Emory Eye Center glaucoma specialists participated in a multi-center, 10-year follow-up clinical trial called the NEI funded Infant Aphakia Treatment Study (IATS). The study findings discovered that children who had undergone cataract surgery as an infant may have an increased risk of glaucoma-related vision damage later in life.
Initially, the study examined 114 infant cataract surgery patients who were randomly given an intraocular lens implant immediately following cataract removal surgery or left with an aphakic eye–the absence of a natural lens–and treated with corrective contact lenses or glasses. One hundred ten patients were reexamined as part of the 10-year follow-up and it was found that 25 eyes (24%) developed glaucoma and 21 eyes (20%) became glaucoma suspect, a condition that puts an individual at a higher risk of receiving a glaucoma diagnosis but had not yet developed glaucoma-related vision damage.
The study also determined that if infant cataract surgery patients do not receive annual exams or are not closely monitored by an eye care specialist, the likelihood of developing glaucoma-related vision damage increases to 9% in the first year, 17% at 5 years, and 22% at 10 years.
The IATS began in 2004 and was funded by the National Eye Institute (NEI), part of the National Institutes of Health (NIH). The results from the study were published in the December 2020 issue of JAMA Ophthalmology.
"These findings underscore the need for long-term glaucoma surveillance among infant cataract surgery patients. They also provide some measure of assurance that it is not necessary to place an intraocular lens at the time of cataract surgery," says Michael F. Chiang, MD, who is the director of NEI.
Some children are born with cataract, a clouding of the lens of the eye, in one or both eyes. Surgery is the only way to remove the cataract. Following cataract removal, the risk of developing glaucoma can increase and without an eye care specialist monitoring the child, this can cause damage to the optic nerve, which is the primary cause of vision damage or loss.
Allen D. Beck, MD, director of Emory Eye Center and a medical monitor for the study says, "The IATS study demonstrated that children who have congenital cataract surgery at an early age have a high risk of developing glaucoma. However, careful monitoring of these children for the development of glaucoma can still lead to good visual outcomes as we have effective medical and surgical treatments for this condition."
As a medical monitor, Beck reviewed all of the adverse events that occurred in the study. He also reviewed the optic disc photographs and optical coherence tomography scans of the anterior chamber and the optic nerve for the 10-year follow-up study.
The IATS also provides evidence that long-term surveillance is needed for patients who had undergone cataract surgery in infancy, which may help reduce the likelihood of developing glaucoma-related vision damage later in life. This means continuous patient monitoring by an eye care specialist is critical to treat glaucoma in its early stages or to assess any vision-related damage as a result of a glaucoma diagnosis.
In the study at 5 years, the investigators found that children who have had cataract surgery and were treated with the use of contact lenses for several years followed by an eventual lens implant had a better outcome than infants who only received the standard of care, the intraocular lens implant immediately following surgery.
"The results challenge the notion that replacing the child's lens with an implanted one protects the child from developing glaucoma, a belief among some pediatric ophthalmology surgeons," says Scott R. Lambert, MD, the trial's principal investigator and professor of ophthalmology at Stanford University, Palo Alto, California.
Emory Eye Center was one of the 12 clinical centers where the study had occurred. Investigators from the following clinical centers also contributed to the trial: Harvard University; Duke University; Indiana University; Vanderbilt University; Medical University of South Carolina; University of Minnesota; Cleveland Clinic; Baylor University; Oregon Health and Science University; Miami Children's Hospital; and the University of Texas Southwestern.
A grant application is being submitted to re-evaluate these children one more time as they near adulthood.
NEI funding includes grants UG1EY013287, UG1EY013272, UG1EY025553, and P30EY026877. The clinicaltrial.gov identifier is NCT00212134.
Reference: Freedman, SF; Beck, AD; Nizam, A; Vanderveen, DK; Plager, DA; Morrison, DG; Drews-Botsch, CD; Lambert, SR; The Infant Aphakia Treatment Study Group. “Glaucoma-related adverse events at 10 years in the Infant Aphakia Treatment Study: a randomized clinical trial”. Published December 17, 2020, Journal of the American Medical Association Ophthalmology. NEI/NIH Media contact: Kathryn DeMott, (301) 496-5248. For more information about the NEI, visit https://www.nei.nih.gov/.