Posterior Subcapsular Cataracts
Patients who present with posterior subcapsular cataracts (PSCs) are often younger than those presenting with nuclear or cortical cataracts. PSCs are located in the posterior cortical layer and are visually significant only when they encroach on the visual axis (Fig 5-8). The first indication of PSC formation is a subtle iridescent sheen in the posterior cortical layer, which is visible with the slit lamp. At later stages, granular opacities and a plaquelike opacity of the posterior subcapsular cortex develop.
Patients with PSCs often report symptoms of glare and poor vision under bright-light conditions, because a central PSC obscures more of the pupillary aperture when miosis is induced by bright lights, accommodation, or miotics. Near vision tends to be reduced more than distance vision in these patients. Some patients experience monocular diplopia. Slit-lamp detection of PSCs can best be accomplished through a dilated pupil. Retroillumination may also be helpful.
Although PSCs are typically related to increasing age, they can also occur after ocular trauma; systemic, topical, inhalational, or intraocular corticosteroid use; inflammation; exposure to ionizing radiation and some medications like tamoxifen; and prolonged alcohol abuse.
On histologic examination, PSCs are associated with posterior migration of the lens epithelial cells from the lens equator to the visual axis on the inner surface of the posterior capsule. During their migration to or after their arrival at the posterior axis, the cells undergo aberrant enlargement. These swollen cells are called Wedl (or bladder) cells (see Fig 9-7B in BCSC Section 4, Ophthalmic Pathology and Intraocular Tumors).
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Keel S, He M. Risk factors for age-related cataract. Clin Exp Ophthalmol. 2018;46(4):327–328.
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Pesudovs K, Elliott DB. Refractive error changes in cortical, nuclear, and posterior subcapsular cataracts. Br J Ophthalmol. 2003;87(8):964–967.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.