Apparatus and methods for ocular injection

A method, comprising:

• inserting a distal end portion of a puncture member of a medical injector into a target tissue to define a delivery passageway within the target tissue;
• applying a first force to a housing of the medical injector such that a distal end surface of the housing contacts a target surface of the target tissue to fluidically isolate the delivery passageway;
• and
• while maintaining the first force, applying a second force to an actuation rod of the medical injector to move the puncture member distally relative to the housing such that a distal end portion of the puncture member moves from a first region within the target tissue to a second region with the target tissue, a substance from within the medical injector being conveyed to the target tissue in response to the distal end portion of the puncture member being disposed in the second region and not the first region,
• the second force being insufficient to overcome a backpressure of the first region to convey the medicament into the first region of the target tissue via the puncture member when the distal end portion of the puncture member is disposed within the first region.

A method, comprising:

• inserting a distal end portion of a puncture member of a medical injector into a first region of a target tissue to define a delivery passageway within the target tissue, the puncture member placing a substance within a housing of the medical injector in fluid communication with the first region, an adjustment member being movably disposed within the medical injector and forming a substantially fluid-tight seal with a side wall of medical injector;
• after the inserting and with the distal end portion of the puncture member disposed in the first region of the target tissue, exerting a force on the adjustment member such that the force in conjunction with the substantially fluid-tight seal produces movement of the distal end portion of the puncture member relative to the housing and from the first region to a second region of the target tissue;
• and
• conveying, in response to the exerting, a substance from the medicament container into the target tissue via the puncture member when the distal end portion of the puncture member is disposed within the second region of the target tissue.