Outcomes of Unilateral Cataracts in Infants and Toddlers 7 to 24 Months of Age

Toddler Aphakia and Pseudophakia Study (TAPS)

      Purpose

      To evaluate outcomes of unilateral cataract surgery in children 7 to 24 months of age.

      Design

      Retrospective case series at 10 Infant Aphakia Treatment Study (IATS) sites.

      Participants

      The Toddler Aphakia and Pseudophakia Study is a registry of children treated by surgeons who participated in the IATS.

      Methods

      Children underwent unilateral cataract surgery with or without intraocular lens (IOL) placement during the IATS enrollment years of 2004 and 2010.

      Main Outcome Measures

      Intraoperative complications, adverse events (AEs), visual acuity, and strabismus.

      Results

      Fifty-six children were included with a mean postoperative follow-up of 47.6 months. Median age at cataract surgery was 13.9 months (range, 7.2–22.9). Ninety-two percent received a primary IOL. Intraoperative complications occurred in 4 patients (7%). At 5 years of age, visual acuity of treated eyes was very good (≥20/40) in 11% and poor (≤20/200) in 44%. Adverse events were identified in 24%, with a 4% incidence of glaucoma suspect. An additional unplanned intraocular surgery occurred in 14% of children. Neither AEs nor intraocular reoperations were more common for children with surgery at 7 to 12 months of age than for those who underwent surgery at 13 to 24 months of age (AE rate, 21% vs. 25% [P = 0.60]; reoperation rate, 13% vs. 16% [P = 1.00]).

      Conclusions

      Although most children underwent IOL implantation concurrent with unilateral cataract removal, the incidence of complications, reoperations, and glaucoma was low when surgery was performed between 7 and 24 months of age and compared favorably with same-site IATS data for infants undergoing surgery before 7 months of age. Our study showed that IOL implantation is relatively safe in children older than 6 months and younger than 2 years.

      Abbreviations and Acronyms:

      AE (adverse event), AUIS (additional unplanned intraocular surgery), D (diopter), IOL (intraocular lens), IATS (Infant Aphakia Treatment Study), logMAR (logarithm of the minimum angle of resolution), PFV (persistent fetal vasculature), TAPS (Toddler Aphakia and Pseudophakia Treatment Study)
      Primary insertion of an intraocular lens (IOL) during pediatric cataract surgery is considered standard of care for children 2 years of age and older.
      • Greenwald M.J.
      • Glaser S.R.
      Visual outcomes after surgery for unilateral cataract in children more than two years old: posterior chamber intraocular lens implantation versus contact lens correction of aphakia.
      • Wilson M.E.
      • Bartholomew L.R.
      • Trivedi R.H.
      Pediatric cataract surgery and intraocular lens implantation: practice styles and preferences of the 2001 ASCRS and AAPOS memberships.
      • Solebo A.L.
      • Russell-Eggit I.
      • Nischal K.K.
      • et al.
      Cataract surgery and primary intraocular lens implantation in children ≤2 years old in the UK and Ireland: finding of national surveys.
      • Solebo A.L.
      • Cumberland P.
      • Rahi J.S.
      British Isles Congenital Cataract Interest Group
      5-year outcomes after primary intraocular lens implantation in children aged 2 years or younger with congenital or infantile cataract: findings from the IoLunder2 prospective inception cohort study.
      • Eibschitz-Tsimhoni M.
      • Archer S.M.
      • Del Monte M.A.
      Intraocular lens power calculation in children.
      • Lambert S.R.
      • Lynn M.
      • Drews-Botsch C.
      • et al.
      Intraocular lens implantation during infancy: perceptions of parents and the American Association for Pediatric Ophthalmology and Strabismus members.
      • Repka M.A.
      Visual rehabilitation in pediatric aphakia.
      • Zwaan J.
      • Mullaney P.B.
      • Awad A.
      • et al.
      Pediatric intraocular lens implantation: surgical results and complications in more than 300 patients.
      • McClatchey S.K.
      • Dahan E.
      • Maselli E.
      • et al.
      A comparison of the rate of refractive growth in pediatric aphakic and pseudophakic eyes.
      • Plager D.A.
      • Kipfer H.
      • Sprunger D.T.
      • et al.
      Refractive change in pediatric pseudophakia: 6-year follow-up.
      • Spanou N.
      • Alexopoulos L.
      • Manta G.
      • et al.
      Strabismus in pediatric lens disorders.
      • Weisberg O.L.
      • Sprunger D.T.
      • Plager D.A.
      • et al.
      Strabismus in pediatric pseudophakia.
      • Raina U.K.
      • Mehta D.K.
      • Monga S.
      • Arora R.
      Functional outcomes of acrylic intraocular lenses in pediatric cataract surgery.
      • Magli A.
      • Forte R.
      • Carelli R.
      • et al.
      Long-term outcomes of primary intraocular lens implantation for unilateral congenital cataract.
      Although IOL implantation increasingly has become more common in patients younger than 2 years, concerns about adverse events (AEs), reoperations, and refractive changes continue to be serious considerations in this younger population.
      • Greenwald M.J.
      • Glaser S.R.
      Visual outcomes after surgery for unilateral cataract in children more than two years old: posterior chamber intraocular lens implantation versus contact lens correction of aphakia.
      • Wilson M.E.
      • Bartholomew L.R.
      • Trivedi R.H.
      Pediatric cataract surgery and intraocular lens implantation: practice styles and preferences of the 2001 ASCRS and AAPOS memberships.
      • Solebo A.L.
      • Russell-Eggit I.
      • Nischal K.K.
      • et al.
      Cataract surgery and primary intraocular lens implantation in children ≤2 years old in the UK and Ireland: finding of national surveys.
      • Solebo A.L.
      • Cumberland P.
      • Rahi J.S.
      British Isles Congenital Cataract Interest Group
      5-year outcomes after primary intraocular lens implantation in children aged 2 years or younger with congenital or infantile cataract: findings from the IoLunder2 prospective inception cohort study.
      • Serafino M.
      • Trivedi R.H.
      • Levin A.V.
      • et al.
      Use of the Delphi process in paediatric cataract management.
      • Lu Y.
      • Ji Y.H.
      • Luo Y.
      • et al.
      Visual results and complications of primary intraocular implantation in infants aged 6 to 12 months.
      • Kumar P.
      • Lambert S.R.
      Evaluating the evidence for and against the use of IOLs in infants and young children.
      • Yen A.G.
      • Kong L.
      • Yen K.G.
      Long term outcomes of primary intraocular lens implantation in patients age 7 to 24 months.
      • Struck M.C.
      Long-term results of pediatric cataract surgery and primary intraocular lens implantation from 7 to 22 months of life.
      • Solebo A.L.
      • Russell-Eggitt I.
      • Cumberland P.M.
      • et al.
      Risks and outcomes associated with primary intraocular lens implantation in children under age 2: the IOLunder2 cohort study.
      • Vasavada A.R.
      • Vasavada V.
      • Shah S.K.
      • et al.
      Five-year postoperative outcomes of bilateral aphakia and pseudophakia in children up to 2 years of age: a randomized clinical trial.
      • Vasavada A.R.
      • Vasavada V.
      • Shah S.K.
      • et al.
      Five-year postoperative outcomes of bilateral aphakia and pseudophakia in children up to 2 years of age: a randomized clinical trial.
      The Infant Aphakia Treatment Study (IATS) studied the outcomes and complications of unilateral cataract surgery in children 1 to 7 months of age.
      Infant Aphakia Treatment Study Group
      The Infant Aphakia Treatment Study: design and clinical measures at enrollment.
      Infant Aphakia Treatment Study Group
      A randomized clinical trial comparing contact lens with intraocular lens correction of monocular infancy: HOTV optotype acuity at age 4.5 years and clinical findings at age 5 years.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications, adverse events, and additional intraocular surgery 1 year after cataract surgery in the Infant Aphakia Treatment Study.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications in the first 5 years following cataract surgery in infants with and without intraocular lens implantation in the Infant Aphakia Treatment Study.
      One strength of the IATS is that participating surgeons were certified and aligned in best practices for surgical and clinical care of pediatric cataract patients during the prospective enrollment period from 2004 through 2010. In view of the associated complications and reoperations found in this study, infants in the first 6 months of life undergoing surgery for a unilateral cataract now commonly are left aphakic.
      The Toddler Aphakia and Pseudophakia Study (TAPS) is a retrospective review of children operated on by IATS surgeons during the IATS enrollment period (2004–2010). Because the surgical and clinical care of TAPS children mirrored those enrolled in the IATS (same surgeon and clinical practice), the outcomes for children undergoing surgery at 7 to 24 months of age in the TAPS may be compared directly with those reported for children undergoing surgery at 1 to 7 months of age in the IATS.

