Cataract removal

Cataract removal can be performed in several ways.

1. Extracapsular cataract extraction (removal) requires a relatively long peripheral limbal incision (8-10 mm), through which the lens nucleus is removed and the cortical masses are aspirated while preserving the posterior capsule, and then an intraocular lens (artificial lens) is inserted.
2. Phacoemulsification has become the preferred method of cataract extraction (removal) over the past 10 years. A small hollow needle, usually titanium, containing a piezoelectric crystal, attached to a handle vibrates longitudinally at an ultrasound frequency. The tip is brought to the nucleus of the lens, as the nucleus is emulsified, a cavity is formed, and an aspiration and irrigation system removes the emulsification material. Then the artificial lens is inserted either folded or by injection through a smaller incision than in EEC. A smaller incision ensures the safety of the operation, since it eliminates the possibility of decompression of the eye and reduces the likelihood of intraoperative complications (suprachoroidal hemorrhage, shallow anterior chamber, vitreous prolapse in case of rupture of the posterior capsule).

This method is associated with minor postoperative astigmatism and early refractive stabilization (usually within 3 weeks). Incision-related postoperative complications (e.g. iris prolapse) are almost excluded.

Extracapsular cataract extraction (removal) technique

1. After peripheral incision of the cornea closer to the limbus, the anterior chamber is perforated with an eratome.
2. A viscoelastic (sodium hyaluronate or hydroxymethylpropyl cellulose) is injected into the anterior chamber to maintain the depth of the anterior chamber and protect the corneal endothelium.
3. A cystotome is inserted into the anterior chamber and several small radial incisions are made in the anterior capsule around the entire 360° circumference. This technique is called a "can opener" capsulotomy. Alternatively, a capsulorhexis can be used - a circular opening of the anterior capsule.
4. The final cut is made with scissors along the limbal notch.
5. Hydrodissection is performed to remove the lens masses from the capsular bag by introducing a balanced saline solution using a special blunt-tipped cannula (Rycroft) between the edge of the capsule and the lens cortex at the periphery.
6. The nucleus is removed by pressing on the area of the upper and lower limbus or using a loop.
7. The coccyx of the infusion-aspiration cannula is inserted into the anterior chamber and passed under the lens capsule in the direction of the 6 o'clock meridian. The cortical masses are collected in the cannula opening by creating a vacuum.
8. The lens cortex is moved to the center and aspirated under direct visual control. These actions are repeated successively until the masses are completely removed. It is important to act carefully so as not to aspirate the posterior capsule and cause its rupture and a number of associated complications. A sign of capsule aspiration is the appearance of thin stripes directed radially from the cannula opening. Aspiration must be interrupted and irrigation activated to release the capsule. Both parts of the haptics are preferably placed in the capsular bag than in the ciliary groove.
9. It is necessary to free the posterior cavity from small residual masses.
10. Viscoelastic is injected into the capsular bag to facilitate subsequent implantation of the artificial lens.
11. The FLOOR is grasped by the optical part and immersed so that the front surface is covered with viscoelastic.
12. The supporting part of the haptic is inserted through the edges of the incision and tucked into the capsular bag in the direction of the 6 o'clock meridian.
13. The edge of the upper hapten is grasped with tweezers and also tucked into the capsular bag.
14. The artificial lens is rotated to a horizontal position using a hook inserted into the holes of the lens.
15. To constrict the pupil, acetylcholine (mioehol) is injected into the anterior chamber, the viscoelastic is aspirated, and a suture is applied.

Phacoemulsification

This technique is constantly changing, there are many different variations. The main stages of the classical technique are as follows:

1. A self-sealing tunnel incision is made with penetration into the anterior chamber on the periphery of the cornea, preferably temporally, or a scleral tunnel incision, usually from above.
2. Viscoelastic is injected into the anterior chamber.
3. A second incision is made on the periphery of the cornea in the projection of the syrinx from the first incision.
4. Capsulorhexis is performed.
5. Hydrodissection causes the nucleus to move. A retrocortical "fluid wave" visible above the fundus reflex is evidence of complete hydrodissection.
6. The nucleus is dissected with the phaco tip, creating a groove. After the nucleus is rotated, a cross groove is created using an instrument inserted through the second opening.
7. The phaco tip and the second instrument are brought to opposite edges of the groove.
8. When a force is applied in the opposite direction, the nucleus at the base of the furrow splits.
9. After turning the core by 90, the perpendicular groove is split in the same way.
10. Each quadrant of the nucleus is then fragmented, emulsified and aspirated.
11. Residual cortical masses are aspirated.
12. Viscoelastic is injected to straighten the capsular bag
13. If necessary, the length of the incision is increased and MOL is introduced.
14. Viscoelastic is aspirated.
15. The self-sealing incision does not require stitches.

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