It is thought that the amount of fluid used to dilute Botox for injection has an effect on the quality of the result and the duration of effect on the treatment of upper face rhytides, even though the dose remains the same.

The study was designed to test this thinking, using the crow's feet wrinkles as the treatment area.

It is thought that the amount of fluid used to dilute Botox for injection has an effect on the quality of the result and the duration of effect on the treatment of upper face rhytides, even though the dose remains the same.

20 female subjects (10 per site), who fit the inclusion/exclusion criteria for study participation were injected with 5 units of Botox (one injection each side) into the crow's feet area. The injections were prepared with one side randomly receiving a five fold difference in volume for dilution.

Response to treatment was evaluated at 14 days, 30 days, 60 days and 90 days after the injection visit. Standardized photography was taken at each visit.

Analysis of the photographs of the lateral orbital (crow's feet rhytides) at maximum attempted contraction (maximum smile) was done by Canfield Scientific, Inc., using a specialized software program created to detect and measure changes.

Inclusion Criteria:

• Female outpatients; at least 18 years of age
• Subjects of childbearing potential must have a negative urine pregnancy test result at the Baseline/Screening Visit and practice a reliable method of contraception throughout the study.
• Bilaterally symmetric moderate (score 2 on Allergan Photonumeric Guide for Crow's Feet) Lateral Orbital Rhytides at maximum smile

Exclusion Criteria:

• Subjects who are pregnant, are planning a pregnancy during the study period, have an infant they are breast feeding, or who are of childbearing potential and not practicing a reliable method of birth control.
• Subjects with a history of injection to the lateral orbital area with botulinum toxin type A within one year of baseline visit.
• Subjects with a history of adverse reaction to botulinum toxin type A.
• Subjects with a diagnosis of Myasthenia Gravis, Eaton-Lambert syndrome, Amyotrophic Lateral Sclerosis, or any other disease which might interfere with neuromuscular transmission.
• Subjects with a history of facial nerve palsy.
• Subjects with profound atrophy or excessive weakness of muscles in the target areas for injections.
• Subjects with a systemic infection or an infection at the injection site.