Trachoma

Trachoma introduction Trachoma is a chronic contagious conjunctival keratitis caused by Chlamydia. It has a rough and uneven appearance on the surface of the palpebral conjunctiva. It is shaped like sand, so it is called trachoma, and the conjunctiva is infiltrated in the early stage of the disease. Such as nipple, follicular hyperplasia, corneal vasospasm at the same time, late due to the involvement of the affected sacral conjunctiva scar, resulting in eyelid varus deformity, aggravating corneal damage, can seriously affect vision and even cause blindness. The incubation period is 5-14 days, and the eyes are sick, mostly in children or adolescence. basic knowledge The proportion of illness: 1% Susceptible people: no special people Mode of infection: contact spread Complications: trichiasis, lacrimal duct obstruction, chronic dacryocystitis

Trachoma

Cause

It is a chronic infectious disease caused by Chlamydia trachomatis infection.

Trachoma prevention

Develop good hygiene practices. Do not rub your hands, towels, handkerchiefs should be washed and dried; nurseries, schools, factories and other collective units should be divided into basins or running water to wash the face, the treatment of trachoma patients should be actively treated, strengthen the hairdressing room, bathroom, hotel and other service industries Hygiene management, strict disinfection system such as towels and washbasins, and pay attention to clean water.

Adjust daily life and workload, conduct activities and exercise regularly, avoid fatigue, maintain emotional stability, and avoid emotional excitement and tension.

Trachoma complication Complications, eyelids, obstruction, chronic dacryocystitis

varus and trichiasis, trachoma corneal ulcer, ptosis, trachoma dryness, lacrimal duct obstruction and chronic dacryocystitis.

Trachoma symptoms common symptoms eye pain ear lymph nodes swelling tear bacterial infection repeated infections yellow white small corneal ulcer conjunctival congestion center dark point or bow dark point photophobia

The incubation period is 5 to 14 days. The eyes are sick, mostly in children or in a small period. Light trachoma can be completely free of symptoms or only slight itching, foreign body sensation and small amount of secretions. In severe cases, the cornea is affected by sequelae and complications. There are irritating symptoms such as fear of light, tears, pain, and conscious vision loss.

Chlamydia trachomatis mainly invades the conjunctiva and ends with scar formation. The characteristics of the examination are as follows:

1, blood and blood vessel blurred: due to vasodilatation, diffuse lymphocytes and plasma cells under the conjunctival epithelium infiltrated with chronic inflammatory cells, making the transparent conjunctiva become turbid and hypertrophic, the blood vessels are unclear, showing a fuzzy congestion.

2, nipple hypertrophy: , , , ,

3, filter hyperplasia: the conjunctival subepithelial tissue on the basis of diffuse infiltration, by the accumulation of localized lymphocytes, at the initial onset, the upper conjunctiva appears scattered fine yellow-white dots, not prominent on the surface of the conjunctiva, Inclusion between the hypertrophied nipples is one of the early diagnosis of trachoma.

4, corneal vasospasm: in the conjunctival lesions, at the same time, the upper half of the corneal gray area of the corneal vascular network is congested, new blood vessels occur, extending into the transparent corneal epithelium and the front elastic layer, accompanied by new blood vessels Gray-white spotted infiltration is a kind of tissue reaction of corneal epithelium to Chlamydia trachomatis, which is called corneal vasospasm. It is one of the basis for early diagnosis of trachoma. As the disease progresses, the vasospasm hangs down to the pupil area, which resembles a drape. When the upper vasospasm falls over the pupil area, the other side of the cornea also grows out of the vasculature to the center, covering the entire cornea. When the cell is infiltrated seriously, it can form a fat-like vasospasm (pannus crassus), which is seriously affected. vision.

5, scar formation: When trachoma is carried out for several years or even decades, all inflammatory lesions such as follicles, nipples, will be ulcerated or necrotic, and gradually replaced by connective tissue, forming scars, which indicates that the lesion has entered retreat period.

The course of trachoma, due to the severity of infection and repeated infections, light or no recurrent infection, the number of months can be more, the conjunctiva left thin or no obvious scars, repeated infection, the course can be lingering for years to decades as long as.

