The Diseases of the Palpebral Muscle
Lagophthalmos, a "hare's" eye, is incomplete closing of the eye provoked by paralysis of the facial nerve (n. facialis), which innervates the circular palpebral muscle. In this disease the eye is more or less open, and it waters; when attempting to close the eyelids the palpebral fissure remains open. Keratitis, ulceration of the cornea can develop due to it. Ectropion of the lower eyelid lead to lacrimation and conjunctivitis.
Besides the paralysis of the facial nerve lagophthalmos can bd caused by congenital shortening of the eyelids, cicatrical ectropion of them, considerable diverticulum of the eye, for example, in the orbital tumors, the Basedow's disease. Loss of consciousness in patients in a severe condition may be also accompanied by lagophthalmos.
Treatment. Besides treatment of paralysis of the facial nerve, it is necessary to protect the eye from outward influences; application of ointments with antibiotics and vitamins is recommended for this. The eyelids should be sutured together in stable lagophthalmos to avoid affection of the cornea.
Ptosis is lowering of the upper eyelid can be congenital and acquired, partial (1/3 is covered), incomplete (1/2 is covered) and complete (the whole eyeball is covered).
Congenital ptosis is usually bilateral and depends on insufficient development of the muscle raising the upper eyelid.
Acquired ptosis depends mainly on paralysis of the muscle rising the upper eyelid, and frequently it is combined with paralysis of another muscles innervated by the oculomotor nerve. The acquired ptosis can be isolated that indicates its central origin (nuclear paralysis).
As the smooth Muller's muscle innervated by the sympathetic nerve takes part in rising of the eyelid ptosis may develop in paralysis of the sympathetic nerve (ptosis sympalhica).
In these cases retraction of the eyeball into the orbital depth (enophlhalmos) and contraction of the pupil (miosis) are observed simultaneously with ptosis. This triad is named the Horner's syndrome (ptosis, miosis, enophthalmos); it is evidence of paralysis of the cervical sympathetic nerve.
Treatment. In congenital ptosis and when the acquired ptosis is not treated conservatively, surgical operation is indicated. The most popular operation is shortening of the levator.
Congenital Anomalies of the Eyelids
Congenital ptosis has been already said above.
Coloboma. This disease often affects the upper eyelid, and it is a triangular defect in the middle part. Quite often a "hare's" lip and palatal fissure are observed in it.
Treatment. Restoration of coloboma edges and their suture. The plastic operation is indicated in great defects.
Epicanthus. Epicanthus is a skin fold on ridge of the nose, due t0 jt the internal angle of the eye and internal part of the palpebral fissure are closed by a semilunar skin fold.
Treatment. Plastic operation gives good results.
Ankyloblepharon is adhesion of the palpebral edges along their length or in separate places. Complication is amblyopia of obscure origin.
Treatment is surgical.