Center scotoma or bow scotoma

Introduction Visual examination of multiple transient white spot syndrome revealed a dark bow, a dark center or a dark center.

Cause

(1) Causes of the disease

Can be related to viral infections and autoimmune diseases.

(two) pathogenesis

The pathogenesis of this disease is not fully understood. Some people think that the infection factor may be related to its pathogenesis, others believe that infection may be a cause, through the mechanism of tissue damage, antigen exposure, new antigen formation and immune dysfunction, eventually causing autoimmune response, causing multiple dissipative A disease such as white spot syndrome.

an examination

Related inspection

Visual field fundus fluorescein angiography

Most patients complain of sudden loss of vision and flashing sensation, and some patients may have dark spots of vision. The range of vision loss can range from 1.0 to 0.05, but mostly mild to moderate. The anterior segment examination is normal. Many white spotted lesions can be seen in the fundus examination. They are located in the deep layer of the retina and RPE. They are mostly distributed in the posterior pole and the macula near the vascular arch, but do not invade the fovea. The lesions near the equator are few and sparse. Typical lesions are approximately circular, unequal in size, 100-500 m, light in color and blurred in borders, much like photo-condensation spots formed by low-power lasers on the retina. Fine pigment particles are often seen in the central recess. In some cases, the disc boundary is unclear. In the acute phase, there are a few cells in the vitreous. In a few cases, vascular white sheath formation is observed.

In the early stage of fundus fluorescein angiography, clustered strong fluorescent spots corresponding to white spot lesions were observed, and fluorescein staining and optic disc capillary leakage were observed in the later stage. The early stage of indocyanine green angiography did not show abnormalities of choroidal vessels, but no dark spots were observed after 10 minutes of contrast. Lesions that are not easily detectable under ophthalmoscopy and fluorescein angiography are clearly visible at this time. The non-fluorescent spot diameter is larger than the corresponding lesions seen at other examinations, and the optic disc is surrounded by a circular weak fluorescent region.

Visual field examination can be seen in a variety of morphological changes, physiological blind spot expansion is the most common, especially in the case of ICG angiography, the case of ring-shaped weak fluorescence of the optic disc. In addition, a bow-shaped dark spot, a side-center dark spot or a central dark spot can be seen. Electrophysiological examination showed that the amplitude of the a wave and early reaction potential of ERG was decreased, and the level 1 retinal function of multifocal ERG showed focal abnormalities in the early stage of the disease, and the EOG test results were also abnormal.

The majority of MEWDS patients have a relatively short duration. The white lesions in the fundus often disappear within 1 to 2 weeks, and the abnormal expression of fluorescein angiography and electrophysiology can be quickly restored. The visual acuity is restored to the pre-morbid level within 3 to 10 weeks, but the physiological blind spot expansion of the visual field and ICG. An angiographically visible, non-fluorescent dark spot can remain for a relatively long period of time. After the healing of MEWDS, there were no scars in the fundus, only a slight change in RPE pigmentation in the macula, and occasional window-like defects in fluorescein angiography.

The diagnosis of this disease is mainly based on clinical data such as typical fundus manifestations and natural regression of lesions. Fluorescein fundus angiography and indocyanine green angiography are helpful for diagnosis, especially for clinical atypical or disease recurrence. It is more diagnostic. Visual field examinations and electrophysiological examinations provide some information for diagnosis.

Differential diagnosis

Central dark spot enlargement: One of the manifestations of central serous chorioretinopathy is the expansion of the central dark spot. Fluorescein fundus angiography, dot enlargement (also known as ink-dispersion type): expands around the point where the dye leaks.

Expansion of the physiological blind spot: Since the optic nerve of the human eye is in front of the retina, they are collected at a point and connected to the brain through the retina. If the image of an object just falls on this point, it will not be seen, called a blind spot. The disease causing the expansion of the physiological blind spot has pseudo-brain tumors and acute angle-closure glaucoma.

Abnormal flash in front of eyes, increased black spots: pathological floaters are generally caused by serious diseases, which are caused by changes in the structure of the omentum, optic nerve, ciliary body and other structures near the vitreous.

Conjunctival sand surface appearance: The appearance of sputum conjunctival sand 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.

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