Phototherapeutic keratectomy promising for treating severe stromal scarring in children

Phototherapeutic keratectomy (PTK) appears to be a viable approach for treating carefully selected pediatric eyes with dense superficial corneal opacity, said Arias N. Kollias, MD.

He reported that PTK was performed in a series of five eyes of five children ages 6 to 8 at the department of ophthalmology, University of Munich. Causes of opacity included uveitis-associated band keratopathy in three eyes, anterior basement membrane dystrophy in one eye, and scarring after keratoconjunctivitis epidemica in one eye.

Patients were selected for this surgical procedure if they had lost more than 2 Snellen lines of best spectacle-corrected visual acuity during the previous 6 months, showed loss of skiascopic reflex, and had a maximum lesion depth of 100 microns.

The PTK procedures were performed under general anesthesia using the Allegretto 200 Hz excimer laser (Wavelight). Depth of PTK ablation ranged from 20 to 100 microns (mean 63 microns). All patients resumed amblyopia therapy after surgery.

Healing was uneventful in all cases, and during a mean follow-up of 9.5 months (range, 1 week to 23 months), visual acuity improved in four eyes and was stable in the fifth that experienced uveitis recurrence.

"Compared with EDTA scrubbing or lamellar penetrating keratoplasty, PTK provides a less invasive and less traumatic therapeutic option for treating severe anterior stromal scarring in pediatric eyes," Dr. Kollias said. "Our experience shows PTK can successfully increase corneal transparency and smooth the corneal surface to provide visual rehabilitation and prevent amblyopia.

"However, it is important to use caution in selecting the ablation depth to avoid causing a hyperopic shift and close collaboration between the departments of refractive surgery and pediatric ophthalmology is critical to maximize anatomical and functional outcomes," Dr. Kollias said.