Outcomes and risk factors associated with endophthalmitis after intravitreal injection of anti-vascular endothelial growth factor agents

Abstract

Objective: To describe outcomes of and risk factors for endophthalmitis after intravitreal anti-vascular endothelial growth factor (VEGF) injection.

Design: Single-center, consecutive, case series and retrospective case-control study.

Participants: Between January 1, 2009, and May 31, 2010, 16 vitreoretinal surgeons administered a total of 27 736 injections. During this period, 23 cases of presumed infectious endophthalmitis occurred. Each surgeon used his own preferred injection technique.

Intervention: Vitreous or aqueous tap, or both, with intravitreal antibiotic injection and subsequent topical antibiotic and steroid drops.

Main outcome measures: Visual acuity, bladed lid speculum use, conjunctival displacement, hemisphere of injection, bevacizumab versus ranibizumab, and infectious organism.

Results: Seven of 23 cases had positive culture results; 3 grew coagulase-negative Staphylococcus. All cases had pain and vitritis on average 3.4 days (range, 1-6 days) after injection, with no difference between culture-positive and culture-negative groups. Eighteen (78%) of 23 cases had a hypopyon. Fifteen of 23 cases returned to baseline vision (±2 lines) within 3 months. Neither lid speculum use (0.10% vs. 0.066% in the no-use group; P = 0.27), conjunctival displacement (0.11% vs. 0.076% in the no-displacement group; P = 0.43), hemisphere of injection (0.11% superior vs. 0.079% inferior; P = 0.56), or bevacizumab versus ranibizumab (0.11% vs. 0.066%; P = 0.21) affected risk. Analysis of only culture-positive results yielded similar results. There was no statistically significant difference between the proportion of culture-negative cases after bevacizumab injection (83%) versus ranibizumab injection (55%; P = 0.13).

Conclusions: Most patients in whom presumed infectious endophthalmitis develop after anti-VEGF injection regained baseline vision after treatment. Bladed lid speculum use, conjunctival displacement, hemisphere of injection, and type of anti-VEGF agent did not affect risk. No difference in culture-negative endophthalmitis rates was detected after bevacizumab versus ranibizumab injection. Neither the presence of pain, vitritis, decreased vision, hypopyon, nor the interval between injection and development of symptoms differentiate culture-positive from culture-negative cases. Because a subgroup of patients had poor outcomes, a low threshold for vitreous tap with intravitreal antibiotic injection may be warranted.

Financial disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article.