Comparison of the tissue penetration and glide force of 22-gauge thin-wall needles for intravitreal implant administration

BACKGROUND AND OBJECTIVE: 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. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSION : 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.