Implants or lenses in infants?

With relatively even visual outcomes, specialists are not yet convinced one treatment fits all

Congenital nuclear cataract Source: Jules Stein Eye Institute

The 1-year results from the Infant Aphakia Treatment Study Group (IATS) found little difference in visual outcomes between the IOL and contact lens (CL) groups, but the former needed more additional surgeries.1 Because there were fewer patients in the CL group who needed additional surgery, some physicians believe CLs must be a better option, but Scott R. Lambert, M.D., professor of ophthalmology, Emory University, Atlanta, noted in clinical settings, "insurance companies don't pay for the lenses, and they can be quite expensive," he said. "If people don't have the financial means to pay for the lenses or are not compliant, there's a compelling argument that IOLs could be better."
Some physicians bristle at the idea of implanting a lens in an infant. "I've always been a fan of CLs in lieu of IOLs in infants," said Alex V. Levin, M.D., chief of pediatric ophthalmology and ocular genetics, Wills Eyes Institute, Thomas Jefferson University, Philadelphia. "I did not have equipoise that it was reasonable to put in IOLs. The study, I think, bore that out to be true."
Conversely, Norman B. Medow, M.D., director of pediatric ophthalmology, Manhattan Eye, Ear and Throat Hospital, New York, prefers to implant IOLs in cases of unilateral cataract, based on his results from an earlier series. If capsular bag support is adequate, "I implant after they're 1 year old," said M. Edward Wilson, M.D., Pierre Gautier Jenkins professor and chair, ophthalmology department, and director, Albert Florens Storm Eye Institute, Medical University of South Carolina, Charleston.
"I would say in the first year of life, certainly in the first 6 months, my default is a CL," he said. "I think the surgery in infants is less traumatic without the IOL and by the time the child grows, we will be able to predict the power of the IOL."
Several studies have been published showing "the visual outcomes of CLs versus IOLs are the same," Dr. Levin said. He expects the 5-year results from IATS to mimic those from other studies. "Contact lenses offer a wonderful ability with minimal risk for these patients," Dr. Levin said.
Children undergoing cataract extraction will end up, inevitably, with some sort of implant. "We're talking about whether it's better now or better later," Dr. Wilson said. "You can't aim for emmetropia in a tiny infant. It just isn't possible because the IOL powers don't go that high unless you piggyback the lens."
Dr. Levin said patients face a "significantly higher risk of reoperation and complications and likely glaucoma if you put in an implant, not to mention the unpredictability of refractive error." CLs are not without their own detractors, however. Cost and convenience are just two factors, Dr. Levin said. "In our hands, with a good CL support team, we have a success rate of about 85-90% with kids wearing a contact lens," he said. "There are, unfortunately, many areas of the world where that's not possible, where CL availability is a big problem." If Dr. Wilson believes parents can manage the expense and maintenance of a CL, "I'd advise them to opt for that, with a planned implant later," he said. "Place that implant in the preschool or early grade school years, when there's a better prediction of growth."

Lens calculations


Even with his successes, Dr. Medow acknowledged IOL calculations in an infant group are, at best, an educated guess. "The lens doesn't change as these infants age, the eyeball does," he said. "Even though we do all the examinations and take all the measurements, and we have our little cookbook of what power to put in, it's a guess."
With CLs, Dr. Wilson is changing the power every 3 months during the infant's first year. "If the eye has grown, the power has changed, and so the CL must change as well. IOLs limit you to glasses," he said. "Another issue is that the infant eye grows so fast that if you implant at 4-5 weeks of age, you probably need to leave 10 D of residual hyperopia just to manage the growth in the first year or two."
IOL calculations are a guess for two reasons, Dr. Levin said: "Just hitting the target for 6 months is difficult, never mind for 60-plus years. We have curves and guidelines that help us guess where the child might be 10 years from now on the refractive curve, but those are all on the 50 percentile curve." Because the infantile eye grows at different speeds, Dr. Medow doubts physicians will ever be able to be precise on the IOL calculations. When there's a unilateral cataract and the family is unlikely to manage CLs or glasses well, Dr. Wilson will use a piggyback lens with planned removal. "These eyes are really small, and placing one IOL is difficult enough, never mind two. I've probably done 60-70 over the years. It can be done safely, but it's more surgically aggressive," he said.
In situations where another option is not realistic, implanting an IOL is better than nothing, but Dr. Levin cautioned that services for amblyopia management and posterior capsule management must be adequate to serve the patient.

Reference

1. Infant Aphakia Treatment Study Group, Lambert SR, Buckley EG, Drews-Botsch C, et al. A randomized clinical trial comparing contact lens with intraocular lens correction of monocular aphakia during infancy: grating acuity and adverse events at age 1 year. Arch Ophthalmol. 2010;128(7):810-818. Epub 2010 May 10.
Editors' note: Dr. Lambert is chair of the IATS group and has financial interests with Alcon (Fort Worth, Texas) and Bausch + Lomb (B+L, Rochester, N.Y.). Drs. Levin and Medow have no financial interests related to this article. Dr. Wilson has financial interests with Alcon and B+L.

Contact information

Lambert: 404-778-3709, slamber@emory.edu
Levin: 267-528-9764, alevin@willseye.org
Medow: 718-920-6178, nmedow@montefiore.org
Wilson: 843-792-7622, wilsonme@musc.edu