What Is the Optic Nerve?

The optic nerve originates from the ganglion cell layer of the retina. It is originated from the fiber on the nasal side of the retina. After the optic cross, it is combined with the fiber on the temporal side of the retina on the opposite eyeball to form the optic bundle. After the neuron replacement, fibers are emitted through the posterior limb of the inner capsule to form optic radiation, which terminates in the central cortex of the wedge gyrus and lingual gyrus on both sides of the occipital lobe, that is, the striatum. The fibers of the macula are projected to the rear of the striated area, and the fibers of the retinal region are projected to the front of the striated area. The path of light reflection does not pass through the lateral geniculate body, and the optic beam passes through the superior thalamus into the midbrain and is associated with the oculomotor nucleus. The examination includes vision, color vision, visual field and fundus examination. ^[1]

Optic nerve is retinal

Optic nerve is

Optic nerve profile

Optic neuropathy mainly includes diseases such as optic neuritis, optic nerve atrophy, ischemic optic disc disease, and optic nipple edema. It is more common in the clinic, more difficult to treat, and the cause is more complicated. Although it is a lesion of the fundus optic nerve, it is closely related to the entire body. Many fundus lesions develop on the basis of systemic lesions. "Nei Jing" cloud: "The essence of the five internal organs and the six internal organs are all focused on the eyes and become fine." The reason why the eyes can be seen is the result of the internal organ infusion of internal organs. Contact with the body as a whole. Of the twelve meridian and eight odd meridians of the human body, there are thirteen meridians that use the eye area as the passing and closing place, respectively. Therefore, the disorders of the viscera and meridians are the main elements of the fundus and optic neuropathy. Such diseases cannot be treated with surgery, and modern medicine has no special effect. Traditional Chinese medicine law, which uses internal governance as its main method, has a wide range of adaptability, especially the treatment method based on dialectical treatment, which has its great advantages.

The human body is a complex moving body. There are many forms of movement, both physiologically and pathologically. Traditional Chinese medicine's "different diseases with the same treatment" and "different diseases with the same treatment" are based on pathological exercise forms. For different tissues and organs, as long as the pathological movement is the same, the same method can be used for treatment, otherwise different treatment methods must be used. Because the optic nerve and retina are high-level neural tissues and are part of the brain's outward extension, nutritional disorders are most likely to occur, causing pathological changes in the necrosis and degeneration of cellular tissues. In the treatment of these diseases, western medicine mostly uses antibiotics, hormones, vitamins, and vasodilators, but many patients have poor efficacy or recurrent episodes. Traditional Chinese medicine is based on the principles of righting and eliminating evils to achieve the effect of both symptoms and symptoms.

Optic nerve clinical manifestations

1. Visual impairment is the most common and most important clinical manifestation. In the initial stage, there is often pain and swelling in the posterior orbit, blurred vision, followed by aggravation of symptoms, which significantly reduces or loses vision. ^[3]

Optic nerve

2. Visual field defects can be divided into two types:

a. Bitemporal hemianopia: If the fibers that are transmitted to the nasal retinal vision from both sides of the nerve due to tumor compression are involved, it cannot accept bilateral light stimulation and bilateral hemianopia occurs. As the tumor grows, one side is completely blind due to the weight loss on one side, the other side is temporally blind, and the last two sides are completely blind. ^[3]

b. Isotropic hemianopia: Damage to the optic tract or lateral geniculate posterior pathway can produce visual field defects on one side of the nose and the other on the other side, called isohemia. The visual beam is different from the central hemianopia. The former is accompanied by the disappearance of light reflection, and the latter has a light reflection; the former is complete, while the latter is more incomplete. It is quadrant hemianopia; the subjective sensory symptoms of the former are more significant than the latter, and the latter are more There was no subjective symptoms; the latter had central vision and was preserved in macular avoidance. ^[3]

Optic nerve differential diagnosis

I. vision loss or loss

(1) Craniocerebralinjury When the skull base fracture passes through the sphenoid bone process or the fracture piece to damage the internal carotid artery, internal carotid artery-cavernous sinus fistula can be produced, which is manifested as continuous noise of the head or orbit, pulsatile Eyeball protrusion, limited eye movement and progressive vision loss. According to a clear history of trauma, the clinical diagnosis of X-ray film with skull base fracture and cerebral angiography is not difficult.

Optic nerve damage

(B) Optic neuromyelitis (opticnearomyelitis) may have a history of upper respiratory tract infection from a few days to two weeks. It can start with ocular or spinal symptoms, or both. Usually one eye is affected first, and the other eye develops within hours to weeks. Vision loss generally develops quickly, with a central dark spot, and occasionally developing almost completely blind. The lesion of the eye can be optic papillitis or retrobulbar optic neuritis. If the former is about to appear papillary edema, if the latter is normal papillae. Symptoms of myelitis occur after the symptoms of the eye, and the first symptoms are mostly back or shoulder pain, which radiates to the upper arm or chest. Immediate paresthesias of the lower limbs and abdomen followed by progressive lower limb weakness and urinary retention. Although the tendon reflexes were initially weakened, the diaphragmatic reflexes were still bilaterally stretched. Sensory loss abnormally to or to the mid thorax. Peripheral blood leukocytes increased and erythrocyte sedimentation increased slightly.

