Ocular delivery systems and methods
Described here are systems and methods for accessing Schlemm's canal, for delivering a fluid composition therein, and for tearing the trabecular meshwork. The fluid composition may be a viscoelastic fluid that is delivered into the canal to facilitate drainage of aqueous humor by disrupting the canal and surrounding trabeculocanalicular tissues. The systems described here may be configured to cut or tear the trabecular meshwork with the body of an elongate member located within Schlemm's canal.
1. A system for use in an eye of a patient, comprising:
an elongate member comprising a lumen, wherein the elongate member is slidable between a retracted position and an extended position;
a reservoir comprising a fluid composition, wherein the reservoir is fluidly connected to the lumen of the elongate member;
a linear gear; and
a linkage coupling the reservoir and the linear gear,
wherein the linear gear comprises a first set of teeth configured to engage the linkage when the system is in a first configuration, and a second set of teeth configured to engage the linkage when the system is in a second configuration,
wherein the first set of teeth allow movement of the linear gear relative to the linkage in a first direction and prevents movement of the linear gear relative to the linkage in a second direction opposite the first direction, and wherein the second set of teeth allow movement of the linear gear relative to the linkage in the first and second directions.
2. The system of claim 1 , wherein the first set of teeth is located in a proximal portion of the linear gear, and wherein the second set of teeth is located in a distal portion of the linear gear.
3. The system of claim 1 , wherein the linkage is fixedly coupled to the reservoir.
4. The system of claim 1 , wherein in the first configuration, the linear gear is movable proximally but not distally relative to the linkage, and in the second configuration, the linear gear is movable proximally and distally relative to the linkage.
5. The system of claim 1 , wherein in the first configuration, the linear gear is movable toward but not away from the reservoir, and in the second configuration, the linear gear is movable toward and away from the reservoir.
6. The system of claim 1 , wherein the first and second sets of teeth are configured to provide haptic feedback when the linear gear and linkage are moved relative to each other.
7. The system of claim 1 , where the second set of teeth is configured to resist distal movement of the linear gear relative to the linkage in response to fluid pressure in the reservoir.
8. The system of claim 1 , wherein the teeth in the first set of teeth are larger than the teeth in the second set of teeth.
9. The system of claim 1 , wherein the linkage comprises a flexible portion, and wherein the flexible portion is configured to flex in a first plane around the second set of teeth when the linear gear moves distally relative to the linkage, and wherein the flexible portion is configured to flex in a second plane around the second set of teeth when the linear gear moves proximally relative to the linkage.
10. The system of claim 9 , wherein the first and second planes are perpendicular to each other.
11. The system of claim 9 , wherein the flexible portion comprises a u-shaped bend.
12. A system for use in an eye of a patient, comprising:
an elongate member comprising a lumen, wherein the elongate member is slidable between a retracted position and an extended position;
a reservoir comprising a fluid composition, wherein the reservoir is fluidly connected to the lumen of the elongate member;
a linear gear; and
a linkage coupling the reservoir and the linear gear,
wherein the linkage comprises a flexible portion configured to flex in two planes that are perpendicular to each other.
13. The system of claim 12 , wherein the flexible portion of the linkage comprises a u-shaped bend.
14. The system of claim 12 , wherein the flexible portion comprises a notch configured to engage the linear gear.
15. The system of claim 14 , wherein the linear gear comprises a first set of teeth and a second set of teeth.
16. The system of claim 15 , wherein the first set of teeth is proximal to the second set of teeth.
17. The system of claim 15 , wherein the first set of teeth is configured to allow the notch to translate in one direction relative to the linear gear, and wherein the second set of teeth is configured to allow the notch to translate in two directions relative to the linear gear.
18. The system of claim 17 , wherein the first set of teeth is configured to allow the notch to translate distally but not proximally relative to the linear gear, and wherein the second set of teeth is configured to allow the notch to translate distally and proximally relative to the linear gear.
19. The system of claim 15 , wherein the notch is configured to generate a proximal force on the second set of teeth to oppose a distal force on the linear gear generated by the fluid composition.