Objective-Cross-sectional studies of optical coherence tomography (OCT) show that retinal nerve fiber layer (RNFL) thickness is reduced in multiple sclerosis (MS) and correlates with visual function. We determined how longitudinal changes in RNFL thickness relate to visual loss. We also examined patterns of RNFL thinning over time in MS eyes with and without a prior history of acute optic neuritis (ON).Methods-Patients underwent OCT measurement of RNFL thickness at baseline and at 6-month intervals during a mean follow-up of 18 months at three centers. Low-contrast letter acuity (2.5%, 1.25% contrast) and visual acuity (VA) were assessed.Results-Among 299 patients (593 eyes) with ≥6 months follow-up, eyes with visual loss showed greater RNFL thinning compared to eyes with stable vision (low-contrast acuity, 2.5%: p<0.001; VA: p=0.005). RNFL thinning increased over time, with average losses of 2.9 μm at 2-3 years and 6.1 μm at 3-4.5 years (p<0.001 vs. 0.5-1-year follow-up interval). These patterns were observed for eyes with or without prior history of ON. Proportions of eyes with RNFL loss greater than test-retest variability (≥6.6 μm) increased from 11% at 0-1 year to 44% at 3-4.5 years (p<0.001).Interpretation-Progressive RNFL thinning occurs as a function of time in some patients with MS, even in the absence of ON, and is associated with clinically significant visual loss. These findings are consistent with sub-clinical axonal loss in the anterior visual pathway in MS and support the use of OCT and low-contrast acuity as methods to evaluate the effectiveness of putative neuroprotection protocols.Address all correspondence to: Dr. Laura J. Balcer, Department of Neurology, 3 E. Gates, 3400 Spruce Street, Philadelphia, PA 19104, 215-349-8072, Fax 215-349-5579, lbalcer@mail.med.upenn.edu. NIH Public Access Author ManuscriptAnn Neurol. Author manuscript; available in PMC 2011 June 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author ManuscriptVisual dysfunction is a common cause of disability and reduced quality of life in multiple sclerosis (MS). 1 The anterior visual pathway is a frequent site for inflammation and demyelination, and axonal degeneration is likely to be a final common pathway to permanent visual loss. [2][3][4][5] Recognized by MS experts as a critical dimension for outcomes assessment, 6 vision has been an important area of investigation. The findings of many studies have supported low-contrast letter acuity as a candidate clinical trial outcome measure. It can capture subtle visual impairment, treatment effects, MRI lesion burden, prolonged visual evoked potential latencies, and quality of life. 1,[7][8][9][10][11][12][13] Many ongoing MS trials have incorporated low-contrast acuity as a tertiary outcome.The emergence of optical coherence tomography (OCT) in MS has brought the anterior visual pathway to the forefront as a model for measuring therapeutic efficacy, particularly for trials involving neuroprotection. 14-32 A reliable marker for axonal loss in MS, 24 retina...

Objective: To evaluate the retinal nerve fiber layer (RNFL) thickness and macular volume in neuromyelitis optica (NMO) spectrum patients using optical coherence tomography (OCT).Background: OCT can quantify damage to retinal ganglion cell axons and can identify abnormali-

OCT segmentation demonstrates in vivo GCIP thinning in all MS subtypes. GCIP thickness demonstrates better structure-function correlations (with vision and disability) in MS than RNFL thickness. In addition to commonly observed RNFL/GCIP thinning, retinal inner and outer nuclear layer thinning occur in MS.

Objective: To determine the effect of clinical and radiologic disease activity on the rate of thinning of the ganglion cell/inner plexiform (GCIP) layer and the retinal nerve fiber layer in patients with multiple sclerosis (MS) using optical coherence tomography (OCT).Methods: One hundred sixty-four patients with MS and 59 healthy controls underwent spectraldomain OCT scans every 6 months for a mean follow-up period of 21.1 months. Baseline and annual contrast-enhanced brain MRIs were performed. Patients who developed optic neuritis during follow-up were excluded from analysis.Results: Patients with the following features of disease activity during follow-up had faster rates of annualized GCIP thinning: relapses (42% faster, p 5 0.007), new gadolinium-enhancing lesions (54% faster, p , 0.001), and new T2 lesions (36% faster, p 5 0.02). Annual GCIP thinning was 37% faster in those with disability progression during follow-up, and 43% faster in those with disease duration ,5 years vs .5 years (p 5 0.003). Annual rates of GCIP thinning were highest in patients exhibiting combinations of new gadolinium-enhancing lesions, new T2 lesions, and disease duration ,5 years (70% faster in patients with vs without all 3 characteristics, p , 0.001).Conclusions: MS patients with clinical and/or radiologic nonocular disease activity, particularly early in the disease course, exhibit accelerated GCIP thinning. Our findings suggest that retinal changes in MS reflect global CNS 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 anterior visual pathway is frequently affected in multiple sclerosis (MS), with 94% to 99% of patients with MS demonstrating optic nerve lesions postmortem.