Postinjection Endophthalmitis in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT)

ObjectiveTo describe the incidence and outcomes of endophthalmitis after intravitreal injections of anti-vascular endothelial growth factor agents in the Comparison of Age-Related Macular Degeneration Treatments Trials (CATT) and to assess the effect of prophylactic topical antimicrobials on incidence.DesignCohort study within a randomized clinical trial.ParticipantsPatients enrolled in CATT.MethodsPatients with neovascular age-related macular degeneration received intravitreal injections of ranibizumab or bevacizumab under 1 of 3 dosing regimens. The study protocol specified preinjection preparation to include use of a sterile lid speculum and povidone iodine (5%). Use of preinjection and postinjection antibiotics was at the discretion of the treating ophthalmologist. Patients were followed up monthly for 2 years.Main outcome measuresDevelopment of endophthalmitis and visual acuity.ResultsEndophthalmitis developed after 11 of 18 509 injections (1 per 1700 [0.06%]; 95% confidence interval, 0.03%-0.11%), and in 11 of 1185 patients (0.93%; 95% confidence interval, 0.52-1.66). Incidence of endophthalmitis was 0.15% among injections with no antibiotic use, 0.08% among injections with preinjection antibiotics only, 0.06% among injections with postinjection antibiotics only, and 0.04% among injections with preinjection and postinjection antibiotics (P = 0.20). All eyes were treated with intravitreal antibiotics and 4 underwent vitrectomy. Among the 11 affected eyes, the final study visual acuity was 20/40 or better in 4 eyes (36%), 20/50 to 20/80 in 2 eyes (18%), 20/100 to 20/160 in 3 eyes (27%), and worse than 20/800 in 2 eyes (18%). The final visual acuity was within 2 lines of the visual acuity before endophthalmitis in 5 eyes (45%).ConclusionsRates of endophthalmitis were low and similar to those in other large-scale studies. Use of topical antibiotics either before or after injection does not seem to reduce the risk for endophthalmitis