The risk that matters: vascular occlusion
This is the section that should decide where you have filler, and it is more important than anything about price or product.
What it is. Filler injected into an artery, or injected in such volume that it compresses one, blocks the blood supply to the tissue that artery feeds. The tissue is starved, and if the blockage is not relieved quickly the skin dies.
What it looks like. Immediate severe pain out of proportion to the injection. Blanching, where the skin goes white. Then a mottled, blue-grey, net-like discolouration over the area supplied by that vessel. It can develop over minutes to hours.
The eye. Certain facial arteries connect backwards to the arteries supplying the retina. Filler forced into one of those can travel to the eye and block the retinal circulation, causing sudden partial or complete loss of vision in that eye. It is rare. It is usually irreversible. The highest-risk areas are between the brows, the nose, the area around the nose, the forehead and the temple, and the area under the eye.
Why hyaluronidase matters so much. Hyaluronidase dissolves hyaluronic acid, and injected promptly and in adequate quantity into an area of occlusion it can restore flow and save the skin. Prompt means within hours, ideally sooner. That is why it must be physically present in the clinic and why the injector must know how to use it in an emergency. A clinic that does not have it should not be injecting filler.
What else should be in place. A protocol the staff know, and a doctor who can recognise the problem. Immediate referral arrangements for a suspected eye event, since that needs ophthalmology urgently.
What reduces the risk. Anatomical knowledge, which is why a doctor rather than a technician. Aspirating before injecting, which some practitioners do. Using a blunt cannula rather than a needle in higher-risk areas, which many do. Injecting slowly, in small amounts, with low pressure. Avoiding the highest-risk areas unless experienced. And never injecting into an area that has been treated with permanent filler.
What you must do. Ask, before any injection: do you have hyaluronidase on the premises, and who here is trained to manage a vascular occlusion? If the answer is not immediate and confident, do not proceed.
And know the warning signs yourself, because you may be the one who notices. Severe pain, blanching, mottling, or any change in vision needs treatment the same hour, not the next day, and not after you have flown home.
