Purpose:
To determine whether there are ethnic differences in spherical equivalent refraction (SER) and ocular biometry in British children aged 7 and 13 years.
Methods:
A cross-sectional survey of 27 schools in the Birmingham area. The sample consisted of 193 South Asian (SA), 36 African-Caribbean (AC) and 51 white European (WE) children aged 6-7 years; 114 SA, 40 AC and 115 WE aged 12-13 years. Assessment of corneal radii (CR), axial length (AL), and anterior chamber depth (ACD) was carried out using non-contact partial coherence interferometric biometry (IOL Master, Zeiss, Jena, Germany). SER was obtained post-cyclopegia (using proxymetacaine 0.5% corneal anaesthesia followed by cyclopentolate 1%) from binocular open field autorefraction (Shin-Nippon SRW5000, Japan). CR, AL, ACD were normally distributed, SER negatively skewed. Mean data from right and left eyes were used in analyses.
Results:
Mean (SD) SER and ocular biometric data for different ethnic and age groups are given in the table. In early adolescence (mean age 13.1, SD 0.3 years), South Asians showed higher levels of myopia (P<0.001) compared to White Europeans and African-Caribbean children. Although there were no statistically significant ethnic differences in CR (P=0.36) or AC (P=0.45) in this age group, there was a suggestion that South Asians had longer axial lengths (P=0.09) compared to White and African-Caribbean children. There were no statistically significant ethnic differences in mean SER, CR, AL or ACD earlier in childhood (mean age 7.1 years, SD 0.3, P>0.15 in all comparisons).
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • myopia • refractive error development