Browsing by Author "Costello, Fiona"
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- ItemOpen AccessA qualitative description of barriers to visual rehabilitation experienced by stroke survivors with visual impairment in Alberta, Canada(2023-01-20) Manhas, Kiran P.; Brehon, Katelyn; Jiang, Jennis; Damji, Karim F.; Costello, FionaAbstract Background Post-stroke visual impairment (VI) is a common but under-recognized care challenge. Common manifestations of post-stroke VI include: diplopia, homonymous hemianopia, oscillopsia secondary to nystagmus, and visual inattention or neglect. In acute care settings, post-stroke VI recognition and treatment are often sub-optimal as emphasis is placed on survival. Stroke survivors with VI often face inconsistencies when accessing care out of hospital because variable availability and subsidization of visual rehabilitation. We sought to identify gaps in care experienced by stroke survivors with VI from stroke survivors’ and care providers’ perspectives. Methods We conducted a qualitative description study across 12 care sites in Alberta, Canada, using semi-structured interviews. Survivor interviews focused on the health system experience. Provider interviews discussed approaches to care, perceived gaps, and current resources. Interviews were audio-recorded and transcribed. Iterative content analysis was completed using NVivo 12. We promoted rigour through an audit trail, open-ended questions, thick description, and collaborative coding. Results We completed 50 interviews: 19 survivor interviews and 31 provider interviews. The majority of survivors were male (n = 14) and recruited from community settings (n = 16). Providers varied in profession and location within the care continuum. Two key themes emerged from the provider and survivor interviews pertaining to (a) facets of visual rehabilitation (sub-themes: access, resources, and multidisciplinary professional interaction); and (b) functioning with post-stroke VI (sub-themes: early experiences post-stroke and living with VI in the real world). Conclusions The visual rehabilitation model needs to be optimized to ensure transparent inter-disciplinary communication and efficient referral pathways. Future research will focus on evaluating the effectiveness of post-stroke care from multiple perspectives in Alberta.
- ItemOpen AccessEvaluating the Use of Optical Coherence Tomography in Optic Neuritis(2011-03-22) Costello, FionaOptic neuritis (ON) is an inflammatory optic nerve injury, which is strongly associated with multiple sclerosis (MS). Axonal damage in the optic nerve manifests as retinal nerve fiber layer (RNFL) deficits, which can be readily quantified with optical coherence tomography (OCT). The RNFL represents the most proximal region of the afferent visual pathway; and, as such, is a unique region of the central nervous system (CNS) because it lacks myelin. Changes in retinal integrity can be correlated with reliable and quantifiable visual outcomes to provide a structural-functional paradigm of CNS injury. Because the eye provides a unique “view” into the effects of CNS inflammation, the ON “system model” may provide greater understanding about disease mechanisms, which underpin disability in MS. This review addresses the applications of OCT in study of ON patients, with specific reference to the published reports to date. The future role of OCT is discussed, both in terms of the potential gains and certain challenges associated with this evolving technology.
- ItemOpen AccessExploring the Association between Retinal Nerve Fiber Layer Thickness and Initial Magnetic Resonance Imaging Findings in Patients with Acute Optic Neuritis(2011-05-29) Costello, Fiona; Hodge, William; Pan, Y. IreneBackground. Recent studies have shown thatOCT-measured retinal nerve fiber layer (RNFL) values may representa marker for axonal damage in the anterior visual pathway of opticneuritis (ON) and multiple sclerosis (MS) patients. The goal ofthis study was to determine the link between RNFL values andinitial magnetic resonance imaging (MRI) evidence of centralnervous system (CNS) inflammation in patients with acute ON.Methods. Fifty patients who experienced ON as aclinically isolated syndrome (CIS) were followed for a mean periodof 34 months with OCT testing. RNFL values in affected (ON) eyesand clinically unaffected (non-ON) eyes were compared betweenpatients with MRI evidence of white matter lesions and those withnormal baseline MRI findings, over a two year period.Findings. Twenty-one patients (42%) developedclinically definite MS (CDMS) during the study. After two years,temporal RNFL values were thinner (P=.07) in ON patients with MRI lesionsat baseline, but the results were not significant.Conclusions. There is no association between RNFLvalues and baseline MRI status in ON patients at risk for futureCDMS over a two year period.
- ItemOpen AccessReproducibility of Retinal Nerve Fiber Layer Measurements with Manual and Automated Centration in Healthy Subjects Using Spectralis Spectral-Domain Optical Coherence Tomography(2012-07-30) Lange, Alex P.; Sadjadi, Reza; Costello, Fiona; Guber, Ivo; Traboulsee, Anthony L.Objective. The aim of this study was to test the reproducibility of the Heidelberg Spectralis SD-OCT and to determine if provided software retest function for follow-up exam is superior to manual centration. Design. Prospective, cross-sectional study. Participants. 20 healthy subjects. Methods. All subjects underwent SD-OCT testing to determine retinal nerve fiber layer (RNFL) measurements sequentially on two different days and with two different centration techniques. Within-subject standard deviation, coefficient of variation, and intraclass correlation coefficient were used to assess reproducibility. Results. RNFL measurements showed high reproducibility, low within-subject standard deviation (1.3), low coefficient of variation (0.63%), and low intra-class correlation coefficient (0.98 (95% CI 0.97–0.99)) in the automated centration and manual centration groups for average RNFL Thickness. Quadrants showed slightly higher variability in the manual group compared to the automated group (within-subject standard deviation 2.5–5.3 versus 1.1–2.4, resp.). Conclusions. SD-OCT provides high-resolution RNFL measurements with high reproducibility and low variability. The re-test function allows for easier recentration for longitudinal examinations with similar results in average RNFL, but less variability in quadrant RNFL. SD-OCT high reproducibility and low variability is a promising fact and should be further evaluated in longitudinal studies of RNFL.
- ItemOpen AccessThe Afferent Visual Pathway: Designing a Structural-Functional Paradigm of Multiple Sclerosis(2013-10-23) Costello, FionaMultiple sclerosis (MS) is a disease of the central nervous system (CNS) believed to arise from a dysfunctional immune-mediated response in a genetically susceptible host. The actual cause of MS is not known, and there is ongoing debate about whether this CNS disorder is predominantly an inflammatory versus a degenerative condition. The afferent visual pathway (AVP) is frequently involved in MS, such that one in every five individuals affected presents with acute optic neuritis (ON). As a functionally eloquent system, the AVP is amenable to interrogation with highly reliable and reproducible tests that can be used to define a structural-functional paradigm of CNS injury. The AVP has numerous unique advantages as a clinical model of MS. In this review, the parameters and merits of the AVP model are highlighted. Moreover, the roles the AVP model may play in elucidating mechanisms of brain injury and repair in MS are described.
- ItemOpen AccessThe role of oral contraceptives in optic neuritis: the story behind the study, initial experiences, and lessons learned(2013-07-15) Trufyn, Jessie J.; Costello, Fiona; Burton, JodieThere is accumulating evidence of sex differences in multiple sclerosis, making hormones a possible research avenue for therapeutic agents. Oral contraceptives are a source of synthetic hormones, however, it is unclear whether hormone-based therapies help, hinder, or have no effect on the disease in women. In an attempt to elucidate the role of sex hormones, we are currently conducting an observational study of oral contraceptives in optic neuritis, a condition that often occurs in parallel with multiple sclerosis. The thesis describes the study rational and supporting evidence for the hypothesis that oral contraceptive use in our study population will be associated with beneficial outcomes. I also share experiences with study implementation and preliminary data. The final section of the thesis offers insight for researchers on the areas of optical coherence tomography, hormones, and human research.