Early versus delayed correction of infantile strabismus in macaque monkeys: Effects on long-term eye alignment

Purpose: To determine how the duration of infantile strabismus influences the eventual eye alignment. Methods: Six infant macaques were fitted with prisms, which were removed after 3 weeks (wks.), 3 months (mos.), or 6 mos. Two control monkeys wore plano lenses. Eye alignment was measured using search coils. Results: Longer duration of infantile strabismus is correlated with a more severe misalignment. The strabismus in the 6-mos. group was 96% greater than that in the 3-mos. group, which, in turn, was 25 times greater than that in the 3-wks group (p < 0.05). Conclusions: Longer duration of infantile strabismus causes larger-angle esotropia. Early correction of infantile strabismus is supported.