Orbit and Ocular Adnexa
During infancy and childhood, orbital volume increases, and the orbital opening becomes less circular, resembling a horizontal oval. The lacrimal fossa becomes more superficial and the angle formed by the axes of the 2 orbits less divergent.
The palpebral fissure measures approximately 18 mm horizontally and 8 mm vertically at birth. Growth of the palpebral fissure is greater horizontally than vertically, resulting in the eyelid opening becoming less round and acquiring its elliptical adult shape. Most of the horizontal growth occurs in the first 2 years of life (see Chapter 17, Fig 17-1).
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.