Retinal nerve fibre layer thickness by OCT3 provides direct assessment of axonal loss in optic neuritis and may help in the early diagnosis and progression analysis of multiple sclerosis

Abstract

Context: Retinal nerve fibre layer (RNFL) being unmyelinated, RNFL thickness (RNFLT) provides direct evidence of axonal loss in optic neuritis (ON) and may prove to be a valuable diagnostic and prognostic tool in the development of multiple sclerosis (MS). Aims: Assessment of RNFLT by OCT3 in patients with recent onset retrobulbar ON, comparison of obtained values based on presence or absence of the periventricular white matter lesion (PVWML) on magnetic resonance imaging (MRI), comparison with the RNFLT of a control group, and analysis of the obtained results. Settings and Design: Cross-sectional study. Materials and Methods: Eighteen patients with Statistical Analysis Used: ANOVA and Student's t test. Results: ON eyes in group B had thinnest RNFLT (average temporal = 39.75 μ), followed by group A (average temporal = 44.3 μ), and finally by group C (average temporal-OU = 80.78 μ). Conclusions: Our study shows that patients with ON, irrespective of detection of PVWML on MRI, have thinner RNFL compared to age-matched controls (P < 0.001). The average RNFLT values are lowest in patients with PVWML. The aspect of RNFL thinning in non-ON eyes should be further studied as a possible subclinical indicator of MS.