Optical coherence tomography as a prognostic tool for disability progression in MS: a systematic review

Since multiple sclerosis (MS) is characterized by an unpredictable disease course, accurate prognosis and personalized treatment constitute an important challenge in clinical practice. We performed a qualitative systematic review to assess the predictive value of retinal layer measurement by spectral-domain optical coherence tomography (SD-OCT) in MS patients. Longitudinal MS cohort studies that determined the risk of clinical deterioration based on peripapillary retinal nerve fiber layer (pRNFL) and/or macular ganglion cell-inner plexiform layer (mGCIPL) atrophy were included. Our search strategy and selection process yielded eight articles in total. Of those, five studies only focused on patients with a relapsing-remitting disease pattern (RRMS). After correction for confounders such as disease duration, we found that (1) cross-sectional measurement of pRNFL thickness ≤ 88 µm; (2) cross-sectional measurement of mGCIPL thickness < 77 µm; (3) longitudinal measurement of pRNFL thinning > 1.5 µm/year; and (4) longitudinal measurement of mGCIPL thinning ≥ 1.0 µm/year is associated with an increased risk for disability progression in subsequent years. Longitudinal mGCIPL assessment consistently resulted in the highest risk estimates in our analysis. Within these studies, inclusion and exclusion criteria accounted for the retinal degeneration inherent to (acute) optic neuritis (ON). This small systematic review provides additional evidence that OCT-measured pRNFL and/or mGCIPL atrophy can predict disability progression in RRMS patients. We therefore recommend close clinical follow-up or initiation/change of treatment in RRMS patients with increased risk for clinical deterioration based on retinal layer thresholds, in particular when other poor prognostic signs co-occur.