Intracorneal lens placement method and apparatus
A method and apparatus for correcting vision, including a corneal-pocket keratome device to create a corneal pocket and a lens to be inserted and retained in the corneal pocket to effect correction. The corneal-pocket keratome includes a drive unit having cutting head elements which contact the subject eye during corneal pocket formation. The cutting head elements may be removeable and may be disposable. The cutting head elements include a corneal restraint device, which may be a positioning ring to position an eyeball with the cornea protruding through the ring; a keratome blade assembly with a corneal-pocket blade; and may also include an applanation shoe surface to restrain the cornea, in addition or instead of the positioning ring. The applanation shoe may be pivotable away from the surgical area. The corneal-pocket blade may include a guide which travels with the blade. The blade assembly oscillates laterally while extending forward into the cornea to form the pocket, and the amplitude of the lateral oscillation is preferably increased as the blade goes beyond an opening incision into the cornea. Lenses for this invention preferably include a feature to impede accidental lens movement after the lens is disposed within the corneal pocket, which may be a swelling after insertion or a circumferential irregularity. Lenses may be of Fresnel or non-Fresnel type, and may employ annular changes in the index of refraction of the lens material, as well as changes in refractive shape which may be annular or not, to effect variations in focal length for relieving presbyopia, astigmatism, and combinations of those as well as myopia and hyperopia. Drive control and vacuum for the positioning ring are provided under user command by a control unit having user inputs.
1. A corneal-pocket keratome, comprising:
a corneal-pocket blade assembly having a corneal-pocket blade supported by a blade support assembly, the blade having a cutting edge on a portion of the blade which is cantilevered from the blade support assembly to protrude therefrom;
a keratome drive mechanism supporting the corneal-pocket blade assembly, the drive mechanism including
a primary drive mechanism to drive the blade assembly in a primary path of travel generally perpendicular to a focal axis of the eye, and
a lateral drive mechanism to impart movement to the blade assembly in a direction lateral to the primary path of travel; and
a corneal restraint device attached to the keratome drive mechanism.
2. The corneal-pocket keratome of claim 1 wherein the primary path of travel is a single direction.
3. The corneal-pocket keratome of claim 1 , wherein the lateral drive mechanism is controllable to vary a length of lateral movement of the blade assembly.
4. The corneal-pocket keratome of claim 1 , wherein the lateral drive mechanism increases a length of lateral movement of the blade assembly as the blade assembly proceeds in the forward direction of travel.
5. The corneal-pocket keratome of claim 1 , wherein the lateral drive mechanism imparts a laterally oscillating movement to the blade assembly.
6. The corneal-pocket keratome of claim 1 , wherein the corneal-pocket blade support includes a corneal pocket wall-thickness guide to control a corneal-pocket outer wall thickness.
7. The corneal-pocket keratome of claim 6 , wherein the corneal-pocket wall-thickness guide includes a guide edge, the guide edge substantially matching a shape of a portion of the cutting edge of the corneal-pocket blade protrusion and being disposed at a controlled distance from said portion of the cutting edge.
8. The corneal-pocket keratome of claim 6 , wherein the corneal-pocket wall-thickness guide is disposed in sliding contact with the corneal restraint device.
9. The corneal-pocket keratome of claim 8 , wherein the corneal-pocket wall-thickness guide is disposed in sliding contact with an applanation shoe side opposite a cornea-restraining side of the applanation shoe.
10. The corneal-pocket keratome of claim 1 , wherein the corneal restraint device is a corneal support shoe for supporting a cornea of the subject eye.
11. The corneal-pocket keratome of claim 1 , further including a cornea positioning ring for restraining the cornea of the subject eye.
12. The corneal-pocket keratome of claim 11 , further including a positioning ring retention feature having a finger-operable mechanism to release the positioning ring from the keratome drive mechanism by finger manipulation without a need for tools.
13. The corneal-pocket keratome of claim 1 , further including a corneal restraint device retaining feature which is engageable and releasable by finger manipulation without a need for tools.
14. The corneal-pocket keratome of claim 1 wherein the corneal restraint device is pivotably disengageable from the cornea.
15. A corneal-pocket blade assembly for use in the corneal-pocket keratome of claim 1 , comprising a corneal-pocket blade to be cantilevered from the blade support assembly so as to protrude therefrom, and having a cutting edge on a portion of the cantilevered blade distal from the blade support assembly.
16. A corneal restraint device for use in the corneal-pocket keratome of claim 13 , including a mating feature engageable with said corneal restraint device retaining feature.