Reduced retinal nerve fibre layer thickness in multiple sclerosis patients with and without history of optic neuritis
Abstract
Purpose
Compare the retinal nerve fibre layer (RNFL) thickness in multiple sclerosis (MS) patients, with and without previous episodes of optic neuritis (ON), to disease-free controls, using optical coherence tomography (OCT).
Methods
The RNFL was measured with a spectral domain OCT (Canon HS-100) in 433 MS patients and in 70 controls. The MS eyes were sorted into three groups: MS non ON eyes (MSON−), MS ON eyes (MSON+) and the fellow eye of MS ON (MSON_fellow). One eye of each patient in the MSON-group and in the control group was selected randomly for analysis.
Results
Seventy control eyes, 327 MSON- eyes, 106 MSON+ eyes and 106 MSON_fellow eyes were analysed in a linear regression adjusting for age. The average RNFL thickness was found to be statistically thinner in the MSON− group (88.2 ± 13.0 µm) compared to the controls (98.1 ± 9.0 µm; p < 0.00).The average RNFL was thinner in the MSON+ group (77.3 ± 15.2 µm) compared to MSON− eyes and the controls (p < 0.00). A paired t-test showed a significant decrease in RNFL thickness in the MSON+ eyes compared to MSON_fellow.
Conclusions
Multiple sclerosis causes RNFL loss. A mean reduction of ~10 µm was found in MS patients without history of ON and a mean reduction of 20 µm was found in MS patients with history of ON compared to healthy controls. This study showed that OCT is a useful tool that provides evidence of neural degeneration in MS patients, with or without the presence of ON.
