papilledema and optic disc edema
Introduction
Introduction to optic nerve head edema and optic disc edema The term papilloedema is strictly limited to the edema of the optic nerve head due to increased intracranial pressure. Optic disc edema caused by various other causes is called optic discecedema. basic knowledge The proportion of illness: 0.14% Susceptible people: no special people Mode of infection: non-infectious Complications: intracranial tumors, hypertension, diabetes
Cause
Optic nerve head edema and optic disc edema
Tumor factors (45%):
The vast majority of intracranial tumors may cause optic nerve head edema: the incidence is estimated to be 60% to 80%; but in recent years, the incidence of papillary edema caused by intracranial tumors has gradually decreased, mainly because of modern The use of examination techniques such as X-ray computed tomography (CT), magnetic resonance (MRI), etc., allows brain tumors to be diagnosed at an early stage.
Other factors (55%):
Non-neoplastic but with increased intracranial pressure: Some neurological diseases that are not intracranial but with increased intracranial pressure are often accompanied by edema of the optic nerve head, such as pseudocephaloma, brain abscess, encephalitis , meningitis, cerebral edema, epidural and subdural hematoma, subarachnoid hemorrhage, intracerebral hematoma, giant aneurysm, brain cyst, cerebral parasitic disease, hydrocephalus, intracranial venous sinus thrombosis, Lead poisoning encephalopathy and malformation of the skull, in addition, there have been reports of optic nerve head edema in individual spinal cord tumors.
Systemic diseases: Some systemic diseases often occur in optic disc edema, such as acute hypertension, nephritis, severe anemia, blood system diseases, emphysema, and some patients with right heart failure.
Eyelid disease: Many eyelid diseases can cause optic disc edema, such as: eyelid tumor, eyelid inflammation and abscess, intraorbital parasite, intraocular cyst, oropharyngeal hemangioma and vascular malformation, etc., usually caused by orbital disease, optic disc edema On the side, only a small number of bilateral eyelid diseases cause bilateral optic disc edema.
Eye disease: Some eye diseases that are confined to the eye itself are also often optic disc edema, such as: optic nerve papillitis, optic retinitis, central retinal vein occlusion, primary or metastatic tumor of the optic nerve, uveitis, and eye trauma or surgery Disc edema can occur if the pressure drops sharply.
In short, there are many diseases that cause optic nerve head edema and optic disc edema, and should look for its primary disease in many ways.
Pathogenesis
The optic disc is in a specific environment, that is to say it is between two cavities with different pressures, the front of which bears the pressure inside the eyeball, while the rear is subjected to the pressure of the intracranial subarachnoid space, the normal eye The pressure is 10~21mmHg, while the normal intracranial pressure is about 120mmH2O (equivalent to 9~10mmHg). Therefore, under normal conditions, the intraocular pressure is always higher than the intracranial pressure, if the pressure in front of the optic disc is too high. (eg glaucoma), the optic disc can produce significant depressions, and conversely, if the pressure behind the optic disc increases (for example, intracranial lesions increase intracranial pressure), it will cause the optic disc to protrude forward, that is, the edema of the optic disc, in addition When the eyeball is traumatized or surgery, the intraocular pressure suddenly drops sharply. At this time, although the intracranial pressure is not high, the pressure behind the optic disc is relatively higher than the pressure in front of it, so that optic disc edema can also occur. If the subarachnoid space of the optic nerve is not connected to the subarachnoid space of the brain (for example, the intracranial segment of the optic nerve is compressed), the optic nerve head will not edema even if the intracranial pressure is higher.
There are several theories about the pathogenesis of optic nerve head edema:
1. Increased intracranial pressure: Most scholars believe that due to the increase of intracranial pressure, the pressure is transmitted to the subarachnoid space around the optic nerve sheath, resulting in an increase in the subarachnoid pressure around the optic nerve sheath. The central retinal vein circulation of the retina and optic nerve head is blocked, resulting in optic nerve head edema, and some experiments have been performed to confirm that the central venous pressure of the retina is increased when the intracranial pressure increases, and the central venous pressure is increased. The sheath can cause the edema to subside.
