Heterochromic iridocyclitis

Introduction to heterochromic iridocyclitis Heterochromic iridocyclitis (Fuchs's syndrome) is a chronic non-granulomatous iridocyclitis involving the monocular. The disease is concealed, inflammation is mild, and there is often a diffuse distribution of the cornea or a distribution of the pupil area. Star KP, iris depigmentation and other changes, prone to complicated cataract and secondary glaucoma. basic knowledge The proportion of sickness: 0.01% Susceptible people: no special people Mode of infection: non-infectious Complications: cataract Glaucoma

Heterochromic iridocyclitis

(1) Causes of the disease

The cause is unknown.

(two) pathogenesis

It is not clear that there are mainly the following views:

1. Abnormal developmental mechanism: Fuchs had speculated that during the fetal period or at the beginning of birth, there were some factors that inhibited the normal development of the uveal membrane, resulting in iris eclipse. Later on this basis, under the influence of unknown pathological factors, it caused continuous Very mild inflammation, gradual KP, aqueous humor, vitreous opacity, iris atrophy, followed by lens metabolism disorder or difficulty in aqueous drainage, complicated cataract or secondary glaucoma.

2. Neurological factors: Many scholars have observed the relationship between HI and Horner syndrome, Parry-Romberg syndrome and animal experiments (resection of one side of the sympathetic nerve), and concluded that HI and the sympathetic nerve pathway in the eye are blocked. It induces trophic defects, which are related to the inhibition of melanin particle formation. At the same time, this factor can also enhance iris vascular permeability and consequent protein leakage, aqueous humor turbidity and release of inflammatory mediators.

3. Genetic factors: Very few cases have a family history, but the probability is very low, which is not enough to prove the heritability of HI. However, compared with the normal population, there is no difference in HLA-A or B antigen distribution, and HLA-CW3, HLA The frequency of -DRw53 is lower than normal, suggesting that genetic factors associated with HLA may play a role.

4. Immune factors: There are plasma cells in the aqueous humor of patients with HI, lymphocytes, inflammation may be caused by immune response, Francois and other applications of electrophoresis first found that the level of aqueous humor gamma globulin is relatively elevated, after Dernouchrnps confirmed by relative concentration method 80 There are IgG in the aqueous humor of the disease, and the level of soluble IL-2 receptor in the peripheral blood is elevated, which indicates that there is systemic lymphocyte activation in HI patients. In addition, about 90% of patients have autoantibodies to the corneal epithelium, and 70% of the patients have corneas. The antigen (mainly 54kD) has a cellular immune response that is not only significantly higher than the healthy control group, but also higher than other types of uveitis. It is also thought to react with circulating immune complexes, alpha lens protein antigens or certain pathogenic microorganisms (tuberculosis, Streptococcus, Toxoplasma) is associated with infectious immunity, etc., and various immunological studies have shown that the immune system is involved in the pathogenesis and development of HI.

Heterochromic iridocyclitis prevention

There is no effective preventive measure for this disease. Early detection and early diagnosis are the key to the prevention and treatment of this disease.

Heterochromic iridocyclitis complications Complications cataract glaucoma

Concurrent cataract is the most common complication of HI, almost 100%, occurring in the late stage of the disease, starting under the posterior capsule of the lens and spreading rapidly to the entire cortex. The opacity is light brown, the same as other chronic uveitis complicated with cataract, no Specificity, secondary open-angle glaucoma can occur in some cases, and the cause of elevated intraocular pressure is still unclear. Fuchs himself believes that the protein concentration in aqueous humor increases, and the flow outside aqueous humor decreases. There are other doctrines, summarized as follows:

1 trabecular mesh inflammation or hardening;

2Sehlemm tube shrinks or collapses;

3 iris corneal angle neovascularization;

4 adhesion before the end of the iris;

5 lens capsule wall dissolution and exfoliation;

6 long-term use of glucocorticoids eye and so on.

