ALS affects visual pathways and by degree that may serve as disease biomarker, study finds

Whether the damage done by amyotrophic lateral sclerosis (ALS) also affects visual pathways, namely the macula, is a matter of debate among scientists and physicians. Researchers at the Feinberg School of Medicine investigated this, comparing the macular structure of ALS patients and examining its correlation with pulmonary function tests, and concluded that macular degeneration was evident in patients and might even serve as a biomarker of disease severity and progression.

The study, “Macular sub-layer thinning and association with pulmonary function tests in Amyotrophic Lateral Sclerosis,” published in Scientific Reports, indicates that the retinal structure is involved in ALS and that thinning of the macula — a small part of the retina involved in central vision and detail definition — correlates with pulmonary function tests and is a possible disease biomarker.

A hallmark of ALS is degeneration of upper and lower motor neurons. However, recent studies show evidence of cognitive impairment and degeneration of non-motor systems in ALS, and ocular motor dysfunction has been described in patients but inconsistently.

Although not a prominent feature in ALS, decreased visual acuity and poor contrast sensitivity in ALS point to the existence subclinical structural defects in the anterior visual pathway. Such findings and the lack of consensus regarding them led the researchers to assess macular changes, using optical coherence tomography (OCT) imaging, in ALS patients and compare them to healthy controls. Pulmonary function tests and time since symptom onset were collected retrospectively to assess if retinal degeneration would correlate with measures of disease severity.

excerpt © 2016 ALS News Today