Traumatic cataract

Introduction to traumatic cataract Any cause such as aging, genetics, local dystrophies, immune and metabolic abnormalities, trauma, poisoning, radiation, etc., can cause lens metabolism disorders, resulting in lens protein denaturation and turbidity, known as cataract. At this time, the light is blocked by the opaque lens and cannot be projected on the retina, so that the object cannot be seen. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: total uveitis glaucoma eyeball rupture sympathetic ophthalmia

Causes of traumatic cataract

(1) Causes of the disease

Lens caster (35%):

Mostly caused by boxing or ball or other objects hitting the eyeball, the water conduction causes external force to act on the lens lacking elasticity, and also rebounds on the surface of the vitreous. Therefore, the blunt contusion causes diversity of lens opacity, that is, Vossius annular turbidity. Rose turbid, nucleus cataract, point cataract and total cataract, in blunt cataract, trauma causes destruction of lens epithelial function, leading to edema and degeneration of superficial cortical lens fibers, resulting in a localized and permanent thin layer of air In the vesicle area, as time progresses, new normal lens cells are formed, and the injured epithelial layer is compressed and embedded, thereby entering the deep cortex and finally forming turbidity.

Eye penetrating injury (30%):

The penetrating injury of the eyeball causes the lens capsule to rupture, and the aqueous humor enters the lens, causing fiber edema, degeneration and turbidity. If the perforation is minimal, it can be closed by itself, causing the lens to have limited local opacity, no longer develop, but the lens capsule is damaged. After that, most people's cortex rapidly appeared turbid, and the large perforation may also cause secondary glaucoma due to excessive expansion of the lens cortex.

Other factors (10%):

Such as eye damage caused by electric shock.

Pathogenesis

In the basic research of traumatic cataract, it was found that various emergency factors, such as oxidizing substances, ultraviolet rays and toxic substances, can initiate apoptosis of lens epithelial cells. Therefore, it is considered that lens epithelial cell apoptosis is non-congenital cataract in humans and animals. A general cytological basis, a rat model of blunt traumatic cataract has been established in China, and the ultrastructure of lens epithelial cells in SD rats has been significantly changed: nuclear membrane damage, invagination, chromatin condensation; mitochondria The structure is destroyed, the vacuole-like changes, the number is reduced; the endoplasmic reticulum is expanded, which is consistent with the morphological manifestation of apoptosis. It can be seen that the occurrence of blunt cataract may be related to the apoptosis of lens epithelial cells.

Studies have found that the accumulation of extracellular matrix is initiated during the healing of lens trauma after penetrating wounds. The main components include chondroitin sulfate, heparin sulfate and collagen. The accumulation of extracellular matrix under the capsule not only causes wrinkles of the lens capsule. The pleats also enhance the adhesion, proliferation and migration of lens epithelial cells, eventually leading to opacity of the lens. Matrix metalloproteinases (MMPs) and their transplanted TIMPs play an important role in the accumulation and degradation of extracellular matrix, MMPs. Promote the accumulation of extracellular matrix, and TIMPs promote degradation. In the study of rabbit penetrating cataract model, the activity of TIMP-1,2 in injured eyes increased significantly on the first day after injury, and then decreased gradually, while MMPs- 2 The change in activity corresponds to this, that is, it is inhibited on the first day after the injury, and then gradually recovers. Therefore, it is presumed that the transient increase of TIMP-1, 2 in the eye of the rabbit changes the balance of MMPs/TIMPs, and may have Antagonizes the degradation of extracellular matrix by MMPs and inhibits the development of intraocular inflammation after injury, resulting in extracellular matrix remodeling and cell proliferation after tissue injury Multiplexing process is enhanced, thereby promoting wound healing, but the excessive accumulation of extracellular matrix and cell proliferation, it could lead to lens opacification.

Traumatic cataract prevention

Traumatic cataract should start from prevention, starting from children, should educate children not to hold sharps, do not play toys that cause eye damage, do not set off fireworks and firecrackers, avoid eye trauma, once eye trauma occurs, Should be taken to the hospital in time, adults pay attention to protect the eyes at work and life, mechanical workers, refining workers should pay attention to safe operation, wear protective glasses, avoid various mechanical damage and radiation damage, long-term contact or Technicians engaged in microwave work should wear anti-microwave glasses.

