Non-penetrating filtration surgery

Abstract

Apparatus for ophthalmic surgery, especially non-penetrating filtration surgery, comprising a laser source that ablates sclera tissue at steps of intermediate thickness. Optionally, the beam is scanned using a scanner and its results viewed using an ophthalmic microscope.

1 . Apparatus for ophthalmic surgery on an eye comprising:
 a laser source that generates a laser beam having a wavelength; and   an ophthalmicly effective position controller adapted to aim said beam at said eye from outside said eye for a dwell time and a power density configured to ablate a sclera tissue thickness of between 5 and 50 microns in a single dwell.   
     
     
         2 . Apparatus according to  claim 1 , wherein said thickness is between 5 and 30 microns. 
     
     
         3 . Apparatus according to  claim 1 , wherein said laser source and said position controller are configured so that said ablation is without causing substantial shockwave or thermal damage to said eye. 
     
     
         4 . Apparatus according to  claim 1 , wherein said beam contacts said eye for a dwell time of above 100 micro-seconds, per dwell. 
     
     
         5 . Apparatus according to  claim 1 , wherein said beam contacts said eye with a spot size of over 100 microns. 
     
     
         6 . Apparatus according to  claim 1 , comprising an ophthalmic microscope operative to view an eye during an ophthalmic procedure that uses said laser beam. 
     
     
         7 . Apparatus according to  claim 6 , comprising a monitor for displaying a view of said tissue removal viewed by said microscope. 
     
     
         8 . Apparatus according to  claim 6 , comprising a beam combiner for combining a line of sight of said laser and said microscope. 
     
     
         9 . Apparatus according to  claim 8 , comprising an optical system integral with said combiner and configured to allow manual adjustment of a focus of said laser source so that it is in a same plane as the focus of said microscope. 
     
     
         10 . Apparatus according to  claim 1 , wherein said position controller comprises an ophthalmic frame operative to fix a relative position and angle of said laser source and an eye of a patient. 
     
     
         11 . Apparatus according to  claim 1 , wherein said position controller comprises a scanner comprising an input for said laser beam and an output of a spatially scanned laser beam. 
     
     
         12 . Apparatus according to  claim 11 , comprising controlling circuitry that drives said scanner to remove tissue in a desired pattern on the eye, said pattern being suitable for non-penetrating filtration surgery on the eye. 
     
     
         13 . Apparatus according to  claim 12 , wherein said pattern has dimensions of between 2 and 5 mm in each of two orthogonal axes. 
     
     
         14 . Apparatus according to  claim 12 , wherein said circuitry controls said laser source. 
     
     
         15 . Apparatus according to  claim 12 , wherein said circuitry drives said scanner to coagulate tissue using said laser source. 
     
     
         16 . Apparatus according to  claim 12 , wherein said circuitry drives said scanner to ablate tissue in an adjustable thickness. 
     
     
         17 . Apparatus according to  claim 12 , wherein said circuitry drives said scanner to perform said ablation by causing repeated ablations of thicknesses at a location, which repeated ablations add up to said thickness. 
     
     
         18 . Apparatus according to  claim 12 , wherein said circuitry drives said scanner to ablate tissue at a location only after a delay from a previous ablation thereat, said delay being configured to be sufficient to detect percolation thereat. 
     
     
         19 . Apparatus according to  claim 12 , comprising an aiming beam laser source and wherein said circuitry drives said scanner to show said pattern boundaries using said aiming beam. 
     
     
         20 . Apparatus according to  claim 12 , comprising a sensor which monitors an indication of progression of said surgery, on said eye, to produce a progression signal. 
     
     
         21 . Apparatus according to  claim 20 , wherein said sensor comprises:
 a camera which acquires an image of said tissue removal; and   an image processor that processes said image.   
     
     
         22 . Apparatus according to  claim 20 , comprising circuitry that uses said progression signal to generate an indication of the tissue removal state. 
     
     
         23 . Apparatus according to  claim 22 , wherein said circuitry uses said indication to close a control loop of said tissue removal. 
     
     
         24 . Apparatus according to  claim 22 , wherein said indication of tissue removal state comprises an indication of the thickness of remaining tissue in the area of tissue removal. 
     
     
         25 . Apparatus according to  claim 22 , wherein said indication of tissue removal state comprises an indication of a percolation rate through the remaining tissue in the area of tissue removal. 
     
     
         26 . Apparatus according to  claim 20 , wherein said sensor is a non-penetrating sensor. 
     
     
         27 . Apparatus according to  claim 20 , wherein said sensor is a contact sensor. 
     
     
         28 . Apparatus according to  claim 20 , wherein said controlling circuitry receives signals from said sensor. 
     
     
         29 . Apparatus according to  claim 20 , comprising a user input, wherein said controlling circuitry is adapted to receive and interpret entries on said input as indicating signals from said sensor. 
     
     
         30 . Apparatus according to  claim 1 , comprising a frame attached to said combiner, which frame blocks said laser beam from at least one part of said eye. 
     
     
         31 . Apparatus according to  claim 1 , wherein said wavelength has an absorption length of 1/e of greater than 5 microns in water. 
     
     
         32 . Apparatus according to  claim 1 , wherein said laser source comprises a CO2 laser source. 
     
     
         33 . Apparatus according to  claim 1 , wherein said laser source comprises an isotopic 13C16O2 laser source. 
     
     
         34 . Apparatus according to  claim 1 , wherein said laser source comprises an Erbium:YSGG laser source. 
     
     
         35 . Apparatus according to  claim 1 , wherein said laser source comprises a diode laser source. 
     
     
         36 . Apparatus according to  claim 1 , wherein said laser source comprises a UV laser source. 
     
     
         37 . Apparatus according to  claim 1 , wherein said laser source generates a second, visible wavelength, aiming beam aligned with said laser beam. 
     
     
         38 . Apparatus according to  claim 1 , wherein said laser beam is a pulsed laser, each pulse corresponding to a single dwell. 
     
     
         39 . Apparatus according to  claim 1 , wherein said laser beam is a pulsed laser, a plurality of pulses being grouped for a single dwell. 
     
     
         40 . Apparatus according to  claim 1 , wherein said laser beam is a continuous laser that is artificially gated to generate shots. 
     
     
         41 . Apparatus according to  claim 38 , wherein said dwell time is over 1 milliseconds. 
     
     
         42 . Apparatus according to  claim 11 , wherein said circuitry is configured to remove sclera tissue in the shape of a reservoir suitable for non-penetrating trabeculectomy. 
     
     
         43 . Apparatus according to  claim 11 , wherein said circuitry is configured to remove sclera tissue in the shape of a percolation area suitable for non-penetrating trabeculectomy. 
     
     
         44 . Apparatus according to  claim 43 , wherein said forming includes removing in a concave pattern. 
     
     
         45 . Apparatus according to  claim 1 , wherein said beam has a power of over 5 watts. 
     
     
         46 . Apparatus according to  claim 1 , wherein said beam has an energy density of between 3 and 20 J/cm 2 , per dwell. 
     
     
         47 . Apparatus according to  claim 1 , wherein said laser ablates between 10 and 30 microns in a single dwell. 
     
     
         48 . Apparatus according to  claim 1 , wherein said laser ablates between 16 and 25 microns in a single dwell. 
     
     
         49 . Apparatus according to  claim 1 , wherein said laser ablates between 16 and 20 microns in a single dwell.