Introduction

Endophthalmitis is a vision-threatening inflammation of the inner eye fluids and tissues. Infectious endophthalmitis results from either exogenous or endogenous entry of microbes into the eye. In reported clinical series, exogenous endophthalmitis is much more common than endogenous (or metastatic) endophthalmitis. By far, the most common cause of exogenous infection is intraocular procedures. Until recently, cataract surgery was the most frequently performed type of intraocular procedure, accounting for the greatest number of exogenous endophthalmitis cases. Intravitreal injection has now surpassed cataract surgery as the most frequently performed intraocular procedure and consequently is a significant contributor to the total number of exogenous endophthalmitis cases reported. Exogenous endophthalmitis can also occur after other types of intraocular surgery, including secondary lens implantation, glaucoma filtering surgery, vitrectomy surgery, and corneal transplantation. Organisms may also enter the eye during penetrating trauma, intraocular injection of medication, and contiguous spread into the eye from an infected corneal ulcer. Gram-positive bacteria are the most common cause of exogenous endophthalmitis.

Incidence

Postoperative endophthalmitis cases from the University of Miami (Bascom Palmer Eye Institute) over an 8-year period (2002 to 2009) demonstrated the incidence of nosocomial endophthalmitis after cataract surgery to be 0.025%. Endophthalmitis occurs after open-globe injuries in 3% to 30% of patients depending on the nature of the injury. The rate of development of Candida endogenous endophthalmitis in patients with documented candidemia has been reported to range from 2.8% to 45%.