Early Versus Delayed Correction of Infantile Strabismus in Macaque Monkeys: Effects on Horizontal Binocular Connections in the Striate Cortex

Abstract

Objective: To determine how the duration of infantile strabismus influences the development of horizontal connections in V1. 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. The number of horizontal connections was determined using neuroanatomic techniques. Results: The 3-wks animal had equal number of monocular (51%) and binocular (49%) connections. In the 6-mos. animal, however, monocular connections (76%) were three times more abundant than binocular (24%) connections (p < 0.001). Conclusions: Longer duration of infantile strabismus causes greater deficit of binocular connections. Early correction of infantile strabismus is supported.

KEYWORDS:

• Binocular connections
• infantile strabismus
• ocular dominance columns
• V1
• primary visual cortex