However, the application of this theory can not fully explain the pathogenesis of optic nerve head edema, because: if the reflow of the central retinal vein is the only cause of edema of the optic nerve head, then the clinical manifestations of optic nerve head edema should be blocked with the central retinal vein. The clinical manifestations are completely consistent, showing that all the large and small vein branches of the entire retina have high blood vessel expansion and distortion; the bleeding and exudation along the venous blood vessels should spread throughout the periphery of the retina, however, the clinical manifestations of optic nerve head edema are only limited. Optic nerve head edema occurs in patients around the optic nerve nipple, never beyond the fundus, and clinically not all patients with central retinal vein occlusion. Therefore, it is not enough to explain the pathogenesis of optic nerve head edema by only central retinal vein occlusion. comprehensive.
2. "Body fluid" in the eyeball Some people think that under normal circumstances, there is a kind of "body fluid" in the eyeball flowing from the ball to the brain through the optic nerve. If the intracranial pressure increases, it can hinder the flow of this "body fluid", thus causing the optic nerve. Papillary edema, but when the intracranial segment of the optic nerve is oppressed by the tumor, according to this theory, optic nerve head edema should be caused by hindering the return of "body fluid" in the eye, but the opposite is true, the optic nerve of the intracranial segment is affected. Pressure, so that the side optic nerve often avoids the occurrence of optic nerve head edema (such as Foster-Kennedy syndrome), therefore, from the above clinical facts, this theory does not explain the pathogenesis of optic nerve head edema.
3. Cerebrospinal fluid into the optic nerve: Others believe that optic nerve head edema occurs because the increased intracranial pressure forces the cerebrospinal fluid to flow into the optic nerve along the peripheral space of the central retinal blood vessels, which is based on the study of optic nerve head edema. In pathological sections, it can be seen that the optic nerve fibers are split into bundles, but many people disagree with this view, pointing out that the division of this nerve fiber is caused by human factors in the process of making slices. If the production process is changed, This phenomenon can be avoided.
4. Optic nerve head edema and cerebral edema: It has been suggested that optic nerve head edema is part of cerebral edema. It has also been suggested that optic nerve head edema is related to local physicochemical and colloidal chemistry.
In short, any of the above-mentioned various theories about optic nerve head edema cannot fully explain its pathogenesis.
In the late 1970s, many scholars conducted a more in-depth study on the pathogenesis of papilledema caused by increased intracranial pressure. The mechanism that has been generally recognized is that optic nerve head edema is due to the transport of optic nerve axoplasm flow. After being blocked, the axonal axon of normal retinal ganglion cells should run from the optic nerve to the lateral geniculate body, called axoplasmic flow, and the axial flow is divided into two types: fast and slow. The slow axial slurry flow can run about 2mm per day, while the fast axial slurry flow can run 500mm per day. The transport of the axial slurry flow depends on the physiological pressure difference between the intraocular pressure and the optic nerve pressure, when the intracranial pressure When the height is increased, the subarachnoid pressure in the optic nerve sheath is also increased, which destroys the normal pressure difference between the intraocular pressure and the optic nerve pressure, causing the axoplasmic transport to be blocked in the sieve plate area, and thus the anterior region of the sieve plate The inner nerve fibers are swollen due to the blockage of the axial flow, the volume of the optic nerve head is increased, and the retinal nerve fibers around the optic nerve head are outwardly displaced to form the optic nerve head. Swelling, as well as swelling of the optic nerve fibers due to blockage of axial flow, increases the pressure of the interstitial space, which in turn causes the blockage of the axoplasmic flow to be more severe, thus more severe swelling of the optic nerve fibers, and because of the optic nerve head The pressure in the interstitial space increases, causing the venules in the optic nerve head to be subjected to such pressure and the swelling of the axons, and the capillaries in the optic nerve head are dilated and leaked, thereby impeding the absorption of fluid in the interstitial space. The retention of fluid in the interstitial space increases the pressure of the interstitial space, thus forming a vicious circle, which promotes the development of optic nerve head edema. It is also believed that the pressure in the subarachnoid space is increased, causing axoplasmic flow disorder of the optic nerve, resulting in Axoplasmic components, water and protein leakage cause these substances to accumulate in the extracellular space in the anterior region of the sieve plate. These protein-rich fluids increase the osmotic pressure of the extracellular space and cause optic nerve head edema.
In patients with optic nerve atrophy, because nerve fibers have been denatured or replaced by gelatin, there is no blockage of axoplasmic flow, so there is no optic nerve head edema, which is the latest theory of the pathogenesis of optic nerve head edema. .