(3) Multiple sclerosis usually develops between the ages of 20 and 40, with various clinical manifestations. It can be the first episode of vision loss, and it is manifested as monocular (and sometimes binocular) vision loss. Fundus examination showed changes in optic papillitis. Cerebellar sign, pyramidal sign, and posterior dysfunction are common. Deep reflection is hyperactive, shallow reflection disappears, and krypton reflection elongation. When the ataxia, interstructural disorder, and intentional tremor appear at the same time, the so-called charcot triad is formed. Remission and recurrence occur alternately in patients with a typical course of the disease. Evoked potential, CT or MRI can find some demyelinating lesions without clinical manifestations, increased cerebrospinal fluid immunoglobulin, protein upper limit or slightly higher.

(4) Optic neuritis (opticneuritis) can be divided into two types of optic papillitis and posterior optic neuritis. The main manifestations are rapid vision loss or blindness, eye pain, central dark spots in the visual field, enlarged physiological blind spots, dilated pupils, direct photoreaction disappeared, and cross-sensitivity reactions were present, mostly unilateral. Papillitis has changes in the papillae, its edges are unclear, red, veins are full or curled, and there may be small pieces of bleeding, and the papillae rises significantly. Optic papillitis is very similar to visual papillary edema. The former has characteristics such as early rapid vision loss, photophobia, pain in the eyeballs, dark spots in the center, and height of the visual papilla less than diopters, which is easy to distinguish from the latter. Posterior optic neuritis is similar to optic papillitis, but ignores nipple changes.

(5) Optic nerve atrophy (opticatrophy) is divided into two kinds of primary and secondary. The main symptoms are vision loss, pale nipples, and disappearance of pupils' light reflection. Primary optic nerve atrophy is caused by optic nerve, optic cross or optic bundle blocking visual conduction due to tumor, inflammation, injury, poisoning, vascular disease and other reasons. Secondary optic nerve atrophy is caused by edema of the optic papilla, caused by papillitis and retrobulbar optic neuritis.

(6) Acute ischemic optic neuron disease (acuteischemicopticnearitis) refers to vision loss caused by optic nerve infarction, sudden onset, and vision loss often reaches a peak immediately. The degree of vision loss depends on the distribution of the infarct. Fundus examination may have papilledema and linear hemorrhage around the nipple. Often secondary to erythrocytosis, migraine, gastrointestinal bleeding, cerebral arteritis and diabetes, more often hypertension and arteriosclerosis. It is easier to make a clinical diagnosis based on the primary disease and sharp vision loss.

(VII) Chronic alcoholism (chronicalcoholism) vision loss is subacute, accompanied by symptoms of alcoholism, such as slurred speech, walking instability and ataxia, and severe mental disorders may occur.

(8) Intracranial tumor (see visual field defect)

Visual field defect

(A) double temporal hemianopia

1, pituitary tumor (pituitaryadenoma) early pituitary tumors often without visual field of vision. If the tumor grows and stretches upward to compress the optic cross, a visual field defect will occur, and the outer upper quadrant will be affected first, and the red visual field will appear first. At this time, when the patient is walking on the road, it is easy to hit a pedestrian or an obstacle on the roadside. Later, when the lesions increase and the compression is severe, the white field of vision is also affected, and it gradually becomes blind to the double temporal side. If it is not treated in time, the visual field defect can be enlarged again, and the vision is also reduced, so that it is completely blind. In addition to changes in visual field of vision, pituitary tumors are most commonly endocrine symptoms, such as adenomas of growth hormone cells, clinical manifestations of acromegaly, if they occur before puberty, giant disease can be present. If adenomas occur in prolactin cells, amenorrhea, lactation, and infertility can occur in female patients. X-ray films of patients with pituitary tumors often have enlarged saddles, damage to the sole of the saddle, CT and MRI of the skull to show tumor growth, and endocrine tests to increase various hormones.

Optic nerve

2, craniopharyngioma (craniopharyngioma) is mainly manifested in childhood growth retardation and increased intracranial pressure. Visual field disturbance occurs when the optic nerve is compressed. Because the tumor growth direction is often irregular, the degree of optic nerve compression on both sides is different, so the degree of vision loss on both sides is often different. Visual field changes are also inconsistent. About half of them are manifested as double-temporal hemianopia. Compression of the optic cross at the early stage of the tumor may appear as double-temporal quadrant blindness. Tumors appearing on the saddle and compressing downward can appear as double infratemporal quadrant blindness. One side of the tumor can be manifested as unilateral temporal hemianopia. Skull plain radiographs include intracranial calcification, CT, MRI examination and endocrine function measurement, and the clinical diagnosis can be clear.

3. The clinical manifestations of saddle nodular meningiomas (tuberdeofsellaearachnoidfibroblastoma) are more common with vision loss and headache symptoms. Visual impairment progresses chronically. The vision loss in one side or the asymmetry in both sides first appears, and the visual field defect in one or both temporal sides occurs at the same time. Later, it develops into bilateral temporal blindness, and finally blindness can occur. Fundus has signs of primary optic nerve atrophy. Late cases cause symptoms of increased intracranial pressure. On CT scan, the typical sign of saddle nodule meningioma is a contrast-enhanced mass image in the upper saddle area. The density is uniform.

(Two) co-direction blindness

The damage of the visual beam and visual radiation can cause the same-side blindness of the opposite visual field of the two eyes. It is more common in the infarct and hemorrhage of the inner capsule area to cause ipsilateral hemianopia, dyskinia, and temporal, parietal tumors that press the optic tract and optic radiation inward to cause hemianopia. These diseases can be diagnosed based on clinical manifestations and skull CT.