Primary retinal detachment

Introduction to primary retinal detachment Primary retinal detachment is a common clinical disease. The number of male patients is more than 3:2 for males. Most of them are adults over 30 years old. Children under 10 years old are rare. The difference between left and right eyes is about the total number of patients. 15%. Occurs in myopia, especially high myopia. At present, primary retinal detachment still takes surgery as the main means. The principle of surgery is electrocoagulation, condensation or extrabulbar, intracoronary photocoagulation in the corresponding scleral surface with the hiatus to cause local choroidal reactive inflammation, causing choroid and retinal nerves. The cortical layer has an adhesive surface that closes the hole. In order to achieve this goal, it is necessary to try to alleviate or eliminate the vitreous traction on the retina, discharge the subretinal fluid, pressurize the bulb wall, shorten the sclera, scleral cerclage to reduce the lumen of the eyeball, or inject a certain gas into the vitreous cavity. A certain kind of liquid is used to strengthen the contact between the neuroepithelial layer and the pigment epithelial layer. If the vitreous traction is severe, vitrectomy is required. basic knowledge Sickness ratio: 0.0002%-0.0005% Susceptible population: The number of males is more than 3:2 for males, and most adults are over 30 years old. Mode of infection: non-infectious Complications: floaters

Primary retinal detachment

Primary detachment is the result of a combination of retinal degeneration and vitreous degeneration. It is easy to say that primary detachment must have these two preconditions, both of which are indispensable.

1. Retinal degeneration and tear formation

Due to the complex structure of the retina, the blood supply is unique, and it is easy to cause degeneration due to various reasons. The peripheral part and the macular part are good degeneration. Retinal degeneration is the basis of retinal tear formation. Before the occurrence of the hole, the following changes are common:

(1) Lattice-like degeneration: lattice-like degeneration is most closely related to retinal detachment, and 40% of the pupils account for the rupture of the hole. It is also visible in the normal eyeball, which is about 7%. The lattice-like degeneration has no race and gender. Difference, infringement of both eyes, its formation and location are often symmetrical, more common in the temporal or temporal upper quadrant between the equator and the serrated edge, in the shape of a fusiform and strip-like, island-like lesion with a clear edge, parallel to the long axis and the serrated edge The lesion area varies greatly. The long right is from 1DD to 1/2 circumference, and the width varies from 0.5DD to 2DD. The lesion retina is thin, and there are many white lines, which are staggered into a grid facade. This line and the lesion are outside. The retinal blood vessels are connected, which is actually a peripheral blood vessel with occlusion or tubular white sheath. The distribution of white pigment clusters is sometimes seen in the lesion, which is called pigmentary lattice-like degeneration. The pigment is derived from the retinal pigment epithelial layer.

(2) cystic degeneration: occurs in the vicinity of the macula and the inferior side of the serrated edge, the edge is clear, round or round, dark red, small cavity can be merged into a large cyst, so the size varies greatly, occurs in the fundus The reticular sac-like degeneration in the peripheral part becomes a cluster-like and slightly elevated red dot. The vitreous or granular opacity in the nearby vitreous, the cystic degeneration of the macula is a honeycomb-like small cyst, and there is no red light. It is particularly obvious during the examination that the small cystic cavity of the peripheral or macular portion gradually merges into a large cystic cavity, and the anterior wall is often broken by the vitreous traction, but only when the anterior and posterior walls are ruptured becomes a true rupture and causes retinal detachment.

Cystic degeneration is caused by a variety of reasons (such as senile changes, inflammation, trauma, high myopia, etc.) affecting the metabolism of the retina, causing the breakdown of its neural components, thereby forming a cavity in its inner plexiform layer or inner and outer nuclear layers. A change in the gap is filled with a liquid containing a mucopolysaccharide component.

(3) frosty degeneration: mostly occurs near the equator and the serrated edge. Some areas covered by tiny white or slightly yellow shiny particles can be seen on the surface of the retina. The thickness is uneven, as if the retina is covered with a frost. It can also appear alone, but also with lattice-like degeneration, cystic degeneration. The frosty degeneration is close to the equator and merges into a band, also known as snail trace degeneration.

