Infrared injury
Introduction
Introduction to infrared injury The wavelength of 760nm to 4000000nm occurs in the sun or hot objects, and the long-wave part does not damage the tissue. It can be focused with a lens or mirror, or it can be dispersed with a prism. The biological effect of infrared is mainly a thermal effect. Infrared rays are easily absorbed by dark objects, and high-intensity infrared rays cause tissue necrosis and protein coagulation. The far-infrared rays can only penetrate into the left side of the tissue 0.5cm, and are almost completely absorbed by the cornea and aqueous humor. The near-infrared rays can penetrate the tissue 3~cm to reach the retina, and the iris and the retina are absorbed by the pigment. There are two types of infrared injuries: cataracts caused by short-wave infrared rays and solar-induced retinal choroidal burns. basic knowledge Sickness ratio: 0.0001% Susceptible people: no specific population Mode of infection: non-infectious Complications: edema, pigmentation spots
Cause
Infrared injury cause
1. Cataract caused by short-wave infrared:
Infrared light easily penetrates into the transparent medium and reaches the eye. The refractive interstitial has no blood vessels, and the heat dissipation performance is poor. Moreover, the adjacent grape film can absorb a large amount of radiation, so it is easily damaged and forms a cataract. If the infrared rays are concentrated in the macula, the macula is caused. Department damage.
2, solar retinal choroidal burns:
Mainly caused by the short-infrared and visible light refraction interstitial tortuous points, the thermal energy caused by retinal choroidal burns, more common in the naked eye to observe the eclipse, young people and emmetropic eyes are more common, while high myopia is rare, and The nature of the solar eclipse, the season, the time, and the weather are related to the weather.
Prevention
Infrared injury prevention
Strengthen industrial hygiene education, choose appropriate protective glasses, the lens contains ferrous oxide and GRB colorless mirror, the absorption rate of infrared spectrum is above 90%, can not look directly at the sun, should wear qualified protection when watching eclipse Glasses, such as the newly produced CR-39 optical resin lens.
Complication
Infrared injury complications Complications edema pigmentation
The lesion is limited to the macular area, the color of the macula is darker in the light; the edema is bulging in the light, and there is a small bleeding point. The typical macular fovea has yellow and white spots, surrounding the pigment spots, and severe perforation can be formed. Retinal detachment Wait.
Symptom
Infrared injury symptoms Common symptoms Increased intraocular pressure, visual distortion, color vision, sensation, illusion, pigmentation
1. Cataract caused by short-wave infrared:
The typical change of infrared cataract often starts from the posterior pole. At the beginning of the crystal, there is a small ink-like wheel-like or disc-like opacity in the cortex. It can also be arachnoid turbid, with bright crystals in the center, with turbid thinness and borders. Clear features, another shallow layer of the anterior capsule can be exfoliated, freely curled, freely fluttering in the anterior chamber, which is different from cystic glaucoma, which is often powdery in the anterior capsule exfoliated, starting at the iris Next, gradually covering the front layer of the iris, blocking the anterior chamber angle, and causing an increase in intraocular pressure.
2, solar retinal choroidal burns:
The main symptoms are initially glare, followed by shame, light illusion and color vision abnormalities (red, yellow, blue). After 24 hours, the floating shadow becomes a dense dark spot, which can be a temporary or permanent central dark spot. Vision decreased to below 0.5-0.1, and there is visual distortion, fundus examination: lesions are limited to the macular area, lighter macular color darkens; severe edema edema, gray, small bleeding point, typical macular fovea There are small spots of yellow and white, around the pigment spots, severe cases can form perforations, retinal peeling and so on.
Examine
Infrared injury check
Physical examination
Focus on checking the history of radiation exposure and radiation injury history.
2. Auxiliary inspection
Feasible vision, fundus fluorescein and other examinations.
Diagnosis
Infrared injury diagnosis and identification
diagnosis:
Caused by short-wave infrared:
Cataract caused by short-wave infrared: The typical change of infrared cataract often starts from the posterior pole. At the beginning of the crystal, there is a small ink-like wheel-like or disc-like opacity in the cortex, which can also be arachnoid turbidity. The center has bright crystals. It has the characteristics of thin turbidity and clear boundary. Another shallow layer, especially for the anterior capsule, can be exfoliated, freely curled, and freely fluttering in the anterior chamber. Unlike cystic glaucoma, the anterior capsule of cystic glaucoma exfoliation often appears as powdery debris, starting under the iris and gradually Covering the anterior layer of the iris, blocking the anterior chamber angle, and causing an increase in intraocular pressure.
Retinal choroidal burns:
The main symptoms of solar retinal choroidal burns are initially glare, followed by shame, illusion of light and color vision (red, yellow, blue). After 24 hours, the floating shadow becomes a dense dark spot, which can be temporary or permanent. Dark center of sex. Vision decreased to below 0.5-0.1. And there is distortion of the object. Fundus examination: the lesion is limited to the macular area, the color of the macular part of the light is darkened; the edema of the light is bulging, gray, with small bleeding points. The typical macular fovea has yellow and white small points, surrounding the pigment spots, and severe perforation can be formed. , retinal detachment, etc.
Differential diagnosis:
1. Corneal epithelial injury: corneal epithelial abrasion, the patient's vision loss, obvious pain, fear of light and tears, fluorescein staining in the epithelial defect area, if the infection occurs, corneal ulcer may occur. For corneal epithelial abrasions, it can be coated with antibiotic eye ointment to promote epithelial healing. If the edema of the corneal stroma is opaque, corticosteroids may be applied locally, and if necessary, a mydriatic agent. The corneal laceration should be surgically sutured and treated according to the corneal perforation.
2. Central serous chorioretinopathy: central serous chorioretinopathy, more common in young and middle-aged men, mostly monocular, with self-healing and recurrence tendencies. Unexplained causes, mental stress, emotional agitation, infection, allergies, choroidal venous drainage disorders, and thermal regulation failure can all contribute to central serous chorioretinopathy.
