Impaired tearing

Phenomenologically, lacrimation disorders can be divided into two types: lachrymation (epiphora) and dry eyes (xerophthalmia, alacrimia - a more precise term for declining production or lack of tears).

Lachrymation is not always associated with hyperfunction of the lacrimal glands, it is more often observed when the outflow of tear fluid is disturbed. Lachrymation can be paroxysmal or permanent, it also depends on the functional state of the brain in the sleep-wake cycle: during sleep, the secretion of tears is strongly inhibited, about 1.22 g of tear fluid partially evaporates during the waking period, the other part is excreted through the nasolacrimal canal .

[1], [2]

Forms of lacrimation

[3], [4], [5], [6]

Cold Epiphany

Lachrymation is observed in cold and windy weather, more often in the elderly. Some authors consider it as a form of cold allergy.

Epiphora in allergic rhinitis

It usually occurs in spring and summer. Simultaneously with lacrimation, patients note nasal congestion. Swelling of the mucous membrane can be limited to the area in the area of the nasolacrimal canal outlet under the lower shell, where there is a dense venous plexus; thus the outflow of a tear in a nasal cavity is complicated.

Epiphora in case of migraine and cluster headache

Worn paroxysmal, usually combined with nasal congestion and observed on the side of the headache.

[7], [8]

The Old Epic

It is often observed in the elderly, associated with age-related changes, worsening the outflow of tear fluid.

Epiphora in diseases accompanied by a decrease in vitamin A This hypovitaminosis is possible with diseases of the gastrointestinal tract, liver diseases, helminthic invasion, monotonous diet. Patients complain of lacrimation, photophobia, a feeling of dryness and rezi in the eyes; in bright light and in the wind the eyes turn red. The skin is dry, flaky, the level of vitamin A is lower in the blood. Alimentary hypovitaminosis A is a serious problem for a number of developing countries.

Epiphora in viral infections of the eye

Observed with eye damage to herpes zoster, herpes simplex, chicken pox virus, may be a complication of vaccination. In these cases, lacrimation is associated with obstruction of tear ducts.

[9], [10]

Epiphora in diseases of ENT organs

The first to this kind of lacrimation attracted attention otolaryngologists. Lachrymation appears on the side of irritation of the nasal mucosa or inner ear (rhinitis, otitis, neoplasms) and passes during the elimination of inflammatory phenomena. Ipsilateral lacrimation can also be caused by severe dental pain.

[11]

Syndrome of "crocodile tears"

About lachrymation during eating known for a long time. However, more attention was paid to this phenomenon after it was described in 1928 by FA Bogorad under the name of the syndrome of "crocodile tears." The syndrome can be congenital (in this case it is combined with a lesion of the distracting nerve) and acquired (usually after traumatic or inflammatory damage of the facial nerve proximal to the knee). A more vivid manifestation of the syndrome is observed with the use of solid and spicy food. It is noted that lacrimation during eating often occurs against the background of incomplete recovery of the facial nerve in the presence of syncopeesis. To date, more than 100 cases have been described. However, with a purposeful poll and taking into account light forms, the phenomenon of "crocodile tears" can be considered more widespread. According to the literature, with incomplete recovery of the facial nerve, the syndrome of "crocodile tears" occurs in 10 100% of patients, that is, in 6-30% of all patients with facial nerve damage.

Particular attention should be paid to the pathogenesis of the "crocodile tears" syndrome. The main mechanism of nutritional lacrimation after traumatic or inflammatory lesion of the facial nerve is the mechanism of abnormal, aberrant regeneration, when efferent and afferent saliva fibers fuse with efferent tear-separating fibers. This theory is confirmed by the presence of a latent period after the lesion of the facial nerve (necessary for regeneration) and the connection with pathological syncopeesis with incomplete recovery of the facial nerve, which is also explained by improper regeneration of motor fibers.

