Alpha-gal syndrome (AGS) in a glaucoma suspect with narrow iridocorneal angles

PURPOSE: Alpha-gal syndrome (AGS) is an allergy to non-primate mammalian carbohydrate (galactose-alpha-1,3-galactose) which may cause anaphylaxis. Allergic patients must avoid ophthalmic drugs containing animal-derived ingredients. OBSERVATIONS: We report a 59-year-old non-Hispanic white woman who was referred for a glaucoma evaluation. She had been diagnosed with AGS after a tick bite in 2017. Ophthalmic exam revealed potentially occludable, narrow iridocorneal angles and laser iridotomy was recommended. Prior to performing the iridotomy, we investigated the ophthalmic medications required for the procedure to identify options that are free of animal-derived products and safe to use. Laser iridotomy was performed without complications or allergy to medications. CONCLUSIONS: Ophthalmologists need to be aware of both the presence of AGS as well as the identity of ophthalmic medications that are safe to use in patients with this condition to avoid potentially lethal allergic responses.