Prevention
Optic nerve head edema and prevention of optic disc edema
Early diagnosis and treatment of the primary disease.
Complication
Optic nerve head edema and complications of optic disc edema Complications intracranial tumor hypertension diabetes
It can be complicated by intracranial tumors, systemic diseases such as hypertension, diabetes, and local optic nerve diseases.
Symptom
Optic nerve head edema and optic disc edema symptoms Common symptoms nausea before the eyes blackened and congested vision often foggy edema edema nausea and vomiting increased intracranial pressure eye muscle paralysis blind spot visual field defect
Symptom
Most of the optic nerve head edema is bilateral, single eye is rare; most patients with optic nerve head edema except for headache caused by the primary disease of the brain, nausea, vomiting and other increased intracranial pressure and local neurological symptoms, even if the optic nerve head edema is very serious Even the disease course is quite long, the patient can have no self-conscious symptoms at all, and his vision and visual field can be completely normal. This visual function maintains normal characteristics for a long time, which is one of the biggest features of optic nerve head edema. In many cases, it is difficult to distinguish under the ophthalmoscope. Whether it is optic nerve head edema or optic nerve papillitis, this feature can often be used to make a differential diagnosis.
However, there are also a small number of patients with optic nerve head edema that have obvious visual symptoms, and sometimes even some tumors located in the "quiet zone" of the brain often seek treatment for these first symptoms.
The symptoms of optic nerve head edema are very special. The patient has many symptoms such as paroxysmal blackening or paroxysmal blurred vision. Each time the hair is transient, it lasts for a few seconds to 1 minute. It is extremely rare for the attack time to last for more than a few minutes. The number of episodes per day is variable, and the visual function is completely restored after the attack. This so-called "amaurosis fugax" occurs more frequently in patients with a longer degree of optic nerve head edema and longer duration, if the original intracranial If the disease affects the motor nerve or visual pathway, there should be corresponding ophthalmoplegia or visual field defects. When the optic nerve head edema lasts for too long, and the optic nerve undergoes secondary atrophy, the visual function can have obvious obstacles, even Completely blind.
2. Signs
Ophthalmoscope observation of optic nerve head edema can be different due to its degree of development, generally can be divided into early mild optic nerve head edema, development of complete optic nerve head edema and advanced atrophic optic nerve head edema stage 3.
(1) Early mild optic nerve head edema:
1 The color of the optic nerve head turns red, so that its color is almost the same as the color of the surrounding retina. It is one of the signs of early optic nerve head edema. However, this sign is sometimes not very reliable because there are many presbyopia and pseudo optic papilla. In patients with edema, the color of the optic nerve nipple is also red, so the color of the optic nerve head is red, which is not unique to the early optic nerve head edema. The reason for the redness of the nipple is because the intracranial pressure is increased, and the central venous reflow is blocked. Causes the expansion of the capillaries in the optic nerve head.
2 The boundary of the optic nerve head is blurred, which is also one of the signs of early optic nerve head edema, but the normal optic papilla is sometimes not very clear, especially the nasal side and the upper and lower borders are more prominent, but the temporal border is generally clearer. When the optic nerve head edema, the initial stage is limited to the upper and lower of the optic papilla and the nasal border becomes blurred, but soon after, the temporal boundary of the optic papilla also begins to blur, but it should be noted that pseudo optic papilledema The nipple boundary is also blurred in all directions.
3 The physiological depression of the optic nerve head disappears, which is also one of the signs of early optic nerve head edema. However, this sign is not absolutely reliable, because many normal people, especially hyperopic eyes and pseudo optic nerve papillary edema, can not see the nipple. Physiological depression.
4 The central retinal vein becomes full, and the proportion of the large, moving, and veins increases from the normal 2:3 to 2:4, which is also one of the signs of early optic nerve head edema.
5 The retinal central venous pulsation disappears, which is an important sign of optic nerve head edema. If the patient has the above-mentioned optic papilla congestion, the boundary is blurred, the physiological depression disappears, the central retinal vein becomes thick and other signs, and the pulsation of the central retinal vein disappears, especially When the eyeball is lightly pressed with a finger, and the pulsation is still not seen, the possibility of optic nerve head edema is greatly increased.
