Biomedical subjects

Heather Winslow

Publications and source records attributed to Heather Winslow.

3 recordsLinked to original sources

PubMed2006

Relation of visual function to retinal nerve fiber layer thickness in multiple sclerosis.

PURPOSE: To examine the relation of visual function to retinal nerve fiber layer (RNFL) thickness as a structural biomarker for axonal loss in multiple sclerosis (MS), and to compare RNFL thickness among MS eyes with a history of acute optic neuritis (MS ON eyes), MS eyes without an optic neuritis history (MS non-ON eyes), and disease-free control eyes. DESIGN: Cross-sectional study. PARTICIPANTS: Patients with MS (n = 90; 180 eyes) and disease-free controls (n = 36; 72 eyes). METHODS: Retinal never fiber layer thickness was measured using optical coherence tomography (OCT; fast RNFL thickness software protocol). Vision testing was performed for each eye and binocularly before OCT scanning using measures previously shown to capture dysfunction in MS patients: (1) low-contrast letter acuity (Sloan charts, 2.5% and 1.25% contrast levels at 2 m) and (2) contrast sensitivity (Pelli-Robson chart at 1 m). Visual acuity (retroilluminated Early Treatment Diabetic Retinopathy charts at 3.2 m) was also measured, and protocol refractions were performed. MAIN OUTCOME MEASURES: Retinal nerve fiber layer thickness measured by OCT, and visual function test results. RESULTS: Although median Snellen acuity equivalents were better than 20/20 in both groups, RNFL thickness was reduced significantly among eyes of MS patients (92 mum) versus controls (105 mum) (P<0.001) and particularly was reduced in MS ON eyes (85 mum; P<0.001; accounting for age and adjusting for within-patient intereye correlations). Lower visual function scores were associated with reduced average overall RNFL thickness in MS eyes; for every 1-line decrease in low-contrast letter acuity or contrast sensitivity score, the mean RNFL thickness decreased by 4 mum. CONCLUSIONS: Scores for low-contrast letter acuity and contrast sensitivity correlate well with RNFL thickness as a structural biomarker, supporting validity for these visual function tests as secondary clinical outcome measures for MS trials. These results also suggest a role for ocular imaging techniques such as OCT in trials that examine neuroprotective and other disease-modifying therapies. Although eyes with a history of acute optic neuritis demonstrate the greatest reductions in RNFL thickness, MS non-ON eyes have less RNFL thickness than controls, suggesting the occurrence of chronic axonal loss separate from acute attacks in MS patients.

Acute Disease↗

PubMed2006

Sympathomimetic-induced kaleidoscopic visual illusion associated with a reversible splenium lesion.

BACKGROUND: Sympathomimetic-induced metabolic derangements within the central nervous system can result in conspicuous changes in neurological functioning and corresponding radiographic abnormalities that can be reversible. OBJECTIVE: To describe a patient with a "kaleidoscopic" visual illusion who was found by magnetic resonance imaging to have a transient lesion in the splenium of the corpus callosum. DESIGN: Case report. SETTING: The University of Texas Southwestern Medical Center, Dallas. PATIENT: A 17-year-old adolescent girl who developed an episode of kaleidoscopic vision while using sympathomimetic-containing diet pills that was associated with a reversible lesion of the splenium of the corpus callosum. Her brother has a history of migraine and experienced a similar episode while using illicit stimulant agents. INTERVENTION: Withdrawal of the medication resulted in the cessation of the episodes and normalization of the magnetic resonance image. MAIN OUTCOME MEASURES: Clinical and radiographic improvement. RESULTS: Sympathomimetic-induced metabolic derangements can be associated with reversible lesions within the brain. CONCLUSIONS: We hypothesize that the visual fragmentation was a manifestation of a migraine triggered by sympathomimetic-containing diet pills, and that the transient lesion in the corpus callosum was a manifestation of a reversible metabolic derangement. Both the visual fragmentation and the lesion in the corpus callosum resolved once the patient stopped receiving diet pills.

Acute Disease↗

PubMed2006

Optical coherence tomography in multiple sclerosis.

We do not have currently satisfactory clinical and anatomical correlates to gauge disability in multiple sclerosis. Structural biomarkers (such as MRI) are hindered because they cannot precisely segregate demyelination from axonal elements of tissue injury within the CNS. Axonal degeneration in multiple sclerosis is related to irreversible disability, which suggests that the confirmation of neuroprotective strategies needs highly quantifiable measures of axon loss that can be correlated with reliable measures of physiological function. The coupling of quantifiable measures of visual function with ocular imaging techniques, such as optical coherence tomography, enables us to begin to understand how structural changes in the visual system influence function in patients with multiple sclerosis. In this review, we consider the usefulness of optical imaging of the retina as a biomarker for neurodegeneration in multiple-sclerosis.

Biomarkers↗