Partial penetrating keratoplasty

1. Corneal degeneration or malnutrition. 2. Corneal leukoplakia caused by various reasons. 3. Infection (virus, bacteria, fungi, amoeba) caused by uncontrolled keratitis or ulceration. 4. Turbulence after corneal stroma, congenital corneal opacity. 5. Keratoconus (denatured phase). 6. Corneal blood staining. 7. Severe corneal trauma, laceration, chemical injury. 8. After the elastic layer bulges, the cornea is paralyzed. 9. Corneal endothelial decompensation, corneal bullous lesions. Best treatment time: 1. Whole corneal leukoplakia or vasospasm leukoplakia after burn, a full-thickness keratoplasty may be performed 2 years after the lamellar keratoplasty of the modified base. A lamellar or full-thickness keratoplasty for at least six months to one year after sputum adhesion separation; 2. Corneal inflammatory lesions should be controlled after surgery, but progressive active lesions such as deep corneal ulcers should be treated in time for prevention of perforation; 3. Alkali burns should be operated at least 1 year later, but the injury is serious. Post-elastic membrane bulging or near-perforation should be treated in time for therapeutic lamellar keratoplasty. Treating diseases: corneal diseases Indication 1. Corneal degeneration or malnutrition. 2. Corneal leukoplakia caused by various reasons. 3. Infection (virus, bacteria, fungi, amoeba) caused by uncontrolled keratitis or ulceration. 4. Turbulence after corneal stroma, congenital corneal opacity. 5. Keratoconus (denatured phase). 6. Corneal blood staining. 7. Severe corneal trauma, laceration, chemical injury. 8. After the elastic layer bulges, the cornea is paralyzed. 9. Corneal endothelial decompensation, corneal bullous lesions. Contraindications 1. Glaucoma, multiple corneal transplantation failed. 2. Severe chemical burns, radioactive burns. 3. Patients with active intraocular inflammation or inflammation subsided within 3 months. 4. There are nystagmus, amblyopia and severe congenital fundus disease. 5. Nerve paralytic keratopathy, moderate to severe dry eye, orbital defect. 6. Patients with heart and lung dysfunction, severe liver and kidney dysfunction. Preoperative preparation 1. The patient has 0.3% norfloxacin eye drops 1 to 2 days before surgery. 2. 0.25% ecsigmine eye ointment on the night before surgery, or 1% pilocarpine eye drops 2 times before surgery. 3. Infectious keratopathy as a pathogen test (smear test + culture). 4. Chemical burns were examined for tear film rupture time and tear secretion test. 5. Wear through the injury to do b-ultrasound or x-ray film. 6. One hour before surgery, 0.5 g of acetazolamide and 5 mg of diazepam, and 20% of mannitol (4 ml/kg) in children. Surgical procedure 1. Suture or opener opening. The upper and lower rectus muscles are fixed with sutures. Corneal fistula, perforation, aphakic eyes and pediatric patients suture fleiringa rings. 2. Select the trephine according to the range of corneal lesions, generally using a 7-7.5mm ring drill to drill the bed. Adults generally choose a 0.25mm trephine drill than the graft, drill the implant bed and cut the diseased cornea. 3. Drill the graft from the epithelial surface, hold the gauze wrapped around the cornea in the left hand, and place the right hand-held trephine vertically in the center of the donor cornea. After drilling through, cut the corneal graft with the cornea. From the endothelium, the cornea with the scleral flap should be removed. Place the corneal endothelium face up on the cutting pillow and cut the corneal graft with a sharp lap. 4. Fix the graft and place the graft on the graft hole. The 10-0 nylon suture is fixed at 12, 6, 3, and 9. Intermittent suture, generally 16 needles, continuous suture 22 ~ 24 needles, intermittent sutures easy to adjust sutures to reduce astigmatism after surgery, continuous suture stimulation, strict wound closure, reducing operation time. Stitching should reach 4/5 of the corneal thickness. 5. Reconstruct the anterior chamber to inject saline or disinfectant air from the edge of the graft to reduce the anterior iris adhesion and turbidity of the graft to achieve watertightness. 6. Astigmatism examination, using a corneal scattered disc under the microscope to adjust the tightness of the suture. 