Walsh & Hoyt: Divergence Weakness and Its Relationship to Abducens Nerve Palsy

Despite the controversy about its cause, divergence weakness appears to be a well-defined entity. It was first described by Parinaud in 1883 and is diagnosed by Bielschowskis five criteria. Divergence weakness is distinguished from convergence spasm because patients with convergence spasm maintain an esotropia at near, have miotic pupils, have reduced distance visual acuity from induced myopia, and show normal fusional divergence. It is possible, however, that these conditions are on a clinical continuum.