Comparison of the Tissue Penetration and Glide Force of 22-Gauge Thin-Wall Needles for Intravitreal Implant Administration

Abstract

To identify a needle to improve intravitreal dexamethasone implant administration by evaluating ease of ocular tissue penetration and glide force, key characteristics of needle performance. Two custom-applicator needles coated with distinct lubricants (needles A and B) and the original dexamethasone implant needle were evaluated by five retina specialists. Ex vivo porcine eyes were injected, and a visual analog scale was used in ratings. Ease of ocular tissue penetration and glide force of needle B were rated significantly higher than that of the original applicator needle (P < .001), but there were no significant differences for needle A. Lot to lot, needle B was not significantly different in penetration and glide, whereas a significant difference was observed for penetration of needle A (P = .043). Needle design and lubricant appear to facilitate penetration and reduce glide force when administering dexamethasone intravitreal implants. Minimal lot-to-lot variation should be considered in needle choice.