Trends in cataract surgery and postoperative endophthalmitis in Western Australia (1980-1998): the Endophthalmitis Population Study of Western Australia.

OBJECTIVES: Postoperative endophthalmitis results from an intraocular infection and usually occurs following cataract surgery. It has significant morbidity and causes severe visual impairment or blindness of the eye. The aim of this study was to assess the trends in the incidence rates of cataract surgery and postoperative endophthalmitis in Western Australia for the period 1980-1998.
METHODS: The Western Australian Record Linkage Project was used to link the morbidity records for all patients treated for cataract surgery in Western Australia in 1980-1998. Patient records were selected using the international classification for diagnosis and procedure codes pertaining to cataract surgery and postoperative endophthalmitis. All cases of postoperative endophthalmitis were validated by case-note review. The separate databases of the Royal Perth Hospital microbiology and anaesthetic departments as well as the vitreo-retinal surgeon logbooks were used to cross-validate the hospital morbidity database. Trends in the incidence rates of cataract surgery and postoperative endophthalmitis were assessed by Poisson regression.
RESULTS: There were 94,653 cataract procedures performed for 63,007 patients in Western Australia during the 19-year period. The majority (88%) of cataract procedures performed were in patients aged 60 years or older. Postoperative endophthalmitis developed in 188 patients, with serious visual impairment occurring in 70.6% of patients for whom visual acuity data was available at presentation. The incidence rate of cataract surgery increased more than three-fold from 1981 (102 per 100,000 person years) to 1998 (345 per 100,000 person years), mainly due to the increase in extracapsular cataract extraction during the 1980s and phacoemulsification extraction from 1990 onwards. In contrast, the average annual incidence rate of postoperative endophthalmitis remained relatively unchanged at around 2 per 1000 cataract procedures over the same period.
CONCLUSION: Cataract surgery is becoming more prevalent in the elderly as the life expectancy of the population increases. There has been a dramatic shift in surgical practice during the last 30 years with small-incision phacoemulsification being the predominant method of intervention used since 1990. Despite changes in surgical practice the incidence rate of postoperative endophthalmitis has remained the same.