7. After the subconjunctival injection of gentamicin 20,000 units, dexamethasone 2.5mg, including both eyes. complication Intraoperative complications (1) Insufficient anesthesia: Care should be taken before the eye socket of the recipient. If eyeball rotation, eyelid tension, and intraocular pressure are not sufficiently reduced, measures should be taken actively, such as supplemental anesthesia, eyeball massage or systemic mannitol. Otherwise, it is not advisable to rush to surgery. If the lens-iris compartment is protruded or the vitreous body has a tendency to escape, the factors of extra pressure of the eyeball should be carefully checked. For example, due to insufficient anesthesia, the anesthesia should be supplemented and sutured. (2) open sputum and poor eyeball fixation: inadequate rotatory anesthesia and small cleft palate can cause difficulty in opening, which can be solved by supplemental anesthesia and external hemorrhoids. The upper and lower rectus fixation lines should pass through the muscle 2mm after the abutment. If necessary, use a fixed forceps to grasp the inner rectus or lateral rectus abutment to assist in fixing the eyeball. It should be borne in mind that it is necessary to create a spacious surgical field, otherwise it will be difficult to successfully complete the surgical procedure. (3) Improper drilling and cutting operation: 1 position deviation. Overcoming methods include: marking the center of the cornea and assisting with surveillance. 2 If the resection of the lesional cornea is too large or insufficient, the size of the lesion should be measured with a caliper before the trephine to select the appropriate diameter of the trephine. 3 Rotating the drill causes double cuts or multiple cuts, which is caused by the circumcision leaving the original cut during the relay. Therefore, the hoisting should always maintain a constant downward force, so that you can do it in one go. Never take a few drills and take off the trephine to see if it is drilled. If double or multiple incisions occur, it is an intractable complication. If the situation is complicated and there is a possibility of defect in the implanted tissue, the operation should be terminated and the surgery should be performed after the tissue is healed. If there is still a possibility of remedying, the cut of the selected trephine should be the best at the beginning of the initial position; the second is to select the deeper cut without obvious deviation; the last is based on the principle of free tissue defects. . Especially when cutting the diseased cornea, if the scissors mistakenly enter the tissue defect caused by the incision, the result is very serious. In particular, care should be taken to ensure that such irreparable negligence occurs when the incision overlaps the line of sight. 4 The inclination of the incision is caused by the improper grasping of the trephine or the uneven force. Poor interfacing of the wound edge can cause edema in the recent implants, membrane proliferation after long-term implantation, or loss of corneal endothelium. 5 inner edge is not complete. It is caused by the failure of the scissors to maintain the vertical state and repeated access to the anterior chamber. In this case, the scissors should be trimmed with a thin curved scissors and then sutured. (4) Part or all of the post-elastic film remains: Due to the small puncture hole, it is caused by separating the scissors from the parenchyma. Since the film is transparent, it is easily overlooked. However, it is not difficult to find out because there is resistance when the scissors advance and the cornea is sunken when the scissors go. Once it should occur, the graft should be sutured. (5) Iris-lens occlusion: often occurs in children or keratoconus, mainly because of the low scleral hardness. After the graft is moved to the acupuncture, the 4-needle basic suture should be sewed as soon as possible, which is the most effective way to eliminate this complication. Peripheral iridotomy sometimes works. For example, a posterior vitreous resection is feasible without a lens. (6) Incision bleeding: occurs in the highly vascularized recipient cornea. Precautionary measures: Before the operation, the corneal nutrient eye drops were given to make the vascular degeneration or occlusion, and then the cornea was transplanted. The limbal blood vessels were gently burned during the operation; the preoperative laser photocoagulation proved to be ineffective. The pre-iris adhesion vessels in the wound site can be cauterized by underwater electrocoagulation. The blood clot in the anterior chamber should be washed away. The most effective method of hemostasis should be a good fit between the graft and the implant bed. To achieve this, it should be emphasized that larger grafts are appropriate. It is forbidden to burn and stop bleeding at the wound edge, which will cause the tissue to shrink and the wound is poorly sealed and leaking. (7) Lens injury: preoperative deflation is not enough, tremor is too strong, shallow anterior chamber, the tip of the anterior chamber, the lower page of the scissors, the flushing needle have the possibility of damaging the lens. If the anterior capsule is damaged, it should be removed immediately. If the condition allows, the intraocular lens should be implanted at the same time. If no lens injury is found during surgery, cataract surgery should be performed at least 1 year after surgery for cataract extraction. (8) Problems often encountered during suturing: 1 The tissue level of the implanted bed is poorly matched. As long as the suture is passed through the shallow layer of the posterior elastic membrane, it can be avoided, especially the first 4 needles. 