2020–2021 BCSC Basic and Clinical Science Course™
2 Fundamentals and Principles of Ophthalmology
Part I: Anatomy
Chapter 2: The Eye
Lens
Epithelium
The lens epithelium lies beneath the anterior and equatorial capsule but is absent under the posterior capsule (see Fig 2-28). The basal aspects of the cells abut the lens capsule without specialized attachment sites. The apices of the cells face the interior of the lens, and the lateral borders interdigitate, with practically no intercellular space. Each cell contains a prominent nucleus but relatively few cytoplasmic organelles.
Regional differences in the lens epithelium are important. The central zone represents a stable population of cells whose numbers slowly decline with age. An intermediate zone of smaller cells shows occasional mitoses. Peripherally in the equatorial lens bow area, there are meridional rows of cuboidal preequatorial cells that form the germinative zone of the lens (see Figs 2-28, 2-29). Here, cells undergo mitotic division, elongate anteriorly and posteriorly, and form the differentiated fiber cells of the lens. In the human lens, cell division continues throughout life and is responsible for the continued growth of the lens.
Excerpted from BCSC 2020-2021 series: Section 2 - Fundamentals and Principles of Ophthalmology. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.