HealthDay News — Patients with multiple sclerosis (MS) with clinical or radiologic nonocular disease activity experience accelerated retinal, study findings published in Neurology indicate, which may be a useful measure of the efficacy of novel MS therapies in future clinical trials.
John N. Ratchford, MD, from the Johns Hopkins University School of Medicine in Baltimore, and colleagues conducted spectral-domain optical coherence tomography (OCT) scans every six months on 164 patients with MS and 59 controls for a mean follow-up period of 21.1 months.
The study included 116 patients with relapsing-remitting MS, 24 with secondary progressive MS, 16 with primary progressive MS, and eight with clinically isolated syndromes (CIS) who experienced a central nervous system inflammatory attack compatible with MS, but did not fulfill MS diagnostic criteria.
Participants underwent OCT, a noninvasive and relatively inexpensive imaging technique, to measure the thickness of the ganglion cell/inner plexiform (GCIP) layer and of the retinal nerve fiber layer (RNFL) every 6 months. Contrast-enhanced brain magnetic resonance imaging scans were performed at baseline and annually.
The rate of GCIP thinning was 46% faster in patients with MS/CIS than in healthy controls (P = .008), whereas the rate of RNFL thinning did not significantly differ between patients with MS/CIS and controls, the researchers found.
The researchers observed significantly faster rates of annualized GCIP thinning in patients with relapses (42% faster: –0.55 vs –0.32 μm/year for those without these relapses; P = .007), new gadolinium-enhancing lesions (54% faster: –0.63 vs –0.29 μm/year for persons without these lesions; P < .001), and new T2 lesions (36% faster: –0.50 vs –0.32 μm/year for those without these lesions; P = .02).
In addition, faster annual GCIP thinning was seen for those with disability progression during follow-up (37% faster: –0.52 vs –0.33 μm/year for persons without this progression; P = .01) and for those with disease duration of less than five vs. more than five years (43% faster).
Patients exhibiting combinations of new gadolinium-enhancing lesions, new T2 lesions, and disease duration less than five years had the highest annual rates of GCIP thinning (70% faster in patients with vs. without all three characteristics; P < .001).
“Our findings suggest that retinal changes in MS reflect global central nervous system processes, and that OCT-derived GCIP thickness measures may have utility as an outcome measure for assessing neuroprotective agents, particularly in early, active MS,” the researchers wrote.