Vitreous Reflux Frequency and Intraocular Pressure After First-Time Intravitreal Aflibercept Injections: Comparison of 30- and 32-Gauge Needles

PURPOSE: To compare the effects of 30-gauge versus 32-gauge needles on vitreous reflux (VR) frequency and intraocular pressure (IOP) following first-time intravitreal aflibercept injections. MATERIALS AND METHODS: Overall, 116 patients (116 eyes) who received intravitreal injections using 30-gauge needles and 104 patients (104 eyes) who received the same injection using 32-gauge needles were reviewed. The medical records of 116 patients who each received an intravitreal injection using a 30-gauge needle (median age: 67.5 ± 13.9 years) and 104 patients who each received the same injection using a 32-gauge needle (median age: 66. 3 ± 10.6 years) from January 2015 to June 2019 were compared. RESULTS: No significant difference in the frequency of VR was observed between patients injected using 30-gauge needles (38/116) and patients injected using 32-gauge needles (31/104, P = 0.64). There were no significant differences in the VR rates of patients with phakic and pseudophakic eyes between those injected using 30-gauge (P = 0.94) or 32-gauge needles (P = 0.77). Axial length did not significantly differ between patients with and without VR when injected using 30-gauge (P = 0.89) and with 32-gauge needles (P = 0.69). IOP immediately after injection was significantly higher in patients injected using 30-gauge needles than in patients injected using 32-gauge needles (P < 0.01). CONCLUSION: VR frequency was not correlated with needle size, lens status, or axial length. Patients receiving injections using 30-gauge needles had higher IOP immediately after intravitreal injection.