EYELIDS AND THEIR DISEASES

Sarcoma is mostly round cell. It grows quickly and it is accom­panied by pains. The prognosis is serious not only for vision but also for the patient's life. The treatment is a surgical removal of the whole orbital content (exenteratio orbitae). After the opera­tion X-ray therapy to prevent the development of recurrences and chemical therapy are administered.

Carcinoma. The original orbital tumours are quite rare. Usual­ly they pass into the orbit from the eyelids, cartilage, and cornea. Metastatic carcinoma of the orbit is mostly observed when there is cancer of the mammary gland or uterus. The treatment is surgi­cal, X-ray and chemical therapy are necessary.

Orbital Manifestations of General Diseases

The orbital manifestations of general diseases are various and are mostly caused by neuroendocrine-humoral dysfunctions in the organism, vessel dysfunctions, pathology of the blood system, etc. The leading sign of the orbital manifestations of general diseases is exophthalmos. Sometimes enophthalmia is observed.

Exophthalmos. A differentiated diagnosis is necessary between exophthalmos in phlegmon, tenonitis and tumours of the orbit. A quiet condition of the eyes and absence of pains are characteristic of exophthalmos which develops when there are dysfunctions of the lipoid and calcium metabolism. X-ray and vasography, and also laboratory examinations allow to specify the origin of exophthal­mos and therefore to reveal the possibilities of its treatment and prognosis.

A reductability (the eye comes into the orbit under the pressure, it reponates), a retraction of the upper eyelid and the extension of the eye-slit (a frightened look, the Dalrimple's symptom), incon­sistency between the motions of the upper eyelid and eyeball in the gaze downwards (a lagging behind the eyelid — the Schtel-vag's symptom), insufficiency of the convergence (the Mebius' symptom) are characteristic of exophthalmos when there is diffuse toxic goiter, and sometimes slight fatiguability of the eyes and lac-rimation.

Malignant exophthalmos. Lately, besides exophthalmos of the Basedow's disease there has been distinguished a special disease called malignant exophthalmos as an independent nosological unit.

The most severe form is progressive malignant exophthalmos. The disease affects mostly the middle-aged people (40-60 years old). Exophthalmos may be unilateral or bilateral. Bilateral exophthal­mos develops rarely, as a rule. The disease is progressive. Sometimes eye-bulging reaches such a stage that arbitrary eyeball dislocation occurs. The pains in the orbital area are sometimes so severe that the patient hardly endures. Diplopia and limitation of the eye mo­tion mostly upwards and outwards are characteristic. Development of the intercurrent conjunctivitis and especially keratitis with a ten­dency to ulceration and destruction of the orbit which is caused not only by lagophthalmia but also by the development of the trophic dysfunctions are characteristic of malignant exophthalmos.

The most characteristic symptom of malignant exophthalmos is oedema of the orbital and periorbital tissues. In the increase of the intraorbital tension the optic nerve changes occur: at first an oede-matous disc and then nerve atrophy develop.

By the opinion of the majority of our country and foreign oph­thalmologists pathogenesis of progressive malignant exophthalmos is associated with an abundant production of the thyroid-stimulat­ing hormone by the anterior hypophysic lobe. Malignant exoph­thalmos can appear after the operation for thyroidectomy. It hap­pens because the thyroid hormone — thyroxine hampers the ac­tion of the thyroid — stimulating hormone of the anterior hypo-physic lobe in the normal conditions.

Treatment of malignant exophthalmos consists of the adminis­tration of the symptomatic and hormonal preparations. In severe cases X-ray therapy of the orbital and hypophysic area is used. Sometimes surgical treatment (decompressive orbital trepanation) is also used.

Pulsating exophthalmos. The disease appears during the rupture of the interior carotid artery in the cavernous sinus. As a result of it blood comes into the sinus and then into the superior orbital vein. In each pulsating wave the eyeball pulsates too; that leads to mi­xing of venous and arterial blood.

The ruptures of the internal carotid artery occur in the fractures of the cranial basis, rarely as a result of other injuries of the ves­sel wall. Sometimes pulsating exophthalmos results from trauma­tic aneurysm of the ophthalmic vessels. The disease begins suddenly with a severe headache and severe tinnitus. The eye-ball bulges and pulsates; pulsation is visible and it is felt on palpation. A systolic murmur is heard, especially over the eye on auscultation. This mur­mur is very troublesome for the patient. A pulsate tumour is formed often from above and inside the eye. The oedematous phenomena are observed rarely in the veins of the conjunctiva, sclera, iris, in­traocular pressure increases, a picture of oedematous optic disc; paralyses of the ophthalmic muscles develop in severe cases.

Treatment is surgical, i.e. ligation of the general carotid artery on the neck. S. S. Golovin proposed a ligation and arterioversion of the superior orbital vein.

