Refractive surgery an option for kids with high bilateral myopia

Orlando-Refractive surgery may be an option for treating children with high myopia and neurobehavioral disorders who are unable to use either of the two principal methods of correcting myopia, spectacles or contact lenses.

Surgery can improve both visual acuity and their functional quality of life, according to Lawrence Tychsen, MD, who discussed the outcomes at the annual meeting of the American Academy of Pediatric Ophthalmology and Strabismus.

"The overall results of our study were promising. Our complication rate was acceptably low," said Dr. Tychsen, a professor of ophthalmology, neurobiology, and pediatrics, Washington University School of Medicine, St. Louis, MO.

"These children have a marked blepharospastic response when you touch the eyelids, and they cannot tell you if their eye is sore or the contact lens is dislodged," making them vulnerable to contact lens complications, Dr. Tychsen explained.

These children may have exceptionally high refractive errors, such as myopia exceeding –8 to –10 D.

"Their focal point is a few inches from their face, and the world beyond that is a blur, exacerbating the baseline neurobehavioral disorder," Dr. Tychsen said.

Visual autism

"We've labeled this a form of visual autism. These kids have vision that is so profoundly blurred that they become more fearful and less willing to interact, reach, or explore. The outside-world images are so degraded that it's not interesting to them," Dr. Tychsen said. "To alleviate this problem, we began to do what others might consider radical therapy, though it has been used in adults with high myopia for several decades."

Children in their study were divided into those with myopia of –12 D or less and those with –13 D or greater. This boundary was chosen based on the findings of an earlier large-scale study the researchers published (JAAPOS 2005) on excimer laser surface ablation for correction of high myopia in children. Treatment with PRK/ LASEK was very effective for children with myopia up to –12 D and beyond, but they noted that in cases of myopia above –12 D regression could approach 1 D per year.

Therefore, in the newer study children whose myopia was –12 D or less underwent surgery with bilateral excimer laser while those with higher myopia had clear lens extraction with or without refractive lens exchange. About half of the second group received an IOL. All procedures were performed by pediatric ophthalmologists in their unit.

The mean age of the children was 10 years (range, 1 to 18 years), and all had profoundly low functional vision from uncorrected high myopia. The average magnitude of myopia was –17 D. The mean follow-up was 4 years (range, 1 to 7 years).

Surgery was performed on 34 eyes in 17 children; 85% had correction to within 2 D of their goal refraction and the remaining 15% to within 3 D. Uncorrected visual acuity improved impressively in all the children, with an average gain of about 2 log units (100 fold).

Myopic regression averaged about 0.7 D per year in the laser-treated children and about 0.2 D per year in those treated with lensectomy.

Capsular opacification was a frequent complication in the lensectomy treatment group.

"One of the big differences between children and adults is that adults seldom develop a marked secondary opacification of the lens capsule, but children typically do," Dr. Tychsen said. "One of our findings was that 42% of the children (independent of age) treated by lensectomy needed a surgical membranectomy months to years following their initial surgery. For this reason we now perform a posterior capsulectomy and anterior vitrectomy at the primary procedure, even in older children."

The rate of retinal detachment was 3%, or one eye. The child experienced a traumatic detachment and also had a history of retinopathy of prematurity (ROP). The detachment was successfully repaired.