6 The retina around the optic nerve head becomes blue-gray, which is also a common sign of early optic nerve head edema. This sign can be seen in most early optic papillary edema, in the congested reddish papillary and dark red Between the retina, the gray-white edema ring around the retina around the optic nerve head is a more striking sign that can be easily detected with an ophthalmoscope.
In short, the early signs of optic nerve head edema are difficult to distinguish, the changes under the ophthalmoscope are often plausible, true and false are difficult to distinguish, even experienced doctors can hardly diagnose the early optic nerve head edema by the performance of the ophthalmoscope alone. Therefore, for the diagnosis of early optic nerve head edema, can not rely solely on ophthalmoscopy, and ignore the clinical manifestations of the system, in the diagnosis of early optic nerve head edema, should combine all the patient's neurological symptoms and other test results, if not Clearly confirm the presence or absence of early optic nerve head edema, and the patient's condition is allowed, it is best to review the fundus after 1, 2 weeks, then you can see the clear optic nerve head edema, it should be emphasized that for the purpose of comparison, In the course of continuous observation, the complete and detailed record of the initial inspection is extremely important. For example, it is possible to make fundus photography in different periods, especially for stereoscopic fundus photography, which is more helpful for diagnosis.
In the early optic nerve head edema that can not be distinguished by the human eye under the ophthalmoscope, if the fundus photography, especially the stereoscopic photography of the fundus, the optic nerve head edema can be found earlier.
Another method for diagnosing early optic nerve head edema is to carefully examine the planar field of view and record the size of the physiological blind spot. The normal person's physiological blind spot is located at the side of the fixation point of 13° to 18.5°, with a width of 5.5° and a height of 7.5. °, if the physiological blind spot is increased, especially the expansion of the horizontal meridian, there is often a very important diagnostic value (vertical meridians are not very reliable due to vascular shadows), therefore, for patients with suspected early optic nerve head edema, regular review Fundus and physiological blind spots help to diagnose the optic nerve head edema.
Fundus fluorescein angiography is of great value in the diagnosis of optic nerve head edema. In the arterial phase of angiography, it can be seen that the radial capillaries of the papillary surface have a very striking expansion. At the same time, many microaneurysms can be seen, and fluorescein is quickly These dilated capillaries leak outward, staining the optic nerve head and its surroundings, showing a strong fluorescence that lasts for a long time (about several hours), but gradually declines in the earliest cases of optic nerve head edema. There was no significant change, but in the late stage of angiography, due to the slight staining of the edge of the optic papilla, the optic papilla showed a plate-like strong fluorescent region with unclear borders. However, angiography did not help the earliest optic nerve head edema and could not be displayed. The earliest changes, therefore, can not exclude the earliest optic nerve head edema due to negative fluorescein angiography. This patient still needs to follow up and observe angiography regularly, so Hayreh et al emphasize the stereoscopic color fundus photography to observe the earliest optic nerve. Papillary edema is far more sensitive than fluorescent angiography.
(2) Early optic nerve head edema generally develops into a relatively obvious optic nerve head edema after about 2 weeks. At this time, the change under the ophthalmoscope is very significant. The optic nerve head is blurred in color, the color becomes red, and the physiological depression disappears. The venous filling, the disappearance of the venous pulsation and the signs of blue-gray around the optic disc become more pronounced, as well as:
1 The diameter of the optic nerve head becomes larger: this is because the optic nerve head extends to the surrounding retina due to its own swelling and edema, so the optic nerve head looks much larger than normal under the ophthalmoscope, but its shape remains circular. At the same time as the diameter of the optic nerve head increases under the ophthalmoscope, the examination of the planar perimetry can find that the expansion of the physiological blind spot is more obvious.
2 optic nerve head bulging bulge: as the disease progresses, the degree of optic nerve head edema is also increasing, the optic nerve head is prominently protruding forward, the central part of the protrusion is the highest, and the peripheral part is slowly ramped and gradually It becomes lower, so the optic nerve head under the ophthalmoscope is very similar to a small mushroom that protrudes into the eye.
