. Past experience with a certain dose or regimen for an established medication does not apply to an altered regimen for a new use. In order to provide the best care for our patients, we need to keep open but critical minds when evaluating new uses for established medications. Lee Shahinian, Jr, MD, and Thomas Claringbold II, DO, have been kind enough to share their thoughts on this subject.

LEE SHAHINIAN, Jr, MD
Some researchers have proposed using 0.5% to 1.0% tetracaine to control pain after surface ablation,1,2 but their studies did not determine the limits of a safe dosing regimen as regards either frequency or duration. Although topical 0.5% tetracaine is a safe medication in single doses, its toxicity with repeated use has been well documented.3-5 Despite the universal taboo on prescribing topical anesthetics for patient use, case reports of corneal ulcers secondary to anesthetic abuse continue to appear.6-9

Managing post-PRK and post-LASEK pain involves a degree of autonomy on the part of patients. They may modify or ignore instructions for using a topical anesthetic. Even when a limited amount of drug is dispensed, physicians should never underestimate their patients' creative ability to obtain more medication. It would therefore be desirable to have a topical analgesic that patients could self-administer frequently and safely in order to relieve ocular pain for several days after undergoing surface ablation. Research in which I have been involved indicates that, with dilute topical proparacaine or tetracaine, it is possible to achieve prolonged analgesia without corneal anesthesia or toxicity. My colleagues and I previously reported10 that topical 0.05% proparacaine (1/10 the normal anesthetic concentration) provides pain relief and appears to be nonanesthetic and nontoxic, even when used frequently for 1 week.

THOMAS CLARINGBOLD II, DO
Like Dr. Nordan, I was also taught the potential complications of prolonged use of anesthetic drops during my residency. One of the first penetrating keratoplasty cases on which I assisted involved a patient who had surreptitiously pocketed a bottle of tetracaine while undergoing treatment for a corneal abrasion in a local emergency department. The sight of this patient's cornea after several bouts of nonhealing epithelial defects, numerous difficult-to-treat ulcerations, and eventual scarring certainly made a strong impression on me.

I think all refractive surgeons would agree that using full-strength tetracaine after refractive surgery is contraindicated. The successful use of dilute anesthetic drops to alleviate discomfort after keratorefractive procedures has been reported anecdotally and in the literature, however.10 Although my refractive practice has been 100% LASEK since late 1999, I do not routinely use dilute anesthetic drops postoperatively. My decision is based, not on a fear of complications, but on the fact that the majority of my patients do not suffer great postoperative discomfort.

I completely agree with Dr. Nordan that there should not be a single standard of care for any medication. By that philosophy, I have significantly reduced my patients' postoperative discomfort through the administration of rofecoxib. Over the past 6 months, I have prescribed rofecoxib 50 mg p.o. q.d. beginning 3 days prior to surgery and continuing until the removal of the bandage contact lens. The decrease in my patients' subjective pain scores has been statistically significant. When answering a standardized questionnaire using a discomfort scale of one (no pain) to 10 (severe pain), the rofecoxib group had a mean score of 3.1 compared to 4.9 in the nonrofecoxib group.

I have recently used dilute proparacaine in a few select patients who were extremely apprehensive about surgery and experienced intraoperative leakage of alcohol from the holding well. I was pleased with the results, but I do not feel proparacaine is needed routinely. Nevertheless, I am thankful to have another tool in my belt.

Lee T. Nordan, MD, is the director of Nordan Eye Laser Medical Group in Carlsbad, California. He holds no financial interest in the products and companies mentioned herein. Dr. Nordan may be reached at (760) 930-9696; laserltn@aol.com.
Lee Shahinian, Jr, MD, is a corneal specialist with the Peninsula Laser Eye Medical Group in Mountain View, California, and Associate Clinical Professor of Ophthalmology at Stanford University in California. He holds patents on dilute topical anesthetics for analgesia. Dr. Shahinian may be reached at (650) 961-2585; lshahinianjr@cs.com.
Thomas Claringbold II, DO, is Chief Ophthalmologist for MidMichigan Physicians Group in Clare and Assistant Clinical Professor at Michigan State University in East Lansing. He holds no financial interest in the products and companies mentioned herein. Dr. Claringbold may be reached at (989) 802-8811; eyeboy@tm.net.
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