Optic neuritis - more than a loss of vision

Optic neuritis (ON) is the presence of an acute inflammation of the optic nerve that results in painful loss of vision. It is the most commonly encountered optic neuropathy in general practice, and is often associated with multiple sclerosis (MS). Studies show that in about 15–20% of MS cases, ON was the presenting symptom and more than half of people with MS experience at least one episode of ON during their disease. The risk of developing MS can be stratified by appropriate imaging investigations at the diagnosis of ON. Therefore, early recognition is important to ensure timely referral, investigation and treatment; prompt treatment can hasten visual recovery

Predicting mercury levels in freshwater fish through biotic and abiotic factors: a case study of Nantucket Island

https://digitalcommons.dartmouth.edu/wetterhahnsymposium-2018/1003/thumbnail.jp

Comparing nearshore benthic and pelagic prey as mercury sources to lake fish: the importance of prey quality and mercury content

Mercury (Hg) bioaccumulation in fish poses well-known health risks to wildlife and humans through fish consumption. Yet fish Hg concentrations are highly variable, and key factors driving this variability remain unclear. One little studied source of variation is the influence of habitat-specific feeding on Hg accumulation in lake fish. However, this is likely important because most lake fish feed in multiple habitats during their lives, and the Hg and caloric content of prey from different habitats can differ. This study used a three-pronged approach to investigate the extent to which habitat-specific prey determine differences in Hg bioaccumulation in fish. This study first compared Hg concentrations in common nearshore benthic invertebrates and pelagic zooplankton across five lakes and over the summer season in one lake, and found that pelagic zooplankton generally had higher Hg concentrations than most benthic taxa across lakes, and over a season in one lake. Second, using a bioenergetics model, the effects of prey caloric content from habitat-specific diets on fish growth and Hg accumulation were calculated. This model predicted that the consumption of benthic prey results in lower fish Hg concentrations due to higher prey caloric content and growth dilution (high weight gain relative to Hg from food), in addition to lower prey Hg levels. Third, using data from the literature, links between fish Hg content and the degree of benthivory, were examined,

Are Vision-Specific Quality of Life Questionnaires Important in Assessing Rehabilitation for Patients With Hemianopia Post Stroke?

This author accepted manuscript (post print) is made available following a 12 month embargo from the date of publication (2011) in accordance with the publisher copyright policy.Objective: To explore the relationship between disability and functional measures with vision-specific quality of life (QoL) measures for people with hemianopia and stroke. Method: The Behavioral Inattention Test (BIT) and the Mayo-Portland Adaptability Inventory (MPAI) were compared with scores on 2 vision-specific QoL measures, the National Eye Institute Visual Function Questionnaire (NEI VFQ-25) and Veteran Low Vision Visual Function Questionnaire (VA LV VFQ-48). Setting: Rehabilitation hospitals in Adelaide, South Australia. Participants: Stroke patients (n = 24) with homonymous hemianopia. Results: Most of the BIT and MPAI scores were significantly associated with the NEI VFQ-25 and VA LV VFQ-48 scores. Behavioral test scores of the BIT and the MPAI total score correlated with more aspects of the QoL measures than the other components of the BIT and the MPAI. Conclusion: BIT and MPAI measure constructs associated with QoL for people with hemianopia following stroke. Vision-specific QoL questionnaires can complement the functional instruments by identifying the domains of difficulty, based on the instrument’s subscale, that can guide rehabilitation therapists to address the person’s deficit

Multiple sclerosis presenting with homonymous hemianopia

Ophthalmic manifestations are a prominent feature of multiple sclerosis (MS). Optic neuritis accounts for 18% of initial MS symptoms and 40–70% of all patients with MS have at least one episode of optic neuritis during their disease course. Eye movement abnormalities such as internuclear ophthalmoplegia are seen in over 50% of patients with MS. This case study describes a rare initial presentation of MS with ‘left eye blurred vision’ and examination findings of a complete left homonymous hemianopia. Although homonymous hemianopia is uncommon (0.5–3.5% of MS cases), this case highlights an important reminder that people with a field defect often complain of ‘blurred vision’ on the side of the defect