      Methods

      This study was approved by the institutional review board or ethics review board at all participating institutions and complied with the Health Insurance Portability and Accountability Act. Data sharing agreements were established between the IATS investigator sites and the Mayo Clinic. All research adhered to the tenets of the Declaration of Helsinki.

       Study Design

      The TAPS was a retrospective consecutive case series of cataract surgery procedures performed in children through the care of surgeons who simultaneously were enrolling younger babies in the IATS (Table 1). The IATS standardized best practice surgical and postoperative care protocol was modeled by surgeons for other children in their practices.
      Infant Aphakia Treatment Study Group
      The Infant Aphakia Treatment Study: design and clinical measures at enrollment.
      Thus, during 2004 and 2010, the surgical and clinical management of older infants and toddlers in the TAPS mirrored that of the IATS. However, as a retrospective study, the TAPS children were not supported by the benefits of a prospective, funded study that included financial support for optical and patching equipment or a standardized protocol and case report forms.
      Table 1Exclusion Criteria
      • 1.
        Anterior segment disease that may limit the visual potential of the eye
      • 2.
        PFV causing stretching of the ciliary processes or tractional detachment of the retina
      • 3.
        Active uveitis or signs suggestive of previous episode of uveitis
      • 4.
        Retinal disease that may limit the visual potential of the eye
      • 5.
        Optic nerve disease that may limit visual potential of the eye
      • 6.
        Previous or other concurrent intraocular surgery
      • 7.
        Cataract known to be the result of trauma
      • 8.
        Glaucoma pre-existing at the time of cataract surgery
      • 9.
        Corneal diameter of less than 9 mm
      • 10.
        Fellow eye having ocular disease that may reduce visual acuity
      • 11.
        Last follow-up before 4 years of age
      PFV = persistent fetal vasculature.