Traumatic cataract complications Complications, uveitis, glaucoma, eyeball rupture, sympathetic ophthalmia

Easy complicated with uveitis, secondary glaucoma, lens dislocation, eye content prolapse, intraocular hemorrhage, eyeball rupture, intraocular foreign body, sympathetic ophthalmia, etc.

Traumatic cataract symptoms Common symptoms Lens opacity, eyelid dislocation, color vision loss, diplopia, visual acuity, pigmented edema, intraocular pressure, eyeball perforation, fundus

(a) blunt cataract cataract

The contusion cataract is rare in clinical practice and can occur alone or in combination with subluxation or total dislocation of the lens. The earliest change is the posterior subcapsular opacity of the pupil area, which forms a star similar to the complicated cataract. Appearance or chrysanthemum turbidity, turbidity can be stable for a long time, can also slowly extend to the depth and breadth, and finally develop into an all-white cataract, it is worth mentioning, turbidity changes do not immediately appear after blunt contusion, but only in the past, the transparent area under the posterior capsule disappears Characteristic, this state can last for several months or even years to form a typical cataract change, the so-called delayed traumatic cataract. In mild cases, the subcapsular epithelial cells can maintain normal activity, with the formation of new fibers, turbidity The zone can be gradually squeezed deep into the ground, presenting a partially retreating state of rest.

In most cases, traumatic iridocyclitis can be combined with post-pupil adhesion. In severe cases, secondary glaucoma such as iris bulging can also occur. One case is related to trauma, that is, the impact external force in front. The iris pigment ring corresponding to the pupil can be printed on the surface of the anterior capsule of the lens, which is called the Vossius ring. It is composed of pigment particles detached from the iris, sometimes mixed with a little red blood cells, such as without the opacity of the lens, generally does not affect vision. .

Can be caused by boxing or ball and other objects hitting the eyeball, contusion cataract has different clinical manifestations, mainly divided into the following five categories:

1. Vossius is annularly turbid, has annular turbidity on the surface of the crystal, and has a pigment of 1 mm width. These turbidity and pigmentation spots can gradually disappear after several days, but they can also exist for a long time.

2, rose pattern cataract due to the impact of the crystal, the structure of the fiber and the seam is destroyed, the liquid moves between the seam and the layer, forming a radial turbidity, such as rose patterns, this type of cataract can be hours or weeks after the injury Occasionally, some patients may be absorbed by turbidity; others may occur only a few years after injury, mostly permanent. In patients under 30 years old, crystal opacity may remain unchanged for many years until turbidity increases after 50 years of age, and vision gradually decreases. .

3, point cataract Many small turbidity points are located under the epithelium, usually after a period of time after the injury occurs, rarely progress, little effect on vision.

4, lamellar cataract due to the integrity of the crystal capsule is affected, permeability changes, causing shallow cortical opacity.

5, the cataract eye is more severe contusion can make the crystal capsule rupture, aqueous humor into the cortex, the crystal can be completely turbid in a short time, after a period of time, the cortex can be absorbed.

In addition to traumatic cataract after eye contusion, anterior chamber hemorrhage, anterior chamber angle retreat, lens dislocation or displacement, elevated intraocular pressure and fundus changes, plus attention disorder.

(2) Cataract caused by penetrating injury

Adult penetrating cataracts are more common in car mechanics and fitters, and iron foreign bodies are worn into the eyeballs; children's penetrating cataracts are more common in knife and scissors and toy stab wounds, cataracts can be limited to turbidity, or static can no longer develop; but most are After the rupture of the crystal capsule, the aqueous humor enters the cortex and causes the crystal to turbid quickly. It can be accompanied by iridocyclitis, secondary glaucoma and intraocular infection.

