Atopia with keratoconus good indication for intervention
Refractive surgery in young patients should be reserved for very select indications, Béatrice Cochener MD, PhD, Brest University Hospital, France, told delegates at the 2016 WSPOS Subspecialty Day in Copenhagen, Denmark.
“Refractive surgery in children is never the first choice, but rather a last option in case of failure of other optical corrections,” said Dr Cochener.
Examples include high anisometropia, psychomotor handicap, keratoconus, severe contact lens intolerance, unilateral cataract and corneal scarring.
Dr Cochener took a close look at a particular “indication niche”, namely the nexus of atopia and keratoconus, noting that this was a particularly good indication for refractive surgery in a young patient. Up to 30% of patients with keratoconus have allergies, which underpins the hypothesis that there is a mechanical factor involved, eye rubbing, in addition to a genetic predisposition.
“In these patients, allergies prevent contact lens tolerance and the best-corrected vision loss due to the keratoconus cannot be corrected by glasses. In these cases, a posterior phakic intraocular lens (IOL), with or without intraocular ring segments, keratoplasty or crosslinking, can offer good results,” she said.
Because it is commonly asymmetrical, with more than a three-dioptre difference between two eyes, the loss of best corrected visual acuity can often not be corrected by glasses.
Dr Cochener emphasised that refractive surgery in children is intended as a therapeutic approach, in which the goal is the development or recovery of stereoacuity and binocular vision, not simply spectacle independence. “In fact, because long-term predictability of refractive outcome is difficult to achieve, spectacle independence is not even a primary goal,” she said.
Further, pseudophakia in children should remain limited to cataract, and then potentially a multifocal IOL as a primary or secondary piggyback implantation, said Dr Cochener. A possible exception to this rule is refractive lens exchange for unilateral high hyperopia with a small anterior chamber depth. The question remains whether monofocal or multifocal IOLs are most appropriate for this patient population.
Surgeons need to be aware that long follow-up periods are required in children after refractive surgery. Postoperative complications that present in adults, such as haze after photorefractive keratectomy (PRK) or LASEK, and dry eye and ectasia after LASIK, can be very difficult to manage in children.
“I realise that refractive surgery in children is a controversial topic. I believe it has a definite place in our arsenal. The goal should always remain: maximal efficacy associated with minimal risk,” added Dr Cochener.