I have read articles that have suggested that using a "blunt cannula" reduces most if not all risks of blood clots/blindness. What is the percentage of this actually happening/is it something I should be scared of? What can do to reduce the risks, like asking my doctor to use an ice pack on my face to shrink the blood vessels or a supplement I can take (Arnica Montana)? If there is a complication, is there no way to correct it? I.E. could you be given a blood thinner to break up a clot?