(4) paving stone degeneration: generally seen in myopia patients over 40 years old, more common in both eyes, occurs in the lower part of the fundus, showing a pale yellow round or round shape with pigmented edges, clear multiple atrophy The lesions, large and small lesions are grouped into a paving stone. The choroidal capillary network in the central part of the lesion is atrophied, exposing the choroidal large blood vessels or even the pale white sclera. If the degeneration area is pulled by the vitreous, the retinal tears are formed.

(5) Retinal pressure whitish and non-pressurized whitish: After the sclera is depressed, the bulge of the fundus becomes opaque grayish white, which is called vaginal whitening. When the lesion is further aggravated, it is grayish white even if it is not pressurized. For the non-pressurized whitish, the trailing edge sometimes forms a clear sputum, which is more common in the peripheral part of the upper fundus. It is considered as an indication of vitreous traction. For example, after the vitreous body is detached and expanded, the trailing edge can be torn to form a slit.

(6) Dry retinal longitudinal fold: wrinkles extend from the tooth edge of the serrated edge to the equatorial direction, which is a fold of overgrowth of the retinal tissue. Generally, there is no need for treatment, but there is also an objectively pulling the vitreous at the posterior end of the fold. may.

2, vitreous degeneration

In order to cause another key factor of retinal detachment, under normal circumstances, the vitreous is a transparent gel-like structure, which is filled in the cavity of the posterior 4/5 of the eyeball, and has a supporting effect on the retinal neuroepithelial layer attached to the pigment epithelial layer. Except for the flat part of the ciliary body to the serrated edge and the adhesion around the optic disc and the retina, the other parts are only closely attached to the inner limiting membrane of the retina, but there is no adhesion.

Before the occurrence of retinal detachment, common changes in vitreous degeneration include: detachment of vitreous, liquefaction, turbidity, membrane formation, and concentration.

(1) detachment of vitreous body: vitreous detachment refers to the gap between the critical surface of the vitreous and the tissue in close contact with it. It is more common in high myopia and elderly patients. The outer interface of each part of the vitreous can be detached. After detachment, the upper detachment is common, and the relationship with the retinal detachment is relatively close.

The reason for the vitreous detachment is mainly the depolymerization and dehydration of hyaluronic acid in the vitreous, forming one or more small liquefied cavities in the vitreous body and merging with each other to form a large cavity, such as the liquid in the cavity breaks through the external interface of the glass and enters the retina. Separation occurs between the vitreous and the inner limiting membrane of the retina. If there is some pathological adhesion to the retina at the detachment, retinal tears may occur due to traction.

(2) Fluidity of vitreous body: Vitreous liquid is a vitreous state that changes from a gel state to a dissolved state. It is a colloidal balance damage caused by a new metabolic disorder of the vitreous. It is also common in high myopia and elderly patients. Liquefaction is generally from the center of the vitreous. At the beginning, an optical space appears, which gradually enlarges. It is also possible to fuse a plurality of smaller liquefied cavities into a larger liquefied cavity, and the liquefied cavity has a translucent grayish white tow or a floc floating.

(3) Vitreous opacities and concentration: There are many reasons for vitreous opacity, but those associated with primary retinal detachment are caused by the destruction of vitreous scaffold structure, so they are often separated from the vitreous, liquefied at the same time, turbid fibrous strip The bundle has the potential to cause retinal tears.

The so-called vitreous concentrating is also a vitreous turbidity. It is an opaque body formed by dehydration and denaturation of the scaffold structure when the vitreous is highly liquid. Therefore, it can be called atrophic concentration, and the membrane turbidity of the outer interface when it is detached from the front vitreous body. Compared with the tow-like or flocculent turbidity in the vitreous liquefaction chamber, there is not much difference in the nature, only the degree of severity is more serious, and the risk of causing retinal detachment is also more intense.

