Retinal alterations induced by amyotrophic lateral sclerosis: An analysis using optical coherence tomography.

Objective: In this study, we aimed to investigate retinal changes in a large cohort of amyotrophic lateral sclerosis (ALS) patients and healthy controls (HCs) to further elucidate their relationship with ALS.

Methods: This was a cross-sectional observational study. We evaluated retinal layer thickness in 134 ALS patients and 66 HCs using optical coherence tomography (OCT). Particularly, we focused on the macular region and peripapillary retinal nerve fiber layer (p-RNFL).

Results: The examination of retinal layers in ALS patients revealed a significant change in the inner nuclear layer (INL), with a pattern of initial thickening followed by thinning, which correlated with disease stages, most notably in the inner nasal quadrant. Moreover, the p-RNFL in the temporal quadrant was thinner in ALS patients compared to HCs. In addition, ALS patients who developed bulbar symptoms exhibited marginally thinner p-RNFL in the temporal quadrant compared to those without bulbar symptoms. Interestingly, a thinner p-RNFL in the temporal quadrant did not correlate with faster disease progression.

Conclusion: This study reveals notable changes in the INL and p-RNFL thickness in ALS patients, highlighting the intricate relationship between retinal changes and ALS progression. Despite these retinal alterations, no correlation with disease progression rate was observed. These findings suggest that while OCT shows potential in monitoring ALS, its role in predicting disease course requires further investigation with long-term longitudinal studies and diverse patient cohorts.