The degree of elevation of the optic nerve head edema can be measured by ophthalmoscopy. Although this is a relatively rough method, from a clinical point of view, this method is sufficient and simple and feasible. The specific method is: The flexor disc on the glasses, with a certain diopter to see the smallest part of the most prominent part of the optic nerve nipple, and then dial the flex disk, with another diopter to see the smallest blood vessels near the macular area of the retina, 2 before and after The difference in diopter, which is the height of the optic nerve head bulge, is usually about 1 mm per 3 diopters.
In general, the degree of optic nerve head edema is consistent with the development of the disease course, severe cases can be as high as 8, 9 diopter or more, but most optic nerve head edema, more than 5,6 diopter, early optic nerve head edema More than one diopter, and more than two diopter optic nerve head edema, the diagnosis is not much difficulty.
3 optic nerve nipple appearance loose: the development of complete optic nerve head edema, due to edema, the nerve tissue is separated from each other, thus making the optic nerve nipple loose, losing the smooth, tight appearance of the normal optic nerve nipple, and showing some subtle stripes or Irregular mesh, even the entire optic nerve nipple forms a tufted appearance, this loose shape of the optic nerve head is a very special sign of optic nerve head edema.
4 retinal vein engorgement, distortion: as the degree of optic nerve head edema increases, the filling of the retinal vein becomes more obvious, resulting in venous engorgement, and even varicose veins, but the arteries generally do not change significantly, therefore, the arteriovenous ratio may sometimes Up to 2:5, and due to the obvious protrusion of the optic nerve head, the blood vessels located at the edge of the optic nerve head appear from the ophthalmoscope, which seems to climb from the retinal plane to the optic nerve nipple. If the nipple is highly elevated, its edge The upper blood vessel can climb the optic nerve nipple at a vertical angle. Therefore, the blood vessel in the segment may not see the red reflection of the blood vessel wall under the ophthalmoscope and appear black, and due to the edema of the optic nerve head and the retina nearby, the blood vessel These segments can be buried in the edema tissue, so some segments of the blood vessels are often hidden. From the ophthalmoscope, it seems that the blood vessels are interrupted, and the blood vessels on the edge of the optic nerve head are climbed, which is the optic nerve head edema. One of the features.
5 bleeding on the surface of the optic nerve head and its adjacent retina: due to retinal venous congestion, some of the hemorrhage can occur on the surface of the optic nerve head and its retina, and the bleeding of the optic nerve head edema is usually radial, distributed around the optic nipple near the retina Beside the large branch of the vein, sometimes the bleeding may be located on the surface of the optic papilla. The bleeding may even partially or completely be covered by the blood clot. However, in general, the farther the bleeding from the optic papilla is, the less chance there is. One of the most important features in the diagnosis of the difference from the central retinal vein occlusion. The latter can bleed up to the peripheral part of the retina, and the bleeding of the optic nerve head edema seems to have no obvious regularity, sometimes bleeding at a very early stage. However, there are some developments that are completely complete. The optic nerve head edema has a long history of no bleeding. However, in general, there is a greater chance of hemorrhage due to a sudden increase in intracranial pressure. The chance of bleeding with a slower increase in intracranial pressure is much less. The shape is not necessarily, most of them are flaming (bleeding is in the visual network) Membrane nerve fiber layer), but there are also a few small spots (hemorrhage is located in the deep layer of the retina), but bleeding on the surface of the optic nerve head or its adjacent area is not a special symptom of optic nerve head edema.
6 white cotton buds on the surface of the optic nerve head and its adjacent retina: optic nerve head edema generally has less chance of exudate, but sometimes some white cotton-like "exudate" can be seen, located in the retina adjacent to the optic nerve head Abovely, this happens mostly in the late stage of optic nerve head edema. In fact, these white cotton linters are not really oozing, but the occlusion of the retinal capillaries, causing ischemia in small areas. Axoplasmic transport of retinal ganglion cell axons is blocked, cytoplasmic debris is accumulated in the nerve fiber layer, and other yellow-white dots on the retina are fat bodies left after hemorrhage or exudate absorption. Severe edema, edema extending to the macular area of the retina, can cause small droplets of exudation to accumulate under the inner limiting membrane between the optic nerve head and the macula. Therefore, under the ophthalmoscope, some radial brightening arranged in a fan shape can be seen. Small white spots, usually the fan-shaped white spots in the macular area, mostly in the nasal side of the macula, between the optic nerve head and the macular area, and One week are arranged macular stellate-shaped rare, when optic disc edema, lint spot on the retina, hard exudates and fan white point can be completely absorbed in the macular area.