(4) Vitreous membrane formation: The mechanism of co-formation of the massive perietinal proliferative membrane is also very complicated. It is not fully understood yet. There may be glial cells, free pigment epithelial cells and macrophages transformed into them. Fibroblasts are involved, and the proliferating membrane grows along the anterior, posterior, or extracorporeal interface of the retina. After contraction, the retina can be collapsed to form some fixed adhesion folds or star folds, and even the entire posterior retina can be shrunk. Together form a closed funnel shape.

Such a proliferative membrane is seen in patients with detachment before retinal detachment, and in detachment and old detachment, which occurs as an important cause of retinal detachment.

In addition, it has been observed that retinal tears occur in the corresponding points of the oblique and oblique points of the fundus, so it is speculated that the holes are related to the traction of these muscles. It has also been found that most patients recall a history of minor trauma at the bottom of the eye and think that the detachment is related to trauma. In fact, in addition to a few special cases such as severe eyeball blunt trauma, oblique muscle traction and trauma can only be considered as the cause of retinal detachment.

Primary retinal detachment prevention

The incidence of primary retinal detachment is about 15%, so when one eye has already detached, the other eye must be fully dilated to check the fundus. If retinal degeneration, a hole has been found, and a shallow detachment has been found, it is necessary to take surgery in time. Prevent the detachment from continuing to expand. There is only a hole or only denaturation and the vitreous has no obvious degeneration. There is no adhesive traction at the hole. The patient does not have a flash illusion in the fixed area. Generally, no preventive surgery is required, but care must be taken to avoid it. Holding heavy and strenuous exercise, it can apply anti-recession for a long period of time, improve the middle and western medicine of the choroidal retinal microcirculation, and vice versa, it should be treated with condensation or photocoagulation. The hole is in the posterior fundus, and there is not much fluid under the retina. Photocoagulation; in the peripheral part of the condensation, condensation can not cut the bulbar conjunctiva, the method is relatively simple, but also very careful, to master the area of condensation, strength, etc., although the macular hole has seen shallow detachment or radial Wrinkles, as long as the vitreous is basically healthy, still maintain a certain vision, it is not suitable for photocoagulation.

Primary retinal detachment complications Complications

The most common complication is visual impairment, and there may be flying mosquitoes.

Primary retinal detachment symptoms common symptoms visual impairment visual field defect visual distortion lattice-like degeneration illusion

Clinical manifestations:

1, symptoms and visual function check

(1) Central visual impairment: Due to the location and extent of retinal detachment, the visual acuity suddenly drops significantly when the posterior pole is detached, and the peripheral detachment has no effect or little influence on the central visual acuity. Only when the disengagement range extends to the posterior pole Central visual impairment.

(2) Allergies: When the detachment occurs in the peripheral part and the posterior part of the sensation occurs, in addition to the decrease in central vision, there are symptoms such as deformation and smallness of the object.

(3) Floats: See the vitreous opacity caused by various reasons. When the mosquitoes suddenly increase, attention should be paid to the prodromal symptoms of retinal detachment.

(4) Flash illusion: it is the most important symptom of retinal detachment. It can be a precursor to detachment. The vitreous degeneration and pathological adhesion of the retina can cause a flashing sensation when the vitreous body of the eye rotates to stimulate the visual cells. If the sensation of flash persists and is fixed at When a certain part of the field of vision is concerned, it should be alert to the occurrence of retinal detachment in the near future. The flashing sensation may also occur in patients with existing retinal detachment, which is caused by the liquefied vitreous from the ruptured pore into the neuroepithelial stimulating retinal cells.

(5) Visual field change: the peripheral retinal detachment, the patient can feel the shadow or visual field defect of the corresponding site on the opposite side of the lesion, but when the temporal retinal detachment, the nasal visual field defect is within the visual field of both eyes, sometimes not perceived by the patient. It was discovered at the time of visual field examination.

Retinal detachment is the detachment of the neuroepithelial layer. Due to the nutritional supply problem, the cells are first damaged, and the visual cell damage first affects the blue sensation. The blue field of the normal eye is larger than the red field of view. The retinal detachment eye is white, blue and red. The target field is inspected, and the corresponding field is not only the visible visual field defect, but also the blue color and the red field of view intersect.