The incubation period is about 5 to 12 days, usually invading the eyes, mostly in children and adolescents.

1, symptoms

Mostly acute, the patient has foreign body sensation, photophobia, tearing, many mucus or mucous secretions, after a few weeks, the acute symptoms subsided, entering the chronic phase, at this time without any discomfort or only eye fatigue, such as this When cured or self-healing, there is no scar, but in the chronic disease, in the epidemic areas, there are often repeated infections, the disease is aggravated, and there are active vasospasm on the cornea, the irritation symptoms become significant, vision loss, late sequelae Such as varus, trichiasis, corneal ulcers and dry eyes, the symptoms are more obvious, and seriously affect vision, and even blindness.

2, signs

(1) Acute trachoma: showing acute follicular conjunctivitis symptoms, redness and swelling, conjunctival hyperemia, rough and uneven conjunctiva due to papillary hyperplasia, conjunctival follicles in the upper and lower iliac crest, combined with diffuse corneal epithelial inflammation and pre-auricular lymphadenopathy, number After the week, the acute inflammation subsided and turned into a chronic phase.

(2) Chronic trachoma: due to repeated infections, the course of disease is prolonged for several years to more than ten years. Although the degree of congestion is reduced, there is diffuse cell infiltration with subcutaneous tissue, conjunctival stains, hypertrophy, nipple hyperplasia and follicular formation, and follicle size. Inconsistent, can be glued, the lesion above the dome and the palpebral conjunctiva is prominent, the same lesion is also seen in the lower conjunctiva and the lower condylar conjunctiva, severe cases can even invade the semi-month wall, corneal vasospasm: it is from the limbus The external normal capillary network enters the clear cornea beyond the limbus, affects vision, and gradually develops into the pupil area, accompanied by cell infiltration and development into shallow small ulcers. After healing, corneal facets can be formed, and when cell infiltration is severe, it can form. Hypertrophic meat-like vasospasm (pannus crassus).

In the chronic course, the lesion of the conjunctiva is gradually replaced by connective tissue, forming a scar, which first appeared in the inferior sulcus of the upper conjunctiva, showing horizontal white streaks, which gradually became reticulate afterwards, and the active lesions completely disappeared. The conjunctiva is all white smooth scars.

The course and prognosis of trachoma, because of the severity of infection and whether it is repeated infection, light or no recurrent infection, can be more than a few months, the conjunctiva left thin or no obvious scars, severe cases of repeated infection, the course of disease can be lingering for several years For more than a decade, chronic diseases can be acutely attacked by other bacteria and repeated infections. In the end, extensive scarring is no longer contagious, but there are serious complications and sequelae, often causing vision loss or even blindness.

In order to prevent trachoma and the needs of investigation and research, there are many clinical staging methods for trachoma. When we discussed the second ophthalmology conference in China in 1979, we redefined the staging of trachoma:

Stage I - the period of implementation: the active period, the nipple and the follicle coexist at the same time, the superficial conjunctival tissue of the upper iliac crest is unclear, and there is corneal vasospasm.

Stage II - Degenerative period: From the onset of scarring to the majority of scars, only a few active lesions remain.

Stage III - complete scarring period: active lesions completely disappeared, replaced by scars, no contagious.

At the same time, the grading standard was also established: according to the active lesions (nipples and follicles), the total area of the upper conjunctiva is divided into light (+), medium (++), and heavy (+++) grades. Those with 1/3 area or less are (+), those with 1/3 to 2/3 are (++), and those with 2/3 or more are (+++).

And the classification method of corneal vasospasm was determined: the cornea was divided into four equal parts, the invasive vasospasm was within 1/4 (+), and the 1/4 to 1/2 was (++), reaching 1/ 3 to 3/4 are (+++), and more than 3/4 are (++++).

1. Normal blood vessels do not invade the clear cornea 2, vasospasm (+)

3, vasospasm (++) 4, vasospasm (+++) 5, vasospasm (++++)

The more common in the world is the MacCallan staging method:

Stage I - Invasion: The conjunctiva and the conjunctiva of the iliac crest are hypertrophied, especially at the top, and may have early follicles and early corneal vasospasm.

