Predicting risk of keratectasia after LASIK is difficult

Las Vegas-No current methodology can reliably predict which corneas will undergo keratectasia after refractive surgery.

"The best defense is clinician education, careful screening, a conservative refractive surgery exclusion strategy, and comprehensive disclosure of potential risks to the patient," said Stephen D. Klyce, PhD, during a refractive surgery subspecialty day presentation here at the American Academy of Ophthalmology annual meeting.

Forme fruste keratoconus is a known risk factor for refractive surgery. In an era in which the number of LASIK litigations is increasing and insurance costs are escalating, the need for careful preoperative screening has never been greater, said Dr. Klyce, professor of ophthalmology, Louisiana State University Health Sciences Center, New Orleans. He referred to a retrospective study of 10 eyes in seven patients in whom keratectasia developed after LASIK; each of these patients had a preoperative risk factor of either forme fruste keratoconus or low residual stromal bed thickness (<250 µm). Yet evidence also indicates that litigation can be successful even when no corneal abnormalities are detected.

"The incidence of keratectasia in patients with risk factors is unknown at this time," he said.

Contact lens history

Obtaining a contact lens history is one of the most critical steps in screening patients, Dr. Klyce said. Contact lens warpage must be excluded. Rigid and soft lenses can cause warpage by molding the cornea into patterns resembling keratoconus. If molding or warpage is apparent, the patient should discontinue wearing lenses and undergo repeat topography and refractions every 2 to 3 weeks until the cornea has normalized and is stable. Normalization may take several weeks for soft lenses and up to 6 months for rigid lenses.