Strabismus presenting after cataract surgery.

Strabismus presenting after cataract surgery is etiologically related to a heterogenous group of disorders. Clinical data from 63 patients so affected revealed four broad etiologic categories: 1) pre-existing disorders that preceded the cataract surgery, but were rendered asymptomatic by the occluding cataract (e.g., thyroid eye disease, cranial nerve palsy, myasthenia); 2) disorders precipitated by prolonged occlusion by a cataract (e.g., sensory deviations, decompensation of heterophorias, and central disruption of binocular vision); 3) disorders resulting from surgical trauma to extraocular muscles and orbital soft tissues. Traumatic injury to the inferior rectus muscle secondary to retrobulbar anesthesia injection, a specific subset, is postulated to result from a Volkmann's type ischemic contracture, a well-known osseofascial compartment syndrome occurring in peripheral skeletal muscles. 4) Disorders related to resulting aphakia/pseudophakia and associated optical aberrations (e.g.; anisophoria, ocular dominance reversal, and color/brightness disparity). The diagnostic and therapeutic implications of these findings are discussed.