Aims To describe and compare the causative organisms, clinical features and visual outcomes of endophthalmitis following intravitreal injection (IVI) to endophthalmitis following cataract surgery.

Methods Patient population and setting: A retrospective case series of patients with acute endophthalmitis following either cataract surgery or IVI presenting to a tertiary referral centre—Sydney Eye Hospital—between 2007 and 2010. Main outcome measures: (1) identification of the causative organism; (2) time to presentation; (3) odds of improvement in visual acuity (VA) following treatment; (4) odds of final VA of counting fingers (CF) or less and (5) odds of enucleation.

Results Of the 101 patients in our study, 48 had preceding cataract surgery and 53 had preceding IVI. There was an increased incidence of Streptococcus spp. endophthalmitis in post-IVI cases (24.53% vs 6.25%; OR 5.85; p=0.022). Endophthalmitis following IVI had increased likelihood of a final VA of CF or less (OR=6.0; p<0.01), decreased likelihood of any improvement in acuity following treatment (OR=0.13; p<0.01) and an increased likelihood of presenting within a week of the procedure (OR=3.93; p<0.01). Endophthalmitis caused by Streptococcus spp. was associated with increased likelihood of a final VA of CF or less (OR=10.2; p<0.01), decreased likelihood of any improvement in acuity following treatment (OR=0.06; p<0.01) and increased likelihood of enucleation (OR=17.11; p<0.01).

Conclusions Endophthalmitis following IVI is associated with an increased incidence of Streptococcus spp. infection, earlier presentation and poorer visual outcomes when compared with endophthalmitis following cataract surgery.