A New Hope

Amblyopia therapy might work well for the majority of patients, but there are cases where all conventional options have been tried – and little hope of achieving visual improvements exists. It is in these children that I think there is a role for refractive surgery, and there is some evidence supporting this approach.

Compiled results of PRK and LASIK in patients aged 2–19 years with anisometropic amblyopia are favorable overall in over 200 eyes, with typical gains in best-corrected visual acuity (BCVA) and ~50 percent improvement in binocular fusion and stereopsis observed, with minimal complications (1)(2)(3)(4)(5)(6)(7). Favorable visual results have also been achieved in children with bilateral high ametropia, with observed improvements in developmental functions such as communication and socialization (8)(9). From our pediatric LASIK study, I have seen the benefits of performing refractive surgery in these children firsthand (10). A clear advantage is full-time correction – these patients no longer need contact lenses or spectacles. There are also subjective benefits; we heard from parents that children had increased self-esteem and were happy to no longer need unbalanced myopic spectacles with one very thick lens. One child even said that they could, for the first time, see the stars. Of course, there are considerations when performing refractive surgery in children. Because anesthetic gases can interfere with excimer laser function (10), patients need to be induced in a separate room or using a laryngeal mask airway to stop gas escaping. There is also the issue of fixation – children under general anesthesia cannot fixate and forceps are needed to keep the iris plane perpendicular to the laser beam. And of course there are risks. High myopia LASIK can lead to ectasia and there are theoretical flap-related issues (although none were seen in our study); with PRK there is worry about haze and regression, and the use of MMC in children can be risky. Children also need steroid drops after PRK surgery, and there can be issues with compliance.

Another option for these children are phakic IOLs, which have multiple advantages including reversibility, exchangeability, high visual quality, lack of regression and no risk of ectasia or haze. Posterior chamber phakic IOLs have shown significant improvements in VA and binocular function over five years with no reported complications, but whilst anterior chamber iris-fixated IOLs have shown promising visual results, complications (including accelerated endothelial cell loss, IOL dislocation and pigment dispersion) have been reported (9)(11)(12)(13)(14)(15)(16). Some groups have also discussed pediatric refractive lensectomy (±IOL), but this has shown mixed results in two studies (33 eyes), and has inherent problems of increased risk of retinal detachment and loss of accommodation (17)(18). To conclude, it is my view that pediatric refractive surgery should be considered in the myopic amblyopic child if conventional therapy has failed and there is no other option, on the provision that proper guidelines are followed, there is great effort to continue amblyopia therapy post-operatively, and ocular health is maintained in the long-term. It is also my view that pediatric refractive surgery is not indicated if the post-operative risks outweigh the benefits, if long-term follow up has not been studied adequately and preliminary data is raising concerns, or if the overall health of the eye might be compromised for short-term benefit. The idea of pediatric refractive surgery might be controversial to some, but we need to offer these children in whom conventional therapies are failing some hope of improvement. Dhaliwal reports the following disclosures: Consultant for Bausch & Lomb; Grant Support from Novabay and Kala Pharmaceuticals.