Heterochromic iridocyclitis symptoms Common symptoms Iris blue iris heterochromic pupil size varies from nodular ciliary congestion

Because the patient has no other symptoms other than the visual acuity before the complications appear, it is easy to be ignored, so the actual onset time may be far lower than the age of the visit.

HI has a long course, mild inflammation, slow and undulating, even if KP is present, there is no ciliary congestion (very few exceptions), KP is characteristic, white is relatively transparent small dots or stellate, diffuse distribution, between KP There is no fusion, sometimes there are fiber-like filaments connected, and the filaments tend to ooze out for a long time. KP can disappear on its own and repeat again. The Tynddall phenomenon is mostly negative, a few weak positives, and individual positives.

For example, in contrast to healthy eyes, the iris color of the diseased eye is shallower than that of the healthy eye. This characteristic change is caused by the atrophy of the anterior boundary layer of the iris, the stromal layer and the pigment epithelium. In addition to the Uyghurs in China, the iris is mostly present. Light brown to dark brown, mildly heterochromatic is not easy to identify, severely has a velvety appearance, occasional vascular exposure, iris atrophy begins in the front boundary layer, and then the stromal layer, and finally the pigment epithelial layer, using a slit lamp strong beam When the pupil is injected into the back of the iris and there is worm-like light transmission on the iris surface, it indicates that the pigment epithelial layer has also collapsed.

At the beginning of the course of the disease, the pupil is smaller than the healthy side, and there are often irregularities in the later stage, suggesting that the pupil sphincter damage, Koeppe nodules, Busacca nodules can also be encountered, but no post-iris adhesions.

HI enhances the vascular permeability of the iris ciliary body or the formation of new blood vessels, and the blood-aqueous barrier is destroyed. For example, intravenous injection of sodium fluorescein is performed by slit lamp microscope plus cobalt blue filter, and iris fluorescence leakage is observed. No perfusion area.

The iris cornea angle is open, occasionally seeing tiny blood vessels, whether new blood vessels, not yet conclusive, some people in the anterior chamber puncture, found that most cases of iris corneal corneal bleeding, bleeding completely absorbed within 24h, leaving no trace, and then The puncture is followed by bleeding, which is called the Amsler sign and is considered to be one of the HI features.

In some cases, the choroid is involved, and the vitreous is grayish-white fine-pointed or membrane-like opacity, which is an indication of choroidal inflammation. Franceschett believes that choroidal damage is a kind of degeneration rather than inflammation. Kimura suggested that peripheral chorioretinal lesions are rare. The parts are concealed and are easily missed during inspection.

Examination of heterochromic iridocyclitis

1. Aqueous cell count and elevated gamma globulin levels: elevated levels of soluble IL-2 receptors in peripheral blood, systemic lymphocyte activation in patients with HI, and levels of circulating immune complexes (CIC).

2. Pathological examination: In the HI iris specimen, lymphocytes, plasma cell infiltration and Russell bodies (crystals that are deposited on the surface of the iris) have been found under light microscopy. The examination also has the same result. Occasionally, a small amount of mast cells, tissue cells, large particle mononuclear cells, eosinophils, such cells can also be freed in the aqueous humor, and all layers of the iris are atrophied and involve all cells, such as Fibroblast-like cells, melanocytes, smooth muscle cells, epithelial cells, in the anterior border layer and stromal layer, melanocytes not only decrease in number, but also change in morphology, are round, lose dendrites, and contain melanosomes that become small. Irregular, the number is significantly rare, in addition to the reduction of epithelial cells in the pigment epithelium, the melanosome is not too abnormal, in addition to atrophy in the stromal layer, there is diffuse fibrotic changes, this change also involves the pupil sphincter, making it change Thin hardening, electron microscopy, numerous isolated mitochondria in fibroblast-like cells and melanocytes in the matrix, indicating the beginning of the atrophy process Endoplasmic reticulum, iris vascular wall with hyaline degeneration and luminal stenosis, also endothelial cell hyperplasia, iris nerve found in the pupil open large intramuscular axon and Schwann cells reduced, or see iris unmyelinated nerve fibers Many degenerative changes, all of the above iris specimens were taken from the iris or removed eyeball after the late complications, no matter what light microscopy or electron microscopy, no different from other types of chronic iridocyclitis, HI Early histological changes are still unclear, so it has been difficult to identify them from a histological perspective so far.

