phacoemulsification cataract extraction

In general, phacoemulsification can be performed in all cases suitable for extracapsular cataract extraction. However, in the case selection, the relative selection criteria should be determined according to their own technical conditions. The following conditions should be used as reference for selection: 1. It is safe to have a large pupil at least 6 mm before the pupil. Beginners must not choose small pupil cases. 2. The corneal cornea is completely transparent and is the basic condition for phacoemulsification. Localized opacity, degeneration, and other lesions that affect its transparency are not suitable for this procedure. 3. The depth of the anterior chamber must be maintained in the anterior chamber, so the intractable shallow anterior chamber should be carefully considered when selecting cases. 4. Lens nuclear hardness beginners should choose a case with appropriate nuclear hardness. With the continuous improvement of proficiency, the range of choice can be continuously expanded. Treating diseases: cataracts Indication In general, phacoemulsification can be performed in all cases suitable for extracapsular cataract extraction. However, in the case selection, the relative selection criteria should be determined according to their own technical conditions. The following situations should be referenced when making choices: 1. Pupil: It is safe to have a large pupil at least 6mm before surgery. Beginners must not choose small pupil cases. 2. The cornea: the cornea is completely transparent is the basic condition for phacoemulsification. Localized opacity, degeneration, and other lesions that affect its transparency are not suitable for this procedure. 3. The depth of the anterior chamber: the anterior chamber must be deep enough during surgery, so those who are intractable shallow anterior chamber should be carefully considered when selecting cases. 4. Lens core hardness: Beginners should choose a case with appropriate nuclear hardness. With the continuous improvement of proficiency, the range of choice can be continuously expanded. Contraindications 1. Cataract with a very hard core (black or partially dark brown nucleus), dislocation or subluxation cataract is not suitable for phacoemulsification. 2. Corneal opacity, intractable shallow anterior chamber, pupillary rigidity, small eyeball small cornea and so on. Preoperative preparation 1. Comprehensive evaluation of systemic diseases and lesions. 2. Start 3 days before surgery, eye with antibiotic eye drops, clear on the day of surgery, rinse the conjunctival sac and lacrimal duct with 0.25% chloramphenicol or gentamicin solution. Surgical procedure 1. Incision: Cut the conjunctiva about 6 mm along the upper limbus, and peel back to expose the sclera to fully stop bleeding. 2mm behind the angle of the sclera, the scleral lamellar incision is parallel, the depth is about 1/2 of the full thickness of the sclera, and the length should be determined according to the size of the lens to be implanted. Slotting from the incision to the limbus, and entering the transparent cornea 1 mm, forming a scleral tunnel. The 3.2 mm puncture knife was used to puncture into the anterior chamber to form a flap-shaped inner port with a self-closing function. The outer surface of the sclera can also be formed into a straight line to form a reverse eyebrow. 2. Capsule: Continuous circular capsulorhexis (ccc) is a typical technique for phacoemulsification. A small triangular flap was made in the anterior capsule of the proximal middle portion by the capsular needle, and the free side was reversed. The inverted capsule was gently pulled by the capsular needle, and the circular tear was pulled in a predetermined direction to make the tear continuous. The arc extends until a circular tear of 6 mm diameter is formed. During the process of capsulorhexis, the pulling point and tearing direction should be changed continuously to avoid radiation to the equator. Side view such as. The above process will be easier if it is done with a capsular sac. 3. Water separation: After tearing the anterior capsule, the bss were injected under the anterior capsule flap of the 9:00 or 3:00 clock position with a water-blown needle. The water is pulsating and the anterior capsule and the subcapsular cortex are separated by the pulsating impact of water. In the same way, the superficial cortex and deep cortex, deep cortex and nuclear cortex can be separated so that the cortex and the nucleus are sufficiently separated to facilitate subsequent emulsification. 4. Lens emulsification: the inner slit was enlarged to 3.2 mm, and the emulsified head was inserted into the emulsified head, and the nucleus was sequentially emulsified and sucked out in a predetermined manner. The basic action of emulsification is sculpting, that is, the energy released by the emulsification head breaks the lens nucleus into a nipple shape. How to emulsifie and suck out the entire lens nucleus in turn is a very complicated problem. In addition to the required basic operation techniques, some special technical actions should be mastered. With the continuous improvement of the overall technology of ultrasonic emulsification, a large number of different new methods have been innovated for various situations encountered in the operation (such as the difference in nuclear hardness). Each new method does not have absolute independence, and should be interspersed and interpenetrated in the overall technology. The more practical technical actions are as follows. The croissant method starts from the middle of the lens and is engraved to the outside of the lens to form a croissant-like groove. After widening and deepening to a certain extent, the rotation is 180°, and the process is repeated. Finally, the residual portion is emulsified by a general emulsification method. After the carousel is carved into the center of the lens, the emulsification head retreats to the upper pupil level; the perfusion is interrupted, and the emulsified head is slightly inclined downward. After the lens core is extremely lifted, the lens is inserted behind the lens core and restored. perfusion. At this point, the emulsification head can emulsify the lens nucleus along the tangential direction of the equator of the nucleus. The lens nucleus will rotate in a carousel and be emulsified by the outer layer. The chip and flip method is used to sculpt the lens into a bowl shape, and then flip it, and the other part of the core is emulsified and removed from the back. The sculpt and tilt method is used to sculpt the lens into a bowl shape, and the residual sheet is lifted from above and emulsified one by one. The divided and conquered method (divided and conguer) is engraved from the top of the lens along the surface of the lens core, deepening and widening until it forms a vertical groove deep into the posterior nucleus of the nucleus, and then cooperates with the emulsification head by means of auxiliary equipment. split into two. Then 1/2 pieces were emulsified and removed. The crisscross method is the development of the divide and conquer method. That is, after the same engraving action is made into a cross-shaped groove, it is divided into four pieces by means of an auxiliary device, and then the pieces are emulsified and sucked in order. Stop and chop in the high negative pressure and low energy conditions, the emulsified head is directly inserted into the nucleus of the lens, and the auxiliary incision is inserted into a special device (such as chopper), which is bypassed from the nucleus and fixed to the emulsification head. Cut the direction and make it split. Repeat this action by rotating a certain angle to make the lens core into several pieces, and then emulsifie them one by one. The chip and chop method firstly thins the center of the core into a bowl shape, and then uses a special instrument to adopt a method similar to intercepting the splitting, splitting the residual part into several pieces, and then emulsification and suction. 5. Clear the cortex: remove the cortex with a mechanical injection-suction device. The basic operating principle is the same as that of the manual injection-suction device, but the suction is large, and the capsule is easily absorbed. The operation should be very careful.