South African Eye Study: Establishing a normative database for retinal nerve fibre layer thickness in a black ethnicity paediatric population

Abstract

Background: The retinal nerve fibre layer (RNFL) thickness in South African children of black ethnicity is not known. Current imaging devices do not include a paediatric normative database. There is also a lack of data on global majority ethnicities. This study used spectral-domain optical coherence tomography (SD-OCT) to describe the average and quadrant RNFL thickness in children of black ethnicity. Methods: A prospective cross-sectional hospital-based study was conducted at McCord Provincial Eye Hospital, Durban, South Africa, with a convenience-based sampling strategy. One normal eye from children between the ages of 5 and 18 were selected. An ocular examination included an autorefraction and an axial length measurement. The RNFL thickness was measured with the iVue-100 SD-OCT™. Results:Seventy-three children were enrolled in this study based on power calculations. The mean (standard deviation) average RNFL thickness was 107.31um (8.1). The mean (standard deviation) inferior, superior, nasal, and temporal quadrant thickness were as follows: 135.1um (13.65), 135.6um (14.59), 83.2um (10.86), and 75.4um (9.03). No correlation was found between the average RNFL thickness and age, sex, spherical equivalent, and axial length with a p-value of 0.438, 0.106, 0.632, and 0.20 respectively. Conclusion: This study described the normative values for retinal nerve fibre layer thickness using SD-OCT in South African children of black ethnicity between 5 and 18 years old and supports paediatric ethnic variation in the RNFL thickness. Establishing a normative database could help screen, diagnose and monitor glaucoma and other optic nerve pathologies in this paediatric ethnic group.