Retinal nerve fibre layer thickness in Black South African children: A preliminary study

Abstract

Background: Spectral domain optical coherence tomography (SD-OCT) provides age-adjusted retinal nerve fibre layer (RNFL) thickness measurements, essential for diagnosing glaucoma. However, normative databases in these devices apply to individuals older than 18 years. The absence of a normative database for individuals younger than 18 years makes diagnosing glaucoma in this age group challenging.

Aim: To describe the average and quadrant RNFL thicknesses in children of Black ethnicity.

Settings: McCord Provincial Eye Hospital, Durban, South Africa.

Methods: A prospective, hospital-based study was conducted using a convenience sampling method. One clinically normal eye was selected from each child participant, aged 5–18 years. The RNFL thickness was measured using the iVue100™ SD-OCT device.

Results: Seventy-three children were enrolled in this study. The mean RNFL thickness was 107.32 ± 8.1 µm. The mean thickness of the inferior, superior, nasal and temporal quadrants was 135.1 ± 13.65 µm, 135.6 ± 14.59 µm, 83.2 ± 10.86 µm and 75.4 ± 9.03 µm, respectively. No statistically significant association was observed between the average RNFL thickness and variables such as age (p = 0.438), sex (p = 0.106), spherical equivalent (p = 0.632) or axial length (p = 0.20).

Conclusion: This study provides normative values for RNFL thickness in South African children of Black ethnicity and suggests potential ethnic variation. Further validation studies are required before these normative values can reliably be used in a clinical setting.

Contribution: This study addressed a gap in research on normative values for RNFL thickness in an under-represented paediatric population.