Preventing endophthalmitis

Abstract

Endophthalmitis is a rare but often devastating eye infection. Determining the optimal method of preventing endophthalmitis is difficult, however, because randomized controlled trials to evaluate rare outcomes such as endophthalmitis require the enrollment of thousands of patients. Therefore, most information about prophylaxis for endophthalmitis has come from studies that evaluate evidence indirectly. These studies are either retrospective, comparing endophthalmitis rates before and after a prophylactic measure was introduced, or employ microbiologic surveillance, evaluating the reduction in bacterial colonization of the conjunctiva preoperatively or contamination of the aqueous postoperatively. Microbiologic studies assume this reduction in colonizing or contaminating bacteria will translate into a reduction in endophthalmitis rates, although no study has demonstrated such a correlation. Studies of surgical prophylaxis should focus on the same type of eye surgery, but some older studies did not do this. The optimal prophylaxis will differ by risk factor: surgery, intravitreal injection, trauma, or other inciting events. This chapter reviews the evidence for various types of prophylactic measures used to prevent endophthalmitis following cataract surgery, intravitreal injection, open-globe injury, and corneal transplantation and in the presence of a filtering bleb, glaucoma drainage device, or keratoprosthesis.