Ocular biometry measures and their correlation with refractive error in Aboriginal and Torres Strait Islander children

Clinical relevance: The ocular biometry measures of the eye determine the refractive status, and while most refractive error develops during childhood, the ocular biometry measures of Aboriginal and Torres Strait Islander children have not previously been reported. Background: To investigate the ocular biometry of Aboriginal and Torres Strait Islander children, including measures important in determining refractive error and those which relate to the risk of ocular disease. Methods: Participants included 252 primary and secondary school children (Aboriginal and Torres Strait Islander: 101; non-Indigenous: 151), aged between 4 and 18 years. Habitual monocular distance visual acuity, cycloplegic autorefraction, and ocular optical biometry were measured in all participants and intraocular pressure measured in secondary school children using rebound tonometry. Results: The mean (±SD) spherical equivalent refractive error of Aboriginal and Torres Strait Islander children was significantly less hyperopic than non-Indigenous children (Aboriginal and Torres Strait Islander: +0.52 ± 0.80 D; non-Indigenous: +0.86 D ±0.58 D; p < 0.001). There were no differences in axial length or axial length/corneal radius ratio between the two groups, however the mean lens power of Aboriginal and Torres Strait Islander children was significantly greater than that of non-Indigenous children (Aboriginal and Torres Strait Islander: 23.62 D; non-Indigenous: 22.51 D; p < 0.001). Aboriginal and Torres Strait Islander children had a thinner central corneal thickness (Aboriginal and Torres Strait Islander: 534 ± 37 µm; non-Indigenous: 543 ± 35 µm; p = 0.04), and lower intraocular pressure compared with non-Indigenous children (Aboriginal and Torres Strait Islander: 14.7 ± 3.8 mmHg; non-Indigenous: 16.0 ± 3.7; p = 0.02). Conclusion: Differences exist in the refractive error, lens power, central corneal thickness, and intraocular pressure of Aboriginal and Torres Strait Islander children compared to non-Indigenous Australian children which have potential implications for the development of refractive error and ocular disease later in life.