       Eligibility Criteria

      Children were eligible for inclusion in the TAPS if they had undergone unilateral or bilateral cataract surgery performed by an IATS surgeon between 210 days and 2 years of age from January 1, 2004, through December 31, 2010 (the enrollment period of the IATS). Exclusion criteria for this study of the unilateral cataract surgeries in the TAPS registry largely paralleled those described for the IATS; however, prematurity was eliminated as an exclusion criteria (Table 1). The following additional exclusion criteria were added: anterior segment disease that may limit the visual potential of the eye and concurrent intraocular surgery (corneal transplant, iris coloboma repair, etc.). Patients were excluded if their last follow-up was before 4 years of age.
      Clinical and surgical records were reviewed for visual acuity, refractive correction, patching compliance (documented as excellent, fair, poor, or unknown), intraocular pressure, ocular motility, and anterior segment and ocular fundus examination findings until the final study visit between 4 and 6 years of age. If multiple visits qualified, preference was given for the examination closest to 5 years of age. Other patient details included gender, age at surgery, cataract description, strabismus measurements, and IOL power. Intraoperative complications and AEs were recorded using the criteria in the IATS study.
      Infant Aphakia Treatment Study Group
      The Infant Aphakia Treatment Study: design and clinical measures at enrollment.
      Infant Aphakia Treatment Study Group
      A randomized clinical trial comparing contact lens with intraocular lens correction of monocular infancy: HOTV optotype acuity at age 4.5 years and clinical findings at age 5 years.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications, adverse events, and additional intraocular surgery 1 year after cataract surgery in the Infant Aphakia Treatment Study.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications in the first 5 years following cataract surgery in infants with and without intraocular lens implantation in the Infant Aphakia Treatment Study.
      Glaucoma and glaucoma suspect status were based on the year 5 examination documentation and any prior medical or surgical management of glaucoma.

       Statistical Analysis

      Continuous variables were summarized with the sample median and range. Categorical variables were summarized with numbers and percentages. Comparisons between the 2 age groups were performed using a Wilcoxon rank-sum test for continuous variables and a Fisher exact test for categorical variables. All statistical tests were 2 sided, and P values of 0.05 or less were considered to be statistically significant. All statistical analysis was performed using SAS software version 9.4 (SAS Institute, Inc, Cary, NC).

      Results

      A total of 96 children (96 eyes) were registered through 10 IATS sites with a history of unilateral cataract surgery between 2004 and 2010. Two prior IATS clinical sites did not participate because of institutional review board limitations. Thirty eyes were excluded because of disqualifying baseline history or clinical findings, and 10 were not included because their follow-up ended before 4 years of age. Fifty-six children were eligible for review. Seven children in the TAPS registry were included previously in a single-site series on bilateral and unilateral cataract outcomes.
      • Yen A.G.
      • Kong L.
      • Yen K.G.
      Long term outcomes of primary intraocular lens implantation in patients age 7 to 24 months.
      The median age at the time of surgery was 13.9 months (range, 7.2–22.9 months), and median follow-up in the study window (age, 4–6 years) was 47.1 months (range, 34.1–61.9 months). Twenty-nine study group patients (52%) were male and 27 study group patients (48%) were female; 47 (84%) were white, 6 (11%) were black, and 3 (5%) were of other or unknown race or ethnicity. The cataract morphologic features were found to be either posterior capsular or subcapsular (n = 16), posterior lenticonus (n = 10), nuclear (n = 10), persistent fetal vasculature (n = 8), anterior capsular or subcapsular (n = 4), cortical and lamellar (n = 4), and unknown (n = 3).
      Surgery was performed on the right eye in 31 children (55%) and on the left eye in 25 children (45%). A primary IOL was inserted in 51 children (91%). Intraocular lenses were implanted in 20 of 24 children (83%) 7 to 12 months of age (median, 10 months of age) and in 31 of 32 children (97%) 13 to 24 months of age (median, 16 months of age). An Alcon AcrySof IOL (Forth Worth, Texas) was implanted in 48 of 51 eyes (94%), and 44 of 51 eyes (86%) were placed in the capsular bag. The reason for sulcus IOL placement was listed as insertion difficulty or capsular instability (n = 4), posterior lenticonus (n = 2), and persistent fetal vasculature (n = 1). Primary posterior capsulotomy and anterior vitrectomy were performed in 98% of eyes (33% with a limbal approach and 66% with a pars plana approach). No other additional surgical procedures were performed concurrently.