2 The internal margin of the wound edge is opened, and the postoperative complications and long-term complications are as described above. The main reason is because the suture is too shallow or too small. When entering the needle, it should be ensured that the level of the elastic membrane is relatively easy to do on the side of the implant bed. The difficulty lies in the side of the graft. Mainly from the epithelial surface into the needle from the wound edge, the accuracy is not easy to grasp, the key to the operation is the proper use of the scorpion and the close cooperation with the needle holder. The correct use of the scorpion is not able to pull the graft too much. Or reflex, but also to ensure that the wound edge is fully exposed to the field of view, the needle point should be after the nipper clamping point, the force arc of the push pin should conform to the inherent curvature of the needle, and it is easy to grasp the essentials when entering the needle. 3 In the continuous suture (or tight line), the suture is broken: after the joint is finished, the knot should be buried in the tissue, and then the other parts should be sutured; when tightening the line, start from the joint part, The initial knot is then tightened from the joint portion to the initial knot at the other direction to ensure that the joint is buried in the tissue. 4 Misplaced iris: When the cornea is cut off, the scissors disturb the iris too much, causing the iris to be weak; the posterior chamber pressure is high, the deflation is not sufficient, and no bubbles or sticky substances are added. When the anterior chamber is fully formed at the end of the operation, if the pupil is not round, the anterior chamber is still shallow, and the unsuccessful pusher with the restorer is an indication of misinterstation. If it is interrupted suture, the line should be removed and re-stitched; if it is continuous suture, the suture should be cut off and the joint should be repaired. 5 Endothelial injury: There is a possibility of injury at any step of the operation without any attention, but it is easy to be neglected by over-rinsing the anterior chamber after suturing, removing blood clots, repairing the iris, and reducing the concentration of the anterior chamber. It should be taken seriously. 6 improper treatment of vitreous: any cause of the formation of the vitreous into the anterior chamber will pose a threat to the graft, such as secondary glaucoma, pre-iris adhesion, must be properly handled. The glass in the anterior chamber can be gently removed with a dry cotton swab and cut off at the iris plane until the vitreous is below the iris plane. Do not excessively pull the vitreous, otherwise it will cause postoperative retinal detachment and cystoid macular degeneration. Cutting the vitreous with a vitreous cutter will be more effective and safe. In the anterior chamber of the operation, the air is injected into the supine position to return the vitreous body. 2. Postoperative complications (1) Failure of the graft: the postoperative grafts continued to be turbid and aggravated, and the obvious posterior elastic layer wrinkles, indicating the failure of the graft. The cause was excessive intraoperative endothelial damage, poor donor corneal preservation, or donor corneal endothelial dystrophy. If the donor corneal tissue needs early re-transplantation. There are also those who advocate re-transplantation after several months, but the incidence of recent rejection is significantly increased after the new blood vessels are admitted. (2) Infection: caused by bacteria or fungi. Corneal infection showed eye pain, severe congestion, corneal infiltration, anterior chamber empyema, loose suture. Once it occurs, it should immediately find the source of infection, do bacterial culture and drug sensitivity test, and immediately include multiple systemic, local injections of antibiotics and eye drops. The drug selection is based on the principle of broad-spectrum, anti-common bacteria, anti-Pythium pyogenes and anti-fungal drugs. The bacteria are cultured and the results are selectively administered. For the occurrence of endophthalmitis, the donor cornea should be actively searched, and the original grafts should be removed for open vitrectomy (if there is a lens-like lens removal), the vitreous of the abscess should be completely removed and cultured. Replanted with fresh grafts in intermittent sutures. Strict use of antibiotics after surgery. Once the endophthalmitis is diagnosed, the surgery should be decided immediately. (3) anterior chamber hemorrhage: mostly from the bed of severe vascularization. Effective intraoperative hemostasis and good anastomosis are the most effective measures to prevent postoperative bleeding. A small amount of blood can be absorbed by itself without special treatment. A large amount of bleeding should be properly dilated, and increasing intraocular pressure