Yellow and white dots on upper eyelid

Introduction One of the symptoms of trachoma is that the conjunctival subepithelial tissue is formed by the accumulation of lymphocytes on the basis of diffuse infiltration. At the initial onset, the upper conjunctiva appears scattered with fine yellowish white dots. Trachoma is a chronic contagious conjunctival keratitis caused by Chlamydia trachomatis. In the early stage of the disease, the conjunctiva is infiltrated such as nipple and follicular hyperplasia, and corneal vasospasm occurs at the same time. In the late stage, the conjunctiva of the affected sac is scarred, resulting in varus deformity. Aggravation of corneal damage can seriously affect vision and even cause blindness.

Cause

(1) Causes of the disease

The research on trachoma pathogens has a long history. In 1907, Halbestaedter and Prowazek used optical microscopy and Giemsa staining to find inclusion bodies in the conjunctival epithelial cells of the trachoma, that is, red-blue protoplasts and dark blue precursor particles in the epithelial cells. The inclusion body has a matrix, which is surrounded by a coat and is mistakenly called "chlamydozoa". Since then, there have been many studies. However, the pathogen of trachoma was not isolated for the first time in 1955 by the method of chicken embryo culture in China, such as Tang Feifan and Zhang Xiaolou. Since this pathogen can pass through a bacterial filter, parasitizes into cells, and forms inclusion bodies, it was considered a virus at that time. Because it is different in size and shape from the general virus, it is called atypical or large virus, similar to the large virus of parrot fever and lymphogranuloma. Since then, scholars from various countries have further studied its molecular biology and metabolic functions, and proved that it has RNA, DNA and certain enzymes, which are multi-divided, have cell membranes and walls, and are sensitive to bacteria. These are not compatible with viruses. The nature, and there are many similarities with Gram-negative bacteria. Therefore, the "Bergey Bacterial Identification Manual" published in 1974 has set a new name for this type of microorganism, called chlamydia. Chlamydia trachomatis is one of them.

Chlamydia trachomatis can be classified into 12 types, such as A, B, C, Ba, D, E, F, G, H, I, J, K, etc. from antigenicity. Trachoma in popular areas is caused by type A, B, C and Ba, and other types cause genitourinary infection and inclusion body conjunctivitis. Some authors said that the former group was the epidemic Chlamydia trachomatis group, and the latter group was the ocular and genital urinary chlamydia group. Chlamydia trachomatis has two biological phases in its life cycle, the original and the original. The elementary body is the infectious phase, about 0.3 m in size, has a cell wall, and can survive outside the cell. The initial body, also known as the reticulate body, is a reproductive phase with a large volume of about 0.8 m and is non-infectious. After the protoplast invades the host cell, it develops into a primordial body and transforms into a progenitor, forming a progeny progeny in a two-dividing manner. When the cytoplasm is filled, it ruptures to release the original body, and the free protoplasts invade the normal epithelial cells to start a new cycle. Each cycle is approximately 48h.

(two) pathogenesis

Chlamydia trachomatis easily invades columnar epithelial cells such as urethra, endocervix, endometrium, fallopian tube epithelium, eye, nasopharyngeal and rectal mucosa and causes lesions, does not invade the vaginal squamous epithelium, so it only parasitizes the vagina after infection but does not cause Vaginitis. In general, the body's reaction is mild and often asymptomatic and there is no acute phase in the clinic. In addition to the lesions caused by chlamydia itself, the body's immune response is also involved in the pathogenesis. LPS on the chlamydial membrane can induce the body's immune response, and its metabolites can also cause the body's allergic reaction, but the pathogen can parasitize into the cells to escape immune defense. Pathogens continue to infect and multiply in cells, and continue to infect new cells, causing repeated infections in the human body. In acute infection, the local is mainly a neutral multinucleated cell reaction, and chronic or reinfection causes a monocyte reaction. Long-term repeated inflammatory lesions, combined with the body's immune response, can lead to scar formation.

an examination

Related inspection

External examination of Chlamydia trachomatis Chlamydia trachomatis antibody

The incubation period is 5 to 14 days, and 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. The severe cases involve the cornea due to sequelae and complications, and there are irritating symptoms such as light, tearing, pain, and conscious vision loss.

