Longitudinal study of vision and retinal nerve fiber layer thickness in multiple sclerosis.

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 3 centers. Low-contrast letter acuity (2.5%, 1.25% contrast) and visual acuity (VA) were assessed. RESULTS: Among 299 patients (593 eyes) with >or=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 2.9microm at 2 to 3 years and 6.1microm at 3 to 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 (>or=6.6microm) increased from 11% at 0 to 1 year to 44% at 3 to 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 subclinical 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.

The long-term outcomes of ocular tics in a pediatric neuro-ophthalmology practice.

PURPOSE: To describe the outcome and comorbidities of ocular tics in children evaluated by a pediatric neuro-ophthalmologist. METHODS: The medical records of all consecutive patients in a pediatric neuro-ophthalmology practice diagnosed with ocular tics (eye rolling, blinking, and widening) were retrospectively reviewed. Children with known secondary causes for tics were excluded. Patients, parents, and/or guardians were contacted by telephone to obtain follow-up information. RESULTS: A total of 43 patients were included in the retrospective cohort, with a mean age of 7.8 ± 4.8 years at diagnosis. Thirty-two patients participated in the follow-up survey, with an average follow-up of 6.1 ± 3.9 years. None of the 43 children carried a diagnosis of Tourette syndrome or obsessive-compulsive disorder (OCD) at presentation; 1 child had attention deficit hyperactivity disorder (ADHD). At follow-up, 14 of the 32 children (44%) had persistent ocular tics, 3 (9%) reported new nonocular motor tics, 5 (16%) reported new vocal tics, and 4 (13%) developed both nonocular motor and vocal tics. One patient (3%) was formally diagnosed with Tourette syndrome during the follow-up interval, and 3 (9%) were diagnosed with ADHD. CONCLUSIONS: Almost half of the children with ocular tics at presentation had persistent ocular tics on follow-up. New nonocular motor and vocal tics occurred in several patients.

The impact of utilizing different optical coherence tomography devices for clinical purposes and in multiple sclerosis trials.

Optical coherence tomography (OCT) derived retinal measures, particularly peri-papillary retinal nerve fiber layer (RNFL) thickness, have been proposed as outcome measures in remyelinating and neuroprotective trials in multiple sclerosis (MS). With increasing utilization of multiple centers to improve power, elucidation of the impact of different OCT technologies is crucial to the design and interpretation of such studies. In this study, we assessed relation and agreement between RNFL thickness and total macular volume (in MS and healthy controls) derived from three commonly used OCT devices: Stratus time-domain OCT, and Cirrus HD-OCT and Spectralis, two spectral-domain (SD) OCT devices. OCT was performed on both Cirrus HD-OCT and Stratus in 229 participants and on both Cirrus HD-OCT and Spectralis in a separate cohort of 102 participants. Pearson correlation and Bland-Altman analyses were used to assess correlation and agreement between devices. All OCT retinal measures correlated highly between devices. The mean RNFL thickness was 7.4 µm lower on Cirrus HD-OCT than Stratus, indicating overall poor agreement for this measurement between these machines. Further, the limits of agreement (LOA) between Cirrus HD-OCT and Stratus were wide (-4.1 to 18.9 µm), indicating poor agreement at an individual subject level. The mean RNFL thickness was 1.94 µm (LOA: -5.74 to 9.62 µm) higher on Spectralis compared to Cirrus HD-OCT, indicating excellent agreement for this measurement across this cohort. Although these data indicate that these three devices agree poorly at an individual subject level (evidenced by wide LOA in both study cohorts) precluding their co-utilization in everyday practice, the small difference for mean measurements between Cirrus HD-OCT and Spectralis indicate pooled results from these two SD-devices could be used as outcome measures in clinical trials, provided patients are scanned on the same machine throughout the trial, similar to the utilization of multiple different MRI platforms in MS clinical trials.