Endophthalmitis following inadvertent intravitreal injection of botulinum toxin: a case report and literature review

Abstract

Background: Botulinum toxin A (BTA) injection is a well-established, minimally invasive treatment for strabismus, offering an alternative to traditional surgery. While generally safe, rare complications like globe penetration and inadvertent intraocular injection have been reported. These can lead to retinal detachment, vitreous hemorrhage, and retinal toxicity. Although most intraocular BTA injection complications are well-documented, endophthalmitis remains extremely rare, with only one previously reported case resulting in total vision loss. Case presentation: A 3-year-old boy with esotropia received a botulinum toxin A injection into the left medial rectus muscle. A globe penetration from the needle was suspected. The dilated fundus exam was unremarkable. However, one week later, he presented with eye pain, redness, and photophobia. Clinical examination confirmed the diagnosis of acute post-operative endophthalmitis. The patient underwent urgent vitreous tap, pars plana vitrectomy, Endolaser, intravitreal antibiotic injection, and silicone oil injection. Subsequently, the silicone oil with epiretinal membrane removal was performed, and the patient’s vision was maintained postoperatively, CUSNM in both eyes. Conclusion: This case emphasizes the rare yet serious complications of Inadvertent Intravitreal Injection of Botulinum Toxin. It underscores the importance of early detection of endophthalmitis and timely intervention for an optimal outcome and to prevent irreversible ocular damage.