Contact probe for the delivery of laser energy
Systems, devices, and methods for treating a glaucomatous eye are provided. An amount of pulsed laser energy is delivered to the pars plana of the eye by a hand-holdable device which comprises a hand-holdable elongate member and a contact member disposed on an end of the elongate member. A contact surface of the contact member is placed in direct contact with the eye so that a reference edge of the contact member aligns with the limbus and a treatment axis defined by the elongate member is angularly offset from the optical axis of the eye. The amount of pulsed laser energy delivered is insufficient to effect therapeutic photocoagulation but is sufficient to increase uveoscleral outflow so as to maintain a reduction from pre-laser treatment intraocular pressure. Amounts of pulsed laser energy will be transmitted to a circumferential series of tissue regions of the eye.
1. A laser treatment method for treating an eye by reducing intraocular pressure, the method comprising:
positioning a contact surface of a probe in contact with a surface of the eye, wherein the contact surface comprises an output aperture for delivering pulsed laser energy, and wherein the contact surface is positioned such that the output aperture is posterior to a limbus of the eye by a desired distance;
performing a first sweep of the output aperture of the probe across the surface of the eye while the output aperture of the probe is maintained at the desired distance posterior to the limbus of the eye; and
delivering pulsed laser energy toward a target region of the eye posterior to the limbus while the output aperture of the probe is swept across the eye and maintained in contact with the surface of the eye such that an aggregate amount of the pulsed laser energy reduces intraocular pressure of the eye.
2. The method of claim 1 , wherein a treatment axis along which the pulsed laser energy is delivered is generally perpendicular to an outer surface of a sclera of the eye.
3. The method of claim 1 , wherein the first sweep comprises sliding the output aperture 360 degrees around the limbus of the eye.
4. The method of claim 1 , wherein the first sweep is performed in a single continuous motion.
5. The method of claim 1 , wherein the first sweep comprises a series of discrete spaced applications.
6. The method of claim 1 , wherein performing the first sweep comprises continuously sliding the output aperture along a 180 degree arc around the limbus of the eye in a first region of the eye.
7. The method of claim 6 , further comprising performing a subsequent sweep of the output aperture, wherein the subsequent sweep comprises continuously sliding the output aperture along a 180 degree arc around the limbus of the eye in a second region of the eye, wherein the second region is distinct from the first region.
8. The method of claim 1 , wherein sweeping the output aperture comprises continuously sliding the output aperture along a first arc around the limbus of the eye in a first region of the eye, the method further comprising:
performing one or more subsequent sweeps of the output aperture, wherein the one or more subsequent sweeps comprises continuously sliding the output aperture along one or more subsequent arcs around the limbus in one or more subsequent regions of the eye until the first sweep and the subsequent sweeps in combination define a 360 degree radial area around the limbus.
9. The method of claim 1 , wherein the desired distance is between about 2 mm to 3 mm.
10. The method of claim 1 , wherein the desired distance is greater than about 3 mm.
11. The method of claim 1 , wherein the target region comprises a pars plana of the eye, a pars plana-pars plicata junction, or a posterior portion of a pars plicata of the eye.
12. The method of claim 11 , further comprising selecting the desired distance based on a location of the target region.
13. The method of claim 1 , further comprising selecting a duty cycle for the pulsed laser energy that is configured to reduce undesired thermal damage to a tissue, wherein the selected duty cycle provides a sufficient “OFF” time to prevent cumulative thermal buildup in the tissue.
14. The method of claim 13 , wherein the pulsed laser energy is delivered with a duty cycle of about 50% or less.
15. The method of claim 13 , wherein the pulsed laser energy is delivered with a duty cycle of about 20% or less.
16. The method of claim 13 , wherein the pulsed laser energy is delivered with a duty cycle of about 15%, with an “ON” time of 300 ms.
17. The method of claim 1 , wherein the pulsed laser energy is delivered from a plurality of fixed probe locations, wherein each pulse has an energy of about 2 mJ, and wherein aggregate amount of the pulsed laser energy directed to the target region is between about 40 J and 100 J.
18. The method of claim 1 , wherein the pulsed laser energy is delivered from a plurality of fixed probe locations, and wherein the aggregate amount of the pulsed laser energy directed to the target region is less than 75 J.
19. The method of claim 1 , wherein positioning the contact surface comprises positioning a reference structure of the contact surface in alignment with a reference feature of the eye such that the output aperture is posterior to the limbus of the eye by the desired distance.
20. The method of claim 19 , wherein the reference structure of the contact surface is at an edge of the contact surface that extends between opposed lateral placement sides of the contact surface, and wherein the first sweep comprises moving the probe in an arc around the limbus with reference to the reference structure.