      Intraoperative complications consisted of inadvertent anterior (n = 2) or posterior (n = 3) capsular disruption in 5 eyes (9%) during lens removal or IOL insertion. Despite these complications, an IOL was inserted in each case (3 in the capsular bag, 2 with sulcus fixation). There were no other intraoperative complications.
      At the study close-out visit, the median visual acuity was 0.80 logarithm of the minimum angle of resolution (logMAR; range, 0.00–2.65 logMAR; Snellen equivalent, 20/125) in the affected eye and 0.05 logMAR (range, –0.12 to 0.48 logMAR; Snellen equivalent, 20/20) in the fellow eye (Table 2). Eleven percent of patients demonstrated visual acuity better than 20/40 in the affected eye, and 44% demonstrated visual acuity of 20/200 or worse. Median final affected-eye visual acuity was 0.65 logMAR (Snellen equivalent, 20/90) in 22 patients who were rated excellent in patching compliance and 1.30 logMAR (Snellen equivalent, 20/400) in 23 patients rated poor or fair in compliance (P = 0.001). No statistically significant association was found between visual acuity outcome and the use of an IOL (median acuity, 0.88 logMAR without IOL and 0.80 logMAR with IOL; P = 0.99), AE (median acuity, 0.80 logMAR without AE and 1.00 logMAR with AE; P = 0.60), or an additional unplanned intraocular surgery (median visual acuity 0.80 logMAR without additional surgery and 1.26 logMAR with additional surgery; P = 0.32) based on the Wilcoxon rank-sum test.
      Table 2Visual Acuity at 5.1 Years of Age by Age at Surgery
      Visual AcuityAge (mos), No. (%)
      7–12 (n = 24)12–24 (n = 32)Total (n = 56)
      20/20–<400 (0)6 (19)6 (11)
      20/40–<806 (25)7 (23)13 (24)
      20/80–<2005 (21)7 (23)12 (22)
      200 or worse13 (54)11 (36)24 (44)
      Median1.00 (20/200)0.70 (20/100)P = 0.086
      Table 3 shows the adverse events in 14 children (27%). Visual axis opacification occurred in 8 children (14%). No pupillary membrane, intraocular hemorrhage, endophthalmitis, or phthisis bulbi were reported. Only 1 pseudophakic patient (surgery at 8 months of age) was diagnosed as glaucoma suspect. No glaucoma surgeries were performed. As detailed in Table 3, 9 additional unplanned surgeries were performed in 8 patients. Clearing of the visual axis, whether through cortex aspiration or anterior vitrectomy, occurred in 9 patients (16%). Neither AEs nor additional intraocular surgeries were found statistically more frequently in children whose surgery was performed between 7 and 12 months of age compared with those whose surgery was performed between 13 and 24 months of age (AE rate, 29% vs. 25%, respectively [P = 0.76]; reoperation rate, 13% vs. 16%, respectively [P = 1.00]). An adverse event was detected in 4 of 7 eyes (57%) with sulcus IOL fixation versus 8 of 44 eyes (18%) with IOL in the capsular bag (P = 0.045) and in 6 of 37 eyes (16%) with pars plana vitrectomy versus 6 of 14 eyes (43%) with anterior approach (P = 0.066).
      Table 3Adverse Events and Additional Unplanned Intraocular Surgery
      OutcomeAge (mos), No. (%)
      7–12 (n = 24)12–24 (n = 32)Total (n = 56)
      Adverse events
       Visual axis opacification3 (13)6 (19)9 (16)
       Corectopia3 (13)0 (0)3 (5)
       Glaucoma suspect2 (8)0 (0)2 (4)
       IOL decentered0 (0)1 (3)1 (2)
       Epiretinal membrane0 (0)1 (3)1 (2)
       Epithelial inclusion cyst1 (4)0 (0)1 (2)
       Total adverse events
      Two patients experienced 2 adverse events.
      98
       Total no. of patients with adverse events7 (29)8 (25)P = 0.77
      Fisher exact test.
      Total additional unplanned intraocular surgery (AUIS)
      Two planned secondary IOL implantations in aphakic group.
       Vitrectomy3 (13)3 (9)6 (11)
       Aspiration of cortex0 (0)2 (6)2 (4)
       IOL repositioning0 (0)1 (3)1 (2)
       Total intraocular reoperations (AUIS)36
       Total patients with AUIS3 (13)5 (16)P = 1.00
      Fisher exact test.
      AUIS = additional unplanned intraocular surgery; IOL = intraocular lens.
      Two patients experienced 2 adverse events.
      Fisher exact test.
      Two planned secondary IOL implantations in aphakic group.
      At 5 years of age, 18 of 56 patients (32%) were orthophoric at distance without prior strabismus surgery (33% for cataract surgery at 7–12 months of age and 42% for cataract surgery at 13–24 months of age and regardless of IOL use). Stereopsis was detected in 3 children (100 seconds of arc in 1 child, 200 seconds of arc in 2 children). There was a trend for children with orthophoria to demonstrate better vision than those with strabismus (median acuity, 0.70 logMAR [Snellen equivalent, 20/100] vs. 1.00 logMAR [Snellen equivalent, 20/200], respectively; P = 0.067). Of the 30 patients with strabismus, exotropia (5–50 prism diopters) was the most common deviation in 16 patients (53%) followed by esotropia (4–45 prism diopters) in 13 patients (43%) and hypertropia (7–16 prism diopters) in 4 patients (13%). Strabismus surgery was performed in 12 patients before 4 years of age (27% in children with initial surgery at 7 to 12 months of age and 5% in those 13 to 24 months of age; P = 0.33). Neither AEs nor additional intraocular surgeries were found statistically more frequently in children who were orthophoric without prior strabismus surgery compared with those with strabismus (AE rate, 33% vs. 22%, respectively [P = 0.52]; reoperation rate, 20% vs. 11%, respectively; [P = 0.69]).

