This is a prospective, randomized, double-masked, comparative study in patients who present at the Robert Cizik Eye Clinic with horizontal forehead rhytides requiring treatment with botulinum toxin Type A (Botox ®; Allergan, Irvine, CA, USA).~The objective of this study is to determine whether there is a difference in clinical effect (weakness/paralysis of the frontalis muscle), duration of effect, level of discomfort and patient satisfaction in patients receiving topical anesthesia (2.5% lidocaine/2.5 % prilocaine cream, Impax Laboratories, LLC) on one side of the forehead and petrolatum ointment on the other prior to BTX-A administration for the treatment of forehead rhytides.~Primary outcome variable is change of eyebrow excursion on each side of the forehead from baseline to each follow-up visit.~Secondary outcome variables~Duration of effect, defined as the elapsed time from injection to the end of botulinum, such that return of baseline frontalis function, i.e. within 2 mm of baseline value~Perception of pain immediately after injection at each side~Patient satisfaction for each side~Patient's perception of difference in efficacy
The purpose of this study is to determine whether there is a difference in clinical effect, duration of effect, level of discomfort and patient satisfaction in patients receiving topical anesthesia on one side of the forehead and petrolatum ointment on the other prior to Botulinum Toxin Type A administration for the treatment of forehead rhytides.