2, intraocular pressure

If the early detachment area is not large, the intraocular pressure is normal or low, and it decreases with the expansion of the detachment range. If the ocular pressure is more than one quadrant, the intraocular pressure is significantly reduced, and even the tonometry cannot be measured. The reason why the intraocular pressure drops may be separated from the retina. The fluid dynamics of the eye is related to the posterior part of the eyeball through the posterior chamber, the vitreous, the retinal fissure and the subepithelial space, transported through the pigment epithelium, and then the choroidal vasculature discharges the misdirected flow of aqueous humor outside the eye.

3, slit lamp microscope and ophthalmoscopy inspection see

The anterior segment of the eyeball is generally normal, the anterior chamber may be slightly deeper, and the detachment of the gyrus may cause a slight inflammatory reaction of the uveal tract. The Tyndall phenomenon of the aqueous humor is weakly positive, and there is a brown point-like deposit after the cornea.

Vitreous opacity and liquefaction, inevitably exist in the primary detachment eye, this change is more clear under the slit-like microscope light section, the liquefaction cavity is an unstructured optical space, between the liquid cavity and the cavity, there is a glass body scaffold tissue dehydration atrophy The formation of silky turbidity, sometimes in the liquid cavity and silky turbidity, there are brown or grayish white turbid spots, the liquefaction cavity gradually expands and fuses with each other, and the liquefied vitreous passes through the external interface into the front of the retina and the external interface of the glass. It becomes a vitreous detachment. There are several types of anterior, upper, lateral and posterior detachment due to different positions. The upper detachment and the posterior detachment are most closely related to retinal detachment. When the vitreous is detached, there is often a degree of pathological adhesion between the vitreous and the retina. It is called incomplete detachment. The adhesion is often caused by traction, causing retinal tears. The slit light is examined by the cut surface. The interface at the detachment of the vitreous is unevenly turbid. When it is detached, a grayish white ring is visible at the rear interface of the detached vitreous. The posterior interface of the vitreous is a hole, which is the tearing of the vitreous and the peripheral edge of the optic disc. , Lasted longer half-moon-shaped or irregular, may also be compressed into a transparent pellet polyethylene.

The various lesions of the above-mentioned vitreous can also be seen under the direct mirror, but it is not as clear as the slit lamp microscope, and the layer is distinct and has a three-dimensional effect.

Under the direct ophthalmoscope, the retina is detached and wavy, bulging, undulating with the rotation of the eyeball, and the fresh detachment of the epithelial layer and its effusion are transparent, which can see the yellow-red or reddish choroidal color under the pigment epithelial layer, but The choroid texture can not be seen clearly, and the retinal blood vessels crawling and undulating on the surface are formed into a light-blocking body, which has a dark red line. It is difficult to distinguish the arteries and veins, and sometimes a vascular projection consistent with the retinal blood vessels can be seen. The detachment time is longer and the neuroepithelial layer is present. Translucent paraffin pattern, detached arteries and veins can be distinguished, longer-term old detachment, effusion under the neuroepithelial layer, due to choroidal exudation, fibrin increased, into a light brown viscous fluid, behind the neuroepithelial layer Yellow-white spotted sediment.

The hole is often seen in the retinal detachment, 1 to several, the upper side of the fundus is the prone site of the hole, but due to the heavy cause, the effusion sinks, but the hole is slightly detached or not detached.

The contact ophthalmoscope can check the fundus within 70o after the pupil is fully scattered and the eye position is rotated. Therefore, the crack in the peripheral part outside the 70o is not easy to find. Indirect ophthalmoscopy should be used for both eyes. If necessary, a scleral compressor should be added. A slit mirror can also be used under a slit lamp microscope to detect and add a scleral compressor to detect some denaturation changes near the serrated edge and the flat portion of the ciliary body or the base of the retina and vitreous.

4, retinal tears

In theory, primary detachment should see 100% of the hole, but for various reasons, although the inspection method has made great progress, the discovery rate is only about 90%.

The hole located within the 70o of the fundus is easier to find than the hole in the peripheral part of 70o; the large crack is easier to find than the small hole. The small hole is often in the vicinity of the retinal blood vessel, which is easily confused with the bleeding spot. It needs to be observed repeatedly to be identified.

