Cataract removal

Cataract can be removed by several types

1. Extracapsular extraction (removal) of cataract requires a relatively long peripheral limbal incision (8-10 mm), through which the lens core is excised and aspirated cortical masses are preserved with the preservation of the posterior capsule, then the intraocular lens (artificial lens) is injected.
2. Phacoemulsification has become the most preferred method of extraction (removal) of cataracts in the last 10 years. Attached to the handle is a small hollow needle, often titanium, containing a piezoelectric crystal, vibrating in the longitudinal direction with the frequency of ultrasound. The tip is fed to the core of the lens, as the core emulsifies, a cavity is formed, the aspiration-irrigation system outputs the emulsion material. Then, the artificial lens is inserted either folded or by injection through a smaller incision than with EEC. A smaller incision ensures the safety of the operation, as it excludes the possibility of decompression of the eye and reduces the likelihood of intraoperative complications (suprachoroidal hemorrhage, small anterior chamber, vitreous prolapse in case of posterior capsule rupture).

This method is associated with minor postoperative astigmatism and early stabilization of refraction (usually within 3 weeks). Postoperative complications associated with the incision (for example, loss of iris) are almost excluded.

The technique of extracapsular extraction (removal) of cataracts

1. After the peripheral incision of the cornea closer to the limbus, the anterior chamber is perforated with the eratom.
2. In the anterior chamber, viscoelastic (sodium hyaluronate or hydroxymethyl propylcellulose) is administered, which maintains the depth of the anterior chamber and protects the corneal endothelium.
3. Into the anterior chamber is injected with cystotomy and several small radial incisions of the anterior capsule are made around the entire circumference of 360. This technique is called capsulotomy by the type of "can opener". Alternatively, capsulorhexis can be used - circular opening of the anterior capsule.
4. Perform a final incision with scissors on the limbal incision.
5. Hydrodissection is carried out to remove the lens masses from the capsular bag by introducing a balanced saline solution with a special cannula with a blunt end (Rycroft) between the edge of the capsule and the lens cortex on the periphery.
6. The nucleus is removed by pressing on the area of the upper and lower limbs or using a loop.
7. The coccyx of the infusion-aspirating cannula is injected into the anterior chamber and carried under the capsule of the lens towards the meridian for 6 hours. Cortical masses are collected in the cannula opening by creating a vacuum.
8. The crust of the lens is pushed back to the center and aspirated by direct visual control. These actions are consistently repeated until the complete elimination of the masses. It is important to act cautiously not to aspirate the posterior capsule and not cause its rupture and a number of concomitant complications. An indication of aspiration of the capsule is the appearance of thin strips radially directed from the cannula opening. Aspiration should be interrupted and activated by irrigation to release the capsule. Both parts of the haptics are preferable to be placed in a capsule bag than in a ciliary furrow.
9. It is necessary to release the posterior calsula from small residual masses.
10. Viscoelastic is introduced into the capsular bag to facilitate subsequent implantation of the artificial lens.
11. LPO is grasped for the optical part and immersed so that the front surface is covered with viscoelastic.
12. The supporting part of the haptics is introduced through the edges of the incision and is filled into the capsular bag towards the meridian for 6 hours.
13. The edge of the upper haptic is gripped with tweezers and also filled into a capsule bag.
14. The artificial lens is rotated to a horizontal position using a hook inserted into the lens holes.
15. To narrow the pupil, inject acetylcholine (mioehol) into the anterior chamber, viscoelastic aspirate, apply a suture.

Phacoemulsification

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

1. A self-sealing tunnel incision is made with penetration into the anterior chamber at the periphery of the cornea, preferably temporally, or a scleral tunnel incision, often from above.
2. Introduce the front chamber viscoelastic.
3. Make a second incision on the periphery of the cornea in the projection of the syrin from the first incision.
4. Perform capsulorrexis.
5. Gildrissection causes the mobility of the nucleus. The retrocortical "fluid wave" visible above the reflex from the fundus is a testament to the completion of hydrodissection.
6. Cut the core with a phaco tip with the creation of a furrow. After turning the core with a tool inserted through the second hole, create a cross groove.
7. Bring the phaco tip and the second tool to the opposite edges of the furrow.
8. When the force acts in the opposite direction, the core splits at the base of the furrow.
9. After turning the nucleus by 90 in the same way, a splitting of the perpendicular furrow is performed.
10. Then, fragmentation, emulsification and aspiration of each quadrant of the nucleus is performed.
11. Aspirate residual cortical masses.
12. Introduce viscoelastic for expanding the capsule bag
13. Increase, if necessary, the length of the incision and inject MOL.
14. Aspirate the viscoelastic.
15. Self-sealing cut does not require suturing.

[1], [2], [3], [4]