Sept. 14, 2019
Primary insertion of an intraocular lens during pediatric cataract surgery is the standard of care for children age 2 years and older. Although intraocular lens implantation has become more common in patients younger than 2 years, concerns about adverse events, re-operations and refractive changes continue to be serious considerations in infants.
To evaluate these concerns, Erick D. Bothun, M.D., and a research team with Ophthalmology at Mayo Clinic in Rochester, Minnesota, conducted a retrospective review of infants ages 7 to 24 months treated by surgeons at 10 Infant Aphakia Treatment Study (IATS) sites during that study's enrollment period.
"The IATS assessed the outcomes and complications of unilateral cataract surgery in infants ages 1 to 7 months," says Dr. Bothun. "This study, the Toddler Aphakia and Pseudophakia Study (TAPS), is a retrospective consecutive case series of cataract surgery procedures performed in infants ages 7 to 24 months by surgeons who simultaneously were enrolling younger babies in the IATS.
"Because the surgical and clinical care of the TAPS mirrored that of the IATS, the outcomes of surgery for children ages 7 to 24 months in the TAPS can be compared with those reported for children ages 1 to 7 months in IATS."
The IATS five-year results from the Infant Aphakia Treatment Study Group appeared in JAMA Ophthalmology in 2014. The first TAPS cohort results were published in Ophthalmology in 2019.
Infants were eligible for inclusion in the TAPS registry if they had undergone unilateral or bilateral cataract surgery performed by an IATS surgeon prior to age 24 months during the IATS enrollment period (Jan. 1, 2004, through Dec. 31, 2010). This first manuscript from the TAPS registry involved only the infants with unilateral cataract, and for this effort, the TAPS exclusion criteria largely paralleled the IATS criteria.
The 10 IATS sites registered 96 infants ages 7 to 24 months with a history of unilateral cataract surgery between 2004 and 2010. Ultimately, 56 infants were included in the unilateral TAPS.
Surgery was performed on the right eye in 31 infants (55%) and on the left eye in 25 infants (45%). A primary intraocular lens was inserted in 51 infants (91%). Intraocular lenses were implanted in 20 of 24 infants (83%) who were 7 to 12 months of age, and in 31 of 32 infants (97%) who were 13 to 24 months of age.
Clinical and surgical records were reviewed for visual acuity, refractive correction, patching compliance, intraocular pressure, ocular motility, and anterior segment and ocular fundus examination findings until the final study visit, when the infants were between 4 and 6 years of age. Other patient details included gender, age at surgery, cataract description, strabismus measurements and intraocular lens power.
Main outcome measures
Intraoperative complications and adverse events were recorded using the IATS criteria. Intraoperative complications occurred in four infants (7%). An additional unplanned intraocular surgery occurred in 14% of infants. Adverse events were identified in 24%, with a 4% incidence of glaucoma suspect. Strabismus surgery was performed in 40% of the infants with strabismus before 4 years of age.
Visual acuity, strabismus, stereopsis and glaucoma outcomes were not statistically different between the study groups. Neither adverse events nor intraocular re-operations were more common for infants with surgery at 7 to 12 months of age than for those who underwent surgery at 13 to 24 months of age.
"Although most infants in TAPS between 7 months and 2 years of age underwent intraocular lens implantation concurrent with unilateral cataract removal, the incidences of complications, re-operations and glaucoma appear much lower than when intraocular lenses were used by the same surgeons in infants younger than 7 months of age in the IATS," says Dr. Bothun. For infants who received an intraocular lens in IATS, intraoperative complications occurred in 28%, adverse events in 81%, and additional intraocular surgeries in 72%.
"Due to inflammatory risks, structural challenges and characteristics of eye growth, the IATS and other efforts showed that cataract surgery risks increase in infancy compared with older children and teenage youth. Prior to the TAPS, the literature has lacked documentation regarding cataract surgery outcomes in infants just older than the IATS group. The TAPS findings support the relatively safe use of intraocular lenses in infants between 7 and 24 months of age," says Dr. Bothun.
For more information
The Infant Aphakia Treatment Study Group. Comparison of contact lens and intraocular lens correction of monocular aphakia during infancy: A randomized clinical trial of HOTV optotype acuity at age 4.5 years and clinical findings at age 5 years. JAMA Ophthalmology. 2014;132:676.
Bothun ED, et al. Outcomes of unilateral cataracts in infants and toddlers 7 to 24 months of age: Toddler Aphakia and Pseudophakia Study (TAPS). Ophthalmology. 2019;126:1189.