Background/aims Most post-traumatic acute infectious endophthalmitis occur within a week of open globe trauma, necessitating early antibiotic prophylaxis. There are few randomised studies that demonstrate the benefits of prophylactic antibiotics. This randomised controlled non-inferiority trial was aimed at determining the incidence of post-traumatic endophthalmitis using established intravenous/oral prophylaxis and comparing this to the incidence using oral antibiotics only.

Methods All adult patients admitted with open globe injury were included. Those with proven endophthalmitis, high-risk features, who underwent primary evisceration and those allergic to the trial antibiotics were excluded. Patients were randomised to receive either intravenous cefazolin and oral ciprofloxacin or oral ciprofloxacin and oral cefuroxime for 3 days from admission. Acute endophthalmitis was the primary outcome. Patients completed the study if they were followed up for 6 weeks post injury.

Results Three hundred patients were enrolled, with 150 in each arm. There were 99 exclusions. Seven patients developed endophthalmitis despite prophylaxis—2.0% (three cases) in the intravenous and oral arm, compared with 2.7% (four cases) in the oral-only arm—this difference was not statistically significant (p=0.703).

Conclusions The incidence of endophthalmitis with prophylaxis was 2–3%. Selected patients with open globe injuries (without high-risk features) may receive either intravenous cefazolin and oral ciprofloxacin, or oral cefuroxime and oral ciprofloxacin as prophylaxis against acute endophthalmitis—the latter regimen has the advantage of shortening patients' hospital stays and reducing costs. Non-inferiority study-design limitations should be taken into account, however.