THU443 Acute Iridocyclitis Associated With Intravenous Zoledronic Acid

Disclosure: A.R. Ankireddypalli: None. S.D. Sibley: None. Introduction: Bisphosphonates are widely used for osteoporosis. Intravenous (IV) zoledronic acid (ZA) is frequently prescribed in cases of oral bisphosphonate intolerance or noncompliance. Well known immediate ZA side effects include flu-like symptoms such as nausea, myalgias and fever. Here we report a case of a rare side effect of acute anterior uveitis following initial ZA dosing. CASE: A 71-year-old female was diagnosed with osteoporosis; DEXA scan had lowest T score of -2.6 at the lumbar spine. Vitamin D level was 10 ng/mL. She received calcium and vitamin D supplementation. Two months later vitamin D level was 31 ng/mL. ZA was recommended due to difficulty with adherence to oral bisphosphonate. Five days after infusion she presented to our emergency department (ED) with progressive symptoms of bilateral eye itching, redness, excessive tearing, blurry vision, photosensitivity, floaters, pain and headaches that had begun 1 day post infusion. She’d had 2 prior outside ED visits for these symptoms and received polymyxin B and later ofloxacin eye drops which did not relieve them. She denied fever, chills, arthralgias and myalgia. She denied any prior known autoimmune disorder or prior history of eye symptoms. On examination she was afebrile and had bilateral conjunctival injection, excess tearing and watery discharge. She was discharged with olopatadine eye drops and cetirizine, diagnosed with allergic conjunctivitis, and referred to ophthalmology. On ophthalmic exam 7 days after her infusion, visual acuity was 20/60 in the right eye, and 20/60 in the left eye. Intraocular pressure was 12 mmHg in the right eye and 16 mmHg in the left eye. Slit lamp eye exam showed diffuse conjunctival injection of the right eye, mild corneal endothelial folds, and flare with cells in anterior chamber and synechiae posterior to the iris. Right acute iridocyclitis was diagnosed, she received prednisolone eye drops and cyclopentolate eye drops. Symptoms improved in 1 week with almost complete resolution after 3 weeks of therapy. She has not had a recurrence of these symptoms; she has declined future treatment with ZA. Conclusion: ZA-associated ocular inflammation is a rare but serious side effect. This adverse effect has been hypothesized to be associated with increased levels of pro-inflammatory cytokines including Interleukin (IL)-1, IL-6, and tumor necrosis factor (TNF)-alpha. As with other acute phase reactions to ZA, it does not appear that ocular inflammation tends to recur with subsequent ZA. Optimizing vitamin D levels prior to treatment may help to prevent this condition. There is some evidence for higher rates of acute phase reaction in patients with lower levels of vitamin D but this patient’s vitamin D status was adequate at the time of treatment. Clinicians should be aware of the rare occurrence of post-ZA ocular inflammation. Early recognition and prompt treatment are essential. Presentation: Thursday, June 15, 2023