Treating Post-Refractive
Surgery Complications

BY WILLIAM TOWNSEND, O.D.
NOV. 1996

As these case studies demonstrate, prompt care is critical when a post-refractive surgery patient complains of pain or inflammation.

POSTSURGICAL ULCERATION

Sally, age 50, was 19 months post-RK/AK and had enjoyed good vision since the surgery. At her one-year postop visit, her best acuities were OD 20/20, OS 20/25.

Sally complained of recent onset pain and injection in her right eye. Her uncorrected acuities were OD 20/30^-, OS 20/25. Gross external examination showed grade III+ injection OD. Slit lamp examination revealed ulceration at the junction of a tangential and radial incision. The incision had gaped open almost the full thickness of the cornea. The ulcer was about one-third the thickness of the cornea.

We explained our findings to Sally and sent her directly to her performing surgeon. He obtained cultures which revealed Pseudomonas aeruginosa and Haemophilus influenza, and prescribed Ciloxan alternating with Tobrex. Although the ulcer cleared nicely, there was still some staining at the junction of the incisions as late as two months after the initial treatment.

I chose to refer Sally because I believe a surgeon should be given the opportunity to treat a patient who develops a serious complication, especially a potentially blinding situation.

EVEN YEARS AFTER RK, INCISIONS MAY GAPE OPEN, PROVIDING AN IDEAL ENVIRONMENT FOR CORNEAL ULCERS.

ADENOVIRAL KERATOCONJUNCTIVITIS

Tim, age 36, had undergone RK three years earlier and had an excellent result in his right eye, but his left eye was significantly overcorrected. His most recent refraction was OD +0.50 -1.00 x 135 = 20/20, OS +4.75 -1.50 x 93 = 20/20. To allow binocular vision, we had prescribed a daily wear disposable soft lens OS.

Tim called us one Sunday to report unilateral pain and injection. He admitted wearing the lenses for up to six weeks at a time with poor compliance in cleaning and disinfecting. We met Tim at the office immediately.

Gross examination showed grade I+ injection of the left eye and diffuse edema and superficial punctate staining of the left cornea. The left preauricular node was tender and swollen. We felt Tim had adenoviral keratoconjunctivitis, but as a precaution we prescribed Voltaren and Ciloxan and instructed him to report any worsening of the symptoms.

Two days later, Tim reported less photophobia and glare. His superficial corneal staining had decreased significantly, but there was slight gaping of the inferior T-cut. He continued the medications. One week later, after we lectured Tim on the possible complications of poor compliance, we told him he could resume wearing his lens.

I opted to treat Tim because his performing surgeon was not in the area, and I never felt that the patient had infectious keratitis.

CORNEAL HEALING

In managing post-RK patients, it's important to understand the mechanism of corneal healing. After the incisions are made, corneal keratocytes become fibroblasts and build collagen 'bridges' across the wound. In some patients, there is complete healing, but patients who develop only superficial closure of the incisions are at risk for complications months or even years after surgery.

The 'ledge' where the edges of an incision meet is a perfect place for bacteria to cling to the cornea and colonize to form an ulcer. In individuals who develop only superficial scarring, the space between two sides of an incision can act as a corridor that allows infection to spread quickly from the anterior cornea to Descemet's membrane. Incomplete healing of incisions may explain why some patients continue to have daily variations in vision months or years after surgery. Fluctuations in IOP can cause significant variations in refractive error.

If a post-RK patient complains of redness, pain or a change in vision, see him immediately. When prescribing contact lenses for these patients, remember that they have a small but serious risk for complications. CLS

Dr. Townsend is in private practice in Canyon, Texas, and is a consultant at the Amarillo VA Medical Center.