What is the recommended injection technique for administering botulinum toxin to treat crow’s feet?

The recommended injection technique for treating crow's feet with botulinum toxin involves subdermal injections in the crow's feet safety zone, which is 1 cm outside the orbital rim. The injections are placed at specific points along the contracted muscle ridges, with 2.5 units of botulinum toxin administered per point. Care is taken to avoid deep injections to prevent complications such as lip ptosis.

To treat crow's feet with botulinum toxin, injections should be placed subdermally within the crow's feet safety zone, which is defined as 1 cm outside the orbital rim, above the level of the superior margin of the zygoma, and extending under the eyebrow to the lateral limbus line. The procedure involves identifying the orbicularis oculi muscle by having the patient contract it through facial expressions like smiling. The injection points are located at the muscle ridges, and each point receives 2.5 units of botulinum toxin. The injections are performed with a 30- or 32-gauge needle, and care is taken to avoid deep injections to prevent the toxin from affecting deeper muscles, which could lead to complications such as lip ptosis or blepharoptosis.