Method of performing subretinal drainage and agent delivery

A method, comprising:

• (a) inserting a flexible cannula between a sclera and a choroid of an eye in an anterior region of the eye;
• (b) after a distal end of the flexible cannula reaches a posterior region of the eye, advancing a needle from the distal end of the flexible cannula, such that the needle pierces the choroid to access a subretinal space of the eye;
• (c) injecting a first volume of bleb fluid into the subretinal space via the needle;
• (d) aspirating at least some of the first volume of bleb fluid from the subretinal space via the needle;
• and
• (e) after aspirating at least some of the first volume of bleb fluid from the subretinal space via the needle, injecting a second volume of therapeutic agent into the subretinal space via the needle, wherein the second volume is smaller than the first volume.

A method, comprising:

• (a) performing a sclerotomy in an anterior region of a sclera of an eye to thereby form an incision through the sclera;
• (b) inserting a flexible cannula through the incision into a space between the sclera and a choroid of the eye such that the flexible cannula is oriented tangentially relative to the incision;
• (c) advancing the flexible cannula within the space to position a distal end of the flexible cannula at a posterior region of a retina of the eye on an opposite side of the choroid from the retina;
• (d) advancing a needle from a distal end of the flexible cannula, such that the needle pierces the choroid to access a subretinal space of the eye;
• (e) aspirating a first fluid from the subretinal space via the needle, and
• (f) after aspirating the first fluid from the subretinal space via the needle, injecting a second fluid into the subretinal space via the needle.