Investigating the effect of signal strength on mean retinal nerve fibre layer
Reviewed by Claire Howard

The aim of this study was to determine the effect of signal strength on mean retinal nerve fibre layer (RNFL) using spectralis optical coherence tomography (S-OCT). Thirty normal subjects were imaged with S-OCT using variably dense Bangerter foils to alter Q value (1 unit signal strength = 4 units Q). Results showed a statistically significant linear relationship between Q and RNFL (1 unit decrease Q = 0.181um mean RNFL increase). The authors also observed high interocular symmetry in RNFL thickness measurements with S-OCT, consistent with previous studies. Future studies are needed to further evaluate the effect of signal strength and / or media opacification on optic nerve head RNFL thickness measurements, particularly in cases of optic nerve pathology, as only normal eyes were used in this study.

Retinal nerve fibre layer thickness increases with decreasing Spectralis OCT signal strength in normal eyes.
Strampe MR, Eldweik L, Chaon BC, et al.
NEURO-OPHTHALMOLOGY
2020;44(2):100-3.