Chlamydia trachomatis mainly invades the palpebral conjunctiva and ends up with scar formation. The characteristics of the inspection 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: is the conjunctival subepithelial tissue on the basis of diffuse infiltration, formed by confined lymphocytes. At the initial onset, the upper conjunctiva appears scattered in the fine yellow-white dots, not prominent on the surface of the conjunctiva, and is intermingled between the hypertrophic nipples, which 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 tissue reaction of the corneal epithelium on Chlamydia trachomatis, 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 passes down the pupil area, the other parts of the cornea also grow out of the vasospasm to the center, spreading the entire cornea. When the cells are infiltrated severely, hypertrophic meaty vasospasm can form. (pannus crassus), seriously affecting vision.

5, scar formation: When trachoma for several years or even decades, all inflammatory lesions such as follicles, nipples, will occur ulceration or necrosis, and gradually replaced by connective tissue, forming scars, which indicates that the lesion has entered the regression period. The course of trachoma varies depending on the severity of the infection and whether it is repeated infection. Light or no recurrent infection, the number of months can be more, the conjunctiva remains thin or no obvious scars. Repeated infections can last for years to decades.

The incubation period is about 5 to 12 days. Usually infringe on both eyes. It occurs mostly in children and adolescents.

1, symptoms

Mostly acute, the patient has foreign body sensation, photophobia, tearing, and many mucus or mucous secretions. After a few weeks, the acute symptoms subsided and entered the chronic phase. At this time, there was no discomfort or only the eyes were prone to fatigue. If you heal or heal at this time, you can leave no scars. However, in the chronic disease, in the endemic areas, there are often repeated infections, and the condition is aggravated. When there is active vasospasm on the cornea, the irritation becomes significant and vision is reduced. Late stage is often due to sequelae, such as varus, trichiasis, corneal ulcers and dry eye, etc., the symptoms are more obvious, and seriously affect vision, and even blindness.

2, signs

(1) Acute trachoma: presented with acute follicular conjunctivitis symptoms, redness and swelling of the conjunctiva, hypertrophy of the conjunctiva due to hypertrophy of the nipple, hyperplasia of the conjunctiva of the nipple, and conjunctival follicles of the upper and lower iliac crest, combined with diffuse corneal epithelial inflammation and swollen lymph nodes. After a few weeks, the acute inflammation subsided and turned into a chronic phase.

(2) Chronic trachoma: It can be delayed for several years to more than ten years due to repeated infections. Although the degree of congestion is reduced, there is diffuse cell infiltration with subcutaneous tissue, conjunctival stains, hypertrophy, nipple hyperplasia and follicular formation (Figure 1), follicular size varies, can be gelatinous, lesions above the dome and seesaw The upper edge of the conjunctiva is significant. The same lesions are also seen in the conjunctiva of the lower jaw and the conjunctiva of the inferior temporal tract. In severe cases, it can even invade the half-month wall. Corneal vasospasm: it is a normal capillary network outside the limbus. It passes through the corneal edge and enters the clear cornea, affecting vision, and gradually develops into the pupil area. It is accompanied by cell infiltration and develops into a shallow small ulcer. After healing, the cornea can be formed. Facet. When cells infiltrate severely, hypertrophic meat-like vasospasm (pannus crassus) can form. In the chronic course, conjunctival lesions are gradually replaced by connective tissue, forming scars. It first appeared in the lower sulcus of the upper sacral conjunctiva, showing horizontal white streaks, and gradually became reticular, and the active lesions completely disappeared, and the lesions and conjunctiva all became white smooth scars.

The course and prognosis of trachoma are different depending on the severity of the infection and whether it is repeated infection. Light or no recurrent infection, the number of months can be more, the conjunctiva remains thin or no obvious scars. In severe cases of repeated infections, the course of disease can be entangled for several years to more than ten years. In chronic diseases, it can be acutely attacked by other bacteria and repeated infections. In the end, widespread scarring is no longer contagious, but there are serious complications and sequelae that often cause vision loss or even blindness. In order to prevent trachoma and research needs, there are many clinical staging methods for trachoma. At the time of the second national ophthalmology conference in 1979, China redefined the staging of trachoma:

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

Stage II - Degenerative period: from scarring to scarring. Only a few active lesions remain.

