Devices and methods for cutting lenticular tissue
An exemplary surgical device includes an element positionable within a shaft having a lumen defined therethrough with the element movable from a stored position to a deployed position in which a larger portion of the element extends out of the distal end of the lumen. The element forming a closed loop which is positioned around the lens while the lens is within a capsular bag. The closed loop is reduced in size to form a cut in the lens.
1. A method of cutting a lens within a capsular bag of an eye, comprising:
introducing a cutting element into an anterior chamber of the eye, wherein at least a portion of said cutting element is positioned in a first, retracted configuration within a lumen, and wherein said cutting element is movable from the first configuration toward a second, expanded configuration comprising a preset, unbiased shape as the portion of the cutting element is extended from the lumen, at least part of the cutting element forming a loop with an open area as the cutting element is moved toward the second configuration;
positioning the cutting element in the first configuration, through an opening in the capsular bag, over an anterior surface of the lens with the lens being whole and inside the capsular bag;
extending the portion of the cutting element from the lumen to move the cutting element from the first configuration toward the second configuration, the open area increasing in size as the portion of the cutting element is extended further from the lumen, wherein the cutting element advances between the capsular bag and the anterior surface of the lens as the cutting element moves toward the second configuration;
positioning the cutting element in the second configuration around a portion of the lens between a posterior portion of the capsular bag and the lens; and
tensioning the cutting element so that the lens is fully sectioned into at least two fragments.
2. The method of claim 1 , wherein during said tensioning the cutting element, a posterior surface of the lens and the anterior surface of the lens are both cut with the cutting element.
3. The method of claim 1 , wherein at least one of said positioning the cutting element between the capsular bag and the lens and said tensioning the cutting element comprises engaging a posterior surface of the lens and the anterior surface of the lens with the cutting element.
4. The method of claim 1 , wherein said positioning the cutting element comprises rotating the cutting element to traverse a space between the capsular bag and the lens.
5. The method of claim 1 , further comprising performing phacoemulsification on one or more of the lens fragments.
6. The method of claim 1 , wherein the loop of said preset, unbiased shape comprises at least a first portion having a first, smaller radius of curvature and a second portion having a second, larger radius of curvature.
7. The method of claim 1 , further comprising:
repositioning the cutting element around at least one of the fragments; and
retensioning the cutting element to further fully section at least one of the fragments to produce smaller lens fragments.
8. The method of claim 7 , further comprising performing phacoemulsification on one or more of the smaller lens fragments.
9. The method of claim 1 , wherein the preset, unbiased shape is similar in shape to a cross-sectional shape of the lens.
10. The method of claim 1 , further comprising removing an anterior portion of the capsular bag to form an opening in the capsular bag, wherein the cutting element is positioned over the anterior surface of the lens after the opening has been formed in the capsular bag.
11. The method of claim 10 , wherein the open area of the loop of the second configuration has a dimension larger than a diameter of the opening in the capsular bag.
12. The method of claim 1 , wherein the cutting element is moved between the capsular bag and the lens so that the lens is positioned in the open area of the loop.
13. The method of claim 1 , wherein a shaft of a hand-held instrument comprises the lumen.
14. The method of claim 1 , wherein the loop is an approximate closed loop.
15. The method of claim 14 , wherein the loop is formed of the cutting element and a distal portion of the support shaft.