Antidepressants and Glaucoma Risk

The relationship between antidepressant use and glaucoma has been raised as a possible risk in certain populations, though remains under-investigated with sometimes conflicting findings.

• Most cases of pre-existing glaucoma is almost always open-angle glaucoma
  • 9 in 10 people with glaucoma have the open-angle type
• Acute angle closure (AAC) glaucoma (also called narrow-angle or acute glaucoma) is an ocular emergency with symptoms of blurred vision, eye pain, headache, nausea, vomiting and reddening of the eye that results from a sudden and increased intraocular pressure. It is mostly unilateral.
  • AAC glaucoma can be treated definitively with iridectomy
  • AAC glaucoma can lead to permanent damage in vision, causing blindness from progressive and irreversible optic neuropathy if left untreated. 

• Glaucoma is reported to be responsible of estimated 12% of all global blindness
• The incidence of drug-induced AAC glaucoma is unknown

• A number of local and systemic medications are thought to either induce or be associated with a risk for AAC, including sympathomimetics, cholinergics, anticholinergics, mydriatics, antihistamines, antiepileptics (e.g. - topiramate), antidepressants (e.g. - tricyclics, SSRIs, SNRIs), antipsychotics, sulfa-based drugs, and anticoagulants
  • These medications have the potential to precipitate AAC via their mydriatic (dilatory) effects.
• With psychotropic medications, topiramate, tricyclic antidepressants are traditionally considered to have a higher risk for acute angle closure.

• Medications are thought to have the potential to precipitate AAC via their mydriatic (dilatory) effects, primarily through their anticholinergic effects
• The specific mechanism for antidepressant-induced AAC remains unclear, but may be due to the direct effect of serotonin on iris or ciliary body, and increased intraocular pressure^[1][2]

• One case control study found an increased risk for acute angle closure glaucoma in immediate SSRI use (within 7 days)^[3]

• 1 case report of acute angle closure in an individual on a combination of escitalopram + mirtazapine, developing acute angle closure within 1 hour of mirtazapine initiation (nausea and severe headache with pain, blurred vision and reddening on the right eye). Mirtazapine was discontinued, and mannitol administered with resolution of symptoms. Subsequent ophthalmological examination remained unremarkable at 1-week and 1-month follow-up visits.^[4]

• Tricyclic antidepressants should be avoided in patients at risk of developing angle closure glaucoma due to their strong anticholinergic and antimuscarinic proprieties.^[5]

• One meta-analysis did not find an increased risk of glaucoma with SSRI or SNRI use. ^[6]
• Another cohort study did not find an association between the long-term use of SSRIs and open-angle glaucoma or acute angle glaucoma in depression patients.^[7]