Glaucoma due to lens dislocation
Introduction
Introduction to glaucoma caused by lens dislocation The change in position of the lens refers to the lens in the posterior chamber under physiological conditions, which deviates from the central position and is clinically characterized by subluxation or total dislocation of the lens, which is collectively referred to as dislocation of the lens. Glaucoma caused by elevated intraocular pressure due to dislocation of the lens is called glaucomaassociated with lens dislocation. basic knowledge The proportion of the disease: 0.2% - 0.7% (the proportion of middle-aged patients above 40 years old) Susceptible people: no special people Mode of infection: non-infectious Complications: edema, vitreous of vitreous and retinal detachment surgery
Cause
Causes of glaucoma caused by lens dislocation
(1) Causes of the disease
Traumatic lens dislocation
Including the contusion and surgical injury, the incidence of traumatic lens dislocation is higher, about half of the lens dislocation is caused by trauma, and glaucoma caused by traumatic lens dislocation is also the most common.
2. Hereditary lens dislocation
Such as long finger - lens subluxation syndrome (Marfans syndrome), short finger - lens subluxation syndrome (Marchesani syndrome), homocystinuria (honocystinuria), no iris, congenital flat cornea, etc., may make the lens Subluxation, an increase in intraocular pressure.
3. Spontaneous lens dislocation may be closely related to some eye diseases, or secondary to other eye diseases, such as high myopia, congenital glaucoma, endophthalmitis, intraocular tumor, perforation of corneal ulcer, etc., spontaneous lens dislocation combined Secondary glaucoma is rare.
(two) pathogenesis
Glaucoma is often secondary to dislocation of the lens, but not all lens dislocations are secondary to glaucoma. Some glaucoma is caused by lens dislocation. In some cases, lens dislocation may be independent of glaucoma, and each is a separate disease.
The pathogenesis of glaucoma caused by lens dislocation is complicated. After the dislocation of the lens, the relative position of the lens and the iris and the vitreous body changes, causing mechanical obstruction of the aqueous humor channel from the posterior chamber to the anterior chamber. The dislocated lens can also be used for the ciliary body. Friction stimulation is generated to increase the amount of aqueous humor. These causes of elevated intraocular pressure may exist at the same time, or may occur separately. The lens that is detached into the anterior chamber may be in direct contact, blocking part of the anterior chamber, and the lens in the anterior chamber will be iris. Pushed to the rear, the posterior capsule of the lens is closely attached to the iris of the pupillary margin, and pupillary blockage occurs. The posterior chamber water cannot flow into the anterior chamber, resulting in a posterior chamber pressure that is significantly higher than the anterior chamber pressure, causing the peripheral iris to stick forward. In the posterior wall of the cornea, atrial angle block occurs, and secondary angle-closure glaucoma occurs. After the lens is completely dislocated into the vitreous, vitreous hemorrhoids may occur, which may cause pupillary block, or the dislocated lens may continue to collide with the ciliary body in the vitreous. Friction stimulation increases the secretion of aqueous humor, and secondary open angle glaucoma occurs. When the lens is subluxated, the vitreous passes through the lens. The gap between the pupillary margins protrudes into the anterior chamber, hindering the aqueous humor from flowing into the anterior chamber from the posterior chamber. The dislocated lens can also be tilted to one side, and the iris is forwardly moved to the front of the iris. Sometimes the dislocated lens can be clamped in the pupil. In the site, pupillary block is formed directly. In some cases, due to long-term pupillary block, the anterior adhesion of the iris is formed. Although the pupillary blockage factor is eliminated, the intraocular pressure is still elevated.
Prevention
Glaucoma prevention caused by lens dislocation
Pay attention to labor protection and work safety.
Complication
Glaucoma complications caused by lens dislocation Complications edema vitreous and retinal detachment surgery caused by glaucoma
Detachment of the anterior chamber causes keratitis to be decompensated and edematous, and devitrification into the vitreous causes vitreous block glaucoma.
Symptom
Symptoms of glaucoma caused by lens dislocation Common symptoms Glaucoma calcification, aphakic eye, diplopia, elevated intraocular pressure, visual dysfunction, swelling of the anterior chamber...
The main symptoms of subluxation or total dislocation of the lens are visual impairment. When the lens is subluxated or tilted, the lens may have myopia and astigmatism. For example, the equator of the lens is located in the center of the pupil, which can produce monocular diplopia and complete lens detachment. When the vitreous body is away from the pupil area, the refractive state of the aphakic body can occur. Careful examination can reveal that the lens is distorted when the lens is dislocated.
The lens is completely dislocated into the anterior chamber, so that the anterior chamber is deepened and the iris is tilted backward. When the light is illuminated, the equator of the lens has a yellowish reflection and exhibits an oil-drop appearance. If the lens has become turbid, it is gray lentils attached to the posterior surface of the cornea. The lens adheres to the posterior wall of the cornea, causing damage to the corneal endothelium, opacity of the cornea, and 78% to 93% of the lens can be glaucoma, which is a symptom of acute angle-closure glaucoma. When the lens is dislocated, the anterior chamber is deepened. The angle of the room is widened. If the lens is not fully dislocated, the depth of the anterior chamber may be different in the same anterior chamber. The anterior chamber of one part becomes shallow, and the corner of the anterior chamber can be found by the corneroscopy. Narrow or closed, the dislocated lens or the vitreous protruding into the anterior chamber obstructs the pupil in the slit lamp microscope. The lens that enters the vitreous often shows calcification, floating in the vitreous or adhering to the retina, and a few cases of lens protein occur. Decomposition, causing uveitis, iris keratoconus and trabecular meshwork blocked by macrophages.
Examine
Examination of glaucoma caused by lens dislocation
Genetic testing excludes Marfan's syndrome, Marchesani syndrome, homocystinuria and other hereditary diseases.
When the lens is dislocated slightly, a careful slit lamp microscope, a corner mirror and a fundus examination should be performed and compared with the contralateral eye to distinguish it from primary glaucoma.
Diagnosis
Diagnosis and diagnosis of glaucoma caused by lens dislocation
Glaucoma is often secondary to dislocation of the lens, but not all cases are complicated with glaucoma. When the intraocular pressure is elevated and the signs of dislocation of the lens are obvious, the diagnosis can generally be determined.
