Abstract
Purpose: :
The literature regarding tear production after botulinum toxin type A injections is in conclusive with several studies reporting increase, decrease or no change in tear production after botulinum toxin injections. Only one case of symptomatic dry eye has been reported after botulinum toxin injection for lateral canthal rhytides. Our purpose is to evaluate the incidence of temporary dry eye following treatment of lateral canthal rhytides with botulinum toxin and the effects of lateral periorbital injections on lacrimal gland tear production.
Methods: :
Twenty–six crow’s feet areas were injected with botulinum toxin ( Botox, Allergan, Irvine, California, USA) in 13 females with an age range of 31–58 years. Botulinum toxin was diluted with unpreserved saline yielding a concentration of 2.5 units/0.1 cc. A total of 10 units of botulinum toxin was injected per side with two separate injections. Schirmer 1 testing was performed before, at 1 week, 1 month and 4 months after the injections. The test was repeated at 6 months for the patients whose schirmer test results were not back to baseline at 4 months follow–up. Statistical significance was evaluated with paired t–test analysis
Results: :
None of the patients developed dry eye symptoms 1 week and 1 month after botulinum toxin injection. No statistical difference was found in Schirmer test results from baseline at 1 week (p=0.23), 1 month (p=0.32) or 4 months (p=0.30) after the injection. Five eyes of 3 patients had significant decrease in Schirmer test results in the range of 24–72% decrease from baseline at 1 week and 11– 60% at 1 month after the injection. Only one patient reported dry eye symptoms at 4 months follow–up. Three eyes of 2 patients had significant decrease in Schirmer test results in the range of 32–84% at 4 months after the injection. Schirmer test results of 2 eyes of one patient remained significantly lower than baseline at 6 months follow–up in the range of 50–80%.
Conclusions: :
Botulinum toxin for lateral canthal rhytides, when properly administered, usually does not suppress tear production but decreased tear production after botulinum toxin for crow's feet is a possible complication and patients should be advised of the small but definite risk of a temporary dry eye.
Keywords: lacrimal gland • eyelid • aging