Toulouse, France—With lengthening follow-up, the posterior chamber implantable collamer lens (ICL) (STAAR Surgical) continues to be associated with encouraging results in the management of refractive amblyopia in children who have not had a response to conventional therapy with contact lenses or spectacles, said Laurence C. Lesueur, MD.
Toulouse, France-With lengthening follow-up, the posterior chamber implantable collamer lens (ICL) (STAAR Surgical) continues to be associated with encouraging results in the management of refractive amblyopia in children who have not had a response to conventional therapy with contact lenses or spectacles, said Laurence C. Lesueur, MD.
Dr. Lesueur and Jean L. Arne, MD, with the department of ophthalmology, Purpan Hospital, University of Toulouse, France, began implanting this phakic IOL model in June 1997 in children with amblyopia associated with high myopia. Through June 2003, they have treated 18 children ages 3 to 16 years (mean, 9 years) with myopia ranging from –8 to –18 D (mean spherical equivalent [SE], –12.5 D). Initial results were published in 1999, a follow-up report was made in 2002, and the current analysis was based on data collected over 7.5 years (minimum, 22 months; mean, 55 months).
The results showed the children achieved good refractive and functional results that allowed for improved quality of life. In addition, the ICL has been associated with excellent tolerance with no early or late-onset significant inflammatory reactions, good stability of IOP and ICL centration, maintenance of a visible space between the ICL and crystalline lens, and no cases of secondary cataract formation.
"Since our very encouraging first results, we have noted a constant increase in functional outcome without anatomic complications in these patients with moderate preoperative amblyopia," Dr. Lesueur explained. "Most importantly, however, all of the parents have reported quality of life benefits for their children as seen by improved school performance, greater recreational participation, and better psychological status."
At last follow-up, mean cycloplegic SE was +0.05 D (range, –2.5 to +2.5 D), and mean uncorrected visual acuity (UCVA) was 20/100 (range, 20/200 to 20/50). Mean best-corrected visual acuity (BCVA) for the series had improved from 20/200 (range, 20/400 to 20/63) before surgery to 20/80 (20/200 to 20/32), with only a single eye losing more than 1 line, after a traumatic retinal detachment. One other eye had unchanged BCVA while the rest benefited with improved BCVA.
"More than half of the eyes had a gain of 2 or more lines, although the best results were seen in cases of low-level preoperative amblyopia without strabismus," Dr. Lesueur noted.
Within the series, nine children had strabismus prior to ICL implantation. Four of those children underwent strabismus surgery to reduce irreversible high-angle deviation (> 40 D) at 6 months after ICL implantation. Ten children recovered orthotropic position, and while only two (12%) children had binocular vision preoperatively, binocular vision was present in seven children (41%) after surgery.
The children are also being followed with measurement of axial length. Mean axial length in the eyes that underwent surgery was longer than in the fellow eyes prior to ICL implantation (26.5 versus 22.8 mm, respectively). However, mean myopic shift over time has been similar in the eyes with implants and contralateral eyes (0.7 versus 0.6 mm, respectively).
Dr. Lesueur noted that in 1995, ophthalmologists started to perform refractive surgery using PRK or LASIK to reduce anisometropia in selected pediatric patients. However, compared with excimer laser ablation, phakic IOL implantation has benefits that include reversibility, better safety for correction of higher refractive errors, and avoiding the need for patient cooperation intraoperatively.
Among phakic IOL options, Dr. Lesueur and colleagues favor the ICL because that foldable model can be implanted through a small, 3.5-mm incision. In addition, because of its posterior chamber position, it avoids problems with endothelial cell loss. However, Dr. Lesueur acknowledged that cataract development remains a concern with the ICL.
"Nevertheless, in these special cases of high unilateral myopia, our primary objective is to win the race against anisometropia," Dr. Lesueur said. "If secondary crystalline lens opacification occurs, cataract surgery with pseudophakic IOL implantation can be performed to restore good vision."
The ICL implantation is performed using general anesthesia with lens delivery through a temporal incision using two forceps. A surgical iridectomy is also performed in all eyes after the implantation, and postoperative care includes use of steroids and antibiotic drops. Amblyopia therapy is started at 8 days after surgery.