METHOD FOR CARRYING OUT POSTERIOR LAMELLAR KERATOPLASTY USING A FEMTOSECOND LASER Russian patent published in 2021 - IPC A61F9/07 A61F9/08 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to ophthalmology. The formation of the programmed intrastromal planar and vertical cuts of the donor cornea (DC) by a femtosecond laser is carried out by means of a one-stage resection. In this case, the donor corneal graft is formed using a femtosecond laser with a wavelength of 1053 nm, a pulse duration of 200-350 ms, a pulse duration of 200-550 f/s, and a maximum laser pulse power of 12 mW. For this, the donor's native corneoscleral disc is fixed in an artificial anterior chamber (AAC) holder with the endothelial side up. Then, using a continuous supply of balanced salt solution (BSS), the AAC is filled with this solution under a pressure of 50 mm Hg. Next, a solution of dispersed viscoelastic - 1% solution of hydroxypropyl methylcellulose is applied to the DC endothelium immediately before applanation of the laser interface, and kept for 30-60 seconds. Next, the laser handle is fixed to the IPC, then the rotation of the threaded ring smoothly makes contact between the DC and the laser head, using intraoperative optical coherence tomography, the contact between the DC and the laser head is monitored and, with close continuous contact, a donor corneal graft with a thickness of 125-130 mcm, diameter 7.0-8.5 mm. In this case, the first cut is carried out in the vertical direction from the endothelium deep into the stroma. Then, by rotating the ring in the opposite direction, smoothly disconnect the laser head and the DC. Then the laser handle is removed from the IPC surface, after interrupting the contact of the DC with the laser head, the cornea with the viscoelastic on it is stained with methylene blue, the colored viscoelastic is washed off. Then, the same dye is applied to the surface of the DC; when staining the endothelium of the DC, the DC is assessed with a suitable graft on less than half of its area. Then the graft is separated from the underlying stroma with a splitter and moved into the funnel of the glide, with the endothelium upwards, after washing the dye from the DR, a strip of cohesive viscoelastic preparation - 1% sodium hyaluronate is applied to the endothelium surface, through a tunnel sclero-corneal incision (TSCI) under conditions of constant maintenance of TSCI the volume of the anterior chamber of the recipient's eye with an irrigation flow, tweezers introduced through the corneal paracentesis, opposite to the TSCI, the graft is pulled into the anterior chamber of the patient's eye and fixed to the posterior layers of its own cornea with an air bubble or an air-gas mixture.

EFFECT: method allows improving the quality of the graft, to preserve the corneal endothelium as much as possible with a minimum loss of PEC and the associated accelerated restoration of the transparency and thickness of the cornea, to ensure the maximum increase in visual functions.

1 cl, 3 ex