EYELIDS AND THEIR DISEASES

Anatomy of the Eyelids

The eyelids are the organ of passive and active protection of the eye. Passive protection consists in that the eyelids always cover a part of the eye, and the whole eye in complete closing. Active pro­tection is accomplished by the eyelids in two directions: first, due to reflex apparatus the eyelids close the eye automatically and instantly in danger; second, the eyelids promote removal of foreign bodies, which have gotten into the eye with the help of their movement.

The eyelids are two skin folds, which edges are connected from the external side forming an acute angle, and from the internal side they form an arched curve before connection.

The space between the upper and lower eyelid is called palpabral fissure; its length is 30 mm on an average in adults, and height is from 10 to 14 mm.

There are four layers in the eyelids: 1) cutaneous; 2) muscular; 3) connective tissue (ciliary cartilage) and 4) mucous.

The eyelid skin is thin. There is no subcutaneous fat. Subcuta­neous fat is porous that makes the eyelid skin very mobile. Oede­ma of the eyelids appearing in various local and some general dis­eases is explained by porosity of the subcutaneous fat.

The circular muscle of the eye (m. orbicularis oculi), which is innervated by the facial nerve (n. facialis), is located immediate­ly under the skin. The muscle is divided into two parts: a palpe­bral part, which is nearer to the free eyelid edge (pars palpebra-lis) and an orbital part, which is nearer to the orbital edges (pars orbitalis).

A contraction of the palpebral part provokes eyelid closing, which is observed, for example, during sleep, and also ensures the blinking movements. A contraction of the orbital part takes place in closing of the eye. When closing the eyelids, the eyeballs are deviated upwards (Bell's phenomenon).

The connective layer is localized under the muscle. The semilu­nar plate is a cartilage, which, however, doesn't correspond to its name, as it consists of not the cartilaginous cells but of compact fibrous connective tissue and occupies its main part. The semilu­nar plates of the upper and lower eyelid are joined with the help of their medial ligament (lig. palpebrale mediale) near the medial angle of the eyelids and near the external angle of the eyelids by the lateral ligament (lig. palpebrale laterale).

The fascia, which stretches to the orbital edges (fascia tarso-orbitalis), is fastened to the convex upper edge of the cartilage. Thus, the cartilage and fascia form a connective septum (septum orbitale), which closes the orbit in front. The muscle (m. levator palpebrale superioris) is fastened to its upper edge. Beginning near the orbital apex from the fibrous ring around the visual foramen, the muscle stretches along the upper orbital wall not reaching its edge; it is fan-like, dilated and divided into three parts. The first (tendinous) part is plaited into the skin and eyelid circular muscle. The second part is fastened to the upper cartilaginous edge. The muscle, which consists of the smooth muscular fibers, is fastened here too; it is called Muller's muscle. The third part is fastened to the conjunctiva of the transitional fold. Such division of the mus­cle fibers lifting the upper eyelid has a great physiological impor­tance, essence of which consists in simultaneous lifting of all eye­lid parts: skin, cartilage and mucosa. The muscle lifting the upper eyelid is innervated by the oculomotor nerve except the Muller's muscle, which is innervated by the sympathetic nerve.

The mucous membrane (conjunctiva) covers the whole posteri­or palpebral surface and anterior surface of the eyeball to the cor­neal edge.

Palpebral edge. There are anterior rounded rib, posterior (right-angle) one, and also intercostal space localized between them on the free palpebral edge. There are 2-3 rows of 100-150 eyelashes on the upper eyelid near the anterior rib and 50-70 eyelashes on the lower one. They are a protective net against foreign bodies and sweat. There are some sebaceous glands (Zaiss' glands) near each eyelash; there are changed sudoral glands between them with ex cretory ducts opening into the hair follicles of the eyelashes. A even row of the punctate foramina is visible somewhat in front o the posterior rib; they are excretory ducts of the meibomian glands. Their secretion greasing the palpebral edges does not permit pour­ing of tears over the edge; it protects the palpebral skin from mac­eration and promotes tight closing of the eyelids and hermetic clos­ing of the conjunctival sac.

Palpebral vessels. Each eyelid is supplied by palpebral arteries: a. palpehralis lateralis (branches of the anterior ethmoidal artery) a. ethmoidalis anterior. A. palpebrals lateralis et medialis are unit­ed, and they form vessels of the arterial marginal arch (arcus tar­seus marginalis): arcus tarseus superior (on the upper eyelid) and arcus tarseus inferior (on the lower eyelid). They are localized in deeply in the eyelids on the posterior surface of the circular mus­cle, in front of cartilage at a distance of 3 mm from the free palpe­bral edge. The shallow sulcus (sulcus subtarsalis) where the small foreign bodies are most often detained corresponds to them on the posterior cartilaginous surface from the conjunctiva side. Branch­es of these arches pass through the cartilage on the conjunctiva, and supply blood to them.

The eyelids have a well developed system of lymphatic vessels. They consist of two nets joined with each other, one of which is localized on the anterior cartilaginous surface, another one — on the posterior one. The lymphatic vessels of the upper eyelid fall into the parotid, and of the lower eyelid — into submaxillary lym­phatic glands.

Date: 2014-12-21; view: 1162