Walsh & Hoyt: Hypolacrimation

The majority of afferent inputs for reflex lacrimation are carried via the ophthalmic division of the trigeminal nerve. Significant hypolacrimation can result from deafferentation of the tear reflex on one side, such as occurs in severe trigeminal neuropathy. However, lesions that damage the trigeminal nerve at the pontine angle, petrous tip, or Meckels cave often simultaneously damage the nearby parasympathetic lacrimal fibers (either the nervus intermedius or the greater superficial petrosal nerve). In these cases, trigeminal nerve-related reduction of tears represents combined dysfunction in the afferent and efferent limbs of the tear reflex. Brain stem lesions. Lesions affecting the greater superficial petrosal nerve. Lesions affecting the sphenopalatine ganglion. Lesions of the zygomaticotemporal nerve.