goniectomy

Congenital glaucoma is caused by dysplasia of the anterior chamber angle during the fetal period, and is mostly present at birth. Because the eye wall of infants and young children is easily expanded by the action of high intraocular pressure, the whole eyeball is continuously enlarged, so it is called "water eye". Congenital anomalies of the anterior chamber are mainly: 1 anterior chamber angle structure is not developed or underdeveloped, scleral sinus and trabecular mesh occlusion; 2 ciliary muscle front end beyond the scleral process, into the trabecular tissue or sinus; 3 rooms The horn is covered by a layer of mesenteric residual membrane, which causes the outflow of aqueous humor to be blocked and the intraocular pressure to rise. Under the effect of sustained high intraocular pressure, the eye wall expands and the rear elastic layer ruptures, resulting in strip turbidity. The angle of the sclera is widened and thinned, and its width can reach more than 5mm. The anatomical landmarks of the limbus and their relative relationships also change greatly. Congenital glaucoma should be treated surgically in the early stage. The purpose is to cut the residual membrane of the mesoderm in the corner of the anterior chamber and reduce the resistance of the aqueous efflux. It is especially effective for children with a complete development of the anterior chamber. The currently used surgery is anterior chamber angle incision and external trabeculectomy. The success rate of anterior chamber angle surgery was 50% on average, and it was reported to reach 70%. The success of the operation is that the optic nerve injury is stopped, the optic cup is no longer enlarged, the corneal edema subsides, and the visual acuity is restored. However, because of poor child cooperation and inconvenient examination, intraocular pressure is still one of the important indicators for determining the effect of surgery. In recent years, dynamic visual field examination and visual evoked potential examination have been used to evaluate visual function status. The success rate of 2 to 3 operations was 75 to 95%. There were other abnormalities in the eye and general anomalies, and the surgical results were poor. In 5% of children, the intraocular pressure increased significantly within a few years after surgery. The success rate of trabeculectomy is higher than that of anterior chamber angle incision, reaching 90%. Accurate anatomical positioning is the biggest advantage of this procedure and is currently the preferred procedure for the treatment of congenital glaucoma. Most of the failure of trabeculectomy occurred 1 year after surgery. The main factor was the failure to find the scleral sinus during the operation; the length of the incision was not sufficient; the trabecular adhesions were still possible, and the reoperation was still possible. In order to ensure the surgical effect, trabeculectomy can be combined. Treating diseases: congenital glaucoma Indication 1. Congenital glaucoma, as well as Barkan membrane covering trabecular meshwork is preferred; 2. Youth glaucoma, elevated intraocular pressure due to trabecular blockage; 3. Secondary glaucoma due to trabecular blockage. Contraindications 1. The corner of the corner is scarred, the trabecular bone and the iris adhere to form scar tissue, and the iris plane of the scar area moves forward, causing the surrounding iris to be uneven. 2. Obvious corneal opacity, can not see the corner structure. Preoperative preparation 1. Introduce the surgical goals and possible risks to the parents in order to get their support and cooperation. 2. Pay attention to whether the child's nasal lacrimal duct is smooth. 3. Preoperative eye drops with antibiotic eye drops. 4. Dilute 1% pilocarpine 1 hour before surgery to reduce the pupil. 5. If corneal edema, anti-ocular pressure medication can be applied, and the cornea is transparent before surgery. If it is only corneal epithelial edema, some corneal epithelium can be removed after surgery and anterior chamber angle incision can be performed. 6. Amplification equipment and anterior chamber angle cutting knife (1) A binocular magnifier with a magnification of 2 times, or a surgical microscope with coaxial illumination, 6 to 20 times magnification, and a mirror axis of 30 to 60 degrees can be selected. (2) anterior chamber angle mirror for surgery: Barkan type, Worst type and Swan-Jacob type are commonly used. (3) anterior chamber angle cutting knife: commonly used Barkan, Swan and Swan needle type anterior chamber angle cutting knife. (4) Opener for children, and self-locking fixation. 