Cataract caused by perforation of the eyeball, this type of cataract is usually accompanied by complicated perforation of the eyeball. Therefore, its clinical course and prognosis are different. In young patients, such as large rupture of the capsule, the lens is rapidly caused by aqueous humor. Fibrillation and turbidity, chyle-like substances can quickly fill the anterior chamber, even from the corneal wounds, the results on the one hand affect the corneal endothelium metabolism, making it edema turbid, on the one hand blocking the aqueous outflow channel and causing elevated intraocular pressure, Secondary glaucoma occurs.

In some cases, the above rupture of the capsule is small and the above sharp changes do not occur at all. The lens remains intact, only local opacity occurs, and it can be static for a long time. This is because small capsule damage can be repaired by lens epithelial cells. And self-healing, or covered by the iris tissue on it and blocking occurs.

Between the above two conditions, there is still a possibility of spontaneous absorption, that is, after penetrating injury, the process of massive exudation of the cortex into the anterior chamber has never been experienced, but the capsule damage cannot be self-healed by repair, thus making the lens The cortex is in the "dipping bath" of aqueous humor for a long time, so that it continues to absorb the lens cortex. As a result, when most of the cortex is finally absorbed, the front and rear capsule walls are attached to form a so-called membranous cataract.

(3) Cataract caused by blast injury

Miners may cause similar to traumatic cataracts due to explosions during mining and firecrackers in children's eyes. Under normal circumstances, damage to the eye tissue is more serious.

The occurrence of traumatic cataract is related to the degree of injury. If the lens in the pupil area is injured, the vision loss will occur quickly; the crystal injury behind the iris will cause a slower decline in visual acuity; the capsule is extensively destroyed, in addition to visual impairment, With obvious inflammation of the anterior segment of the eye or secondary glaucoma, in the examination of traumatic cataract patients, it is necessary to pay attention to the presence or absence of intraocular foreign bodies, and sometimes the wound of the sclera is difficult to detect and cause misdiagnosis.

(4) Crystal rust

Iron is the most common intraocular foreign body. Foreign matter in the crystal can form a localized cataract. If the iron foreign body is small, it can exist in the crystal for many years without obvious reaction. Iron can be oxidized in the eye and gradually in the eye. Diffusion, the formation of eye rust, including the cornea, iris, lens, retinal rust, eventually leading to blindness, the rust of the eye is related to the size and position of the foreign body in the eye, the larger and the iron in the back of the eye is easy to the eye After the section moves.

There are small brownish yellow spots under the anterior capsule of the initial crystal, and there are brown rust spots under the anterior capsule in the late stage. The initial stage must be enlarged after the pupil is enlarged. The late stage crystal fiber degeneration gradually develops into an all white cataract, and finally the crystal is curled, or Due to the degeneration of the suspensory ligament, the cataract occurs because of the cataract caused by the absorption of iron by the epithelial cells, and the growth of new fibers is blocked. At this time, even if the cataract is removed, the visual acuity cannot be recovered quickly.

Lens rust, copper rust: eyeball perforation, such as foreign bodies in the eye, may be more complicated, on the one hand is the direct consequences of mechanical acute injury; on the other hand, the physical and chemical properties of the foreign body itself to the lens chronic damage, Of particular significance is the long-term persistence of copper and iron, which are prone to oxidation, in the eye, resulting in so-called "chalcosis lentis" and "siderosis lentis", the turbid form of the former is mostly sunflower The appearance is copper-green reflective; the latter is part of the denaturation of the entire ocular tissue, and the lens is cloudy and yellow.

(5) Crystalline copper deposition

If the copper content is more than 85%, it has obvious damage to the eye tissue. Pure copper can cause suppurative changes in the eye. The cataract caused by copper foreign matter in the crystal can cause iridocyclitis in the anterior chamber. In the posterior pole, damage to the optic nerve, retina and choroid is caused. Copper ions are deposited in the tissues of the eye as copper rust. The posterior corneal elastic layer can have a blue-green ring (Kayser-Fleisher ring), and the iris becomes pale green. There are many color bodies in the vitreous, green pigment in the retina, sunflower-like cataract due to copper deposition, rainbow-like changes in the pupil area, crystal surface such as velvet, crystal posterior capsule such as green shark grass, sunflower-like cataract The effect of vision is not very serious. If there is copper foreign matter in the crystal, it must be taken out as soon as possible, because even if there is tissue wrapped around the foreign body, it will cause necrosis of the eye tissue and cause blindness, which is different from the iron foreign matter in the crystal.

