Electron Microscopy of Needle Tips Following Intravitreal Injections Using 30-Gauge Needles

Abstract

Purpose: To observe the degree of damage in a 30-gauge injection needle by observing the changes in needle tip following an intravitreal injection with the use of a scanning electron microscope. Methods: The present study evaluated 11 injection needles collected following the use of an intravitreal injection of bevacizumab. Ten unused injection needles were selected as the control group. Needle examination was performed using a scanning electron microscope. Results: Following 11 intravitreal injections, seven bent needle tips, two stubbed needle tips and two almost normal needle tips were observed following intravitreal injections. In the control group, a single damaged needle tip was observed. Conclusions: Significant damage to the needle tip was observed following intravitreal injection using a 30-gauge injection needle. The results indicate that needles should be manipulated carefully during an intravitreal injection. Additionally, in the control group where no procedures were performed, a single injection needle with damaged status was found. These results indicate that needles should be replaced in cases in which resistance is perceived during the procedure.