Anatomy physiology pathology of the organs of

«Anatomy, physiology, pathology of the organs of hearing and vision and speech» для специальности 5 В 010500 – «Дефектология»

Theme 4: Pathology of an organ of vision Plan of lecture: 1. Anomalies of eyelids (blepharon, palpebra) 2. Pathology of a connecting cover of an eye (conjunctivitis) 3. Trachoma. 4. Strabismus 6. Scleritis 7. Crystalline lens pathology 8. Glaucoma

1. Anomalies of eyelids (blepharon, palpebra) Аt adults At children's congenital inflammatory tumoral

on emergence acquired local and system by the form skin inflammatory muscular dystrophic ferruterous congenital local and system on localization tumoral diseases of edge of eyelids post-traumatic

on an etiology: on a current: infectious sharp allergic subsharp fungal chronic

Cryptophthalmos is a rare congenital anomaly in which the skin is continuous over the eyeball with absence of eyelids. It is classified into three types: complete, incomplete and abortive. Failure of eyelid separation can be associated with maldevelopment of the underlying cornea and microphthalmia. Cryptophthalmos usually occurs on both sides and occurs in association with other multiple malformations collectively referred to as Fraser syndrome.

Cryptophthalmos

Epicanthic fold, epicanthal fold, epicanthus, or simply eye fold are names for a skin fold of the upper eyelid, covering the inner corner (medial canthus) of the eye. Other names for this trait include plica palpebronasalis and palpebronasal fold.

Epicanthic fold, epicanthal fold One of the primary facial features often closely associated with the epicanthic fold is the nasal bridge; all else equal, a lower-rooted nose bridge is more likely to cause epicanthic folds, and a higher-rooted nose bridge is less likely to do so. There are various factors that influence whether someone has epicanthic folds, including geographical ancestry, age, and certain medical conditions.

Ptosis (Ptosis "Blepharoptosis", to "fall") is a drooping or falling of the upper eyelid. The drooping may be worse after being awake longer, when the individual's muscles are tired. This condition is sometimes called "lazy eye", but that term normally refers to amblyopia. If severe enough and left untreated, the drooping eyelid can cause other conditions, such as amblyopia or astigmatism. This is why it is especially important for this disorder to be treated in children at a young age, before it can interfere with vision development.

Myogenic ptosis Aponeurotic ptosis Neurogenic ptosis Ptosis Mechanical ptosis Neurotoxic ptosis Pseudo ptosis

2. Pathology of a connecting cover of an eye (conjunctivitis) Conjunctivitis is an inflammation of the external mucous membrane (conjunctiva) and the most common cause for visiting an ophthalmologist. According to various data, this disorder accounts for 20– 30% of all ocular pathology.

The occurrence of these disorders depends on the season and the climatic/geographical zone. Conjunctivitis affects children of different ages and its causes are varied. More often there are conjunctivitis cases of bacterial, viral, and allergic genesis. In the past, there were mostly bacterial cases of conjunctivitis (mainly of staphylococcus origin), whereas today there is a trend towards a greater nuber of viral and allergic cases of conjunctivitis. In spite of the great variety of root causes, the clinical picture of conjunctivitis displays a number of common features: reddening and edema of the conjunctiva with discharges. The disorder often causes a burning pain, itching, feeling of a foreign body ("sand") in the eye, photophobia, watering and eyelid spasms.

Causes of conjunctivitis Conjunctivitis is an inflammation of the external mucous membrane (conjunctiva) and the most common cause for visiting an ophthalmologist. According to various data, this disorder accounts for 20– 30% of all ocular pathology. In spite of the great variety of root causes, the clinical picture of conjunctivitis displays a number of common features: reddening and edema of the conjunctiva with discharges. The disorder often causes a burning pain, itching, feeling of a foreign body ("sand") in the eye, photophobia, watering and eyelid spasms.

Conjunctivitis Viral conjunctivitis Herpetic conjunctivitis is usually unilateral, has acute beginning and prolonged and often complicated clinical course. Adenoviral conjunctivitis raises the temperature of the body, swells the lymph nodes and causes inflammation of the pharyngonasal cavity. Bacterial conjunctivitis Pneumococcus Streptococcus Staphylococcus Diphtheria Acute epidemic (Kokh-Whiks) Gonoblenorrhea, etc. The main manifestations of conjunctivitis are photophobia, feeling of a foreign body ("sand") in the eye, watering and mucopurulent discharge. Quite often local manifestations of the disease are accompanied with general symptoms of coryza with fever, headache, Allergic conjunctivitis The main symptoms are strong itching, pain in the eyes, edema of the pupils Alimentary conjunctivitis (food) Seasonal conjunctivitis Helminthic (parasitic) Allergic infectious Spring catarrh

Treatment for conjunctivitis The treatment for conjunctivitis is mainly through local administration: eye drops or special medications. General treatment is rarely practiced and mainly done in the case if the cornea of weakened children is involved in the disorder; but even this is not always the case. Antibiotics are not recommended because the pathogen develops immunity to the drug and the drug may cause allergy. General treatment is applied to combat accompanying general diseases. In case of viral conjunctivitis, general treatment is seldom applied and only in the form of antivirals.

