corneal injury
Introduction
Introduction to corneal injury Corneal injury refers to the damage caused by the cornea itself under the influence of external factors or body factors, including corneal abrasion, deep corneal tissue loss, corneal contusion, corneal interlaminar laceration, corneal penetrating injury and rupture injury. The cornea is a anterior convex posterior concave exposed to the outside of the body. It is a curved, avascular transparent membrane with a tough and elastic texture, but it is very fragile and easily damaged. In severe ocular trauma, corneal damage accounts for approximately 51%. The cornea is an important refractive medium. After the corneal injury, different degrees of scars may be formed, or the curvature of the cornea may change, which seriously affects vision. Therefore, corneal trauma should be treated correctly and timely to minimize the formation of scars and astigmatism, in order to retain and restore visual function. If the vision recovery is hopeless, the eye shape should be restored as much as possible. basic knowledge The proportion of illness: 0.005%-0.008% Susceptible people: no specific population Mode of infection: non-infectious Complications: fundus hemorrhage, endophthalmitis, vitreous hemorrhage, lens ectopic
Cause
Causes of corneal injury
1, corneal abrasions are more common in corneal blunt injuries, such as nails, branches, plastic rubber products, sand and other tangential directions on the cornea, causing the corneal epithelium to fall off, the epithelial cell layer and the front elastic layer separation.
2. Deep corneal tissue loss is a deep corneal tissue defect caused by severe corneal abrasion.
3. Corneal contusion is caused by local damage caused by the impact of the cornea by blunt objects, high pressure liquid or gas.
4, corneal interlaminar laceration is caused by contusion of the cornea, some patients with severe corneal invagination and collagen matrix fiber or elastic layer fracture, without corneal perforation.
5, corneal penetrating wounds and ruptures are often caused by sharp objects such as scissors, knives, broken glass, wire, wooden sticks, etc., directly stabbed or cut, blast injury or metal or non-metallic objects splashed during construction work. Impact, such as metal fragments, stones and other causes of full-thickness corneal laceration, can also be seen in severe blunt trauma caused by a sharp increase in intraocular pressure, causing corneal rupture.
Prevention
Corneal injury prevention
Corneal abrasions and contusions, if properly treated, generally have a good prognosis, but if secondary infection, corneal rupture and eye content prolapse are poor prognosis, seriously affecting vision, so in the diagnosis and treatment process, strictly according to aseptic operation Avoid rubbing your hands, and do not use unsterilized handkerchiefs or paper towels to wipe your eyes. Specific dietary recommendations need to consult a doctor according to the symptoms, a reasonable diet, to ensure that the nutrition is comprehensive and balanced, diet should be light, do not eat spicy spicy food, add more protein, vitamins, such as eggs, milk, vegetables, fruits and so on.
Complication
Corneal injury complications Complications, fundus hemorrhage, endophthalmitis, vitreous hemorrhage, lens ectopic
Blunt contusion can cause damage to the eye appendage or eyeball, causing multiple structural lesions in the eye, such as retrograde corner, anterior chamber or vitreous hemorrhage, lens dislocation, choroidal rupture, macular hole and scleral rupture, etc. In severe posterior segmental injury, there may be no or only a slight anterior segmental injury.
Symptom
Corneal damage symptoms common symptoms eye pain eye redness
1, corneal abrasions
The patient's visual acuity decreased, and the corneal sensory nerve endings were exposed. Immediately after the injury, there was severe pain, photophobia, foreign body sensation, eyelids, and a lot of tears. The contralateral healthy eyes also shed tears. The degree of symptoms is related to the extent of the injury. Under the slit lamp, the striated band-shaped lesion of the corneal epithelium or the flaky epithelial defect with clear boundary was observed. The lower part was a smooth and smooth front elastic layer. The pupillary reflex is reduced, and the limbus is congested with ciliary congestion. To further examine the extent of epithelial edema and defect, a drop of 1% to 2% sodium fluorescein solution can be instilled into the conjunctival sac. The corneal epithelial edema or the defect area in the cobalt blue light is bright green. Corneal abrasions are most likely to be complicated by infection, because the corneal epithelium is an important protective barrier for the eye. Corneal abrasions can cause local infiltration of the corneal stroma, causing the symptoms of the pathogens carried by the wounds to worsen.
2, deep corneal tissue loss
Symptoms of corneal abrasions such as pain, photophobia, foreign body sensation, and tearing are present, but are less severe. Under the slit lamp, the edema, thickening and turbidity of the corneal stroma were observed, and the posterior elastic layer showed wrinkles, which may be limited. Sometimes a corneal lamellar laceration can occur and infections and ulcers can be combined.
3, corneal contusion
Mainly manifested as pain, photophobia, tearing, ciliary congestion and decreased vision. Mild corneal contusion causes local corneal tissue damage, visible linear, lattice-like and discoid opacity of the cornea; heavier contusion can cause corneal endothelial cell damage, so that the pumping function in the matrix is weakened or even lost, resulting in corneal inclusion As the amount of water increases, there is a mass or diffuse edema in the corneal stroma.
