Pediatric Refractive Surgery

To the Editor: I applaud Alió et al1 for providing a comprehensive and meticulous meta-analysis of peer-reviewed articles on pediatric laser refractive surgery, which appeared in the May 2011 issue of the Journal of Refractive Surgery. I appreciate this complex undertaking. The study adds knowledge to our understanding of laser refractive surgery on the treatment of high anisometropic ametropia and amblyopia in children. I would like to add a few comments. The title of the article and the purpose state that the metaanalysis was undertaken “to provide an overview of the visual outcomes after pediatric refractive surgery in anisometropic amblyopia and to analyze the relationship of these outcomes with age and the type of refractive surgery.” Using data available in the peer-reviewed literature, the authors sought to offer a comprehensive perspective about the potential visual benefi t of pediatric refractive surgery. However, to meet this goal, the authors should have included, rather than excluded, articles on phakic intraocular lenses (PIOLs) in children. Their aim cannot be fully realized without incorporating the PIOL data in children.2-5 Without including these data from various intraocular refractive surgery articles with/without the implantation of PIOLs, no true conclusion can effectively be reached in the meta-analysis of published articles on refractive surgery for treatment of amblyopia in children. The authors should have clearly stated in the title of their article, as well as in the purpose and introduction, that the intended aim of their study was only a meta-analysis of peerreviewed articles on pediatric refractive laser surgery and its role in the treatment of amblyopia. The authors, by omitting this important and integral term from their report, thus have created their own bias as well as deviated from their own stated purpose of intended analysis of all published refractive surgery reports in children. Moreover, the authors did not explain why “articles about IOLs in children were excluded” in their work. Phakic intraocular lens implantation as well as clear lens extraction for high myopic anisometropia and amblyopia comprises a critical subgroup of refractive amblyopia in children. By including this group of patients and publications, they could have made a stronger conclusion regarding refractive surgery (laser, PIOL, and clear lens extraction) and its positive predictive value on the treatment of amblyopia in children, thus strengthening their argument and article.2-5 Although Alió et al did not report any incidents of signifi cant decentration in their study, a previous report has shown “slight decentration in axis of 5% can cause a 17% to 20% undercorrection.”6 Although they make an observation that children under general anesthesia are unable to fi xate on the laser target beam for proper central fi xation, they do not mention that the surgeon must rely on his/her best judgment to assume where the proper center of optical to visual axis lies under general anesthesia. Pupil centroid shift and cyclotorsional variations occur under general anesthesia as well as under supine positions, both of which may cause a signifi cant induction in higher order aberrations, leading to a variable reduction in contrast sensitivity as a result.7-9 Haze, interface keratitis, and fl ap dislocation may all lead to a reduction in contrast sensitivity, which has never been calculated in the pediatric population due to diffi culty in capturing the data in this particular age group. Our goal in pediatric refractive surgery, laser or IOL implantation, beyond improving the visual acuity should be to strive to achieve the same standard we apply for our adult refractive population. At a minimum, we should improve visual acuity, but at best, we should aim to induce minimal higher order aberrations, so that we can improve both quality and quantity of vision for our pediatric patients. Amir Pirouzian, MD Irvine, California