Circular holes are more common. Those located in the macula are called macular holes. They are also described in the previous section. They can also be located in the peripheral fundus, single or multiple clusters of polymerization, or they can be scattered, sharp edges, caused by cystic degeneration. A membrane-like flap corresponding to its size cannot be seen before the hole is broken. The upper vitreous adhesion can be seen, and the flap (avoided neuroepithelial layer) can be seen.

Horseshoe-shaped or similar cracks, such as crescent, tongue-shaped, open-mouth and other cracks, the most common, accounting for about 25% to 68% of all retinal detachment, especially in the case of single holes, horseshoes and the like. The fissure is also caused by the vitreous traction of the retina. The adhesion range is wider than that of the circular fissure. The size of the hole is consistent with the extent of adhesion and the traction strength. Since the end of the adhesion is on the surface of the retina and the other end is rich in vitreous, the horseshoe shape The base of the hole is always facing the peripheral part, and the tip is directed to the rear pole. The trailing edge of the larger horseshoe-shaped split is crimped, and the flap is picked up. The actual area of the split hole is often larger than that of the ophthalmoscope.

Irregular tears in the retina of the peripheral fundus are relatively rare. The holes are linear or irregular. If the lines are very thin and the surrounding retina is not detached, it is often mistaken for peripheral blood vessels.

The serrated edge is caused by the serrated edge (the base of the vitreous body) and its vicinity. It is the largest area of the various holes. It is located in the inferior quadrant, and the truncation line is parallel to the limbus, occupying one quadrant or half a week, or even the whole week. Intercepted, so the reason for the special name is that the huge hole has no leading edge, and the retinal contraction curl of the trailing edge is gray-white curved, which is in sharp contrast with the dark red without retina. The serrated edge is more common in young people, most of them. Have a history of blunt trauma to the eye, or secondary to retinoschisis.

5. Formation and classification of vitreous membrane

The formation of vitreous membrane actually includes the membrane-like hyperplasia in the retinal neuroepithelial layer and the outer interface. The formation of the texture is based on the premise, the formation of the vitreous membrane, the formation of retinal detachment, the choice of surgical methods and the prognosis. It is of great significance. The classification commonly used in China is the classification method proposed by Zhao Dongsheng and the classification method proposed by the International Retinal Association.

Zhao Dongsheng classification method:

Grade 0: There is vitreous liquefaction, and then detachment, but no proliferation.

Grade I: the vitreous liquefaction cavity wall is thickened, the posterior fissure hole is formed, the vitreous base is moved backward, the serrated edge and the lattice-like degeneration edge membrane proliferate, and the horseshoe-shaped hiatus posterior lip has a flap and a membrane-like traction strip. The flap is formed, and the intravitreal membrane is formed, which can be greatly fluttered.

Grade II: In addition to grade I changes, there are also retinal fixed folds or ring folds, both at or near the equator, and the annular fold may be a further development of the posterior movement of the vitreous base.

Grade III A: Fixed folds are located in the vicinity of the upper and lower vascular arches of the retina after the equator. The vitreous has a concentration change and the annular fold reaches the equator.

Grade III B-1: Fixed folds and ring folds are all near the optic disc, with a shallow funnel shape and concentrated vitreous.

Grade III B-2: The same folds form a deep funnel, the proliferating membrane spans the funnel, the vitreous is concentrated, and the retinal vitreous is extensively adhered.

Grade III B-3: The same folds form a funnel, the funnel is closed, the optic disc is not visible, and the vitreous is concentrated.

International Retinal Association classification method:

Class A: There are vitreous concentrates and pigment agglomerates in the vitreous.

Grade B: There are wrinkles on the inside of the retina and/or the retinal tears have curling, and the blood vessels in the retina fold are obviously distorted.

Grade C: Retinal full-layer fixed wrinkles, divided into three levels: C1, fixed wrinkles only occupy one quadrant; C2: fixed wrinkles up to two quadrants; C3, fixed wrinkles up to three quadrants.

