Abstract: A system for treating an eye of a patient in need including a delivery device having a housing sized to be held by an operator, an actuator and a distal nose cone; a needle coupled to and extending distal from the nose cone, the needle having a lumen and a beveled distal end defining a distal opening having a sharpened tip and heel proximal the distal opening; and a retention plug positioned within and spanning the lumen of the needle proximal to the heel; and an intraocular implant positioned within the lumen of the needle proximal to the retention plug. The retention plug is formed from a flowable retainer solution of hydroxypropyl methylcellulose (HPMC) in water having a concentration that is greater than 2.5% w:w and less than about 4% w:w. Related devices and methods are provided.