Infant Aphakia Treatment Study (IATS)
Condition: Congenital Cataract
MeSH terms: Cataract; Aphakia
Study type: Interventional

Summary: 
      The primary purpose is to determine whether infants with a unilateral congenital cataract are
      more likely to develop better vision following cataract extraction surgery if they undergo
      primary implantation of an intraocular lens or if they are treated primarily with a contact
      lens. In addition, the study will compare the occurrence of postoperative complications and
      the degree of parental stress between the two treatments.
    

Detailed description: 
      Intraocular lenses are now a commonly accepted treatment for cataracts in older children and
      are used increasingly in younger children and infants. Intraocular lenses are superior to
      contact lenses in that they more closely replicate the optics of the crystalline lens, do not
      require daily ongoing care, and ensure at least a partial optical correction at all times.
      The simplicity and improved visual outcome of an intraocular lens correction may make caring
      for a child with a unilateral congenital cataract less stressful for parents. However,
      contact lenses remain the accepted treatment for children under 1 year of age due to concerns
      about the long-term safety of intraocular lenses and the potential for a large myopic shift
      developing in these eyes as they grow. Contact lenses provide excellent visual results in
      infants treated for bilateral congenital cataracts; however, two-thirds of infants treated
      with contact lenses for unilateral congenital cataracts remain legally blind in their aphakic
      eye. These poor visual outcomes are usually ascribed to competition from the sound eye and
      poor compliance with patching and contact lens wear regimens. Data from our pilot study and
      the literature suggest that superior visual results can be obtained if an intraocular lens is
      used to correct unilateral aphakia during infancy, but these eyes will experience more
      complications. Intraocular lenses will be increasingly implanted in infants regardless of
      whether or not we perform this trial. By performing this clinical trial, we can determine if
      the higher rate of complications with intraocular lenses is offset by improved visual outcome
      and decreased parenting stress.

      The Infant Aphakia Treatment Study (IATS) is a multi-center randomized clinical trial
      comparing intraocular lens and contact lens correction for monocular aphakia. Infants will be
      enrolled over a 4 year period. Infants 28 to 210 days of age with a visually significant
      cataract in one eye are eligible. Cataract surgery will be performed in a standardized
      fashion by a surgeon who has been certified for the study. Surgery consists of a lensectomy,
      posterior capsulotomy, and anterior vitrectomy. Infants will be randomized at the time of
      surgery to one of two treatment groups. Infants randomized to the intraocular lens group will
      have an intraocular lens implanted into the capsular bag. Spectacles will subsequently be
      used to correct the residual refractive errors. Infants randomized to the contact lens group
      will be fitted with a contact lens immediately after surgery. Both groups will receive the
      same patching therapy and follow-up. All children will be examined by Investigators at fixed
      intervals using standard protocols with the major endpoint assessed at age 12 months by a
      Traveling Vision Examiner.

      We are currently in a continuation of this project (beyond 5 years) in order to assess which
      of these patients have glaucoma or glaucoma suspect at age 10.5 years. Our goal is to
      understand which type of initial optical correction, an IOL or a CL, results in the best
      long-term visual outcome following unilateral congenital cataract surgery during infancy. Our
      central hypothesis is that primary IOL implantation will result in a better visual outcome.
      The rationale for this proposal is that final visual acuity cannot be determined by 5 years
      of age and the recommendation for early treatment can only be substantiated by adequate
      long-term assessment in this unique cohort. We chose a follow-up to age 10.5 years because it
      will provide a more accurate assessment of visual acuity and will allow us to diagnosis most
      cases of glaucoma.
    

Intervention name(s): Contact lens correction of aphakia; Intraocular lens implantation
Intervention type(s): Device; Device
Intervention description(s): optical correction of infant surgical aphakia with Contact lens; optical correction of surgical aphakia with intraocular lens
Other intervention name(s): Silsoft aphakic contact lens; rigid gas permeable contact lens; Alcon SA60AT; Alcon MA60AC
Intervention MeSH terms: Dipivefrin
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Phase 3 is 10.5-year follow-up study since Phase 1. There is no intervention.
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: cataract surgery; intraocular lens; contact lens; infants; aphakia