contact lens case reports

When Post-RK Pain Persists

BY PATRICK CAROLINE, FAAO, & MARK ANDRE, FCLSA
JUNE 1998

Patient L.M. is a 26-year-old student who underwent bilateral, eight-incision radial keratotomy about three years ago. Three months after the initial procedure, an enhancement procedure was performed on the left eye only. Uncorrected visual acuities had remained stable at 20/20. While the right eye recovered uneventfully and was asymptomatic, the left eye exhibited ongoing episodes of irritation of unknown etiology. Symptoms included a scratchy or rough sensation with eye movement, a dull ache with tactile pressure and sensitivity to moving air.

Before presenting to us a few months ago, L.M. had undergone bilateral occlusion of his lower puncta and had used preservative-free artificial tears every other hour and preservative-free ointment at night. He had also experimented with hypertonic drops and ointments, but none of these treatments had improved his symptoms.

The Elusive Etiology of L.M.'s Post-RK Pain

Up to 24 hours following RK, most patients experience a moderate throbbing, aching pain which is usually controlled by oral analgesics such as acetaminophen or codeine. However, some patients experience severe ocular pain that lasts 12 hours to two days and requires oral narcotics. Pain beyond 72 hours is uncommon.

Factors that may contribute to persistent ocular discomfort include: underlying basement membrane changes (Fig. 1), epithelial erosions, intersecting incisions with excessive wound gape, multiple scars from repeated operations, abnormal apposition of the wound (Fig. 2) and lid anomalies. In our case, L.M. had been examined repeatedly for the presence of any surface irregularities, dry eye or lid anomalies. All serial corneal mapping and biomicroscopy examinations were negative. The cause of his symptoms continues to remain an enigma.

A Disposable Bandage Enhances Comfort

L.M. was asymptomatic while his eyes were closed during sleep. Therefore, we placed him in a 1-Day Acuvue daily disposable contact lens: 8.5mm base curve, -0.50D power, 14.2mm diameter. This afforded him the benefit of applying a new, sterile lens every day. After one day of daily lens wear, his symptoms improved dramatically (Fig. 3).

We instructed L.M. to continue wearing the lens until his symptoms resolve.

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Patrick Caroline is an assistant professor of ophthalmology at Oregon health Sciences University and an assistant professor of optometry at Pacific University. Mark Andre is a fellow of the Contact Lens Society of America and director of Contact Lens Services at the Oregon Health Sciences University.