Best treatment plan available for pediatric refractive surgery

Older children can be treated with laser surgery, but posterior chamber phakic lenses can successfully be implanted at an earlier age.

PARIS — With more than a decade of experience and results, refractive surgery in pediatric patients has become an established practice, and some reliable conclusions on indications and best treatment choices have been achieved, according to a presentation at the meeting of the French Society of Ophthalmology here.

“Indications of pediatric refractive surgery are rare and very specific, aimed at the correction of anisometropic amblyopia and bilateral high ametropia, when spectacles and contact lenses are not sufficient to guarantee the quantity and quality of vision that allows the child to lead a normal, happy life,” Laurence C. Lesueur, MD, said.

Different techniques can be offered in relation to the age of the patient, to the amount and type of refractive error, and to the lifestyle and habits of the child and his or her family.

Eyes of pediatric patients have been implanted with the Visian ICL. To date, 18 patients treated for high myopic amblyopic anisometropia have achieved 12 years of follow-up. Images: Lesueur LC

Laser surgery

The first cases of pediatric PRK date back to 1995, and since then, a small number of peer-reviewed journal articles describing small case series of children with a variable age and myopia from about –2.5 D to –14 D or, in fewer cases, hyperopia from +4 D to +8 D have been published.

The results followed the evolution of excimer lasers, particularly in relation to haze, the most typical complication of PRK in its early years.

“As time passes, we can observe that haze in the results of these studies changes from severe to moderate and is no longer mentioned as a complication at the turn of the century,” Dr. Lesueur said.

Also, case series tend to become larger and the age range wider. Visual results, which were good from the beginning, become even better, with a faster recovery time and more stability.

LASIK was introduced a few years later, about 1999. Because of potential problems related to the flap, it is used in older children, who are able to refrain from rubbing their eyes after surgery. Good results and no major complications have been reported by the few studies published on this technique. Some authors corrected highly myopic eyes with LASIK, up to –23 D, but Dr. Lesueur said better results in high ametropia can be achieved with phakic IOLs.

Ultrasonographic biomicroscopy and WaveLight Allegretto images of eyes implanted with Visian ICL.

Phakic IOLs

Good results have been shown by some authors with the anterior chamber iris claw Artiflex (Ophtec) or Artisan/Verisyse (Ophtec/Abbott Medical Optics) implants. According to Dr. Lesueur, however, posterior chamber phakic lenses should be the first choice in young patients.

In her hospital in Toulouse, France, the Visian ICL (STAAR Surgical) has been implanted for many years with successful outcomes and few complications. To date, 18 patients treated for high myopic amblyopic anisometropia have achieved 12 years of follow-up.

The mean age of the patients at the time of implantation was 9 years, ranging between 3 years and 16 years. Preoperative refraction ranged between –8 D and –18 D.

“Following implantation, the range of refractive error was –4.5 D to +2 D. Mean [best corrected visual acuity] improved from 20/200 preop to 20/60 postop, with 33% of the patients gaining more than three lines,” Dr. Lesueur said.

In cases of moderate amblyopia with controlled phoric deviation, a significant reduction of the strabismus and regain of binocular vision were obtained after ICL implantation.

“All our patients showed a very good tolerance of the lens, with no sign of inflammation or intraocular pressure rise. The implants have remained stable over so many years,” she said.

Only one case of mild, transient subcapsular opacification with the V2 model with low vaulting (150 µm) of the lens was observed. However, the good posterior chamber depth (3,015 µm) allowed the cells to migrate spontaneously from the capsule and dissolve over the years. One case of retinal detachment was reported, probably as a consequence of ocular trauma with no relation to the lens.

In all of these patients, ultrasonographic biomicroscopy and WaveLight Allegretto images showed a well-balanced relation between posterior chamber depth and lens vaulting, sufficient to maintain a continuous, healthy circulation of fluids that prevents cells deposits on both the ICL and the crystalline lens.

The endothelial cell loss was minimal in all the cases, and at 12 years, the mean endothelial cell count was 2,375 cells/mm² compared with 2,991 cells/mm² in the contralateral, non-implanted eye.

From the analysis of Dr. Lesueur’s personal results and other studies, she said best results are obtained with phakic posterior chamber implants, such as the Visian ICL, in children aged less than 10 years treated for unilateral high myopia and moderate amblyopia. Older children with accommodative hyperopic esodeviation, mild amblyogenic spherical anisometropia and cylindrical anisometropia, laser refractive surgery — LASIK or PRK — can be used. — by Michela Cimberle

• Laurence C. Lesueur, MD, can be reached at Service d’Ophtalmologie, CHU Toulouse Purpan, Place Baylac, 31059 Toulouse cedex, France; +33-561772161; e-mail: laurence.lesueur@club-internet.fr.

Refractive surgery has become a reasonable option in the treatment of selected cases in the pediatric age group, such as unilateral high myopia or significant but stable bilateral refractive errors. Ten years ago, very few refractive surgeons and none of the pediatric ophthalmologists considered excimer laser a possible therapy in children unable to use contact lenses in unilateral high myopia. Today, refractive surgery is proposed by one of nine ophthalmologists in the above mentioned conditions.

Further research is always needed and will provide us with more evidence-based data, especially in the promising field of phakic IOLs.

– Paolo Nucci, MD
Milan University School of Medicine, Italy