Stage II - active period: There are obvious active lesions, namely nipple, follicle and corneal vasospasm.

Stage III - Pre-scarring period: the same as China's second period.

Stage IV - complete crusting period: same as China's third period.

Trachoma inspection

Pathogenic detection

(1) Smear detection of chlamydial inclusion bodies: In recent years, Papanicolaon staining has been reported to detect Chlamydia trachomatis inclusion bodies with a sensitivity of 83%. The method is simple and is the most commonly used screening method, which can be used for screening high-risk groups.

(2) Cell culture method: It is considered to be the gold standard for detecting Chlamydia trachomatis, but it is time consuming and requires certain equipment technical conditions, which is difficult to be used as a routine clinical detection method.

2. Molecular biology methods

In situ hybridization was used to detect Chlamydia trachomatis DNA in cervical or rectal biopsy specimens. It can also be detected by PCR, which can significantly improve the detection sensitivity, and can be used to identify its species and serotype. It can be used for diagnosis, efficacy judgment and epidemiological investigation. The detection rate of this method is higher than other methods. Hot start PCR (HSPCR) has also been reported to significantly reduce non-specific amplification and reduce false positive reactions.

Trachoma diagnosis

diagnosis

Typical trachoma, clinically based on sacral conjunctiva with nipple and follicular hyperplasia, corneal vasospasm and conjunctival scars, easier to diagnose. There are certain difficulties in the diagnosis of early trachoma. Sometimes it can only be initially diagnosed as "suspected trachoma." According to the decision of the Ophthalmology Branch of the Chinese Medical Association in 1979, the diagnosis of trachoma was based on: 1 the conjunctival vascular congestion of the upper iliac crest and the upper epithelium, nipple hyperplasia or follicular formation, or both. 2 Check the corneal vasospasm with a magnifying glass or slit lamp. 3 Scars appeared in the upper iliac crest or / and the upper conjunctiva. 4 Conjunctival scrapings have trachoma inclusions. On the basis of the first item, one of the other three items can diagnose trachoma.

Suspected trachoma: Conjunctival hyperemia of the upper palate and palate, a small number of nipples (nipple is normal tissue) hyperplasia or follicles, and other conjunctivitis have been ruled out.

Differential diagnosis

1. Conjunctival folliculosis is common in children, both of which are bilateral and have no symptoms. Follicles are more common in the lower iliac crest and the lower conjunctiva. The follicles are small, the size is evenly similar, translucent, the boundary is clear, the conjunctiva between the follicles is normal, no congestion, no corneal vasospasm, no scars. The trachoma follicles are more common in the upper iliac crest and the upper conjunctiva. The opacity is unclear, the size is not uniform, the arrangement is not neat, and there are symptoms such as conjunctival hyperemia and hypertrophy.

2. Chronic follicular conjunctivitis (chronic follicular conjunctivitis) is common in school-age children and adolescents, all of which are lateral, and B. granulosis may be the cause. There are often secretions in the morning, and the eyes have discomfort. Follicles are more common in the lower iliac crest and lower conjunctiva, uniform size, neatly arranged; conjunctiva is congested, but not hypertrophic; self-healing after 1 to 2 years, no scar formation; no corneal vasospasm.

3. Vernal conjunctivitis This disease is seasonal, the main symptom is itching. The nipple on the conjunctiva is large, flat and hard, and the upper iliac crest has no lesions and is easy to identify. Eosinophilia is seen in the secretion smear.

4. Inclusion conjunctivitis Adults and neonatal inclusion body conjunctivitis can be seen in the conjunctival scrapings, the morphology of which is the same as the trachoma inclusions, difficult to distinguish. However, allogeneic conjunctivitis begins with an acute start. The follicles are all below the iliac crest and the lower conjunctiva. There is no corneal vasospasm. It can heal itself in a few months to one year. It does not form scars and can be distinguished from trachoma.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.