Effect of Penetration Angle and Velocity During Intravitreal Injection on Pain.

To evaluate the effect of velocity and angle of the intravitreal injection of anti-vascular endothelial growth factors on pain sensation. Patients were randomly assigned to one of four injection methods: straight and fast, straight and slow, tunneled and fast, and tunneled and slow. Later, they graded their pain sensation on a Visual Analog Scale (range 0-10). The cohort included 180 patients. Mean pain score was 2.81 ± 2.34. There was no statistically significant difference in mean pain score among the four groups ( = .858); between the slow-injection (straight and tunneled) and fast-injection groups ( = .514); and between the straight-injection (fast and slow) and tunneled-injection groups ( = .992), nor other background variables. Velocity and angle of intravitreal injections are unrelated to the pain sensation. Therefore, the method may be left to the clinician's discretion. This implies that the sensation is mostly subjective.