The effect of two different intravitreal injection techniques on frequency of vitreous reflux and on treatment response in neovascular AMD patients

Purpose. - To determine the effect of two distinct intravitreal injection (IVI) techniques on the frequency of vitreous reflux (VR) and on treatment response at cumulative dosages in neovascular age-related macular degeneration (nAMD) patients. Patients and methods. - Ninety-three eyes of 93 nAMD patients were included in the study. IVI was performed in 47 eyes using the straight technique (ST) and 46 eyes with the tunneled technique (TT). Patients received three loading doses of intravitreal bevacizumab, and substantial VR was noted for each IVI. Central (CMT), 1 mm (MT1), and 3 mm (MT3) macular thicknesses were measured before and after treatment. VR frequency and treatment response were compared in both groups, and correlation analysis was performed. Results. - Post-treatment VR was seen in 91 of 141 IVI with the ST and 33 of 138 IVI with the TT. The decrease in CMT, MT1, and MT3 after treatment with the ST was 121.4 +/- 92.5 mu m, 65.3 +/- 50.6 mu m, 28.8 +/- 30.8 mu m, respectively, and with the TT was 114.0 +/- 97.5 mu m, 67.8 +/- 72.6 mu m, and 27.1 +/- 31.4 mu m, respectively. The ST substantially increased the rate of VR compared to the TT (P < 0.001), whereas the decrease in CMT, MT1, and MT3 did not vary significantly (P > 0.05). There was no correlation between VR rate and decreases in CMT, MT1, or MT3 (P > 0.05). Conclusions. - According to our findings, the ST resulted in a higher frequency of VR than the TT, but VR did not affect the treatment response, despite multiple doses. Complication rates were negligible with both approaches. As a result, it appears that practitioners may use either IVI approach. (C) 2022 Elsevier Masson SAS. All rights reserved.