Which of the following is NOT one of the 3 main types of acquired ET?

Which of the following is NOT one of the 3 main types of acquired ET?

• A. Infantile ET
• B. Accommodative ET
• C. Acute ET
• D. Mechanical ET

Answer: (A)

The main idea here is that acquired esotropia is commonly categorized into three types: accommodative esotropia, acute esotropia, and mechanical (restrictive) esotropia. Accommodative ET arises from excessive focusing to compensate refractive error and often changes with glasses. Acute ET refers to a sudden-onset esotropia, frequently presenting with diplopia and sometimes related to neurologic or vascular events. Mechanical ET results from a loss of muscle freedom or restrictive forces around the eye, such as from scarring or thyroid eye disease. Infantile esotropia, on the other hand, is not acquired. It appears in infancy and is a separate, congenital/early-onset condition with a different onset and natural history. That’s why it is not counted among the three main types of acquired esotropia.

The main idea here is that acquired esotropia is commonly categorized into three types: accommodative esotropia, acute esotropia, and mechanical (restrictive) esotropia. Accommodative ET arises from excessive focusing to compensate refractive error and often changes with glasses. Acute ET refers to a sudden-onset esotropia, frequently presenting with diplopia and sometimes related to neurologic or vascular events. Mechanical ET results from a loss of muscle freedom or restrictive forces around the eye, such as from scarring or thyroid eye disease.

Infantile esotropia, on the other hand, is not acquired. It appears in infancy and is a separate, congenital/early-onset condition with a different onset and natural history. That’s why it is not counted among the three main types of acquired esotropia.