Demographics and ocular biometric characteristics of patients undergoing cataract surgery in Auckland, New Zealand

Abstract

Background: The aim is to investigate ethnic variation, in presentation and biometric parameters, within the population undergoing cataract surgery in Auckland. Design: The design is a retrospective study. Participants: Four thousand nine hundred thirty-one eyes of 3524 consecutive patients undergoing cataract surgery in Auckland Public Hospital over 18months were included in the study. Methods: Analysis of preoperative medical records was performed. Main Outcome Measures: Age, gender, self-reported ethnicity, keratometry, anterior chamber depth, axial length and intraocular lens (IOL) power data were collected. Results: Māori (4.7%) were under-represented compared with the proportion of Māori attending the eye clinic (5.5%) and in the major patient catchment area (8.2%). People of Māori, Pacific and Indian ethnicities presented at a significantly younger age (66.4, 65.9 and 67.9years, respectively) than those of Caucasian and Asian ethnicities (76.4 and 71.3years, respectively, P<0.001). Advanced cataract was more likely in Pacific peoples and Māori than Caucasians. The mean axial length was longest in Asian eyes (23.83±1.52mm). The mean anterior chamber depth in the eyes of Pacific peoples (3.20±0.39mm) was significantly greater than that of Caucasians (3.09±0.42mm, P=0.001) and Asians (3.05±0.49mm, P<0.001). The mean IOL power in Asian eyes was 19.45D. This was significantly lower than the IOL power required by Caucasian (20.72D, P<0.001) and Pacific ethnicities (20.61D, P=0.001). With-the-rule astigmatism was highly prevalent in Māori and Pacific peoples, whereas in all other ethnicities, against-the-rule astigmatism was more common. Conclusions: This study identified significant ethnic variation in presentation for cataract surgery and ocular biometric parameters. These data may help identify potential biometric refinements and those at risk of developing ocular morbidities known to be associated with these parameters.