Is Infantile XT or Infantile ET more likely to be a constant, unilateral deviation?

• A. Infantile XT
• B. Infantile ET
• C. Both equally
• D. Neither

Answer: (B)

Constant, unilateral deviation in infancy is most characteristic of infantile esotropia. This condition typically appears within the first six months of life as a large-angle esotropic misalignment that remains present in all gazes and tends to stay on the same eye. The early neural-muscular imbalance driving inward turning sets a fixation that is rarely alternating in early infancy, so the deviation is usually constant and unilateral.

Infantile exotropia, on the other hand, often shows more variability. Many cases are intermittent or alternating, with the deviation not consistently fixed in a single eye, especially in the early years. That makes a purely constant unilateral exotropia less likely compared with infantile esotropia.

So the form more likely to be a constant, unilateral deviation is infantile esotropia.