7. Basic anesthesia combined with local anesthesia, or general anesthesia. 8. Conjunctival sac culture should be done when conditions are available. Surgical procedure Lateral angle incision Lateral angle incision is a method of incision of the nasal side angle through the temporal corneal incision. 1) The surgeon sits on the side of the eyelid, and the head of the child is deflected to the opposite side of the operator by an angle of 30° to 40°, so that the anterior chamber corner portion to be cut can be directly seen through the microscope eyepiece. 2) Open the device. Check the cornea. If there is corneal edema, drop 1-2 drops of pure glycerin to keep the cornea dehydrated, or scrape the edema of the corneal epithelium. 3) Hold the corneal limbus with the gums and turn the eyeball so that the upper rectus muscle and the inferior rectus muscle are clamped by the self-locking fixation. 4) Gently place the anterior chamber angle mirror (with the Barkan front angle mirror as the side) on the cornea. The mirror should be biased toward the nasal side of the cornea so that the anterior chamber angle incision enters the anterior chamber from the half-moon portion of the exposed temporal cornea about 2 mm wide. The operator's left hand indicator can fix the anterior chamber corner mirror. 5) The anterior chamber angle incision knife penetrates the cornea 1 mm from the temporal margin of the temporal side, parallel to the iris surface, and slowly advances across the pupil area to the nasal anterior chamber angle. Pay attention to the direction of the feed. 6) Look at the anterior chamber angle and cut the tip so that it reaches the first 1/3 of the trabecular meshwork. Pierce into the 4 o'clock position (right eye) about 0.5mm inside the trabecular meshwork, turn the knife tip against the clock, and slowly cut the trabecular tissue. The cutting range is approximately 120°. 7) The surgeon should see the incision after the tip of the knife. At this time, it can be seen that the root of the iris is retracted backward, and the local anterior chamber is widened, and the incision tissue is a pale gray-white tissue boundary line. 8) After the anterior chamber angle is cut, remove the anterior chamber angle and cut the knife. 9) Check if the corneal incision is good, otherwise you can suture 1 needle with a 10-0 nylon thread. For the simultaneous binocular surgery, it should be strictly disinfected before surgery, and the surgical field and surgical instruments should be avoided during the operation. The contralateral eye surgery method is the same as in the first phase, and the angle of the incision is still rotated counterclockwise (10 to 8 o'clock) (Fig. 8.7.3-7 to 8.7.3-9). 2. Direct angle incision This kind of operation does not require the use of the anterior chamber corner mirror, and directly cuts the corner of the room under direct vision, so the operation is simple. Suitable for second surgery and cases with corneal opacity. 1 preoperative preparation is the same as anterior chamber angle incision. 2 The surgeon sits directly above the patient, the microscope shaft maintains a vertical position, the opener opens the eyelid, and the upper rectus suture is pulled and fixed. 3 Make a 5mm arc incision in the horizontal limbus, make a radial incision at each end of the incision, and extend to the posterior anterior chamber angle to make it a scleral-based angular scleral flap with a width of 1~ 1.5mm, about 2/3 sclera. A suture is sewn in the middle of the flap. 4 1mm corneal puncture in the nearby limbus, a little sodium hyaluronate injected into the anterior chamber. The assistant gently lifts the preset suture and opens the entire corner of the sclera to the back for peripheral iris resection. 5 Increase the magnification of the microscope to about 16 times, and see the structure of the corner structure. The angle of the incision knife is facing the trabecular meshwork in front of the sclera, and the trabecular tissue is cut horizontally. At this time, the root of the sclera recedes, and the position of the incision portion presents a wide gray line. 6 assistants relax the preset line, ligature, and add 1 stitch to the flap angle, balance the saline solution to wash the anterior chamber, and replace the sodium hyaluronate.

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