Millions of Americans take monthly injections to keep migraines at bay. Now researchers say those same drugs may be protecting them from glaucoma, a leading cause of blindness.
Glaucoma is a leading cause of blindness, and the two conditions have a lot in common.
Researchers analyzed data from more than 36,800 people between 2018 and 2024, comparing those on CGRP inhibitors—such as erenumab, fremanezumab, galcanezumab, and eptinezumab—to those taking other migraine prevention drugs. About 0.4 percent of people taking CGRP inhibitors developed glaucoma, compared with 0.6 percent of those on other medications—a 25 percent reduced risk.
What Are CGRP Inhibitors?
CGRP is a protein involved in blood pressure regulation, tissue repair, wound healing, and inflammation.During a migraine, CGRP is released in the brain and affects the trigeminal nerve, which transmits pain signals. Increased CGRP levels can cause inflammation and worsen headache pain, prolonging migraine attacks.
CGRP inhibitors are medications that block the protein from attaching to its receptors, blunting these effects.
CGRP inhibitors are recommended as a first-line treatment for preventing episodic migraines (up to 14 headache days per month) and chronic migraines (15 or more headache days per month).
Why It Might Work
Independent experts say the connection between the two conditions is biologically plausible. Both migraine and glaucoma involve problems occurring with the blood vessels, disrupting blood flow to the brain and the optic nerve.“In glaucoma, chronic inflammation can lead to the degeneration of retinal ganglion cells,” Dr. Andrew Lee, professor of ophthalmology, neurology, and neurosurgery at Houston Methodist Research Institute, told The Epoch Times. “Researchers hypothesize that CGRP inhibitors may help stabilize vascular tone, ensuring the optic nerve receives a consistent blood supply and preventing the ‘starvation’ of retinal cells.”
Since the study is observational, it cannot prove that CGRP inhibitor drugs directly cause the reduced risk of glaucoma, Weng told The Epoch Times. It only shows an association.
Like all observational studies using large healthcare databases, the study has some limitations. Researchers relied on diagnostic codes in medical records rather than direct clinical measurements such as eye pressure or optic nerve imaging, and could not fully rule out unmeasured factors such as migraine severity or family history of glaucoma.
“These unanswered questions highlight why prospective and more detailed clinical studies are needed,” he said.
Preventing Glaucoma
Untreated, glaucoma can irreversibly damage eyesight.Preventive measures should focus on managing systemic health issues, avoiding unnecessary corticosteroid use, and addressing vascular factors “such as nocturnal hypotension (low blood pressure) or untreated sleep apnea,” Dr. Karen Allison, associate professor of clinical ophthalmology at the University of Rochester Medicine and not involved in the study, told The Epoch Times.
Early detection through proactive screening, she said, is the most effective tool available to preserve vision before symptoms occur.
People at higher risk include those with a family history of glaucoma and those of African or Hispanic descent, as well as people with thin corneas, elevated intraocular pressure, systemic vascular conditions such as migraine, Raynaud’s phenomenon—which causes blood vessels in the extremities to narrow—or sleep apnea.
“Age is also a key factor, with incidence rising notably after age 60,” Allison said.
There is currently no cure for glaucoma, and its cause is still not well understood.
Regarding CGRP inhibitors as a way to prevent glaucoma, Weng said it’s still “too early” to say. However, he said he believes that if future research confirms the study’s findings, it’s possible that this drug class will lead to new prevention strategies.
