Endophthalmitis is defined by an intraocular inflammation, due mainly to infection. Peri-ocular skin flora from the patient plays a significant role incausing the intraocular infection, and Staphylococcus epidermidis accounts for 81.9% of all cases of endophthalmitis.1
Endophthalmitis infection is an infrequent but devastating consequence of cataract surgery; in fact, cataract surgery is the leading cause of endophthalmitis. Infection after cataract surgery leads to increased health costs2 and also causes devastating clinical consequences, even blindness. This has led to frequent medical lawsuits.3 Despite advances in microsurgical techniques, a recent population-based study reviewingMedicare claims in the US revealed that endophthalmitis following cataract surgery is becoming more prevalent.4 The incidence of endophthalmitis rose from 1.79 cases per 1,000 in 1994 to 2.49 cases per 1,000 in 2001 – an overall increase of 37%.
To date, the best approach to or surgical regimen for cataract surgery to reduce the risk of endophthalmitis remains unclear. The European Society of Cataract and Refractive Surgery (ESCRS) Endophthalmitis Study examined the impact of intracameral cefuroxime and topical levofloxacin on post-operative infection. This article outlines risk factors for endophthalmitis, summarises the ESCRS Endophthalmitis study and discusses the implications of the study results on the future of endophthalmitis prevention within the context of cataract surgery.
Risk Factors Identified Prior to the Study
Risk factors for endophthalmitis are largely the same in both Asian and Western populations.5 Two reports have noted that diabetes mellitus increases the likelihood of developing staphylococci.6,7 Diabetes causes alterations in immunity and consequently leaves sufferers with a higher susceptibility to developing an infection after surgery. In addition, visual prognosis after endophthalmitis treatment is poor in diabetic patients in comparison with non-diabetic patients. Systemic or topical immunosuppressant drugs also alter the immune response, leading to an increased risk of endophthalmitis.6 Patients on antimetabolites or corticosteroids also have a higher incidence of endophthalmitis.
Certain procedures and materials used in cataract surgery have also been found to alter the risk of endophthalmitis.8,9 One study has suggested that the implantation of a heparinised intraocular lens (IOL) and the creation of a tight seal may protect the patient from infection.8 The type of IOL material and the location of the incision were examined in 5,797 small-incision cataract patients at Toyama Medical and Pharmaceutical University Hospital from March 1998 to March 2001.9 The results suggested that temporal corneal incisions may lead to an increased risk of endophthalmitis. Lens material had no effect on risk of endophthalmitis.
Other risk factors identified include infectious respiratory or skin agents from surgeons or other healthcare personnel present in the operating room (OR) coming into contact with the patient’s eye.10 In addition, the cleanliness of the OR air affects the incidence of endophthalmitis.10 Finally, the longer the duration of surgery, the higher the infection rates, most likely due to increased exposure of the eye.11