Abstract
Purpose :
Recent evidence accumulates that amyotrophic lateral sclerosis (ALS) has a widespread pathology in peripheral nerve system besides the progressive degeneration of motor neurons in brain and spinal cord. This study evaluated the corneal nerves and retina involvements in ALS patients as well as their correlations with disease severity.
Methods :
Both eyes from 40 patients with ALS, 28 patients with POAG and 44 healthy subjects were analyzed in the study. ALS functional rating scores (ALSFRS) and sympathetic skin response (SSR) were recorded for ALS patients to evaluate their disease severity and sympathetic fibers function. Images of corneal sub-basal nerve plexus were collected by corneal confocal microscopy (CCM) and following parameters were computed: nerve fiber length (NFL), nerve fiber density (NFD), nerve fiber tortuosity (NFT) and nerve branch density (NBD). Peripapillary retinal nerve fiber layer (RNFL), ganglion cell layer plus inner plexiform layer (GC-IPL) and macular thickness were measured with optical coherence tomography (OCT) in all cases. Correlations between the ocular findings and ALSFRS, SSR and disease duration were analyzed for ALS group.
Results :
Significant reduction of NFL, NFD and NBD (p=0.006, 0.001, 0.000, respectively), and an increase of NFT (p=0.000) in ALS patients were observed. ALS patients showed an increase of RNFL and GC-IPL compared to controls but without statistical difference (table 1). Macular thickness showed no significant difference between ALS and controls, and the outer macular thickness in POAG group was significantly thinner than ALS (table 2). Neither the corneal parameters nor the RNFL had statistical correlations with ALSFRS, SSR or disease duration in ALS group. However, GC-IPL and outer macular thickness in ALS had significant correlations with ALSFRS and disease duration.
Conclusions :
Corneal nerve damage is revealed by CCM in ALS, but it is not associated with the overall neurodegeneration. RNFL increase is observed by OCT but it needs further investigation to confirm the role of retinal changes in early diagnosis or disease progression for ALS.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.