Spasm of accommodation associated with closed head trauma.

Spasm of accommodation, creating pseudomyopia, is generally associated with miosis and excess convergence as part of spasm of the near reflex. It may also exist as an isolated entity, usually attributed to psychogenic causes. We present six cases of accommodative spasm associated with closed head injury. All patients were male, ranging in age between 16 and 37 years. The degree of pseudomyopia, defined as the difference between manifest and cycloplegic refraction, was 1.5 to 2 diopters. A 3-year trial of pharmacologically induced cycloplegia in one patient did not lead to reversal of the spasm when the cycloplegia was stopped. All patients required the manifest refraction to see clearly at distance. The pseudomyopia endured for at least 7 years following head trauma. This phenomenon may represent traumatic activation or disinhibition of putative brain stem accommodation centers in young individuals.