Presumed Sterile Cluster Endophthalmitis following Intravitreal Triamcinolone Acetonide: A Rare Case Series

Presumed sterile endophthalmitis (PSE) is a noninfectious inflammatory reaction that mimics infectious endophthalmitis following intravitreal injections. It is a rare but clinically significant complication of intravitreal triamcinolone acetonide (IVTA). This case report describes the clinical presentation, diagnosis, and management of PSE following combined IVTA and anti-vascular endothelial growth factor (VEGF) therapy in patients with chronic diabetic macular edema.

In a single operative theater setting, 8 patients received intravitreal anti-VEGF injections and 3 patients received a combination of anti-VEGF (ranibizumab) with triamcinolone acetonide (Aurocort). All injections were performed under sterile precautions. All 3 patients who received combined therapy developed sudden-onset of symptoms within 24 h post-injection, presenting with severe pain, redness, and marked vision loss. Initial visual acuity ranged from hand motion to perception of light. Clinical findings included lid and periorbital edema, severe conjunctival congestion, corneal edema with Descemet membrane folds, anterior chamber cells and flare, sluggish pupils, and dense vitreous inflammation. Vitreous tap and core vitrectomy with intravitreal vancomycin, ceftazidime, and dexamethasone were performed in 2 patients. Cultures from the vitreous, triamcinolone acetonide vial, and ranibizumab vial were negative for organisms. Final visual acuity improved to 6/9-6/12 in treated patients; 1 patient was lost to follow-up.

PSE may occur after combined IVTA. Early diagnosis, prompt vitrectomy, and intravitreal antibiotics with steroids are critical for favorable outcomes. The visual prognosis is generally good and depends largely on timely intervention and the status of the underlying retinal disease.