Method for treatment of eye disease using injection system

A method for treatment of an eye disease, the method comprises:

• pre-inserting, into a sclera of a patient, a puncture element of an injection system, the injection system comprising:
• a syringe barrel defining a lumen between a proximal end and a distal end;
• a first sealing element moveably disposed within the lumen;
• a second sealing element moveably disposed within the lumen proximal to the first sealing element, wherein the first sealing element and the second sealing element form a seal with the lumen and define an injection chamber between them;
• the puncture element extending from a distal end of the first sealing element, the puncture element being in fluid communication with the injection chamber to deliver an injection agent from the injection chamber into a space in a tissue of the patient;
• wherein one or more of the syringe barrel, the first sealing element, and the second sealing element are configured to prevent proximal movement of the first sealing element past a pre-selected location, while allowing the second sealing element to come in contact with the first sealing element;
• advancing the puncture element through the sclera by applying a force onto the second sealing element, the force being sufficient to move the first sealing element in a distal direction to advance the puncture element in the distal direction, without conveying the injection agent through the puncture element;
• and
• maintaining the force onto the second sealing element as the puncture element passes through the sclera and opens into a suprachoroidal space (SCS) such that the injection agent is conveyed from the injection chamber through the puncture element into the SCS, without further distal movement of the first sealing element.