Anterior chamber pigmentation

Introduction Anterior chamber pigmentation is mainly seen in the melanoma of the eye, usually the ciliary body and choroid. Can also be seen in the expansion of cataract secondary to glaucoma. Generally with the anterior chamber hemorrhage, anterior chamber empyema appears together. It is the most common primary intracranial malignancy in adults. Occurs in 40 to 60 years old, unilateral onset. 85% occur in the choroid, 9% in the ciliary body, and 6% in the iris.

Cause

(1) Causes of the disease

It is still unclear and may be related to race, family and endocrine factors. Of the 3706 cases of uveal melanoma that were followed up for 17 years, 16 cases (0.4%) were pregnant women, aged around 30 years old, all of which were found in the second half of pregnancy. The relationship between the onset and pregnancy and endocrine is uncertain. Genetic factors: Singh conducted a family survey of 4,500 patients with uveal melanoma and found that there were 56 families with 56 patients with this disease and 0.6% with a family history. Other factors: sun exposure, certain viral infections, exposure to certain carcinogenic chemicals may be related to the onset of the disease.

(two) pathogenesis

Most tumors originate in the choroidal macrovascular layer. Regarding the origin of tumor cells, it is generally believed that there are two possibilities, one from the ciliary nerve sheath cells, namely Schwann cells; the other from the stromal melanoblast, which is commonly referred to as the pigment. Carry a small cell (chromatophore). The incidence of the former is high, accounting for about 4/5 of all uveal malignant melanoma, while the latter is only 1/5. Under the action of tumorigenic factors, malignant transformation of melanocytes in the choroid leads to the formation of tumor-like nodules.

an examination

Related inspection

Visual field examination of maxillofacial five-dimensional CT examination of intraocular pressure

In addition to detailed medical history and clinical symptoms, detailed clinical examinations, especially ophthalmoscopy can be used as a basis for diagnosis, and the following must be noted.

1. Early tumor: Some cases may have visual distortion and discoloration. The number of farsightedness in individual cases continues to increase, suggesting that the posterior choroid has a space-occupying lesion, and the retina is moved forward.

2. Visual field examination: The visual field defect of malignant melanoma is larger than the actual area of the tumor. The blue visual field defect is larger than the red visual field defect.

3. Anterior segment examination: Corneal sensation in the vicinity of choroidal melanoma can be reduced. The adjacent sclera and iris vessels can expand. The iris can be combined with iris sputum, iris neovascularization, and pupillary pigment valgus. When the tumor is necrotic, it may be combined with iridocyclitis, anterior chamber empyema, anterior chamber pigmentation, and anterior chamber hemorrhage.

4. Scleral transillumination: The diagnostic value of scleral transillumination is not reliable. For example, hemorrhage under the retinal pigment epithelial layer can also cover the light, and the tumor with a small volume or a small cystic pigment can also see through the light.

5. FFA comprehensive analysis of the early, venous and advanced stages of angiography, attention to the differentiation of choroidal hemangioma and choroidal metastasis.

6. Ultrasound exploration: A solid image of the tumor can be detected. It is more valuable when the refractive interstitial opacity ophthalmoscope cannot be examined, or if there is severe retinal detachment and the tumor is covered by it. However, small tumors with an area of <2 mm2 and a degree of elevation <1.5 mm are sometimes difficult to detect.

7. CT scan and magnetic resonance imaging (MRI): CT scan shows the thickening of the eye ring, protruding into the ball or outside the ball. In the enhanced examination, the tumor blood vessels are rich, the blood-retinal barrier is destroyed, and the vortex vein is involved and strengthens. However, similar to ultrasound exploration, regardless of CT scan or magnetic resonance, one is not qualitative, and the other is limited for small tumors.

8. Intraocular pressure: Different from the location, size and various complications of the tumor, the intraocular pressure can be normal, reduced or increased. The anterior choroidal melanoma is compressed by the lens and iris, which can close the corner of the anterior chamber to produce secondary glaucoma. Tumor necrosis, macrophage phagocytic cells, pigment particles or necrotic debris, etc., are released into the anterior chamber resulting in an increase in intraocular pressure. It can also cause an increase in intraocular pressure caused by neovascular glaucoma or anterior chamber hemorrhage due to iris neovascularization.

9. Total physical examination: Because choroidal malignant melanoma is most likely to transfer to the liver via blood circulation, liver ultrasound exploration and liver scintigraphy can check for tumor metastasis. Similarly, chest X-ray or CT scans are also necessary.

Differential diagnosis

Pseudo anterior chamber empyema: anterior chamber empyema caused by intraocular tumors, also known as pseudo anterior chamber empyema, because its clinical manifestations resemble endophthalmitis, also known as camouflage syndrome.

Hemiplegia in the anterior chamber: After the eyeball injury, the vascular permeability of the iris increases or the blood vessels rupture due to rupture of the blood vessels, and the blood accumulates in the anterior chamber called the traumatic anterior chamber. Traumatic anterior chamber hemorrhage is more common in eyeball contusion, which is a common complication. Domestic statistics account for 11.3% of outpatient eyeball contusions and 39.8% of inpatients. Lighter ones can heal themselves, most of them can be completed in about 6 days. Absorption, visual recovery, but a large number of bleeding or repeated secondary anterior chamber blood, secondary glaucoma and corneal blood stains can cause blindness.

Anterior chamber empyema: This disease is characterized by acute onset, obvious eye irritation, grayish yellow or yellowish white infiltration or ulceration of the cornea. There is iritis in the early anterior chamber, and the reaction develops in a severe stage, which is a yellow-white suppurative ulcer, which often spreads to one side. Each anterior chamber has an empyema ulcer, and the base matrix may have abscess formation. The main symptoms may have a tingling or a burning sensation of foreign body sensation, mixed conjunctival conjunctiva, and severe edema ulcer.

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