      Discussion

      The low rate of complications, reoperations, and AEs after unilateral primary IOL implantation in older infants and toddlers (7–24 months of age at surgery) in this registry stands in striking contrast to that reported in IATS infants younger than 7 months at surgery. Despite the limits of retrospective data, the TAPS data are compelling because these procedures were performed through the care of IATS surgeons during the same period as the IATS.
      In the early 2000s, a debate arose regarding the risks of IOL implantation in infants and toddlers. In 2001 a survey revealed that the preferred minimum age for IOL insertion was 17 months for AAPOS members.
      • Wilson M.E.
      • Bartholomew L.R.
      • Trivedi R.H.
      Pediatric cataract surgery and intraocular lens implantation: practice styles and preferences of the 2001 ASCRS and AAPOS memberships.
      A more recent study in Great Britain found that 62% of pediatric patients younger than 2 years of age received an IOL at the time of cataract surgery.
      • Solebo A.L.
      • Russell-Eggit I.
      • Nischal K.K.
      • et al.
      Cataract surgery and primary intraocular lens implantation in children ≤2 years old in the UK and Ireland: finding of national surveys.
      • Solebo A.L.
      • Cumberland P.
      • Rahi J.S.
      British Isles Congenital Cataract Interest Group
      5-year outcomes after primary intraocular lens implantation in children aged 2 years or younger with congenital or infantile cataract: findings from the IoLunder2 prospective inception cohort study.
      • Solebo A.L.
      • Russell-Eggitt I.
      • Cumberland P.M.
      • et al.
      Risks and outcomes associated with primary intraocular lens implantation in children under age 2: the IOLunder2 cohort study.
      The increase in IOL implantation in patients younger than 2 years led to an increase in AEs and undesirable refractive changes.
      • Greenwald M.J.
      • Glaser S.R.
      Visual outcomes after surgery for unilateral cataract in children more than two years old: posterior chamber intraocular lens implantation versus contact lens correction of aphakia.
      • Wilson M.E.
      • Bartholomew L.R.
      • Trivedi R.H.
      Pediatric cataract surgery and intraocular lens implantation: practice styles and preferences of the 2001 ASCRS and AAPOS memberships.
      • Solebo A.L.
      • Russell-Eggit I.
      • Nischal K.K.
      • et al.
      Cataract surgery and primary intraocular lens implantation in children ≤2 years old in the UK and Ireland: finding of national surveys.
      • Solebo A.L.
      • Cumberland P.
      • Rahi J.S.
      British Isles Congenital Cataract Interest Group
      5-year outcomes after primary intraocular lens implantation in children aged 2 years or younger with congenital or infantile cataract: findings from the IoLunder2 prospective inception cohort study.
      • Lu Y.
      • Ji Y.H.
      • Luo Y.
      • et al.
      Visual results and complications of primary intraocular implantation in infants aged 6 to 12 months.
      • Kumar P.
      • Lambert S.R.
      Evaluating the evidence for and against the use of IOLs in infants and young children.
      • Yen A.G.
      • Kong L.
      • Yen K.G.
      Long term outcomes of primary intraocular lens implantation in patients age 7 to 24 months.
      • Solebo A.L.
      • Russell-Eggitt I.
      • Cumberland P.M.
      • et al.
      Risks and outcomes associated with primary intraocular lens implantation in children under age 2: the IOLunder2 cohort study.
      • Vasavada A.R.
      • Vasavada V.
      • Shah S.K.
      • et al.
      Five-year postoperative outcomes of bilateral aphakia and pseudophakia in children up to 2 years of age: a randomized clinical trial.
      Infant Aphakia Treatment Study Group
      The Infant Aphakia Treatment Study: design and clinical measures at enrollment.
      Infant Aphakia Treatment Study Group
      A randomized clinical trial comparing contact lens with intraocular lens correction of monocular infancy: HOTV optotype acuity at age 4.5 years and clinical findings at age 5 years.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications, adverse events, and additional intraocular surgery 1 year after cataract surgery in the Infant Aphakia Treatment Study.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications in the first 5 years following cataract surgery in infants with and without intraocular lens implantation in the Infant Aphakia Treatment Study.
      As recently expressed by a Delphi study, there has been no consensus surrounding the minimum age for primary IOL implantation.
      • Serafino M.
      • Trivedi R.H.
      • Levin A.V.
      • et al.
      Use of the Delphi process in paediatric cataract management.
      The IATS randomized children 1 to 7 months of age at 12 sites across the United States to unilateral cataract surgery with or without IOL implantation. Visual acuity, strabismus, stereopsis, and glaucoma outcomes were identical statistically between the study groups. Unfortunately, infants undergoing IOL implantation proved to have a more complicated course, including high rates of additional intraocular surgery (72%) and AEs such as lens proliferation into visual axis (44%), pupillary membrane (28%), corectopia (28%), glaucoma (19%), and glaucoma suspect (9%).
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications, adverse events, and additional intraocular surgery 1 year after cataract surgery in the Infant Aphakia Treatment Study.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications in the first 5 years following cataract surgery in infants with and without intraocular lens implantation in the Infant Aphakia Treatment Study.
      The value of the IATS stemmed from the design, the consistency in techniques and clinical care protocols of the surgeon investigators, and the duration of follow-up.
      Questions remain regarding the outcomes and complications for the use of IOLs in children older than those studied in the IATS.
      • Solebo A.L.
      • Cumberland P.
      • Rahi J.S.
      British Isles Congenital Cataract Interest Group
      5-year outcomes after primary intraocular lens implantation in children aged 2 years or younger with congenital or infantile cataract: findings from the IoLunder2 prospective inception cohort study.
      • Yen A.G.
      • Kong L.
      • Yen K.G.
      Long term outcomes of primary intraocular lens implantation in patients age 7 to 24 months.
      • Struck M.C.
      Long-term results of pediatric cataract surgery and primary intraocular lens implantation from 7 to 22 months of life.
      • Solebo A.L.
      • Russell-Eggitt I.
      • Cumberland P.M.
      • et al.
      Risks and outcomes associated with primary intraocular lens implantation in children under age 2: the IOLunder2 cohort study.
      • Vasavada A.R.
      • Vasavada V.
      • Shah S.K.
      • et al.
      Five-year postoperative outcomes of bilateral aphakia and pseudophakia in children up to 2 years of age: a randomized clinical trial.
      A small study examining IOL implantation in patients 7 to 24 months of age documented better visual outcomes and a lower rate of complications and AEs than those reported for children younger than 7 months.
      • Yen A.G.
      • Kong L.
      • Yen K.G.
      Long term outcomes of primary intraocular lens implantation in patients age 7 to 24 months.
      Two large cohorts have been reported, one by a single surgeon in India and a second from a consortium of surgeons in the United Kingdom and Ireland. Limitations of these studies in determining the effect of age on complications and adverse events include the grouping of children from birth to age 24 months and nonstandardized surgical techniques in the group of 63 surgeons in the United Kingdom consortium.
      • Solebo A.L.
      • Cumberland P.
      • Rahi J.S.
      British Isles Congenital Cataract Interest Group
      5-year outcomes after primary intraocular lens implantation in children aged 2 years or younger with congenital or infantile cataract: findings from the IoLunder2 prospective inception cohort study.
      • Solebo A.L.
      • Russell-Eggitt I.
      • Cumberland P.M.
      • et al.
      Risks and outcomes associated with primary intraocular lens implantation in children under age 2: the IOLunder2 cohort study.
      • Vasavada A.R.
      • Vasavada V.
      • Shah S.K.
      • et al.
      Five-year postoperative outcomes of bilateral aphakia and pseudophakia in children up to 2 years of age: a randomized clinical trial.
      The participating surgeons in the IATS were aligned in their surgical practice, clinical care, and documentation of pediatric cataract. They were each certified to perform both arms of the IATS via submission and review of unedited surgical videos. This TAPS retrospective review of children just older than the IATS cohort but operated on by the same surgeons during the same study time frame (2004 through 2010), is uniquely qualified to clarify the outcomes for these children as they age and transition from the higher IOL-risk age group as studied in the IATS into older childhood. The TAPS series is the largest cohort of unilateral cataract outcomes in this age group. Despite the limitations of retrospective data, including the use of nonrandomized patients and nonstandardized documentation, we believe that the close parallels between the care provided to TAPS and IATS patients allows for comparison in determining the effect of age on outcomes.

