Multiple sclerosis (MS) patients who are obese experience faster degeneration in optic nerve tissue than do those of normal weight, an observational study found.
Since optic nerve degeneration correlates with greater nerve loss in the brain, measuring changes in this tissue may be a feasible way to determine whether lifestyle changes that lead to body fat loss improve patient outcomes.
The study, “Association of body mass index with longitudinal rates of retinal atrophy in multiple sclerosis,” was published in the Multiple Sclerosis Journal, and supported by the National MS Society.
MS is chronic neurodegenerative disease caused by a combination of genetic and environmental factors. Studies suggest that obesity is linked to greater MS disability and disease progression, as well cognitive deficits.
Optical nerve tissue has been shown to mirror changes in overall brain health in people with MS, according to a society release. Degeneration in a particular layer in the back of the eye, called the ganglion cell and inner plexiform layer (GCIPL), appears to correlate with worse disability, increased disease activity, and greater brain atrophy in MS.
Johns Hopkins University researchers set out to investigate whether obesity also increased the damage to, and loss of, neurons in this region of the eye, as previous MS research has suggested.
Their study included 513 people being followed at the Johns Hopkins MS Center, who were classified as being of normal weight (214 patients), overweight (153), or obese (146) depending on their body-mass index (BMI).
Damage to the optic nerve was assessed using a rapid, non-invasive, and high-resolution method called optical coherence tomography (OCT). This method uses light waves to capture cross-sectional pictures of the retina, allowing ophthalmologists to map and measure the thickness of layers of the eye.