Correlation between morphological and functional retinal impairment in multiple sclerosis patients

PURPOSE. TO assess whether a correlation exists between optic nerve fiber l ayer (NFL) thickness and the retinal or visual pathway function in multiple sclerosis (MS) patients previously affected by optic neuritis. METHODS. Fourteen patients with a diagnosis of definite,MS were examined. A ll had been affected by optic neuritis (,MSON) with complete recovery of vi sual acuity (14 eyes included in study). These were compared with 14 eyes f rom 14 age-matched control subjects. NFL thickness was measured by optical coherence tomography (OCT). Three different measurements in each quadrant ( superior, inferior, nasal, and temporal) were taken and averaged. The data in all quadrants (12 values averaged) were identified as NFL Overall, where as the data obtained ill the temporal quadrant only (3 values averaged) wer e identified as NFL Temporal. Retinal and visual pathway function was asses sed by simultaneously recording pattern electroretinograms (PERGs) and visu al evoked potentials (VEPs) using high-contrast (80%) checkerboard stimuli subtending ii minutes anti 60 minutes of the visual are (min are) and rever sed at the rate of two reversals per second. RESULTS. III MSON eyes there was a significant (P < 0.01) reduction in NFL thickness in both NFL Overall and NFL Temporal evaluations compared with th e values observed in control eyes. PERG, (15-min are checks) and VEP (15-mi n are and GO-min are checks), showed a significant (P < 0.01) delay in late ncy and reduction in amplitude. NFL Overall and NFL Temporal values were Si gnificantly correlated (P < 0.01) to the PERG P50 latency and P50 to N95 am plitude recorded with 15-min are checks. No correlations (P > 0.01) between NFL values and the other electrophysiological data (PERG recorded with 60- min are checks and VEP recorded with 15-min arc and 60-min are checks) were found. CONCLUSIONS. There is a correlation between PERG changes and NFL thickness in MS patients previously affected by optic neuritis, but there is no corre lation between VEP changes and NFL thickness.