Methodology for preventing Botulinum toxin-A eyelid ptosis: Risk index derivation, safety rules, and evidence-graded management algorithm

Table 1 Botulinum toxin A: Ten practical rules to reduce Botulinum toxin A diffusion toward the levator complex through safe landmarking, point selection, depth/vector control, conservative delivery, and post-injection precautions

Rule	Safety rules
1	Baseline assessment and documentation: Record eyelid/brow position at rest and with animation; document margin reflex distance 1, asymmetry, and frontalis compensation (photo if possible)
2	Mark bony landmarks: Palpate/mark the superior orbital rim and brow to create a clear “orbital safety boundary” before injecting
3	Respect an orbital-rim buffer: Keep all glabellar/brow points superior to a predefined safety margin above the orbital rim
4	Keep frontalis injections high (especially laterally): Avoid low frontalis points near the brow; tailor placement to brow position and baseline frontalis recruitment
5	Medial corrugator: Controlled deep placement at safe origin: Use a stabilizing technique (e.g., pinch/Lift) and place toxin in the intended deep plane at the medial corrugator origin - avoid low/inferior drift
6	Lateral corrugator: Stay more superficial and superior: Avoid deep lateral placement that increases diffusion risk toward the levator complex and septal planes
7	Needle vector away from the orbit: Orient the needle/force superiorly and away from the orbital cavity; avoid directing the tip toward the orbit
8	Minimize diffusion drivers (dose/volume/pressure): Use the lowest effective dose, small per-point volumes, slow injection, and low pressure; avoid large boluses and unnecessary re-injection in the same session
9	Avoid clustering near high-risk zones: Maintain deliberate spacing; avoid multiple closely placed points in the superomedial orbital region and other areas near the orbital boundary
10	Post-procedure diffusion precautions: Avoid rubbing/massage and sustained pressure/heat/exertion on the treated region; remain upright in the immediate post-injection period (per protocol); report ptosis/diplopia promptly