Grade D: Fixed wrinkles involving four quadrants, showing a radial fold centered on the optic disc, huge stellate wrinkles throughout the retina, and can be divided into three levels: D1 is a wide funnel shape; D2 is a narrow funnel shape (indirect inspection Under the glasses, the front of the funnel is within 45o of the +20D lens); the D3 funnel is narrow or closed and the disc is not visible.

Several special types of retinal detachment

1. Congenital choroidal defect combined with retinal detachment congenital choroidal defect is caused by fetal regurgitation during embryonic development. The retinal neuroepithelial layer in the defect area is also easy to detach. The defect is transparent under the retina and is the white sclera. Most patients cannot be found. Retinal tears, such as bleeding spots at the choroidal defect, the hole is mostly in the vicinity, the operation should pay attention to the closure of the posterior edge of the choroidal defect, but due to the large range of defects, the effect is poor.

2, retinal detachment of the aphakic eye occurs 1 to several years after cataract surgery, because the iris crystal barrier advances, especially in the operation of the vitreous detachment, most of the postoperative vitreous detachment, retinal tears round, 1 ~ Several, can also be scattered in each quadrant, mostly located in the periphery of the fundus, sometimes visible adhesion to the vitreous.

Primary retinal detachment examination

1. Intraocular pressure: the early detachment area is not large, the intraocular pressure is normal or low, and decreases with the expansion of the detachment range. If the detachment is more than one quadrant, the intraocular pressure is significantly reduced, even if it is not measured by the tonometer, the reason why the intraocular pressure drops May be related to the fluid dynamics of the retina from the eye. There is a posterior chamber, vitreous, retinal fissure and subepithelial space in the posterior part of the eyeball. It is transported through the pigment epithelium and then discharged from the extraocular water by the choroidal vascular system. Wrong flow.

2. Slit lamp microscope and ophthalmoscopy examination: the anterior segment of the eyeball is generally normal, the anterior chamber can be slightly deep, and the detachment is long, causing a slight inflammatory reaction of the uveal membrane. The aqueous humor Tyndall phenomenon is weakly positive, and there is a brown spot after the cornea. Sinking.

3. Under direct ophthalmoscopy, the retina is detached and wavy, bulging, undulating with the rotation of the eyeball, fresh detachment of the epithelial layer and its effusion transparent, visible yellow-red or reddish choroidal color under the pigment epithelial layer However, the choroidal texture is not visible, and the retinal blood vessels that crawl and undulate on the surface are formed into a light-blocking body, which has a dark red line. It is difficult to distinguish the arteries and veins, and sometimes a vascular projection consistent with the retinal blood vessels can be seen. The cortex is translucent paraffin-like, the detached arteries and veins can be distinguished, the longer-term old detachment, the neuroepithelial effusion, and the choroidal exudation, fibrin increased, into a light brown viscous fluid, neuroepithelial There are yellow and white spots on the back.

Diagnosis and diagnosis of primary retinal detachment

Primary retinal detachment needs to be differentiated from the following diseases

1. Retinal cleft palate Degenerative retinoschisis is located in the lower peripheral fundus. It is a hemispherical lobe. It is developed by cystic degeneration. The inner wall is thin and transparent, and the outer wall is pigmented. If both inner and outer walls are ruptured, It becomes a true hole and a retinal detachment occurs. Congenital retinoschisis is found in school-age children. It has a family history. The retinal vessels are often accompanied by white sheaths. The lesions are located below the fundus or below the eyelids. The eyes are symmetrical, such as the inner wall is broken. Large split hole, similar to the serrated edge.

2, central serous chorioretinopathy (referred to as "middle pulp") "middle pulp" itself is also a slight detachment of the neuroepithelial layer in or near the macula, is a self-limiting disease that can resolve itself, and primary retinal detachment Different, the retinal detachment invades the common plaque and the visual distortion and the small vision, the same as the "middle pulp" symptoms, should be dilated to check the peripheral part.

3, uveal effusion (choroidal effusion), often accompanied by retinal detachment, hemispherical bulge, easy to move with body position changes, no holes.

4, solid retinal detachment vitreous height opacity, more easily misdiagnosed, can be identified by ultrasound or CT scan.

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