Infant Aphakia Treatment Study (IATS)

Inclusion Criteria: * Visually significant unilateral congenital cataract (central opacity equal to or greater than 3 mm in size). * Cataract surgery performed when the patient is 28 to 210 days of age and at least 41 post-conceptional weeks. Exclusion Criteria: * The cataract is known to be acquired from trauma or as a side-effect of a treatment administered postnatally such as radiation or medical therapy. * A corneal diameter less than 9 mm measured in the horizontal meridian using calipers. * An intraocular pressure of 25 mm Hg or greater in the affected eye measured with a Perkins tonometer, tonopen, or pneumatonometer. * Persistent fetal vasculature (PFV) causing stretching of the ciliary processes or a tractional retinal detachment. * Active uveitis or signs suggestive of a previous episode of uveitis such as posterior synechiae or keratic precipitates. * The child is the product of a pre-term pregnancy (\<36 gestational weeks). Screening for prematurity will be based on the clinician's best assessment of gestational age. If a physician is uncertain regarding the gestational age, review of medical records or contact with the pediatrician and/or obstetrician should be used to confirm gestational age at delivery. Unless a clinician is uncertain as to whether a child was born at less than 36 weeks or not, confirmation of gestational age via medical record review may be delayed until after enrollment. * Retinal disease that may limit the visual potential of the eye such…