Method of laser photoablation of lenticular tissue for the correction of vision problems

A method of increasing an accommodation amplitude of an ocular lens within a lens capsule of an eye, said method comprising the steps of:

• establishing a desired accommodation amplitude for an ocular lens to be treated;
• measuring an actual accommodation amplitude for said ocular lens to be treated;
• calculating a volume of lens tissue to be removed by subtracting said desired accommodation amplitude from said lens actual accommodation amplitude, said volume of lens tissue being of a size enabling resolve by adjacent healthy ocular lens tissue;
• and
• directing a laser at said calculated amount of lens tissue to be removed through the cornea and open iris of said eye, at a nucleus and centrally located older fibers of said ocular lens and into a cortex region thereof without causing substantial photoablation damage to surrounding tissue regions, including the lens capsule, and thereafter directing the laser towards less centrally located fibers of said ocular lens.

A method for the selective removal of ocular lens tissue of an eye for the removal of incipient cataract, said method consisting essentially of the steps of:

• selecting a volume of the ocular lens tissue within a lens capsule to be removed so as to remove incipient cataract, said volume being of a size enabling resolve by adjacent healthy ocular lens tissue;
• measuring the incipient cataract and calculating the amount of lens tissue to be removed from said selected volume so as to remove said incipient cataract;
• directing an infrared laser beam from the exterior of the eye, through the cornea and open iris thereof, at a point in said selected ocular lens tissue volume at an anterior surface of the ocular lens;
• pulsing said laser beam at a frequency between about 1 and about 1000 Hertz and a pulse width of between about 1 femtosecond and about 1 millisecond;
• directing the infrared laser at points in said selected ocular tissue volume interior to the ocular lens anterior surface;
• adjusting the energy level of said pulsed laser beam so that the beam provides an amount of per-pulse energy without causing substantial shock wave damage to lens tissue, including the lens capsule, surrounding said region;
• and
• allowing the selected amount of ocular tissue to be absorbed by healthy tissue adjacent the ocular lens anterior surface.

A method for the selective removal of ocular lens tissue of a human eye for the correction of vision defects, including myopia, hyperopia, or presbyopia, said method comprising the steps of:

• measuring the physical parameters of said ocular lens tissue shape in order to characterize said vision defect;
• selecting a region of the ocular lens tissue within a lens capsule of an eye to be removed in order to correct said vision defect;
• calculating from said measured physical parameters a selected amount of lens tissue to be removed from said selected region, the selected amount being a volume of lens tissue necessary to correct said vision defect;
• directing an infrared laser beam from the exterior of said eye through the cornea and iris opening thereof and at a point in said selected ocular lens tissue region below an anterior surface of the ocular lens;
• and
• pulsing said laser beam at a frequency of between about 1 and about 1000 pulses a second, at a pulse width of between about 1 femtosecond and about 1 millisecond and with an amount of per-pulse energy without causing substantial shock wave damage to lens tissue, including the lens capsule, surrounding said region, said selected region being of a size enabling resolve by adjacent healthy ocular lens tissue.