Second pass femtosecond laser for incomplete laser full or partial thickness corneal incisions
A method for forming an incision in an eye, the method including performing a first pass of a first laser beam along a path within an eye, wherein after completion of the first pass there exists a residual uncut layer at an anterior surface of a cornea of the eye. The method further including performing a second pass of a second laser beam only along a portion of the path that contains the residual uncut layer, wherein after completion of the second pass, the residual uncut layer is transformed into a full complete through surface incision.
1. A method for forming an incision within an eye, the method comprising:
determining a path extending from a location below a surface of a cornea of the eye to location above the anterior surface of the cornea;
performing a first pass of a first laser beam along a first portion of the path within the cornea, the pass starting from a point within the cornea and moving toward the anterior surface of the cornea; thereby forming an incision within the cornea; wherein after completion of the first pass there exists a residual uncut layer at the anterior surface of the cornea;
performing a second pass of a second laser beam along a second portion of the path; the first and second portions of the path at least partially overlapping; wherein the second portion of the path contains the residual uncut layer, wherein after completion of said second pass, the residual uncut layer is transformed into a full complete through surface incision.
2. The method of claim 1 , wherein said first laser beam has a low numerical aperture and passes through a liquid-filled patient interface before penetrating said eye, and wherein said residual uncut layer is the result of said first laser beam passing through said liquid-filled patient interface.
3. The method of claim 1 , wherein said path is formed in a cornea of an eye.
4. The method of claim 1 , wherein said first laser beam has a different energy than said second laser beam.
5. The method of claim 4 , wherein said first laser beam is at a first energy of 3 μJ to 5 μJ, wherein the first energy exceeds a photodisruption threshold and said second laser beam is at a second energy that is higher than the first energy.
6. The method of claim 5 , wherein said first laser beam is scanned along said path at a different rate than said second laser beam is scanned along said portion of said path that contains said partial thickness incision.
7. The method of claim 1 , wherein said first laser beam is scanned along said path at a different rate than said second laser beam is scanned along said portion of said path that contains said partial thickness incision.
8. The method of claim 1 , wherein said path is a linear path and said portion of said path that contains said residual uncut layer is linear.
9. The method of claim 1 , wherein said path is an angular path and said portion of said path that contains said residual uncut layer is linear.
10. The method of claim 1 , wherein said path is an angular path and said portion of said path that contains said residual uncut layer is angular.
11. The method of claim 10 , wherein said angular path is a zigzag angular path and said portion of said path that contains said residual uncut layer is L-shaped.
12. The method of claim 1 , wherein said first laser beam has a pulse width that is less than one femtosecond and said second laser beam has a pulse width that is less than one femtosecond.
13. The method of claim 1 , wherein after completion of said second pass, a full thickness corneal incision is formed.
14. The method of claim 1 , wherein after completion of said second pass, a partial thickness corneal incision is formed.