       Vision and Strabismus

      Vision and strabismus outcomes in the unilateral TAPS registry seem similar to the unilateral IATS results. In the TAPS, median visual acuity of children with a history of monocular IOL implantation at 7 to 24 months of age was 20/125 (0.80 logMAR). This result (approximately 50% of eyes worse than 20/200) due to amblyopia was consistent with the aphakic and pseudophakic arms of IATS. As seen in the IATS, affected eye visual acuity correlated with the graded success of patching compliance as documented at the time of the outcome examination.
      • Drews-Botsch C.D.
      • Celano M.
      • Kruger S.
      • et al.
      Adherence to occlusion therapy in the first six months of follow-up and visual acuity among participants in the Infant Aphakia Treatment Study (IATS).
      Although there was not a statistical difference in median visual acuity based on age, a higher number of toddlers 13 to 24 months of age achieved visual acuity of better than 20/40 than children who underwent surgery between 7 and 12 months of age (19% vs. 0%). Potentially because of differences in the type and timing of cataract onset or postoperative refractive management, this result is consistent with that of other series, which have suggested that older infants and toddlers with unilateral cataract may have better visual acuity than those operated on in the first months of life.
      • Repka M.A.
      Visual rehabilitation in pediatric aphakia.
      • Zwaan J.
      • Mullaney P.B.
      • Awad A.
      • et al.
      Pediatric intraocular lens implantation: surgical results and complications in more than 300 patients.
      • Magli A.
      • Forte R.
      • Carelli R.
      • et al.
      Long-term outcomes of primary intraocular lens implantation for unilateral congenital cataract.
      • Lu Y.
      • Ji Y.H.
      • Luo Y.
      • et al.
      Visual results and complications of primary intraocular implantation in infants aged 6 to 12 months.
      • Struck M.C.
      Long-term results of pediatric cataract surgery and primary intraocular lens implantation from 7 to 22 months of life.
      In children up to 21 months of age, Magli et al
      • Magli A.
      • Forte R.
      • Carelli R.
      • et al.
      Long-term outcomes of primary intraocular lens implantation for unilateral congenital cataract.
      documented final best-corrected visual acuity of 0.61 LogMar (Snellen equivalent, 20/81) to 0.91 (Snellen equivalent, 20/166). In another small cohort of children 7 to 24 months of age, Struck
      • Struck M.C.
      Long-term results of pediatric cataract surgery and primary intraocular lens implantation from 7 to 22 months of life.
      reported mean best-corrected visual acuity of 0.29 logMAR (Snellen equivalent, 20/40) in series of 14 consecutive eyes.
      Strabismus and strabismus surgery are common after infant cataract surgery.
      • Greenwald M.J.
      • Glaser S.R.
      Visual outcomes after surgery for unilateral cataract in children more than two years old: posterior chamber intraocular lens implantation versus contact lens correction of aphakia.
      • Spanou N.
      • Alexopoulos L.
      • Manta G.
      • et al.
      Strabismus in pediatric lens disorders.
      • Weisberg O.L.
      • Sprunger D.T.
      • Plager D.A.
      • et al.
      Strabismus in pediatric pseudophakia.
      • Bothun E.D.
      • Cleveland J.
      • Lynn M.J.
      • et al.
      One-year strabismus outcomes in the Infant Aphakia Treatment Study.
      • Bothun E.D.
      • Lynn M.J.
      • Christiansen S.P.
      • et al.
      Strabismus surgery outcomes in the Infant Aphakia Treatment Study (IATS) at age 5 years.
      • Bothun E.D.
      • Lynn M.J.
      • Christiansen S.P.
      • et al.
      Sensorimotor outcomes by age 5 years after monocular cataract surgery in the Infant Aphakia Treatment Study (IATS).
      • Hartmann E.E.
      • Stout A.U.
      • Lynn M.J.
      • et al.
      Stereopsis results at 4.5 years of age in the Infant Aphakia Treatment Study.
      In the present series, 32% of patients maintained orthophoria without strabismus surgery. This is slightly better than the IATS results, in which 19% of children maintained orthophoria.
      • Bothun E.D.
      • Cleveland J.
      • Lynn M.J.
      • et al.
      One-year strabismus outcomes in the Infant Aphakia Treatment Study.
      • Bothun E.D.
      • Lynn M.J.
      • Christiansen S.P.
      • et al.
      Strabismus surgery outcomes in the Infant Aphakia Treatment Study (IATS) at age 5 years.
      Consistent with prior pediatric cataract literature, slightly older children in this study more commonly demonstrated exotropia compared with the esotropia more frequently seen in the IATS: 50% esotropia and 27% exotropia.
      • Greenwald M.J.
      • Glaser S.R.
      Visual outcomes after surgery for unilateral cataract in children more than two years old: posterior chamber intraocular lens implantation versus contact lens correction of aphakia.
      • Spanou N.
      • Alexopoulos L.
      • Manta G.
      • et al.
      Strabismus in pediatric lens disorders.
      • Weisberg O.L.
      • Sprunger D.T.
      • Plager D.A.
      • et al.
      Strabismus in pediatric pseudophakia.
      • Bothun E.D.
      • Cleveland J.
      • Lynn M.J.
      • et al.
      One-year strabismus outcomes in the Infant Aphakia Treatment Study.
      • Bothun E.D.
      • Lynn M.J.
      • Christiansen S.P.
      • et al.
      Strabismus surgery outcomes in the Infant Aphakia Treatment Study (IATS) at age 5 years.
      • Bothun E.D.
      • Lynn M.J.
      • Christiansen S.P.
      • et al.
      Sensorimotor outcomes by age 5 years after monocular cataract surgery in the Infant Aphakia Treatment Study (IATS).
      Similar to IATS, TAPS visual acuity and strabismus results do not seem to be influenced by the use of an IOL, the presence of an AE, or the need for additional unplanned intraocular surgery.