3. Trachoma, also called granular conjunctivitis, Egyptian ophthalmia, and blinding trachoma is an infectious disease caused by the bacterium Chlamydia trachomatis. The infection causes a roughening of the inner surface of the eyelids. This roughening can lead to pain in the eyes, breakdown of the outer surface or cornea of the eyes, and possibly to blindness. The bacteria that cause the disease can be spread by both direct and indirect contact with an affected person's eyes or nose. Indirect contact includes through clothing or flies that have come into contact with an affected person's eyes or nose. Many infections are usually needed over a period of years before scarring of the eyelid becomes so great the eyelashes begin to rub against the eye. Children spread the disease more often than adults. Poor sanitation, crowded living conditions, and not enough clean water and toilets also increase spread.

Нas an incubation period of 5 to 12 days, after which the affected individual experiences symptoms of conjunctivitis, or irritation similar to "pink eye. The conjunctival inflammation is called “active trachoma” and usually is seen in children, especially pre-school children. It is characterized by white lumps in the undersurface of the upper eyelid (conjunctival follicles or lymphoid germinal centres) and by non-specific inflammation and thickening often associated with papillae. Follicles may also appear at the junction of the cornea and the sclera (limbal follicles). Active trachoma will often be irritating and have a watery discharge. Bacterial secondary infection may occur and cause a purulent discharge.

Mc. Callan's classification Mc. Callan in 1908 divided the clinical course of trachoma into 4 stages Stage 1 (Incipient trachoma) Stage 2 (Established trachoma) Hyperaemia of Appearance of palpebral mature follicle & conjunctiva papillae Immature follicle Progressive corneal pannus Stage 3 (Cicatrising trachoma) Stage 4 (Healed trachoma) Scarring of palpebral conjunctiva Disease is cured or is not markable Scars are easily Sequelae to visible as white cicatrisation cause bands symptoms

Treatment Efforts to prevent the disease include improving access to clean water and decreasing the number of people infected by treatment with antibiotics. This may include treating, all at once, whole groups of people in whom the disease is known to be common. Washing by itself is not enough to prevent disease but may be useful with other measures. Treatment options include oral azithromycin or topical tetracycline. Azithromycin is preferred because it can be used as a single oral dose. After scarring of the eyelid has occurred surgery may be required to correct the position of the eyelashes and prevent blindness.

4. Strabismus (heterotropia) means disruption in the position of one or both eyes during which looking forward results in the deviation. With the symmetric position of the eyes, the image of objects falls on the central sections of the retina of both eyes. The cortical sections of the visual analyzer merge the two images into a single binocular picture. In case of strabismus, this merging does not occur. In order to prevent ghosting vision the central nervous system blocks the image coming from the squinting eye. The lengthy existence of this state leads to amblyopia (a functional and reversible reduction of vision during which one of the eyes is not involved partly or fully in the vision process).

Causes for development of strabismus Strabismus may be caused by numerous factors of an inherent or acquired nature: the existence of ametropia (hyperopia, myopia, astigmatism) of a moderate or high degree stress infectious diseases (measles, scarlet fever, diphtheria, flu, etc. ); traumas; psychic traumas (fright) diseases of the central nervous system; somatic diseases paralysis and paresis anomalies in the development and attachment of eye muscles sharp reduction of vision acuity of one eye

Type of strabismus in terms of its nature Specialists differentiate two forms of strabismus: conjugated paralytic

The following types of strabismus are also identified (In terms of type of deviation) : converging squint (often combined with far sight) when the eye is directed at the bridge of the nose diverging squint (often combined with short sight) when the eye is directed at the temple vertical squint (in cases when the eye is turned up or down)

Strabismus may be classified on the basis of several criteria In terms of time of its occurrence: inherent acquired In terms of deviation stability: permanent variable

Treatment for strabismus may comprise: optical correction (glasses, soft contact lens); stimulation of vision acuity of both eyes (treatment of amblyopia) with the help of instrumental procedures; orthoptic and diploptic treatment (development of binocular vision); consolidation of monocular and binocular functions; surgical treatment.