(6) Electric shock cataract

Catching high voltage or being struck by lightning can sometimes cause cataracts in both eyes. The shape is similar to blunt cataract, but it develops much faster and can be turbid in weeks or even days.

1. History of trauma: There are signs of trauma in the eye of this disease.

2. Vision loss: the patient has blurred vision, single eye double vision or multiple vision, or vision quickly drops to light perception.

3. Lens opacity: turbidity is localized or diffuse. Turbidity mainly occurs in the cortex, also in the nucleus. It is rare in the capsule. This is because the capsule is thin, elastic, and the capsule is broken after injury. The outer or inner pleats, the thickening of the capsule or the scarring of the epithelial proliferation, forming a "capsule opacity".

Traumatic cataract examination

Understand the whole picture of the crystal, check it in the dark room after fully diverging, the specific method is as follows:

First, the focus lighting inspection method: direct illumination with light to see if the crystal is turbid and dislocated.

2. Iris projection method: The thin light is projected at 45 degrees from the pupil edge to the crystal. If the crystal turbidity is located at the core, there is a crescent-shaped transparent area between the turbid area and the pupil edge. The heavier the turbidity, the narrower the shadow. If the crystal is completely turbid, the crescent shadow disappears completely.

Third, the ophthalmoscope according to the law: the light into the pupil area, normal uniform red shadow, such as crystal or refractive interstitial opacity, it can be seen in the red shadow there are black spots or black blocks, the patient can be rotated when examined Eyeball, see if the shadow moves or not to understand the turbid part.

IV. Slit lamp inspection method: The slit lamp is used for optical section inspection. From front to back, there are many layers of light and dark layers, which represent the nucleus of the lens at different periods. The transparency of each layer is not completely consistent. The former capsule, the adult anterior surface And the surface of the embryo is relatively clear.

When emergency surgery is needed, routine tests such as blood routine, PT, APTT, blood biochemistry, etc. are required before surgery.

For cases of complicated ocular trauma, in the early stage of the disease, when the refractive interstitial involvement is unable to peek into the intraocular condition, it is necessary to use B-ultrasound, X-ray and CT to determine the internal damage of the ball. When foreign matter remains, it needs to be positioned and the foreign body is taken out. Methods: In the late stage of trauma, after the intraocular condition was stabilized, corneal endothelial cell count, electroretinogram (ERG) and visual evoked potential (VEP) were performed according to the routine preoperative cataract. The postoperative visual acuity was predicted.

Diagnosis and diagnosis of traumatic cataract

Differential diagnosis

1. Radiation cataract:

(1) The patient has a history of radiation.

(2) Chronic X-ray and other radiation damage to the lens, turbidity often starts from the posterior pole, and there may be three types of posterior subcapsular vesicles in the posterior capsule, haze turbidity in the posterior capsule, and flaky opacity in the posterior capsule. Occurs, but mostly mixed.

(3) There are vacuoles in the cortex of the posterior capsule. The vacuoles are small and round, or remain unchanged for a long time, or become a small white spot through cheese. They cannot absorb themselves and gradually expand to the front and the equator.

(4) For a long time, the cortical opacity of the posterior capsule is mostly foggy and dotted, and the whole is thin and round. The initial stage is limited to the radius of 2mm near the posterior pole, and is close to the posterior capsule and far from the posterior nucleus. .

2. High myopic posterior capsule cortical opacity: often brown, and the cortex is completely turbid after self-nuclear.

3. Diabetic lesions caused by diabetes: Although it can be located in the posterior capsule of the posterior capsule, small vacuoles are large, not round, and the number is large. The integrated group, which is fused to each other, can be enlarged or reduced, and the vesicles caused by radiation are mainly located. Under the posterior pole posterior capsule, it does not reach the posterior pole. Its characteristics are small and round, and the vesicles are stable in shape and long-term unchanged. These vesicles are different from those caused by diabetes.

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