After a filler injection the eye goes to the contour. The skin around it needs a look too, because tissue ischemia is easy to overlook while you are admiring the shape.
What the guideline puts first
PubMed Central carries the guideline, and its position is clear: "The delivery of optimal care begins with an understanding of the underlying pathophysiology and the ability to assess and elicit clinical signs."
That sentence puts understanding ahead of action. The full text is the guideline for the management of hyaluronic acid filler-induced vascular occlusion, and it is where to read the detail this note does not repeat.
Reading the wider literature
A clinician near Parsippany, New Jersey should not rely on one guideline alone. A literature review and meta-analysis of vascular complications after facial filler injection gathers the wider evidence on the same problem.
For the patient-facing side, the American Society of Plastic Surgeons publishes a page on dermal filler risks and safety.
Look before the patient leaves
Before you treat, decide which signs you will look for and when you will look. Then look before the patient leaves the chair, not after they have gone home.