may be effective in preventing continuous bleeding. If secondary glaucoma occurs, the anterior chamber puncture should be done in time, and the hemorrhage block should be punched to prevent the suture from breaking. (4) anterior chamber disappearance or iris prolapse: local factors include anastomotic leakage or tissue defect, loose or broken suture, air bubbles entering the posterior chamber, Uretts-Tavalia syndrome; systemic factors include urinary closure, constipation, cough, excessive separation Bed activities, etc. The tissue defect should be reinforced with silk thread. The loose sutures of the sutures are removed and re-sewed. After suturing, the anterior chamber should be fully formed and the adhesion should be strictly checked. Patients with systemic factors should be treated with catheterization, laxation, antitussive, and restricted activities. Bubbles entering the posterior chamber are often accompanied by anastomotic leakage, which is difficult to maintain due to leakage of the anterior chamber, thereby forcing air bubbles into the posterior chamber. In the presence of a lens, if there is an iris detachment or a clip-in wound, the bubble may exist between the iris and the lens. If the iris is not accompanied by the iris problem, the bubble is pushed into the lens, and the bubble pushes the iris-crystallage forward when the patient is supine. More promote the disappearance of the anterior chamber Adhesion before the occurrence of glaucoma must be dealt with in a timely manner. First of all, pay attention to find the presence or absence of anastomotic leakage and give reinforcement. After the iris is repaired, the anterior chamber is deepened with balanced saline. After the operation, the sitting position or the lateral position allows the air bubbles to self-absorb after leaving the lens. For this reason, it is not necessary to use bubbles to form the anterior chamber. Once the Uretts-Tavalia syndrome occurs, systemic sedatives, supine, and intraocular pressure-lowering agents can generally work, and if necessary, the lens is removed. Choroidal detachment is also one of the causes of shallow anterior chamber. It often occurs after corneal transplantation with glaucoma and aphakic eyes. It is also detected by fluorescein staining without water leakage, but the intraocular pressure is low, the anterior chamber is shallow, and sometimes the indirect ophthalmoscope is used. A brown bulge in the periphery can be found. Early use of hypertonic agents, calcium agents, generally can be self-leveling. If the anterior chamber cannot be formed after 5 days, the choroidal fluid should be placed in time, and the anterior chamber should be injected to form the anterior chamber. Otherwise, the anterior chamber adhesion, iris-anastomosis adhesion, and secondary glaucoma should be caused. (5) Pre-iris adhesion: The main reason is that the suture is not effectively formed in the anterior chamber or the shallow anterior chamber after surgery. The hazard lies in: in the near future, the post-elastic membrane, poor healing of the endothelium, edema of the graft, transparent transfusion, secondary glaucoma; long-term rejection in the adhesion site. Some cases of keratoconus vaginal adhesions in the leukoplakia, some of the surrounding white spots still firmly adhere to the iris, the iris should be separated from the corneal scar during surgery (cut the iris does not hurt the endothelium), and the iris is separated from the corner by sticky substances. Do not rush this sticky substance after surgery to make it short-term support. Otherwise, as the healing process progresses, the adhesion begins to expand from this part. It is often seen in practice that part of the adhesion after surgery eventually develops into extensive adhesion. (6) edema of the graft: mainly manifested as posterior elastic layer wrinkles, planting sputum, should be distinguished from the failure of the graft. Generally, it gradually improves with the time of surgery. (7) Degenerative choroidal hemorrhage: rare in the aphakic eye. Once it occurs, the intraocular pressure rises sharply, and the patient has severe pain and vomiting. In severe cases, the suture is broken and the content is prolapsed. The superior choroidal drainage should be performed urgently. The general prognosis is extremely poor. (8) pupillary block: in the absence of lens surgery, the use of bubbles to form the anterior chamber, the bubble block the pupil caused by the circulation of aqueous humor. Prevention: Intraoperative air bubbles should not be too large, and half of the vitreous cells in the anterior chamber are most prone to this complication. Once it occurs, the pupil should be scattered and the head high, so that the air bubbles leave the pupil. (9) corneal epithelial defect: generally occurs in dry eye and burns, or long-term use of a large number of hormones. Artificial tears, soft contact lenses and bandages, less glucocorticoid eye drops will help epithelial growth.