METHOD OF FEMTO-LASER REFRACTIVE AUTO-KERATOPLASTY IN KERATOCONUS Russian patent published in 2019 - IPC A61F9/08 

FIELD: medicine.

SUBSTANCE: invention relates to medicine, specifically to ophthalmology. For femtolaser refractive auto-keratoplasty in keratoconus with average keratometry values ≥55 dioptre cornea is resected with the help of a femtosecond laser, during which an annular incision of the cornea is performed, passing at distance of 1.5–2.0 mm from the limb area, at an angle to the surface of the cornea at a depth of up to 90 % of the thickness of the cornea. Second annular incision of the cornea passes perpendicular to its surface, at a distance from the first one, so that these sections crossed at the specified depth and a ring-shaped flap of corneal tissue with a wedge-shaped profile was formed, after removal of which the corneal wound edges are closed. Both annular incisions of the cornea are performed within the framework of one femto-laser procedure, and the distance between the incisions is calculated by formula:

where S is distance between annular incisions of cornea; h is the height of the keratoconus based on the spectral optical coherence tomography (SOCT) of the anterior segment of the eye; d is keratoconus base diameter according to anterior eye SOCT; R is planned radius of corneal curvature.

EFFECT: method provides accurate, graduated corneal resection with consideration of individual corneal parameters of the patient, flattening of the cornea to the calculated values, improved corrected and uncorrected visual acuity.

1 cl, 1 ex