EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/78721
30 EW CATARACT January 2012 Implants or lenses in infants? by Michelle Dalton EyeWorld Contributing Editor With relatively even visual outcomes, specialists are not yet convinced one treatment fits all T he 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 pa- tients in the CL group who needed additional surgery, some physicians believe CLs must be a better option, but Scott R. Lambert, M.D., profes- sor of ophthalmology, Emory Uni- versity, 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 compli- ant, there's a compelling argument that IOLs could be better." Some physicians bristle at the idea of implanting a lens in an in- fant. "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 Jeffer- son University, Philadelphia. "I did not have equipoise that it was rea- sonable to put in IOLs. The study, I think, bore that out to be true." Conversely, Norman B. Medow, M.D., director of pediatric ophthal- mology, 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. EyeWorld factoid The prevalence of pediatric cataract in developing countries is 10 times more common than in developed nations Source: Pediatric Cataract Initiative 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 hit- ting the target for 6 months is diffi- cult, 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 refrac- tive curve, but those are all on the 50 percentile curve." Because the infantile eye grows Congenital nuclear cataract Source: Jules Stein Eye Institute If capsular bag support is ade- quate, "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 trau- matic 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 pub- lished showing "the visual outcomes of CLs versus IOLs are the same," Dr. Levin said. He expects the 5-year re- sults from IATS to mimic those from other studies. "Contact lenses offer a wonder- ful 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 be- cause the IOL powers don't go that high unless you piggyback the lens." Dr. Levin said patients face a "significantly higher risk of reopera- tion and complications and likely glaucoma if you put in an implant, not to mention the unpredictability of refractive error." CLs are not with- out 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 prob- lem." If Dr. Wilson believes parents can manage the expense and main- tenance 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 edu- cated 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 meas- urements, and we have our little cookbook of what power to put in, it's a guess." With CLs, Dr. Wilson is chang- ing the power every 3 months dur- ing the infant's first year. "If the eye has grown, the power has changed, and so the CL must change as well. at different speeds, Dr. Medow doubts physicians will ever be able to be precise on the IOL calcula- tions. 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 aggres- sive," he said. In situations where another op- tion is not realistic, implanting an IOL is better than nothing, but Dr. Levin cautioned that services for am- blyopia management and posterior capsule management must be ade- quate to serve the patient. EW Reference 1. Infant Aphakia Treatment Study Group, Lambert SR, Buckley EG, Drews-Botsch C, et al. A random- ized clinical trial comparing contact lens with in- traocular 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 inter- ests 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