What Are the Effects of Botox on the Upper Eyelids?

Canada
Great question. The art of injecting Botox in the Crow's Feet area is - placing the right amounts in the right places! The injector must understand the anatomy of the Obicularis muscle which surrounds the eye and when it contracts the eyelid skin bunches up. Botox relaxes this muscle which smoothes out the Crows Feet and if placed properly will allow the eyebrows to elevate slightly - tightening the upper eyelid skin. Of course, if you have a lot of loose skin, Botox is not a replacement a standard blepharoplasty.
Now if the Botox is injected into the wrong muscles in the wrong amounts, then you can have drooping skin or eyelids. This is why it is so important to seek consultation with a Board Certified Plastic Surgeon.

Dear Canada,
Depending how the BOTOX treatment was performed, treatment of the crows feet can affect the upper eyelids. The incidence of upper eyelid droop, which is an unwanted side effect of the treatment, occured in a small but not zero percentage of treated patients described in the initial studies looking at how to create a forehead lift effect with BOTOX.This includes the studies by Frankel and Chen (Alterning brow contour with botulinum toxin, Facial Plast Surg Clin North Am, 2003;11:457) as well as Huilgol and the Carruthers (Raising eyebrows with botulinum toxin, Derm Surg 1999, 25:373).
This led these authors to significantly restrict how close to the orbital rim they recommended treatment to avoid drift of the BOTOX into the eyelid where it causes drooping of the upper eyelid.
It is possible to get significant brow elevation by treating at the level of the eyebrow by controlling the depth and volume of the BOTOX injections and this is the basis for Microdroplet BOTOX forehead lift. How long the drooping upper eyelid lasts varies.
I studied seven patients referred for management after developing drooping of the upper eyelid. These patients were chosen for study because their droopy upper eyelid after BOTOX lasted 7 weeks or more and in one case took a full year to resolve. This study suggests that if you respond to Iopodine, a drop that stimulates the Mueller muscle in the upper eyelid and is used to help lid droop after BOTOX, then it is likely that the heaviness will wear off in 4 to 6 weeks.
On the other hand, if you don't respond to the drops initially, it is likely that your upper eyelid droop following BOTOX could last 3 to 6 months and rarely longer.