This is an observational retrospective cohort study presenting the data of 188 patient diagnoses with multiple sclerosis at two specialist centres. All included patients were adults below the age of 70 years, stable on their disease modifying treatment for at least one year if relevant and had spectral-domain optical coherence tomography (SD-OCT) within a four-year period. Those with other significant ocular pathology, high refractive error and eyes with previous optic neuritis were excluded. Standardised protocols conducted by one neurologist were used for performing the SD-OCT with scans falling below international quality control criteria excluded from the analysis (n=8). The final analysis included 180 patients. The authors report that their finding that disability up to five years follow-up using the Expanded Disability Status Scale (EDSS) is associated with the thickness of the ganglion cell and inner plexiform layer (GCIPL) even when adjusted for baseline EDSS. No association was found for the thickness of peripapillary retinal neve fibre layer (pRNFL). The authors acknowledge the possibility that these findings may be related to the study design with adjustments made for baseline disability and analysis on all retinal layers opposed solely on the pRNFL. The suggestion by the authors is that their findings may indicate that the GCIPL may be the better OCT measure for capturing neuroaxonal degeneration in patients with relapsing-remitting MS for predicting the short-medium term risk of higher disability. Further studies are required to confirm this predictive value of the GCIPL.
