Posterior scleritis following a single infusion of zoledronate for osteoporosis: A case report and literature review.

The most frequently reported adverse reaction to zoledronic acid is an acute phase reaction resembling influenza. While rarer adverse events such as osteonecrosis of the jaw and atypical femoral fractures have gained significant recognition, the ocular adverse effects, particularly scleritis, are not yet fully comprehended. Here, we present the case of a 75-year-old female patient with osteoporosis who developed bilateral redness and intense eye pain 48 h after receiving a 5 mg intravenous dose of zoledronic acid. Clinical presentation suggested bilateral conjunctivitis, but treatment with levofloxacin eye drops and acyclovir ophthalmic gel exacerbated the symptoms over 2 days, predominantly affecting the left eye. Ocular ultrasonography revealed thickening of the left eyeball wall with a "T" sign, while an orbital CT scan showed increased thickness of the left sclera. Treatment with methylprednisolone 80 mg intravenous infusion twice daily led to gradual symptom improvement and eventual resolution of inflammation. This report, based on a review of relevant literature, investigates the treatment and outcomes of zoledronic acid-induced scleritis, emphasizing the importance for clinicians to promptly identify and manage this rare and serious ocular adverse reaction.