However, in the experiment on animals it was established that the appearance of the syndrome of "crocodile tears" is possible immediately after damage to the facial nerve, i.e. Before the regeneration of the nerve fibers. In this case, lachrymation was caused in dogs not only by food stimuli, but also by stroking and scratching the coat, which makes it possible to explain the syndrome of "crocodile tears" by the summation reflex, but in pathological conditions. In the parasympathetic nuclei innervating the lacrimal glands, and normally normal summation phenomena (eg, increased moistening of the eyeball during meals) easily occur. The lacrimal and salivary glands simultaneously appear in the phylogenetic series, have a single embryonic origin, which probably explains the anatomical proximity of the stem centers of tear and salivation. With incomplete lesion of the facial nerve, a partial denervation of the center of tearing occurs, in which the processes of summation of excitations take place more easily.

The congenital symptom of "crocodile tears", combined with ipsilateral lesion of the nerve, is described as a consequence of the teratogenic effect of thalidomide. The most logical explanation for the combination of oculomotor and lacrimal disorders is damage by the type of dysgenesis of the brain tissue in the immediate vicinity of the nucleus of the nerve.

Epiphora in Parkinsonism

Often combined with other vegetative disorders, characteristic of parkinsonism (sialorrhea, seborrhea, constipation, etc.). In lateral forms, parkinsonism is usually observed on the side of the lesion.

[12], [13], [14]

Violent crying

Occurs with pseudobulbarnom syndrome in the defeat of corticoneural pathways or subcortical nature.

Xerophthalmia can be observed both in lesions of the lacrimal glands, and in neurogenic impairment of lacrimal fluid secretion. The following forms of xerophthalmia are known.

Xerophthalmia in Sjogren's syndrome

Dry keratoconjunctivitis is one of the main manifestations of Sjogren's syndrome - exocrins of autoimmune nature. Characteristic gradual onset, a slow course, a combination with a xerotomy, dryness of the nasal mucosa, pharynx, stomach, joint syndrome.

Xerophthalmia in Mikulich syndrome

Characterized by a gradual symmetrical increase in lacrimal and salivary glands and a decrease in their secretion. The disease was first described in 1892 by JF Mikulicz-Radecki. The nature of the disease is not known exactly, many consider it as lymphoepithelioma. Characteristic is also an increase in bronchopulmonary lymph nodes.

Syndrome of alacrimia in combination with achalasia of the esophagus and adrenal insufficiency

Symptomatic develops at the age of 1-5 years. The first sign may be the appearance of crying without tears. The disease progresses, later peripheral vegetative neuropathy in combination with pyramidal, cerebellar signs, features of parkinsonism, mild mental retardation can develop. It is assumed that the disease has an autosomal recessive pathway.

Congenital anacrimia in Riley's syndrome - Deia

The syndrome is caused by congenital disorders of predominantly autonomic apparatuses of the peripheral nervous system and is manifested by reduced tearing, violation of thermoregulation, orthostatic hypotension, episodes of severe vomiting. The disease has an autosomal recessive type of inheritance.

Xerophthalmia in acute transient total disautonomy

Reducing the secretion of tears along with other sympathetic and parasympathetic disorders is reversible. The nature of the disease is probably infectious-allergic.

Xerophthalmia in case of facial nerve injury

It is observed with lesion of the facial nerve in the bone channel before the departure of the large stony nerve. Dryness of the eye is noted on the side of paralysis of the facial nerve, combined with a violation of taste and salivation. Reducing the secretion of tears is possible in other forms of nerve fibers that go to the lacrimal gland: with herpetic lesions of the geniculate ganglion, fractures of the base of the skull, when the large stony nerve is damaged, after surgery for trigeminal neuralgia and neuroma of the auditory nerve.