7 Concentric curved line around the optic nerve head: due to optic nerve head edema, the adjacent retina is displaced to the surrounding, causing retinal wrinkles, sometimes these retinal folds can be seen under the ophthalmoscope, manifested in the optic nerve There are 3 to 4 thin concentric curved lines along the nipple (Fig. 5). The concentric curved lines around the nipple are also called Patons lines.
(3) advanced atrophic optic nerve head edema: If the cause of optic nerve head edema is not relieved in time, the long-term development of optic nerve head edema will eventually lead to secondary optic atrophy. Once the optic nerve shrinks, the patient has progressive vision loss. In addition, the ever-developing vision is narrowed, and finally the symptoms that cause complete loss of visual function such as blindness, the changes that can be detected by the ophthalmoscope are:
1 The color of the optic nerve head becomes white: the optic nerve head is congested from the original edema, and the redness gradually turns grayish white. In the initial stage, only the edge of the optic nerve head becomes grayish white, and the center of the optic nerve becomes white in the late stage. The reason for the discoloration of the optic nerve head is because Long-term edema causes degeneration of nerve fibers, and as a result of gliosis, the whitening of the optic nerve head is one of the early signs of optic nerve atrophy. Therefore, once the patient's optic papilla is found to be whitened by edema, it should be Immediately think that the optic nerve has begun to shrink.
2 retinal vascular stenosis: When the optic nerve begins to shrink, another important sign is that the central retinal artery is narrowed, the central retinal artery becomes very thin, and the central retinal vein is gradually reduced, and the venous diameter is from the original edema. Filled, angered, distorted, tapered, restored to the original normal diameter, and even become thinner.
3 The degree of elevation of the optic nerve head is gradually reduced: although the cause of optic nerve head edema still exists (for example, intracranial pressure is still high), once the optic nerve shrinks, the elevation of the optic nerve head is inevitably reduced, gradually forming a blurred border, color Pale, with a slight augmentation of advanced atrophic optic nerve head edema, the final optic nerve head will be completely flattened, showing a typical secondary optic atrophy.
Examine
Examination of optic nerve head edema and optic disc edema
It is mainly used for the necessary laboratory tests for the diagnosis of the primary diseases of optic nerve head edema and optic disc edema, such as biochemical and white blood cell count examination of cerebrospinal fluid, blood biochemical examination, blood routine examination and so on.
Color stereoscopic fundus photography can distinguish small changes in early signs of edema.
Diagnosis
Diagnosis and differentiation of optic nerve head edema and optic disc edema
diagnosis
It is difficult to diagnose the complete optic nerve head edema. Generally, as long as you have seen several typical optic nerve head edema, you can make a correct diagnosis, especially in combination with the patient's visual function and characteristic "paroxysmal black."" and other characteristics, combined with other manifestations of increased intracranial pressure, diagnosis is relatively easy.
Differential diagnosis
Optic disc edema of hypertensive retinopathy is sometimes not easy to distinguish from optic nerve head edema with increased intracranial pressure. The former has a lighter degree of optic disc edema, the elevation is not too high, and there is no mushroom-shaped protrusion, but its fundus Bleeding and cotton buds are more than the latter, and the bleeding and cotton vellus of hypertensive retinopathy are scattered throughout the fundus, unlike the papillary edema with increased intracranial pressure, which is limited to the vicinity of the optic nipple. Hypertensive patients have arterial diameter thinning and irregularity, as well as arteriosclerosis signs such as cross-invasion of arteries and veins, hypertension in patients with hypertensive retinopathy, and no obvious signs of nervous system, these are with the intracranial The point of identification of increased papilledema in pressure.
The degree of optic disc edema caused by central retinal vein occlusion is often very slight, and the degree of filling, anger, and distortion of the vein is very serious. This is the opposite of optic nerve head edema with increased intracranial pressure. The latter has more serious edema of papillary edema. The venous filling, varicose and other changes are often less serious, and the retinal vein occlusion, the bleeding can be scattered in the peripheral part of the retina, and the bleeding of the optic nerve head edema, mostly confined around the optic papilla, retinal vein obstruction, absolutely Most of them occur on one side, while optic nerve head edema is mostly bilateral, with few on one side.
