LAGOPHTHALMIA (lagophthalmus; grech, lagoos hare + ophthalmos of eyes; synonym hare eye) — an incomplete smykaniye a century owing to what the palpebral fissure remains constantly open.
Etiology and pathogeny
Most often L. it is caused by paralysis of the facial nerve innervating a circular muscle of an eye, the cut happens to the help a smykaniye a century. L. it is observed, as a rule, at peripheral defeat of a facial nerve owing to otitises, fractures of base of the skull and other diseases. At the central defeat of a facial nerve the circular muscle usually is not involved in process. There is a spastic L much less often., caused by a spasm of the muscle raising an upper eyelid, edges it is innervated by a third cranial nerve, or a spasm of circular fibers of a ciliary muscle (Müller's muscle) which is taking part in a raising of an upper eyelid.
Reasons of L. there can be also inborn shortening a century, cicatricial their ectropion after burns, wounds, sharply expressed exophthalmos at tumors of an orbit and at severe forms of a bazedovy disease.
The palpebral fissure is wider, than usually. In attempt to close eyelids the palpebral fissure remains partially open, in it the bottom of a cornea is visible. The lower eyelid does not prilezhit to an eyeglobe (fig.), the lacrimal opening departs from an eye, and persistent dacryagogue develops. Owing to a nesmykaniye of a palpebral fissure the conjunctiva and a cornea are exposed to external irritations, dry (see. Xerophthalmia ). Conjunctivitis, a trophic keratitis, a keratohelcosis and its opacification can result hron.
At long incurable paralysis of a facial nerve the circular muscle atrophies. It is shown by thinning a century, especially lower, the edge to-rogo departs from an eye even more that strengthens dacryagogue.
Diagnosis the wedge, signs is put on the basis.
Treatment of paralysis of a facial nerve is carried out by the neuropathologist. For protection of an eye from drying and infection let in drops a conjunctival cavity or put the ointments containing streptocides and antibiotics. At a cicatricial ectropion the century is made by operations for its elimination. In case of resistant L. partial sewing up of a palpebral fissure is shown (see. Blepharorrhaphy ). The considerable otstoyaniye of a lower eyelid from an eyeglobe is also corrected by means of operation — carry out through all length of a century (from internal to outside commissure) a ligature from synthetics or a strip from an autofastion of a hip.
L., connected with acute neuritis of a facial nerve, can completely pass. At resistant L. operational treatment quite often eliminates it and prevents development of a dystrophic keratitis.
See also Eyelids .
Bibliography: Zaykova M. V. Plastic surgeries in ophthalmology, M., 1969, bibliogr.; Callahan A. Surgery of eye diseases, the lane with English, M., 1963; Colin A. A. The guide to plastic surgery in an eye, M., 1950; The Multivolume guide to eye diseases, under the editorship of V. N. Arkhangelsky, t. 2, book 1, page 32, M., 1960; The Guide to eye surgery, under the editorship of M. L. Krasnov, M., 1976.
V. S. Belyaev.