Brief physiology of lacrimation and pathogenesis of its disorders. Like most organs, the lacrimal glands have a double innervation. Segmental parasympathetic innervation is carried out by cells located in the brainstem in the region of the brain bridge near the nucleus of the abduction nerve. These neurons are excited by impulses from the hypothalamic or limbic system, as well as signals from the neuron of the sensory trigeminal nucleus. Preganglionic fibers in the large stony nerve approach the wing-palatine ganglion, posttanglionic fibers in the lacrimal nerve innervate the secretory cells directly. Sympathetic stimulation is performed by the neurons of the lateral horns of the upper thoracic segments of the spinal cord; preganglionic fibers end in the neurons of the upper cervical ganglion (GSH), postganglionic fibers in the circumvascular plexus of the carotid artery reach the salivary gland. Sympathetic fibers innervate mainly the gland vessels and cause vasoconstriction, but can also less stimulate the production of tears.

There are two main mechanisms of lacrimation: violation of outflow of tear fluid and reflex enhancement, and a combination of these mechanisms is possible. An example of increased lacrimation, caused by the difficulty of outflow of tears, is lacrimation in allergic rhinitis, viral infections of the eye, post-traumatic or congenital narrowing of the nasal canal. The paroxysmal epiphore with migraine and bundle headache, combined with nasal congestion, is also associated with temporary obstruction of the tear duct, but the role of sympathetic activation is not excluded. The age-old epiphany is explained by the age-related changes in the protective apparatus of the eyes: a decrease in the tone of the eyelid tissues, which leads to a lag of the lower eyelid from the eyeball, as well as the dislocation of the lower lacrimal point, which worsens the outflow of tears. With parkinsonism, lachrymation can develop along two mechanisms. On the one hand, a rare blinking and hypomia, weakening the suction of the nasolacrimal canal, leads to a difficulty in the outflow of tears; on the other hand, the activation of central cholinergic mechanisms may be important.

Reflex lacrimation accounts for approximately 10% of all cases of epiphora. Most of the reflexes that cause an increase in the secretion of tears are triggered from the eye's receptors, the afferent impulses go along the I branch of the trigeminal nerve. A similar mechanism of lacrimation takes place with cold epiphora, lachrymation with pronounced exophthalmos and vitamin A deficiency. In the latter case, more vulnerable conjunctiva and cornea perceive natural stimuli (air, light) as excessive, which leads to a reflex increase in the secretion of tears.

However, reflex lacrimation is also possible with stimulation of the receptor fields of the second branch of the trigeminal wart (epiphore in ENT diseases - rhinitis, otitis, neoplasms).

Sensation of dry eyes (xerophthalmia)

Can be as in the pathology of the lacrimal gland, and with neurogenic violation of secretion. The pathology of the lacrimal glands causes a decrease in the production of tears in the syndromes of Sjogren and Mikulich. The defeat of peripheral autonomic tear lacrimal fibers explains the ailacrimia in Reiley-Deia syndrome, with acute transient total disautonomy, the syndrome of alacrimia in combination with esophagus achalasia and adrenal insufficiency, facial nerve neuropathies with a level of lesion below the geniculate ganglion, with herpetic lesions of the geniculate ganglion.

Treatment of tearing disorders

Treatment of epiphora depends on the correct cause of lacrimation. With an epi-phore associated with allergic mechanisms, a complex of antiallergic therapy is performed. There are known attempts to treat reflex lachrymation with a novocaine blockade of the lacrimal gland. Lachrymation associated with a violation of the outflow of tear fluid due to various causes (chronic karatoconjunctivitis, congenital narrowing or pathology of the development of tear ducts) is about 80% of cases of epiphora. In these cases, the treatment is mostly operational. Preparations used for conservative correction of lacrimation act on the basis of anticholinergic direct or side effect (anticholinergic and antihistamines, lithium, diazepam, imipramine). With vitamin A deficiency, vitamin A is prescribed for 50 000-100 000 ME.

For various forms of xerophthalmia (alacrimia), not associated with systemic lesions of the glands (as with the syndromes of Sjogren and Mikulich), the most successful is the transplantation of the parotid (stenon) duct into the conjunctival sac followed by radiotherapy of salivary glands to reduce "lachrymation". With Sjogren's syndrome, the main disease is treated, various lacrogenic substances (kinins and direct agonists of postsynaptic receptors) are used: pilocarpine, bromhexine (effective at a daily dose of 48 mg), as well as various compositions of artificial tears.