Stage III - complete crusting period: active lesions completely disappeared, replaced by scars, non-infectious.

At the same time, the classification criteria were also established: according to the active lesions (nipples and follicles), the total area of the upper conjunctiva was divided into light (+), medium (++), and heavy (+++) grades. Those who account for less than 1/3 of the area are (+), those who account for 1/3 to 2/3 are (++), and those who account for 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 (++++).

Corneal vasospasm

1, normal blood vessels do not invade the transparent cornea

2, vasospasm (+)

3, vasospasm (++)

4, vasospasm (+++)

5, vasospasm (++++)

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

Stage I - early infiltration: Conjunctival and conjunctival conjunctival hyperemia, especially at the top, may have initial 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: the same as China's third period.

Differential diagnosis

The huge nipple of the palpebral conjunctiva: The nipple hyperplasia of the palpebral conjunctiva caused by diseases such as keratoconjunctivitis in spring, which is the giant nipple of the conjunctiva, is one of the clinical manifestations of spring conjunctivitis. Spring keratoconjunctivitis, also known as spring catarrhal conjunctivitis, seasonal conjunctivitis. Pre-puberty onset, lasts 5-10 years, mostly for both eyes, the incidence of boys is higher than girls. The disease has a high incidence in the Middle East and Africa, low incidence in temperate regions, and almost no cases in cold regions. The incidence rate in spring and summer is higher than that in autumn and winter. The more accurate name for vernal conjunctivitis is vernal keratoconjunctivitis (VKC), a bilateral chronic external eye disease in which atopic individuals can respond to antigens prevalent in the environment. The main atopic diseases include eczema, asthma and urticaria. VKC mainly affects children and young adults, and is most common in spring, so it is called "spring" conjunctivitis. The affected patients are mainly characterized by external eye diseases, and the main symptoms are itching, tearing, shame and sticky secretions. The disease is "self-limiting." Currently available drugs have topical glucocorticoids and mast cell stabilizers. Spring keratitis is a recurrent conjunctivitis that is often affected by both eyes and can damage the corneal surface.

The hard and flat nipple of the conjunctiva: due to the clinical manifestations of catarrhal conjunctivitis in the spring, the conjunctival hyperemia is very dramatic at the beginning, and then many hard and flat nipples occur in the upper conjunctiva, varying in size. It is covered with pebbles on the conjunctiva. The crack between the nipples is light blue, and the surface of the nipple presents a milky turbidity. There are not many secretions, it is very sticky, and it is drawn into a filament. For smear examination, it can be seen that eosinophils increase. If there is a lesion in the conjunctiva of the lower jaw, the nipple is small and small, and it is not as prominent as the conjunctiva. Spring vernal conjunctivitis is an allergic disease with a strong seasonality and often invades both eyes. Whenever the spring blossoms, the symptoms disappear and the symptoms disappear when the cold is late in the autumn. Recurrence every year, mild cases will not be issued after 3 to 4 years, severe cases can continue to relapse for more than 10 years. The disease is characterized by itchy eyes, large and flat nipples and conjunctival hyperplasia near the limbus, and a large number of eosinophils in the secretion.

Conjunctival sand appearance: It is one of the symptoms of trachoma. Trachoma is a chronic contagious conjunctival keratitis caused by Chlamydia and is one of the blinding diseases. Because it forms a rough and uneven appearance on the surface of the palpebral conjunctiva, it is shaped like sand, hence the name trachoma. In the early stage of the disease, the conjunctiva is infiltrated such as nipple and follicular hyperplasia, and corneal vasospasm occurs at the same time. In the late stage, the scar of the conjunctiva is affected, resulting in varus deformity and aggravation of corneal damage, which may seriously affect vision and even cause blindness. The incubation period is 5 to 14 days, and 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. The severe cases involve the cornea due to sequelae and complications, and there are irritating symptoms such as light, tearing, pain, and conscious vision loss.

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