Reflux, Intraocular Pressure Variation and Pain Following Intravitreal Ranibizumab Injections Using 30-Gauge or 32-Gauge Needles for Patients With Retinal Pathologies: A Randomized Clinical Trial

Purpose: To compare reflux, intraocular pressure (IOP) variation and pain following intravitreal (IV) injections using 30-gauge and 32-gauge needles in patients with retinal pathologies in Saudi Arabia. Methods: A double-blind randomized clinical trial was conducted in 2018. Participants were randomized to receive IV injections of Ranibizumab using 30-gauge (Gr(1)) or 32-gauge (Gr(2)) needles. The amount of reflux of injected material, IOP before (IOP(1)) and five minutes after injection (IOP(2)) were measured. The patient-perceived pain score was assessed using a visual analogue score (VAS). Outcome variables were compared. Results: The study sample was comprised of 86 eyes (86 patients) in each group. Gender (P=0.76), laterality (P=0.55) and age (P=1.0) were not different between groups. The reflux in Gr(1) [34.9% (95% confidence interval {CI}, 24.8; 45.0)] was significantly higher compared to Gr(2) [22.1% (95% CI, 13.3; 30.9)] (P=0.007). The median pain score was 1 in both Gr(1) [interquartile range (IQR) 1.0: 3.0] and Gr(2) (IQR 0.0; 2.0) (P=0.04). Among 56 eyes without reflux in Gr(1), the IOP(1) and IOP(2) were 13.6±2.7 mmHg and 16.4±5.0 mmHg, respectively. Among 67 eyes without reflux in Gr(2), the IOP(1) and IOP2 were 13.6±2.9 mmHg and 17.0±5.2 mmHg, respectively. The change in percentage in IOP in Gr(1) and Gr(2) was not significantly different (Mann Whiney P=0.3). Conclusions: IV injection given by 30-gauge needle compared to 32-gauge needle resulted in greater patient-perceived pain and more reflux of injected material from the injection site. An increase in IOP was not associated with the gauge of the needle used for IV injection.