System and method for controlling the focal point locations of a laser beam

A system for maintaining precise focal point placements during an ophthalmic surgical procedure which comprises:

• an imaging unit for creating an image of a selected volume of tissue within an eye of a patient;
• a laser unit for generating a laser beam;
• a focusing element included in the laser unit for focusing the laser beam to a focal point in the volume of tissue to perform an ophthalmic surgical procedure in accordance with a particular protocol, wherein the protocol requires maintaining the laser beam focal point within a predetermined tolerance;
• and
• a computer for moving the focal point within a predetermined scanning range and along a defined path through the volume of tissue, while maintaining the focal point within the predetermined tolerance.

A method for establishing precise locations for a focal point of a laser beam in a predetermined scanning range, wherein the focal point remains within a predetermined tolerance, the method comprising the steps of:

• providing a laser unit to generate a laser beam;
• positioning a lens for focusing the laser beam to the focal point;
• defining a path for movement of the focal point in an x-y-z space within the predetermined scanning range, wherein the path is defined by a computer;
• selectively mounting an arrestor on the laser unit to interact with the lens to establish a start point for the scanning range;
• and
• using an actuator to move the lens in response to instructions from the computer, to move the focal point of the laser beam along the defined path in the predetermined scanning range to maintain the focal point within the tolerance.