Slit lamp examination revealed characteristic KP, anterior chamber flash, iris depigmentation nodules, but no post-iris adhesion.

3. Fluorescein angiography abnormality: Fluorescein angiography of the patient can be found in the affected eye with significant iris vascular leakage, mainly in the iris vessels near the pupil, near the neovascularization, fluorescein leakage is more Prominent, in addition, there are also found filling defects and perfusion delay, suggesting the presence of ischemia, these ischemic areas often accompanied by new blood vessels, in some patients' contralateral eyes, also found fluorescein leakage at the pupillary margin, but no newborn In the vascular and fan-shaped ischemic areas, some authors have performed this test on other types of patients with chronic anterior uveitis and found these results. Therefore, these angiographic changes are not unique to Fuchs syndrome.

4. Abnormal angle of the anterior chamber: The angle of the patient's anterior chamber is generally open and wide-angled. However, the angle of the anterior chamber is sometimes seen with abnormal blood vessels at the proximal corner. Some people think that these blood vessels are newly formed blood vessels. They are weaker than normal blood vessels. Causes Amsler linear hemorrhage, but the increase of anterior chamber vascular is not a constant manifestation of this disease, but also can be seen in other diseases. It is not yet certain whether these blood vessels are indeed pathological, sometimes in the corner of patients with Fuchs syndrome. The scattered peripheral anterior adhesion can be seen, and undifferentiated tissue or transparent membrane is observed, but there is no abnormal pigmentation and exudation. The abnormality of the angle of the anterior chamber is not related to the occurrence and severity of glaucoma.

5. Ultrasound biomicroscopy: The ciliary body can be found, and the basal line of the vitreous body oozes back to the sound and shadow.

Diagnosis and differentiation of heterochromic iridocyclitis

The diagnosis is mainly based on the following clinical features:

1 The vast majority of monocular morbidity, the course of the disease is long and undulating, the visual acuity is not affected before the complications occur;

2 The iris color of the diseased eye is shallower than the healthy side;

3 There is obvious characteristic KP, Tyndall phenomenon is negative or weakly positive, no ciliary congestion or minimal white eye, no pain, irritating symptoms such as photophobia;

4 diffuse iris atrophy;

5 no post-iris adhesions.

HI is identified with the following diseases:

1. Irregularity of iris caused by sympathetic damage: Sympathetic damage can decolorize the iris, which has been confirmed by animal experiments, such as Horner syndrome, Parry-Romberg syndrome, and Horner syndrome except for monocular iris In addition to signs of iridoscopic ciliary body inflammation, there are signs of ptosis, eyeball invagination, dilated pupils, signs of sweating on the side of the skin, and signs of sympathetic damage (trauma, surgery, Pancoast mass, aorta) Tumor, internal carotid artery thrombosis, etc., is generally easy to discriminate; Parry-Romberg syndrome is rare, also monocular, ocular lesions are basically the same as HI except KP, and can be identified from the side of the affected side with or without muscle atrophy.

2. Simple iris heterochromia: abnormal iris development, no inflammation, more eyes.

3. Other causes of diffuse iris atrophy caused by chronic iridocyclitis can be seen in pigment KP, anterior lens pigmentation, and post-iris adhesion.

4. HI with secondary glaucoma should be differentiated from glaucomatocyclitic crises syndrome, both of which are secondary open angle glaucoma, but the latter KP is round, larger, in the cornea After the triangle distribution, there is no filament-like connection between KP, and the iris has no color.

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