When we inject the dispersive viscoelastic at the beginning of the case, our goal is to protect the corneal endothelium while maintaining space in the anterior chamber. We want to perform an exchange with the viscoleastic going into the eye while the aqueous is being pushed out of the eye. This is why I bring the cannula across the anterior chamber to the opposite angle of the eye.
When injecting the dispersive viscoleastic, we want to avoid the spaghetti effect which is when strings of viscoelastic are injected. These strings do not adhere to anything within the eye and they are quickly and easily washed out. Instead we want a wave of dispersive viscoelastic to fill the eye to coat and protect the delicate structures like the corneal endothelium. We can even use the viscoelastic to perform visco-mydriasis to expand the pupil and keep the iris pushed towards the angle of the eye.
The main key to achieving the desired viscoelastic wave is the force of the injection. If we push on the plunger too timidly, then we will get spaghetti string. We must use a bit more force in order to achieve the goal of the viscoelastic wave.
Click below to learn how to properly achieve the dispersive viscoelastic wave: