Human posterior subcapsular cataract. An ultrastructural study of the posteriorly migrating cells
J. Eshaghian and B. W. Streeten
Thirteen human lenses posterior subcapsular cataracts were examined by
transmission electron microscopy to study the lens epithelial cells that
characteristically migrate posteriorly in this disease. A sequence of
histologic changes was identified from the equatorial region to the
posterior pole. The cells became increasingly more active cytologically,
culminating in lens-fiber-like formation or cell death at the posterior
pole. Moderate amounts of extracellular granular and fibrillar material
were produced, especially in the more advanced cases. No mature collagen
was found. The liquefied posterior cataracts contained cellular debris from
both degenerate lens fibers and necrotic migrating cells. The migrating
lens cells thus contributed to the cataract by secretion, cytolysis, and
probably by release of lysosomal enzymes. Bladder cells had many of the
characteristics of lens fibers so that the term "abortive" or dysplastic
lens fibers is appropriate for them.
