Phakic IOL may help in refractory amblyopia

By Dermot McGrath in Paris
WHILE refractive surgery is usually contraindicated in paediatric patients, a phakic IOL (ICL, Staar Surgical) for correcting amblyopia in highly myopic children appears to be a viable alternative in cases where conventional treatments have failed, according to a French researcher.

Presenting the results of a study conducted at Purpan Hospital, University of Toulouse between June 1997 and August 2002, Laurence C. Lesueur, MD, told the annual meeting of the French Implant and Refractive Surgery Association (SAFIR) that the ICL had proven itself over time to be well tolerated in implanted eyes with stable refractive results.

ICL is positioned behind the iris	Procedure concluded with aspiration of viscoelastic, miosis, and iridectomy

The six-year study comprised 17 eyes in children ranging from three to 16 years of age (mean age nine years), with high myopic amblyopia, all of whom had failed to respond to conventional therapy with spectacles, contact lenses and patch occlusion.



Mean preoperative spherical equivalent was –12.5D (range –8 to –18D) and the mean follow-up was 34 months. The eyes were operated on under general anaesthesia. Surgeons implanted the ICLs through 3.5 mm temporal corneal tunnel incisions, using two forceps.

The haptic edges were placed behind the edge of the iris and the ICL was centred. After suturing the clear corneal incision, surgical iridectomy was performed through the enlarged paracentesis.

All children followed a course of antibiotic/corticosteroid eyedrops and amblyopia re-education after surgery. Post-operative examination included slit-lamp cycloplegic refraction, strabismus evaluation and quality-of-life assessment.
The patients’ mean refraction after surgery was +0.5D ( range -2.5 D to 2.5 D). After six years, none of the children experienced a loss of Snellen lines in the BSCVA of their treated eye, while 40% gained one line, 27% gained two lines and another 27% gained more than three lines.

Dr Lesueur said that the ICL was well tolerated anatomically in all eyes and there were no serious post-operative complications. Intraocular pressure was normal and there were no problems with inflammation.

The ICLs remained well supported and centred and no pigment deposits were observed in any of the children. There were also no problems with lens opacification, one of the major concerns after implantation of a posterior chamber phakic lens.

She added that difference in axial length in operated eyes showed no statistically significant difference with unoperated eyes. Seven children (41%) achieved binocular vision after surgery compared to two (12%) preoperatively. The incidence of strabismus was also reduced from nine children (53%) preoperatively to five cases (30%) after surgery.

Dr Lesueur noted that the best results were achieved in cases of moderate amblyopia without associated strabismus.
All parents said that the children’s quality of life had improved since having surgery. Parents reported that the children participated more in games and sports activities and seemed happier overall. None of them reported any problems of eye pain, headaches, halos or photophobia.

"Use of the ICL in managing refractive amblyopia in children shows encouraging short-term results in terms of its effects on visual function and enhancement of social and psychological aspects of life. All of these children have achieved a subjective improvement in their daily activities, especially at school and in sports participation," said Dr Lesueur.

Dr Lesueur added that implanting ICLs in paediatric patients offered a number of advantages in such cases. Firstly, the procedure was reversible and entailed only a small incision. Moreover, because children rubbed their eyes frequently, there was less risk of corneal endothelial cell loss with an ICL situated in the posterior chamber than with phakic anterior intraocular lenses.
Finally, the fact that were no changes to the corneal structure was also important, noted Dr Lesueur.

"PRK and LASIK induce particular modifications of the cornea and the healing process of a child’s cornea after excimer laser treatment is not well understood," she said.
Dr Lesueur concluded that the evidence of implanting phakic posterior lenses thus far was very encouraging, with consistently good refractive results and no anatomical complications after six years.

Laurence Lesueur, MD,
laurence.lesueur@club-internet.fr

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