Biometric Differences Between a Singaporean Chinese and UK Caucasian Population With Primary Angle Closure

Abstract

 

Introduction:

 

Table of Contents

 

Purpose:

 

To compare biometric parameters in Caucasian and Chinese patients with primary angle closure

 

Methods:

 

Consecutive patients with a diagnosis of iridotrabecular contact (ITC) or primary angle closure (glaucoma) PAC(G) were recruited from glaucoma clinics at two hospital sites (in Birmingham UK, and Singapore). Autorefraction and ocular biometry using A-scan ultrasonography were performed on all subjects. Axial length, Lens thickness, anterior chamber depth, absolute lens position (ALP) = ACD + LT/2 (mm) and relative lens position (RLP)= (ACD + LT / 2) / AL (no units) were measured for all eyes. The data was matched for age and sex. The pooled two sample t test was used to compare measurements between the two populations.

 

Results:

 

Data was collected on 99 eyes of 99 UK Caucasian subjects (36 male and 63 female age range 40-89 years) and 151 eyes of 151 Singaporean Chinese subjects (66 male, 85 female, age range 44-90 years) Table 1 shows the mean value for each parameter in the two different ethnic groupsThe mean axial length was significantly shorter (p<0.03) and anterior chamber depth was shallower (p<0.03) in Caucasian eyes when compared with Chinese Singaporean eyes. The lens thickness was greater in Caucasian eyes (p<0.0001).

 

Conclusions:

 

There appears to be significant differences in the biometric measurements of anterior chamber depth, lens thickness and axial length between Chinese and Caucasian eyes with primary angle closure. These differences lend support to the theory of differences in mechanisms of angle closure in different populations.  

 

Keywords: clinical (human) or epidemiologic studies: risk factor assessment • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)