Traumatic dislocation lens extraction

Under normal circumstances, the lens is suspended by the lens suspensory ligament on the ciliary body, and the anteroposterior axis of the lens is almost identical to the visual axis. If the lens ligament is partially or completely broken or defective, the suspension force can be weakened and asymmetrical, resulting in abnormal position of the lens. If the lens is not in the normal position at birth, it is called ectopic lens. If the position of the lens changes due to congenital factors, trauma or some diseases after birth, it is called dislocation of the lens. The causes include congenital suspensional ligament hypoplasia or relaxation weakness; trauma causes suspensory ligament rupture; some lesions in the eye, such as grape swelling, bull's eye or eyeball expansion, cause the suspensory ligament to mechanically elongate, intraocular inflammation such as ciliary body inflammation Ligament degeneration can cause dislocation or subluxation of the lens. Curing disease: Indication The lens is located in the anterior chamber, the subluxation stimulates the glaucoma, and the entire dislocation is located in the anterior vitreous. Contraindications The lens is removed from the posterior vitreous or posterior pole. Preoperative preparation 1. Comprehensively evaluate the systemic and local lesions and perform necessary treatment. 2. Topical application of antibiotics was started 3 days before surgery. The conjunctival sac and lacrimal passage were washed with 0.25% chloramphenicol or gentamicin on the day of surgery. Surgical procedure The complete removal of the lens in the anterior chamber is still removed as a classic procedure with a corneal incision, but it should be noted that a layer of viscoelastic material should be applied between the lens and the corneal endothelium before the lens is pulled out. It is not recommended to use the general cataract to pull the nucleus to pressurize the lower edge of the cornea, but the frozen head should be used to stick the upper pole of the lens and slowly pull it out. Completely removing the lens in the anterior vitreous body, it is the simplest and practical to evaluate the fundus of changing the position before the treatment is determined. When the patient is in the supine position, if the dislocated lens is still located in the lower anterior vitreous, the lens can be removed after the corneal incision and the anterior chamber vitreous should be treated after the incision is sutured. If the lens is in the lower vitreous when sitting and the lens is moved to the posterior in supine, the lens must be removed by vitreous surgery. The lack of adequate preoperative evaluation and inadequate surgical preparation, the intraoperative lens moved to the posterior pole, the conversion surgery is more difficult. It is better not to blindly fish the lens in the dark environment of the eye, which is quite risky. Sometimes it is difficult to determine which procedure to take before surgery. The wise choice is to pre-fill the needle at the 3.5mm scleral posterior margin of the iliac crest, but not to establish perfusion. Once the lens is removed through the corneal incision, it can be established immediately. Perfusion and transfusion of vitreous surgery. Don't underestimate such an operation that seems redundant, but it creates great mobility for surgery. More importantly, it provides a safety guarantee for the operation. Even if the surgery is successful, the removal of the perfusion head is a matter of doing things. But remember: before establishing the perfusion, you must check that the perfusion head is indeed in the vitreous cavity! The semi-dislocated lens indicates that some of the ciliary zonules have not yet been broken, and the dislocation to the posterior pole during surgery may not be large, so the risk of surgery is also small. It is easier to remove it with a spoon by a limbal incision. Also pay attention to the treatment of the anterior chamber vitreous after suturing the incision. After the removal of the semi-dislocated lens, most of the eye pressure of the injured eye can be stabilized, and it is generally not necessary to cooperate with the external filtration surgery. Extracorporeal filtration surgery is only considered if the intraocular pressure is still difficult to control after surgery and there is extensive angular damage. complication The main complication of lens removal in the anterior chamber is corneal endothelium injury. The intraoperative incision is large enough, the application of viscoelastic material and the operation to avoid damage to the endothelium are fundamental measures to prevent endothelial injury.