Cortical Cataract

Definition: An opacity in the cortex of the lens, for which the key histologic criterion is the presence of globular degeneration.
Incidence/Prevalence: It is a common form of cataract and usually cortical changes are found accompanying nuclear sclerosis
Etiology: The eosinophilic globules are aggregates of lens crystallins.
Clinical Findings: Symptoms include glare while driving and, if the cataract is axial, a decrease in vision particularly with reading. Degenerative changes in the lens cortex may take on various appearances; spokes, fissures, lamellar separations, dot and wedge shaped opacities, rosettes and even a sunflower appearance have been described. With progression, the cortex may become mature and the nucleus floats within the bag. If the cortical material escapes from the lens capsule and produces wrinkles in the capsule, the lens is said to be hypermature.
Histopathology: The hallmark of the cortical cataract is globular degeneration. The process starts with alterations in cellular morphology with swelling and aggregation of protein. The lens cell membranes eventually break down releasing globules. Morgagnian globules consist of eosinophilic collections of protein (aggregates of lens crystallins) of various sizes that have lost cell membranes. Slits that appear as a result of cortical cataract usually contain eosinophilic material. This distinguishes cataract from artifactual separation of fibers during sectioning. As slits coalesce to form larger clefts, the cataract manifests spoke-like or wedge-shaped opacities.

Treatment: Surgical removal of the cataract generally restores vision.