The morphology and natural history of childhood cataracts

The morphology of congenital cataract reflects a combination of the timing and nature of the cause, the anatomy of the lens including its capsule, its development, and changes that take place with time. Morphology may variably affect prognosis, give a clue to the etiology and the age of onset and, in an isolated case, sometimes suggest heritability. The spectrum of morphological variations is enormous and can be complex. A comprehensive approach is to classify the variations according to the area of the lens involved, and sub-dividing them by a detailed description of the shape and appearance. Each specific morphological type is then analyzed determining the etiology, visual prognosis, and management. The use of gene markers has allowed many of these variations to be identified and categorized. Cataracts in childhood can involve the whole lens, in which case they are called total, Morgagnian, or disk-like. They can affect only the center of the lens: lamellar, nuclear, oil droplet, cortical, or coronary. They can be anterior: anterior polar, anterior subcapsular, or anterior lenticonus. The posterior aspect of the lens can also be affected in different fashions: Mittendorf's dot, posterior lenticonus, posterior cortical cataracts, or posterior subcapsular. There are five more forms that must be described separately: punctuate lens opacities, sutural cataracts, coralliform or crystalline, wedge-shaped, and persistent hyperplastic primary vitreous.