       Comparing the Infant Aphakia Treatment Study and the Toddler Aphakia and Pseudophakia Treatment Study

      This surgeon group reported a high rate of intraoperative complications, AEs, and reoperations for unilateral cataract surgery in infants younger than 7 months of age in the IATS. The TAPS registry revealed that during the same years surgeons were participating in the IATS, they implanted an IOL in 91% of comparable children between 7 and 24 months of age. Despite expected limitations of retrospective data, the 51 eyes with IOL implantation in TAPS followed up for a mean of 5.1 years can be compared with the 57 eyes with IOL implantation in IATS followed up for 4.5 years (Table 4).
      Table 4Comparing Intraocular Lens Cohort in the Infant Aphakia Treatment Study with Intraocular Lens Eyes in the Toddler Aphakia and Pseudophakia Treatment Study
      OutcomeInfant Aphakia Treatment StudyToddler Aphakia and Pseudophakia Treatment StudyP Value
      Age at surgery (mos)1 to <77–24
      No. of IOL patients5751
      Mean age at follow-up (yrs)4.55.1
      Intraocular complications, no. (%)16 (28)4 (8)P = 0.012
      Fisher exact test.
      Adverse events, total46 (81)12 (24)P ≤ 0.001
      Fisher exact test.
       Visual axis opacity23 (40)9 (18)
       Glaucoma or glaucoma suspect16 (28)1 (2)
       Corectopia16 (28)1 (2)
      Patients reoperations41 (72)8 (16)P ≤ 0.001
      Fisher exact test.
       Clearing visual axis39 (68)7 (16)
       Glaucoma surgery5 (9)0 (0)
      Pseudophakic refractive error at 5 yrs of age (D)
       Mean–2.25+1.1
       Range–19 to 5–3 to 6
      D = diopter; IOL = intraocular lens.
      Boldface values signify the grouped data (followed by P value).
      Fisher exact test.

       Intraoperative Complications and Adverse Events

      Intraoperative complications in 10% of this unilateral IOL series is in striking contrast to the 28% of children receiving an IOL in the IATS.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications, adverse events, and additional intraocular surgery 1 year after cataract surgery in the Infant Aphakia Treatment Study.
      For TAPS, the complications exclusively involved anterior or posterior capsular tears. Unlike eyes in the IATS, in which iris prolapse was identified in 11% of patients, iris damage in 3% of patients, and hyphema in 2% of patients, these complications were not recorded in TAPS patients. Additionally, at 5.1 years of age, AEs were present in only 24% of TAPS registry children compared with 81% of pseudophakic eyes in IATS.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications in the first 5 years following cataract surgery in infants with and without intraocular lens implantation in the Infant Aphakia Treatment Study.
      The morphologic features of cataract study eyes documented in the physician notes of this TAPS registry may be different from those studied through independent video review in IATS. Mild persistent fetal vasculature (PFV), associated with higher AEs, was diagnosed at the same frequency (12%) of pseudophakic eyes in both IATS eyes and TAPS eyes (7/57 vs. 6/51, respectively).
      • Wilson M.E.
      • Trivedi R.H.
      • Morrison D.G.
      • et al.
      The Infant Aphakia Treatment Study: evaluation of cataract morphology in eyes with monocular cataracts.
      • Morrison D.G.
      • Wilson M.E.
      • Trivedi R.H.
      • et al.
      Infant Aphakia Treatment Study: effects of persistent fetal vasculature on outcome at 1 year of age.
      In this study, a lower rate of any AE was identified with IOL placement in the bag. Recurrent visual axis opacification (18%) was the most common adverse event in the TAPS and resulted in a number of additional intraoperative surgeries as reported in prior studies.
      • Magli A.
      • Forte R.
      • Carelli R.
      • et al.
      Long-term outcomes of primary intraocular lens implantation for unilateral congenital cataract.
      • Lu Y.
      • Ji Y.H.
      • Luo Y.
      • et al.
      Visual results and complications of primary intraocular implantation in infants aged 6 to 12 months.
      • Kumar P.
      • Lambert S.R.
      Evaluating the evidence for and against the use of IOLs in infants and young children.
      • Struck M.C.
      Long-term results of pediatric cataract surgery and primary intraocular lens implantation from 7 to 22 months of life.
      Infant Aphakia Treatment Study Group
      A randomized clinical trial comparing contact lens with intraocular lens correction of monocular infancy: HOTV optotype acuity at age 4.5 years and clinical findings at age 5 years.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications, adverse events, and additional intraocular surgery 1 year after cataract surgery in the Infant Aphakia Treatment Study.
      This is consistent with the other single-surgeon series in the literature suggesting that the rate of AEs in children between 7 and 24 months of age may approach that of children 2 to 16 years of age.
      • Greenwald M.J.
      • Glaser S.R.
      Visual outcomes after surgery for unilateral cataract in children more than two years old: posterior chamber intraocular lens implantation versus contact lens correction of aphakia.
      • Yen A.G.
      • Kong L.
      • Yen K.G.
      Long term outcomes of primary intraocular lens implantation in patients age 7 to 24 months.
      • Struck M.C.
      Long-term results of pediatric cataract surgery and primary intraocular lens implantation from 7 to 22 months of life.
      • Vasavada A.R.
      • Vasavada V.
      • Shah S.K.
      • et al.
      Five-year postoperative outcomes of bilateral aphakia and pseudophakia in children up to 2 years of age: a randomized clinical trial.
      Corectopia was documented less frequently in the pseudophakic patients in this series than in the younger children of the IATS (2% vs. 28%).
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications, adverse events, and additional intraocular surgery 1 year after cataract surgery in the Infant Aphakia Treatment Study.
      • Plager D.A.
      • Lynn M.J.
      • Buckley E.G.
      • et al.
      Complications in the first 5 years following cataract surgery in infants with and without intraocular lens implantation in the Infant Aphakia Treatment Study.
      No pupillary membrane, intraocular hemorrhage, endophthalmitis, retinal detachment, or phthisis bulbi were reported in our series.

