Purpose
Intravitreal injection technique varies widely among ophthalmologists, including the selection of needle gauge. We performed a retrospective observational clinical study to better understand the effect of needle bore size on the rate of complications in patients receiving intravitreal anti-VEGF injections.
Methods
A master list of patients receiving intravitreal anti-VEGF injections from two retinal specialists at the University of Vermont Medical Center within a one year time frame was created from billing records. The two physicians consistently used either 30G or 32G needles. From this list, electronic medical records were abstracted for adult patients who received bevacizumab (Avastin), ranibizumab (Lucentis), or aflibercept (Eylea) within the study period with at least one post-injection follow-up. Data regarding demographics, ocular/systemic medical and surgical histories, clinical variables, and indications for therapy were recorded from eligible charts. Primary outcomes were complication rate and type.
Results
Data from 1008 injection charts (407 30G, 601 32G) were included. Cohorts were similar with regard to age (median 74 years), sex (~60% female), and indication for therapy (~70% wet age-related macular degeneration, ~20% proliferative diabetic retinopathy). Within the one year study period, complication rates were 0.74% and 2.33% for 30G and 32G needles, respectively, with a 1.59% difference in complication rate (p = 0.054). The most commonly reported complications were new floaters (41%), eye pain (18%), new flashes (12%), and headache/migraine (12%). There was no detectable association between complication rate and medical/surgical history, smoking/diabetes status, or anti-coagulative therapy.
Conclusions
There was no significant difference in complication rate between 30G and 32G needles during our study period. These data suggest that needle bore alone does not significantly affect the rate of complications from intravitreal injections. Further comprehensive investigation stratified by medical problems and clinical variables will be needed to understand the risk factors contributing to injection complications.