More money spent on sterilization does not equate to a lower incidence of endophthalmitis

June 1, 2006

Postoperative endophthalmitis is a rare but potentially devastating intraocular infection, which could lead to severe and permanent visual impairment or even the loss of an eye.1-3 With the average life expectancy on the increase, the prevalence of cataract in the older population and therefore the cataract surgical rate has increased in recent decades.1,3 Many have voiced their concerns that this rise in the number of surgical procedures could bring with it a rise in incidence of endophthalmitis, hence, evaluation of postoperative infection incidence is extremely important in every clinical setting.

Reports on incidence of this devastating infection have varied. In a national prospective study in Sweden, the incidence of postoperative endophthalmitis was 0.0595% in 188,151 cases.4 In another study performed in the United Kingdom, an overall incidence of endophthalmitis of 0.16% was reported from a 10-year retrospective survey.5 In general, incidence is estimated to be between one and two cases per 1,000 cataract procedures.1,6 In the quest for elimination of this disease, naturally, various risk factors have been studied in relation to endophthalmitis, as have several protective methods. Among these are the pre-, peri- or postoperative use of antibiotics, lachrymal system irrigation and the use of topical povidone–iodine solution.6 The latter of these seems to be the most effective in prevention of the disease because it significantly reduces the bacterial load in the conjunctiva, which is the primary source of ocular infective microorganisms.7

Most endophthalmitis studies are retrospective, primarily because of the infrequent presentation of the disease. It is for this reason that the use of randomized clinical trials to study the disease may often be difficult and inappropriate.1 Most studies also aim to compare the aforementioned risks, but do not detail the characteristics of the operating environment and sterilization techniques.8

The main purpose of the study presented here was to compare the incidence of endophthalmitis in three very different teaching hospitals and to analyze the role of the surgical environment on the incidence of the disease.

Under the microscope: UK, Sri Lanka & Paraguay

The authors conducted a retrospective study based on the patient records of all cataract surgeries performed within a two-year period in three teaching hospitals in three different countries; the United Kingdom, Sri Lanka and Paraguay. A thorough analysis was conducted of the files of patients who were diagnosed with endophthalmitis, unfortunately however, because the format of the records varied between the three study centres, the authors were unable to perform standardization. Those patients who were scheduled for other intraocular surgery or who presented with traumatic aetiology were excluded from the study.

The incidence of endophthalmitis for each hospital was calculated and expressed as a percentage and, in order to compare the overall incidence of the disease, only descriptive analyses were performed. Because the main purpose of this study was to compare the antisepsis methods employed and their relationship to the occurrence of endophthalmitis, information relating to these factors; including details on techniques used by the surgeons to avoid contamination, patient preparation for surgery, instrument handling and sterilization, and the operating room environment, was obtained from the three hospitals.