4, corneal interlaminar laceration
Patients often present with pain, photophobia, tearing, and decreased vision. Patients may have a significant foreign body sensation due to ruptured corneal flap edema or lifting. Under the slit lamp, the torn corneal flap is turned up, curled, and the corneal flap and surrounding matrix edema.
5, corneal penetrating injury and rupture injury
Corneal rupture caused by large external force occurs mostly near the limbus because the structure is relatively weak here. The patient has a clear history of ocular trauma and may experience transient pain and persistent pain after injury. Due to the full-thickness of the cornea and the outflow of water, the patient will feel a hot water flowing out of the injured eye. The injured eye has symptoms such as photophobia, tearing, eyelids and decreased vision due to corneal damage. Most of the corneal wounds are located in the cleft palate, and the Seidel test can be used to determine whether the wound is closed. Larger lacerations or irregular wounds, due to the outflow of aqueous humor, cause the anterior chamber to become shallow, the pupils are pear-shaped or displaced, and the iris is often seen to be invaded at the corneal wound. The iris corresponding to the corneal wound may have iris perforation, and severe contusion may also cause the iris root to be broken, accompanied by anterior chamber hemorrhage. Deeper corneal penetrating injury can cause lens damage. The damage may cause rupture of the anterior capsule of the crystal, opacity of the crystal cortex or spillage into the anterior chamber. It may also cause rupture of the posterior capsule of the crystal. Serious damage may lead to subluxation or even complete detachment of the crystal. Inside the vitreous cavity. Due to the large force of the trauma and the dislocation of the crystal, the vitreous body is often embedded in the anterior chamber, even with the retina, and the slit lamp should be carefully examined and identified.
Corneal penetrating injury caused by foreign bodies, the location of foreign bodies may be anterior chamber angle, iris surface, crystal, and may also be stuck in the retina or stay in the vitreous cavity, causing retinal detachment and vitreous hemorrhage. As the wound carries the infection of the pathogenic microorganism, it can cause suppurative endophthalmitis, which makes the condition worse.
Reduced intraocular pressure is an important sign of corneal penetrating injury. Severe corneal full-thickness laceration caused by retinal, choroidal detachment and ciliary body dissociation due to aqueous outflow, vitreous spillage or trauma, can cause a significant drop in intraocular pressure. In order to prevent the eyeball from causing further damage from the eyeball and aggravating the injury, the intraocular pressure measurement is generally not performed for the patient with corneal penetrating injury, and the intraocular pressure can be initially determined by the fullness and shape of the eyeball.
Examine
Corneal injury examination
Auxiliary inspection:
The corneal epithelial defect can be found by oblique illumination of the focus light (such as a flashlight source). At the same time, attention should be paid to the presence or absence of cornea or conjunctival foreign bodies. In particular, the aforementioned conjunctival foreign body not only has symptoms similar to corneal abrasion, but is often the cause of corneal abrasion, and if the epithelial defect is not found by oblique irradiation, fluorescein staining can be used. The method is to use a 20% fluorescein sodium sterile solution, drop into the conjunctival sac, and the patient closes the eye for 5 minutes, then pauses for a while, then the patient's tears can wash away the remaining dye in the conjunctival sac (if there are still more The dye can be removed by washing with physiological saline, and it is easy to find out because the corneal epithelial defect is stained green.
In addition, since the aqueous solution of fluorescein is a good medium for Pseudomonas aeruginosa and is easily contaminated by such bacteria, causing serious infection of the corneal wound surface, it has recently been dyed with fluorescein paper, that is, a disinfecting fluorescein paper tape, Drop a drop of sterile saline and contact one end with the sacral conjunctiva. In addition, if fluorescein is not used, small inconspicuous scratches can be detected by means of projection. Then, with a good focus light source to cast the cornea, it can be seen that there is a projection on the surface of the iris in the epithelial defect area. If the angle of projection is changed, the projection has a corresponding reverse movement. If the patient is in contact with a hospital in an ophthalmic device, it is of course more convenient to perform a slit-like microscope.
Diagnosis
Diagnosis of corneal injury
diagnosis
It can be diagnosed based on clinical symptoms and laboratory data.
Differential diagnosis
First of all, attention should be paid to the presence or absence of corneal or conjunctival foreign bodies, especially conjunctival foreign bodies, which not only have symptoms similar to corneal abrasions, but also often cause corneal abrasions. Corneal abrasions are caused by focal light (such as flashlight light source). The corneal epithelial defect can be found. If the epithelial defect cannot be found by oblique irradiation, fluorescein staining can be used. If the patient is in contact with the hospital for ophthalmic equipment, the examination of the fracture-like microscope is more convenient.
