Short duration pulse grid pattern laser treatment and methods
The procedures described herein may involve using one or more treatment beams to induce one or more therapeutic benefits. In some embodiments, a series of short duration light pulses may be delivered to ocular tissue at a plurality of target locations with a thermal relaxation time delay to limit the temperature rise of the target ocular tissue and thereby limit a thermal effect to only a desired portion of the ocular tissue. The thermal relaxation time delay may be roughly equivalent to a duration of a scan of the treatment beam between each of the target locations. Such procedures may be used to treat diabetic retinopathy, macular edema, and/or other conditions of the eye. The treatment beam may be delivered at each target location within a sufficiently short duration so as to produce a visual appearance of a treatment pattern on the ocular tissue of the patient's eye.
1. A method for treating an eye of a patient comprising:
defining a plurality of target positions for a treatment beam, the plurality of target positions comprising a first target position, a second target position, and a plurality of intermediate target positions, wherein each target position corresponds to a treatment site for treating ocular tissue of the patient's eye;
delivering a first pulse from the treatment beam onto the ocular tissue at each of the first target position, the second target position, and the plurality of intermediate target positions;
scanning the treatment beam incrementally among the first target position, the second target position, and the plurality of intermediate target positions so that the beam is fixed during delivery of each of the first pulses, wherein the treatment beam is scanned among the first target position, the second target position, and the plurality of intermediate target positions between each of the first pulses;
returning the treatment beam to each of the first target position, the second target position, and the plurality of intermediate target positions;
delivering an additional pulse from the treatment beam onto the ocular tissue at each of the first target position, the second target position, and the plurality of intermediate target positions; and
rescanning the treatment beam incrementally among the first target position, the second target position, and the plurality of intermediate target positions during delivery of each of the additional pulses to provide an additional treatment to the ocular tissue, wherein the treatment beam is scanned among the first target position, the second target position, and the plurality of intermediate target positions between each of the first pulses,
wherein:
a duration of each pulse is between 50 and 1000 microseconds,
a time interval between consecutive pukes delivered to the first target position is greater than 1900 microseconds,
each pulse delivered to the second target position and the plurality of intermediate target positions is delivered during the time interval of 1900 microseconds; and
a cumulative effect of the pules delivered to the first target position, the second target position, and the plurality of intermediate target positions is sufficient to induce photoactivation that is effective to treat the retinal tissue at the respective target positions.
2. The method of claim 1 , further comprising: directing an aiming beam onto the ocular tissue to define the plurality of target positions on the ocular tissue.
3. The method of claim 1 , wherein a time interval between consecutive pulses delivered at the respective target positions is equal to a duration of the scan of the treatment beam among all the target positions.
4. The method of claim 3 , wherein the time interval between consecutive pulses is equal to the total number of target positions multiplied by the sum of an average duration of each pulse and an average duration of movement of the treatment beam between adjacent target positions.
5. The method of claim 1 , wherein a duty cycle for a laser the provides the treatment beam at each target position is no greater than 9%.
6. The method of claim 1 , wherein the scan among the target positions defines a treatment cycle, and wherein the method comprises providing between 10 and 10,000 treatment cycles to treat the ocular tissue of the eye.
7. The method of claim 6 , wherein each pulse is delivered to the respective target positions in each treatment cycle in a manner that results in a visual pattern of the target positions on the ocular tissue.
8. The method of claim 1 , wherein the ocular tissue comprises retinal tissue.
9. The method of claim 1 , wherein a duration of each pulse is between 50 and 150 microseconds.
10. A system for providing a therapeutic treatment to a patient's eye, the system comprising:
a treatment beam source configured to transmit a treatment beam along a treatment beam path;
a scanning device disposed along the treatment beam path and configured to scan the treatment beam along ocular tissue of the patient's eye; and
a processor operable with the scanning device and configured to:
A) define a plurality of target positions relative to the ocular tissue for the treatment beam, the plurality of target positions comprising a first target position, a second target position, and a plurality of intermediate target positions;
B) scan the treatment beam incrementally among the first target position, the second target position, and the plurality of intermediate target positions;
C) deliver a pulse from the treatment beam to the ocular tissue at each of the first target position, the second target position, and the plurality of intermediate target positions as the treatment beam is scanned incrementally among the first target position, the second target position, and the plurality of intermediate target positions;
D) return the treatment beam to the first target position; and
E) repeat B) and C) to deliver at least one additional pulse from the treatment beam to the ocular tissue at each of the first target position, the second target position, and the plurality of intermediate target positions as the treatment beam is scanned incrementally among the first target position, the second target position, and the plurality of intermediate target positions;
wherein:
a duration of each pulse is between 50 and 1000 microseconds;
a time interval between consecutive pulses delivered to the first target position is greater than 1900 microseconds;
each pulse delivered to the second target position and the plurality of intermediate target positions is delivered during the time interval of 1900 microseconds; and
a cumulative effect of the pulses delivered to the first target position, the second target position, and the plurality of intermediate target positions is sufficient to induce photoactivation that is effective to treat the retinal tissue at the respective target positions.
11. The system of claim 10 , further comprising an aiming beam source configured to transmit an aiming beam along an aiming beam path, wherein the scanning device is further configured to scan the aiming beam along the ocular tissue to define the first target position, the second target position, and the plurality of intermediate target positions on the ocular tissue.
12. The system of claim 10 , wherein a time interval between consecutive pulses delivered at each of the respective target positions is equal to a duration of the scan of the treatment beam among all the target positions.
13. The system of claim 10 , wherein the ocular tissue comprises retinal tissue.
14. The system of claim 10 , wherein the scan of the treatment beam incrementally among the target positions defines a treatment cycle, and wherein the processor is configured to provide between 10 and 10,000 treatment cycles.
15. The system of claim 10 , wherein the scanning device is disposed within an adapter device that is removably couplable with an ophthalmic measurement instrument and that is optically couplable with the light beam source.
16. A system for providing a therapeutic treatment to a patient's eye, the system comprising:
a treatment beam source configured to transmit a visible treatment beam along a treatment beam path;
a scanning device disposed along the treatment beam path and configured to scan the treatment beam along ocular tissue of the patient's eye; and
a processor operable with the scanning device and configured to:
A) define a plurality of target positions relative to the ocular tissue for the treatment beam, the plurality of target positions comprising a first target position, a second target position, and a plurality of intermediate target positions;
B) deliver a pulse from the treatment beam to the ocular tissue at each of the first target position, the second target position, and the plurality of intermediate target positions;
C) scan the treatment beam incrementally among the first target position, the second target position, and the plurality of intermediate target positions during delivery of the pulses; and
D) repeat B) and C) to deliver at least one additional pulse from the treatment beam to the ocular tissue at each of the first target position, the second target position, and the plurality of intermediate target positions;
wherein:
a duration of each pulse is between 50 and 1000 microseconds,
a time interval between consecutive pulses delivered to the first target position is greater than 1900 microseconds,
each pulse delivered to the second target position and the plurality of intermediate target positions is delivered during the time interval of 1900 microseconds between consecutive pukes delivered to the first target position; and
a cumulative effect of the pukes delivered to the first target position, the second target position, and the plurality of intermediate target positions is sufficient to induce photoactivation that is effective to treat the retinal tissue at the respective target positions.
17. The system of claim 16 , wherein the ocular tissue comprises retinal tissue.