       Glaucoma and Glaucoma Suspect

      The rate of glaucoma has an inverse correlation to age at surgery after infantile cataract surgery.
      • Lambert S.R.
      • Purohit A.
      • Superak H.M.
      • et al.
      Long-term risk of glaucoma after congenital cataract surgery.
      • Egbert J.E.
      • Christiansen S.P.
      • Wright M.M.
      • et al.
      The natural history of glaucoma and ocular hypertension after pediatric cataract surgery.
      • Mataftsi A.
      • Haidich A.B.
      • Kokkali S.
      • et al.
      Postoperative glaucoma following infantile cataract surgery: an individual patient data meta-analysis.
      • Freedman S.F.
      • Lynn M.J.
      • Beck A.D.
      • et al.
      Glaucoma-related adverse events in the first five years after unilateral cataract removal in the Infant Aphakia Treatment Study. The Infant Aphakia Treatment Study Group.
      As articulated in a recent meta-analysis, it remains a challenge to remove the risk of age bias when deciphering whether IOL use affects the rate of glaucoma in retrospective data.
      • Serafino M.
      • Trivedi R.H.
      • Levin A.V.
      • et al.
      Use of the Delphi process in paediatric cataract management.
      For infants 1 to 7 months of age in the IATS, the 5-year risks for glaucoma and glaucoma suspect were 17% and 31%, respectively.
      • Freedman S.F.
      • Lynn M.J.
      • Beck A.D.
      • et al.
      Glaucoma-related adverse events in the first five years after unilateral cataract removal in the Infant Aphakia Treatment Study. The Infant Aphakia Treatment Study Group.
      The implantation of an IOL did not affect this outcome significantly. In this study of children older than 6 months of age, the rate of glaucoma suspect was 2% in children with primary IOL insertion. Although other series have shown that older infants and toddlers remain at risk for glaucoma, it seems that the risk decreases when surgery is performed after 6 months of age.
      • Yen A.G.
      • Kong L.
      • Yen K.G.
      Long term outcomes of primary intraocular lens implantation in patients age 7 to 24 months.
      • Struck M.C.
      Long-term results of pediatric cataract surgery and primary intraocular lens implantation from 7 to 22 months of life.
      • Mataftsi A.
      • Haidich A.B.
      • Kokkali S.
      • et al.
      Postoperative glaucoma following infantile cataract surgery: an individual patient data meta-analysis.

       Comparing Older Infants (7–12 Months of Age) with Toddlers (13–24 Months of Age) in the Toddler Aphakia and Pseudophakia Treatment Study

      Exploration of data from the TAPS registry revealed a much lower risk profile for lensectomy with IOL implantation in children 7 to 24 months of age compared with those 1 to 7 months of age. We compared the risk of IOL placement in older infants (7–12 months of age) with that of toddlers (13–24 months of age). Vision outcomes and low rates of operative complications and AEs seemed comparable for children 7 to 12 months of age and those 13 to 24 months of age. This study suggested that there is no additional reduction, through 24 months of age, in the risk of visual axis opacification and reoperations as soon as the child is beyond 6 months of life at the time of IOL implantation.

       Refractive Change

      Target IOL selection requires an estimation of myopic shift of refraction over time. This is a challenge for pediatric cataract surgeons. Anticipating a myopic refraction shift with axial growth, infants typically are targeted to be moderately hyperopic immediately after IOL implantation.
      • Wilson M.E.
      • Bartholomew L.R.
      • Trivedi R.H.
      Pediatric cataract surgery and intraocular lens implantation: practice styles and preferences of the 2001 ASCRS and AAPOS memberships.
      • Repka M.A.
      Visual rehabilitation in pediatric aphakia.
      • Plager D.A.
      • Kipfer H.
      • Sprunger D.T.
      • et al.
      Refractive change in pediatric pseudophakia: 6-year follow-up.
      Our surgeons chose a target of between 6 and 8 diopters (D) of hyperopia for infants in the IATS, leading to a 5-year mean refractive error of –2.25 D at 5 years of age (range, –19.00 to 5.00 D). The postoperative hyperopic target refraction for the slightly older children in this retrospective review often was not recorded but was presumed to be somewhat less hyperopic. The refraction for the TAPS patients at 5 years of age was 1.1 D (range, –3.00 to 6.00 D). The reduced range suggests a more predictable and somewhat smaller myopic shift in children older than 6 months of age at surgery.
      In conclusion, although most children between 7 months and 2 years of age underwent IOL implantation concurrent with unilateral cataract removal, the incidence of complications, reoperations, and glaucoma was significantly lower than when IOLs were used by the same surgeons in infants younger than 7 months of age in the IATS. Our findings support the relatively safe use of IOLs in infants between 7 and 24 months of age.

      Supplementary Data

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