2020–2021 BCSC Basic and Clinical Science Course™
11 Lens and Cataract
Chapter 5: Pathology
Myotonic dystrophy is an inherited autosomal dominant condition characterized by delayed relaxation of contracted muscles, ptosis, weakness of the facial musculature, cardiac conduction defects, and prominent frontal balding in affected male patients. Patients with this disorder typically develop polychromatic iridescent crystals in the lens cortex (Fig 5-22), with sequential PSC that progresses to complete cortical opacification. These polychromatic iridescent crystals are composed of whorls of plasmalemma from the lens fibers. Iridescent crystals that are similar in appearance are occasionally seen in the lens cortex of patients who do not have myotonic dystrophy; those crystals are thought to be caused by cholesterol deposition in the lens.
Figure 5-22 Polychromatic iridescent crystals in a patient with myotonic dystrophy.
(Courtesy of Karla J. Johns, MD.)
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.