A study on the incidence, microbiological analysis and investigations on the source of infection of postoperative infectious endophthalmitis in a tertiary care ophthalmic hospital: an 8-year study

Abstract

Background: The objective of the study was the determination of the incidence of culture-proven postoperative endophthalmitis and probable sources of infection.

Materials and methods: It was a prospective study on the microbiology, incidence and probable sources of infection in patients with postoperative infectious endophthalmitis carried out in a tertiary care eye hospital. Consecutive patients diagnosed with postoperative infectious endophthalmitis during the years 2000-2007 were investigated for the causative infective agent and possible sources of infection. The surgical data and microbiological data including the investigations performed to trace the source were recorded in a specific formatted form and were gathered and compiled for analysis.

Results: Data of analysis showed that 98 (0.042%) out of 2,31,259 patients who underwent intra-ocular surgery developed infectious endophthalmitis. Among these, 70 (0.053%) occurred after cataract, 10 (0.5%) after penetrating keratoplasty (PK) and 18 (0.018%) following other types of intra-ocular surgeries. The predominant infectious agents isolated were bacteria (89.7%), with equal proportions of gram-positive and gram-negative bacteria. Polymicrobial infection was noted in four and fungi in seven patients. Occurrence of postoperative endophthalmitis was sporadic and not related to any specific part of period in a year. Sources of infection were donor corneal rim in six post-PK patients and phaco probe in one who had postphacoemulsification endophthalmitis

Conclusions: Overall incidence of postoperative endophthalmitis over an 8-year period was quite low. The sources of infection could be established in six post-PK endophthalmitis patients and in a postcataract surgery.

Figure 1

Number of postoperative infectious endophthalmitis and the percentages of the same for each year. The percentages varied from 0.01 to 0.07, with an average of 0.042%

Figure 2

Ninety-eight postoperative endophthalmitis during the years 2000 and 2007 distributed according to the month when the surgery was performed. The average percentage for each of the months is shown in parenthesis. The lowest rate of postoperative infectious endophthalmitis was during February and during all other months, the rate varied from 0.017 to 0.05%, indicating only sporadic occurrence without any outbreak