Optic nerve disease

Introduction to optic nerve disease The optic nerve refers to the visual circuit from the optic disc to the optic chiasm. It is divided into the inner segment of the ball, the inner segment of the ankle, the inner segment of the bone tube and the intracranial segment. The optic nerve is surrounded by a three-layer sheath. The three layers of the sheath are continuous with the dura mater and arachnoid in the cranium. The three layers of the sheath and the wall of the eye fuse together in the posterior sphere to form a blind tube. The gap is in communication with the intracranial subdural space and the subarachnoid space, and the cavity is filled with cerebrospinal fluid. Therefore, when the intracranial pressure is increased, the intracavitary pressure is also increased, which constitutes the basis of optic disc edema. The outermost layer of the sheath is rich in sensory nerves. Therefore, when the optic nerve is inflamed, there is pain when turning or pressing the eyeball. The incidence of optic nerve is closely related to its structural characteristics: there are abundant capillary network around the optic nerve fiber bundle, so the optic nerve fiber can cause inflammation and poisoning under the action of infection and toxic substances. The central blood vessel of the retina enters the eye through the optic nerve. Due to the increase of intra-orbital mass or intracranial pressure, the axoplasmic flow in the ganglion cell axon in front of the scleral sieve plate is blocked, resulting in obvious swelling of the axon, leading to papilledema; when the intraocular pressure is increased, Cause glaucoma papillary depression and atrophy. basic knowledge The proportion of sickness: 0.0031% Susceptible people: no special people Mode of infection: non-infectious Complications: optic atrophy

Cause of optic nerve disease

There are three common causes of optic nerve disease: inflammation, vascular disease, and tumors. Middle-aged and elderly patients first consider vascular disease, and young people should consider inflammation and demyelinating diseases.

The optic nerve is actually a bundle of nerve fibers of the central nervous system, an extension of the white matter of the brain, composed of axons of retinal ganglion cells. Anatomically divided into the inner segment of the eye, the inner segment of the ankle, the inner segment of the optic canal, and the intracranial segment. The front end of the inner segment of the eye is the optic disc, visible under the ophthalmoscope. After the eyeballs, the nerve fibers are surrounded by myelin, while the pia mater, arachnoid and dura contain the optic nerve. The subarachnoid space is continuous with the subarachnoid space of the brain. The dura mater continues with the outer layer of the meninges of the brain, so central nervous system diseases often affect the optic nerve.

The incidence of optic nerve is closely related to its structural characteristics: there are abundant capillary network around the optic nerve fiber bundle, so the optic nerve fiber can cause inflammation and poisoning under the action of infection and toxic substances. The central blood vessel of the retina enters the eye through the optic nerve. Due to the increase of intra-orbital mass or intracranial pressure, the axoplasmic flow in the ganglion cell axon in front of the scleral sieve plate is blocked, resulting in obvious swelling of the axon, leading to papilledema; when the intraocular pressure is increased, Cause glaucoma papillary depression and atrophy.

The transmission of visual information depends on the optic nerve. The incidence of optic nerve disease is high. Common are: papillitis, retrobulbar optic neuritis, papilledema, optic nerve anterior ischemic papillary disease and optic atrophy. Depending on the nature of the cause, vision is affected to varying degrees. If the cause can be eliminated more quickly, the function of the optic nerve can be completely or partially restored, and vision can be restored to normal or part of it. If the cause cannot be removed, the optic nerve will be affected for a long time, which will eventually lead to optic atrophy, severe vision loss, or even complete blindness.

Optic nerve disease prevention

1. Eat more foods containing vitamins.

2. Take care to protect your eyes.

Optic neuropathy complications Complications optic atrophy

If the cause cannot be removed, the optic nerve will be affected for a long time, which will eventually lead to optic atrophy, severe vision loss, or even complete blindness.

Symptoms of optic nerve disease Common symptoms Visual impairment Eyelid pain Eyelid foreign body

Specifically, it can be divided into:

First, optic neuritis: refers to the inflammation, metamorphosis and demyelination of the optic nerve. Due to different lesions, it is divided into papillary inflammation and retrobulbar optic neuritis. The former is more common in children, and the latter is more common in young adults. Mostly unilateral. It manifests as a sharp drop in vision, a sense of flash, eyelid pain, especially when the eyeball turns. About half of children with optic neuritis are suffering from both eyes, and the onset is acute, but the prognosis is good, and the rate of binocular involvement in adult optic neuritis is low.

2. Anterior ischemic optic neuropathy: ischemia occurs in the small branch of the posterior ciliary vasculature supplying the anterior region of the optic disc and the sieve plate area, resulting in local infarction in the supply area. It is a group of syndromes characterized by sudden vision loss, optic disc edema, and characteristic visual field defects (fan-shaped defects associated with physiological blind spots). The posterior ischemic optic neuropathy is mostly confirmed by lack of pathology, so it is not described.

Third, optic atrophy: refers to any disease caused by retinal ganglion cells and their axon lesions (between the retina to the lateral geniculate body) caused by axonal degeneration. Clinically, it is mainly divided into two major categories: primary and secondary. The disease should actively treat the primary disease.

Fourth, optic nerve tumors: rare, clinical manifestations of eyeballs and vision gradually decline. There are two types of optic glioma and optic nerve meningioma. The former is more common in children under 10 years old; adults are rare, and those who occur in adults are mostly malignant. The latter is more common in adults over the age of 30, more women than men, although benign tumors, but easy to relapse; and most children are malignant. Optic nerve tumors can be surgically removed. Tumors that occur on the optic disc are rare, such as papillary hemangioma and melanoma. The former may be the ocular manifestation of vonHippel-Lindau disease; the latter is a black mass on the optic disc, which develops very slowly, is a benign tumor, and has no significant effect on visual function.

Examination of optic nerve disease

Except for the optic disc lesions can be examined by ophthalmoscopy, the rest of the optic nerve can not be directly viewed. Therefore, the diagnosis of optic nerve disease must be based on medical history, vision, visual field, pupil, dark adaptation, color vision, etc., and with the help of VEP, FFA, eyelids and skull X-ray, CT, B-ultrasound, MRI and other detection methods. Among them, the visual field is the most important for positioning diagnosis.

Diagnostic identification of optic nerve disease

diagnosis

Diagnosis can be based on medical history, clinical symptoms, and laboratory tests.

Differential diagnosis

Optic neuritis, anterior ischemic optic neuropathy, optic atrophy were identified.

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