Noninfectious endophthalmitis following intravitreal triamcinolone acetonide: clinical case and literature review

Objective: To review the literature on noninfectious endophthalmitis (NIE) following intravitreal triamcinolone acetonide (IVTA). Design: A literature review and case report. Participants: Individuals who developed NIE after IVTA injection. Methods: A review of the literature was undertaken using Ovid MEDLINE and EMBASE databases, and articles available up to and including December 30, 2019, were included. A total of 518 articles were identified, of which 27 were selected. We also present an illustrative case report. Results: The incidence rate of NIE lies between 0.1% and 7.3% in most studies. Although the etiology of NIE is still the subject of investigation, proposed mechanisms include excipients and rheologic stress caused by small crystals. The time to presentation of NIE is often 1-3 days after IVTA injection, with symptoms of moderate to marked reduction in visual acuity along with signs of anterior chamber inflammatory reaction, hypopyon, and vitritis. Resolution occurs in 1-3 weeks in the majority of patients, and almost all return to their pre-injection visual acuity. Differences in the presentations of NIE, infectious endophthalmitis, and pseudo-endophthalmitis are discussed. We also present an illustrative case report of an 80-year-old woman who developed NIE after an IVTA injection for cystoid macular edema. Conclusions: It is important to distinguish NIE from other forms of endophthalmitis because they have different natural histories and require different interventions and follow-up. NIE is rarely accompanied by significant pain or conjunctival erythema. Visual acuity is inconsistently affected and is therefore not a good criterion for identifying the type of presenting endophthalmitis.