LASIK feasible in pediatric patients, surgeon says

Challenges include anesthesia, flap creation and laser ablation centration.

Issue: August 1, 2003

ByBob Kronemyer

SAN FRANCISCO – LASIK appears to be a viable refractive procedure in children, according to the outcomes of two eyes (two patients) who were treated with myopic LASIK under diprovan anesthesia.

One eye was that of a 7-year-old girl who had –10 D of anisometropia, with best corrected visual acuity of 20/80 in the amblyopic eye. The other eye, of a 34-month-old boy, had –6 D of anisometropia, with BCVA of 20/200.

“Both patients were refractory to repeated attempts with conventional amblyopia therapy,” said Jonathan M. Davidorf, MD, of West Hills, Calif., who performed both surgeries. The two patients tolerated LASIK well. There was no adverse reaction to the diprovan anesthesia, and the flaps healed without incident. The first eye achieved BCVA of 20/50, and the second eye achieved 20/40.

Few candidates

Despite these encouraging results, only a small percentage of children are possible candidates, Dr. Davidorf said at the American Society of Cataract and Refractive Surgery meeting. The incidence of anisometropic amblyopia cases that have failed conventional treatments “is tenfold greater than the incidence of juvenile onset diabetes, which is a well-known disease,” he said.

“Of course, this refractive surgery is experimental, and we need to follow the results very carefully. Only after gaining experience with these critical cases might we even consider performing refractive surgery on patients under 18 years of age for purely elective reasons,” he cautioned.

Dr. Davidorf divided the potential indications for pediatric refractive surgery into three categories: critical, functional and elective. The two LASIK cases represent critical indications, in part because patients were younger than 8 years old.

“The goal here is not to achieve perfect uncorrected vision, as in the adult population, but rather to reduce the level of anisometropia, so that conventional amblyopia therapy may meet with better success,” he said.

Patient response

In the case of the 7-year-old girl, LASIK was performed after long discussion with the family. Surgery was performed in the right eye, with a target of –10 D to balance refractive error with the nonamblyopic left eye.

“Surgery is done without the eye tracker because the patient is asleep,” Dr. Davidorf said.

Patients are able to breathe on their own with the diprovan anesthesia.

“The postoperative course was essentially unremarkable,” he said.

Amblyopia treatment consisted of merely wearing a –9 D spherical soft lens in the treated eye, leaving the other myopic eye (the good eye) at –10 D.

The improvement from 20/80 to 20/50 “was pretty impressive,” Dr. Davidorf said. Unfortunately, a retinal detachment occurred 2 years postop in the untreated eye, reducing the girl’s vision to 20/400.

“I think that’s a very powerful testimony to the benefit of LASIK. Her good eye is now the eye we treated,” he said.

For the nearly 3-year-old boy, LASIK was performed in the left eye, improving from 20/200 to 20/40. As with the girl, surgery was without incident, and the postop course was uneventful, along with intensive amblyopia treatment.

“We achieved a very immediate response with the BCVA. I think this was because of the child’s young age,” Dr. Davidorf said. A slight myopic shift occurred, however.

“Glasses were prescribed when his vision dropped from 20/40 to 20/60, but then the vision was recouped,” he said.

At 5 to 6 months postop, the boy is able to read letters on the 20/30 acuity line.

Goals of LASIK

“The goal of these two LASIK cases is an attempt to reduce the refractive error in the amblyopic eye to make it more equal to the fellow eye,” Dr. Davidorf said. “We are trying to improve spectacle or contact lens tolerance, and trying to improve amblyopia therapy. Remember, though, that this is not a one-time fix. We need to be aggressive with amblyopia treatment postoperatively.”

Implantable contact lenses would obviate some technical considerations.

“But this is something we are unable to do here in the United States,” he said.

Because inhalation anesthetics interfere with the laser, the child is started on an IV outside of the laser suite.

“Then once the child is administered diprovan, he can breathe on his own, and we don’t need the inhalation anesthetics anymore. This is the same type of anesthesia many ENT physicians use for placing ear tubes,” he said.

Bell’s phenomenon is another challenge with these patients.

“Centering the microkeratome is the most difficult part of the procedure,” Dr. Davidorf said.

However, he did not have to resort to a lateral canthotomy.

“The exposure was fine. It is very similar to an adult eye, even on the boy who hadn’t turned 3 years old yet,” he said. Using a microkeratome with low suction is helpful. “I had to manually fixate the eye when performing the LASIK ablation,” he said.

Although Dr. Davidorf is excited about the prospects for pediatric LASIK, he and others are fearful that more families will become amblyopia therapy failures if they know this new procedure is an option.

“They won’t want their child to wear glasses or have to wear a patch,” Dr. Davidorf said.

For Your Information:
Jonathan M. Davidorf, MD, can be reached at 7320 Woodlake Ave., Suite 190, West Hills, CA 91307; (818) 883-0112; fax: (818) 883-2767.