US 12,746,155 B2 · Corneal lenticular formation using a femtosecond laser for hyperopia and mixed astigmatism correction

Abstract

An ophthalmic laser system and related method for performing corneal lenticule incision and extraction for treating hyperopia and mixed astigmatism of the eye are described. Various techniques are used to optimize the procedure for concave lenticule incisions. One technique employs a fast-scan-slow-sweep scanning scheme to form the lenticule incisions, where the sweep angle increment is set to ensure at least double-pass cut for the entire lenticule. Another technique allows for desired distribution of refractive powers between the top and bottom lenticule incisions. Other techniques configure the lenticule such that its edge thickness is a constant; or such that the highest point of the top lenticule incision, located near the lenticule periphery, is at a predefined depth below the anterior corneal surface; or to maximize lenticule thickness for refractive treatment while ensuring that minimum anterior depth and minimum residual bed thickness in the peripheral region of the lenticule are maintained.

Claims20

Dependent claims

A method implemented in an ophthalmic surgical laser system for forming a lenticule in a cornea of a patient's eye to treat hyperopia or mixed astigmatism, the method comprising:

by a laser source, generating a pulsed laser beam comprising a plurality of laser pulses;
by a high frequency scanner, scanning the pulsed laser beam back and forth at a predefined frequency to form a laser beam scanline, the scanline being a straight line having a defined length;
by a scanline rotator, rotating a direction of the scanline around an optical axis of the laser beam;
by a scanning system including an XY-scanner and a Z-scanner, delivering the scanline to the cornea and moving the scanline within the cornea in a depth direction along the optical axis of the laser beam and in two lateral directions perpendicular to the optical axis;
and
by a controller, controlling the laser source, the high frequency scanner, the scanline rotator, and the scanning system to successively form a first plurality of scanline sweeps which collectively form a first lenticule incision of the lenticule in the cornea, wherein each sweep is formed by placing the scanline perpendicular to a meridian of the first lenticule incision and moving the scanline along the meridian from one edge of the lenticule incision to an opposite edge of the lenticule incision, wherein a sweep angle increment between the meridians of adjacent sweeps is equal to or smaller than a value θ0=sin−1(L/D), wherein L is the length of the scanline and D is a diameter of the lenticule incision.

3 more elements

An ophthalmic surgical laser system for forming a lenticule in a cornea of a patient's eye to treat hyperopia or mixed astigmatism, comprising:

a laser source configured to generate a pulsed laser beam comprising a plurality of laser pulses;
a high frequency scanner configured to scan the pulsed laser beam back and forth at a predefined frequency to form a laser beam scanline, the scanline being a straight line having a defined length;
a scanline rotator configured to rotate a direction of the scanline around an optical axis of the laser beam;
a scanning system including an XY-scanner and a Z-scanner, configured to deliver the scanline to the cornea and move the scanline within the cornea in a depth direction along the optical axis of the laser beam and in two lateral directions perpendicular to the optical axis;
and
a controller configured to control the laser source, the high frequency scanner, the scanline rotator, and the scanning system to successively form a first plurality of scanline sweeps which collectively form a first lenticule incision of the lenticule in the cornea, including forming each sweep by placing the scanline perpendicular to a meridian of the first lenticule incision and moving the scanline along the meridian from one edge of the lenticule incision to an opposite edge of the lenticule incision, wherein a sweep angle increment between the meridians of adjacent sweeps is equal to or smaller than a value θ0=sin−1(L/D), wherein L is the length of the scanline and D is a diameter of the lenticule incision.

3 more elements

Dependencies are inferred from the claim text.

Corneal lenticular formation using a femtosecond laser for hyperopia and mixed astigmatism correction

Life of this patent

Corneal lenticular formation using a femtosecond laser for hyperopia and mixed astigmatism correction

Life of this patent

Abstract

Claims20