Patients with benign essential blepharospasm should be screened for dry eye disease (DED) before being treated with botulinum neurotoxin A, according to a recent study in the Journal français d’ophtalmologie. Patients with blepharospasm should be prescribed artificial tears to treat DED based on their specific tear osmolarity.

Although DED has been previously linked with eyelid spasms, it was unclear which condition developed first in patients. Dry eye can affect vision; so, accurate, early identification and treatment is necessary.

To assess the severity of DED in patients with blepharospasm before and after injection, investigators divided a group of 101 blepharospasm patients with no known history of dry eye symptoms prior developing eyelid spasms into 4 groups (mean age 67 years, 86 women). During the study, 17 patients were untreated, while 26 were treated with onabotulinumtoxinA), 23 were treated with abobotulinumtoxinA and 35 were treated with incobotulinumtoxinA every 3 months.

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The research team found that, postinjection mean tear osmolarity was not significantly higher for patients treated with onabotulinumtoxinA, abobotulinumtoxinA, or incobotulinumtoxinA (P =.65, P =.92, and P =.15, respectively), compared with the control group. Tear osmolarity remained under 308 mosm/mL, while mean Schirmer I-test results stayed under 5 mm and did not vary between the study’s  4 groups.

“The results clearly demonstrate that reduced tear secretion appears to be present in BEB patients even prior to treatment,” report the investigators. “This decreased lacrimal secretion was not correlated with hyperosmolarity. Clinicians should proactively treat dry eye syndrome in conjunction with management of the blepharospasm.”

The study’s authors note several limitations to their work, including not randomizing patients in the study’s four groups, and discontinuing lacrimal supplementary eye drops the night before examination. 

Disclosure: One of the study’s authors declared an affiliation with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Girard B, de Saint Sauveur G. Tear osmolarity, dry eye syndrome, blepharospasm andbotulinum neurotoxin. J Fr Ophtalmol. Published online October 30, 2021. doi:10.1016/j.jfo.2021.05.00.