The study was designed to determine which treatment for aphakia (absence of the eye’s natural lens) is better for infants between the ages of four weeks to seven months, born with a cataract (congenital) in one eye. The study’s findings were reported in the May 10, 2010, issue of the Archives of Ophthalmology.
The treatments under study used a contact lens or surgically placing a plastic (acrylic) lens in the baby’s eye after removing the cataract.
Results of Infant Aphakia Treatment Study (IATS) show that there is not a difference in visual acuity in children, whether the child is fitted with a contact lens or given an IOL immediately following cataract removal.
However, there was nearly a three-fold higher rate of complications during surgery and five-fold higher rate of additional surgeries in the children treated with an IOL compared to the children treated with contact lenses.
The purpose of the clinical trial was to determine if the higher rate of complications with intraocular lenses is offset by improved visual outcome and decreased parenting stress.
With the condition of aphakia, there is no focusing mechanism, since the eye’s natural lens has been removed. That missing lens must be replaced with another lens in order to be able to focus, and thus, to see. When the eye cannot focus, the eye can become amblyopic, or “lazy,” and it will lose the ability to see at all over time. Replacing that lens is crucial to a child’s vision.
In past decades, thick glasses followed a cataract extraction. Today, IOLs are commonplace. Since the 1970s, the standard of care following a baby cataract removal has been to focus a baby’s eye with a contact lens and later, to implant an IOL when the child entered school. The study sought to determine if immediately implanting an IOL was a better choice for the child’s visual acuity.
The authors say because contact lenses are a challenge with babies – they are hard to insert, they are often lost and there are a variety of other problems – IOLs for these babies may seem to be an answer, particularly in cases where there may be adherence issues or cost factors for numerous contact lenses. Quite simply, they are easier for parents.
IOLs have improved over recent years and focus the eye very much like the natural lens. Additionally, they provide at least partial correction at all time for the child, though there are more complications with IOLs.
Children were randomly chosen to receive either a contact lens or an IOL immediately following their surgery. Children enrolled underwent cataract extraction between ages one to six months. Half of these children received the contact lens and half received the IOL. There were 114 children enrolled from the 12 study sites. The median age of these children at the time of surgery was 1.8 months for both groups.
These children were followed for one year after surgery. An extension of the study through 2014 will allow these children to have their vision tested again when they are age four and one-half years. While there is no short-term visual benefit and some increased risk to implanting IOLs in infants, there remains a possibility that IOLs may be found to be beneficial after a longer follow-up.
The study was sponsored by the National Eye Institute, part of the National Institutes of Health. It was based at Emory Eye Center, Emory University School of Medicine. The clinical trial was conducted at 12 centers throughout the country. The IATS Clinical Coordinating Center participants include Emory Eye Center’s Scott Lambert, MD, the national study chair, and Lindreth DuBois, MEd, MMSc, CO, COMT, the national coordinator.
The Data Coordinating Center, the group responsible for the statistical and data management activities of the study, was located at the Rollins School of Public Health of Emory University and was directed by Michael Lynn, MS. The Visual Acuity Testing Center directed by E. Eugenie Hartmann, PhD was located at the School of Optometry at the University of Alabama, Birmingham.
“Intraocular lenses have become the standard means of focusing the eyes of adults and older children after cataract surgery,” says Scott Lambert, MD, Emory Eye Center pediatric ophthalmologist and national study chairman. “However, the eyes of babies behave quite differently than adult eyes after cataract surgery and our study was designed to determine if a child would see better if the eye was focused with an IOL and glasses versus a contact lens.”
In addition to Emory Eye Center, the study was conducted at the following 11 centers:
- Medical University of South Carolina, Charleston
- Harvard University, Boston
- University of Minnesota, Minneapolis
- Cleveland Clinic, Cleveland
- Baylor College of Medicine, Houston
- Oregon Health and Science University, Portland
- Duke University, Durham, N.C.
- Vanderbilt University, Nashville, Tenn.
- Indiana University, Indianapolis
- Miami Children’s Hospital, Miami
- Texas Southwestern, Dallas
Arch Ophthalmol. 2010;128(7:(doi:10.1001/archophthalmol.2010.101) Trial registration: clinicaltrials.gov Identifier: NCT00212134
About the Emory Eye Center
Emory Eye Center has a mission to conduct pioneering research into blinding eye diseases, to educate and train eye professionals, and to provide excellent patient care. The Department includes 33 ophthalmologists, eight optometrists, 11 basic scientists, 11 post-doctoral fellows, and nine researchers in other Emory departments who hold joint appointments in the Emory University School of medicine’s Department of Ophthalmology. Ophthalmology research is supported by current NIH funding of $20 million through 2010. The Department remains in the top rankings (#9 – 2009) by U.S. News & World Report for the 14 years the magazine has held a ranking for Ophthalmology. It also ranks in the Top Ten in the peer-reviewed Ophthalmology Times annual report.
The Robert W. Woodruff Health Sciences Center of Emory University is an academic health science and service center focused on missions of teaching, research, health care and public service. Its components include the Emory University School of Medicine, Nell Hodgson Woodruff School of Nursing, and Rollins School of Public Health; Yerkes National Primate Research Center; Winship Cancer Institute of Emory University; and Emory Healthcare, the largest, most comprehensive health system in Georgia. Emory Healthcare includes: The Emory Clinic, Emory-Children’s Center, Emory University Hospital, Emory University Hospital Midtown, Wesley Woods Center, and Emory University Orthopaedics & Spine Hospital. The Woodruff Health Sciences Center has a $2.5 billion budget, 17,600 employees, 2,500 full-time and 1,500 affiliated faculty, 4,700 students and trainees, and a $5.7 billion economic impact on metro Atlanta.