Intravitreal Antibiotics versus Early Vitrectomy plus Intravitreal Antibiotics for Post-Injection Endophthalmitis: an IRIS® Registry (Intelligent Research in Sight).

Purpose: To determine if intravitreal injection of antibiotics alone versus early pars plana vitrectomy (PPV) plus injection of intravitreal antibiotics predicted better or worse visual outcomes for patients with endophthalmitis after anti-vascular endothelial growth factor (anti-VEGF) injections.

Design: Retrospective cohort study PARTICIPANTS: Patients developing endophthalmitis after receiving an intravitreal anti-VEGF injection from the American Academy of Ophthalmology IRIS® Registry between 2016 and 2020.

Methods: Inclusion criteria were endophthalmitis diagnosis within 1 to 28 days after anti-VEGF injection and a recorded visual acuity (VA) at baseline, on the day of diagnosis, and post-treatment. Patients in the Injection Only group underwent intravitreal injection of antibiotics alone and in the Early Vitrectomy group received PPV with intravitreal antibiotics or intravitreal injection followed by PPV within 2 days of diagnosis. Patients were excluded if they had cataract surgery during the study, intravitreal steroids before endophthalmitis, or intermediate/posterior uveitis or cystoid macular edema. The study created a 1:1 matched cohort using Mahalanobis Distance Matching, accounting for the differences in VA at baseline and diagnosis.

Main outcome measures: Post-treatment logMAR VA RESULTS: 1,044 patients diagnosed with post-injection endophthalmitis met the inclusion and exclusion criteria. In the unmatched cohort, there were 935 patients in the Injection Only and 109 in the Early Vitrectomy group. In 1:1 matched cohort 218 patients (109 in each group) were included; the median logMAR VAs were 0.32 [20/40-20/50] at baseline, 0.88 [∼20/150] at diagnosis, and 0.57 [20/70-20/80] post-treatment. There were no statistically significant differences in the visual outcomes between the two matched treatment groups (b = 0.05, p = 0.23); including the subgroup of patients with VA worse than 1.0 logMAR (b = 0.05, p = 0.452).

Conclusions: There was no significant difference in final VA outcomes between patients receiving Injection Only and those treated with Early Vitrectomy for post-injection endophthalmitis. The findings support the use of either treatment strategy.