Conjunctiva study
Last reviewed: 23.04.2024
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Conjunctiva is easily accessible for research and diagnosis of many of its diseases, does not require any special equipment.
When examining the conjunctiva, it is necessary to pay attention to its color, transparency, gloss, surface condition, the presence of films, scars and detachable. Normal conjunctiva has a pink coloration, smooth, shiny and transparent (through it the meibomian glands shine in the form of yellowish stripes parallel to each other and perpendicular to the edge of the eyelid).
With inflammation of the conjunctiva ( conjunctivitis ), it acquires a rich bright red color and loses its transparency due to the fact that its tissue swells (the meibomian glands are indistinguishable). The surface of the conjunctiva becomes rough and velvety due to the fact that the papilla invisible to the naked eye in the normal conjunctiva swell and increase; develop lymphatic follicles, having the form of grayish-yellow nodules. Sometimes a conjunctiva forms a film (with diphtheria and some acute conjunctivitis ). With some diseases ( trachoma, diphtheria, burns, etc.) on the conjunctiva appear scars - from minor superficial to coarse and extensive scars of silvery-white color. As a result of scarring, the conjunctiva wrinkles and shortens, especially in the area of transitional folds. The conjunctiva of the sclera during inflammation also loses its luster and transparency. On the eyeball, it is necessary to distinguish between surface vessels and deep ones; Thus, here it is possible to observe the expansion of both surface vessels - conjunctival injection, hook and deep vessels in the limb of the cornea - pericorneal, or ciliary, injection. Two types of these injections are very important to distinguish in a diagnostic manner. Superficial injection, or conjunctival, indicates a lesion of the connective membrane, while deep ciliary. Or pericorneal, the injection contributes to the defeat of the horn and vascular membranes.
With conjunctival injection, the conjunctiva is bright red; The dilated vessels are displaced along with the conjunctiva. Pericorneal injection is expressed mainly around the cornea; it refers to the deeper vessels lying in the surface layers of the sclera; this hyperemia has a lilac or purple hue, and in this case the dilated vessels with conjunctiva are not displaced.
If there is one or the other injection, we are talking about a mixed injection.
It is necessary to pay attention to the presence of a detachable conjunctiva, which can be mucous, mucopurulent and purely purulent. If the amount of detachable is small, clumps on the conjunctiva are found, especially in the transitional folds, as well as in the corners of the eyes; with a large amount of detachable flows down through the edge of the eyelid, falls on the cheeks, glues together eyelashes and eyelids. In the presence of a detachable, bacteriological studies are performed to find out the nature of the pathogenic microorganisms - investigate the smear or do sowing on various nutrient media.
The clinical symptoms of common conjunctival diseases are so typical, and the medical measures are so simple that recognition and treatment do not present difficulties for a doctor not a specialist. Under the supervision of the doctor and the average medical workers can cure conjunctival diseases.
[Laboratory studies of conjunctiva
Indications
- Severe purulent conjunctivitis: identify infectious agents and prescribe adequate antimicrobial therapy based on the sensitivity of the infectious agent.
- Follicular conjunctivitis: differentiate the viral from early chlamydial infection.
- Conjunctival inflammation, the clinical picture of which is not typical enough to accurately assume etiologic diseases.
- Conjunctivitis of newborns.
Special studies of conjunctiva
- Studies of tissue culture are now performed rarely, as they have been replaced by more accurate and rapid methods.
- Cytological research based on the detection of typical cellular infiltrates is insensitive and subjective.
- Sowing sensitive cell lines and observing the cytopathic effect or visualization with various chemicals and immunological staining methods.
- Detection of viral or chlamydial antigens in conjunctival and corneal preparations.
- Impression cytology: cellulose acetate filter paper is pressed against the conjunctiva or cornea, the surface epithelial cells adhere to the paper, then they are examined. It helps in the diagnosis of ocular surface neoplasia, "dry eye", ocular cicatricial pemphigus, damage to limbal stem cells and infections.
- The polymerase chain reaction allows us to quickly identify an extremely small amount of DNA with a very high degree of specificity. The reaction is used to detect adenovirus, herpes simplex virus and Chlamydia trachomatis in conjunctival smears.