Effects of season on electro-oculographic ratio in winter seasonal affective disorder

Clinical Psychobiology Branch, National Institute of Mental Health, Building 10, Room 4S-239, 9000 Rockville Pike, Bethesda, MD 20892, USA
Psychiatry Research (Impact Factor: 2.47). 12/1995; 59(1):151-155. DOI: 10.1016/0165-1781(95)02788-2


Low electro-oculographic (EOG) ratios have been reported in patients with seasonal affective disorder (SAD) during the winter. This study evaluated the effects of the changing seasons on EOG ratios in SAD patients. Sixteen outpatients with SAD and 16 age-, sex-, and medication-matched normal volunteers had EOG testing during the winter and again during the summer. There was a significant season × group interaction in EOG ratios, with normal subjects showing higher ratios in winter than in summer — a seasonal variation not observed in SAD patients. SAD patients may have a subsensitivity to environmental light that leads them to experience symptoms during the winter.

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    • "Furthermore using electroocculography (EOG), it has been shown that healthy individuals have higher EOG ratios in winter than in summer. This seasonal difference was not evident in SAD patients, which can be seen as an indicator for a pathological lack of up-regulation of electrical potential and activity in the retina of SAD patients (Ozaki et al. 1995; Roecklein et al. 2013). Studies incorporating electro-retinography (ERG) showed a lower sensitivity of rods (scotopic vision) in SAD patients, underscoring the retinal subsensitivity hypothesis (H é bert et al. 2004; Roecklein et al. 2013). "
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    ABSTRACT: Objectives. Seasonal affective disorder (SAD) is a subtype of recurrent unipolar or bipolar depressive disorder with a higher prevalence in winter than in summer. The biological underpinnings of SAD are so far poorly understood. Studies examining SAD have found disturbances between the molecular and connectivity scales. The aim of the study was to explore changes in functional connectivity typical for SAD. Methods. We investigated unmedicated, untreated SAD patients and healthy controls using resting-state functional magnetic resonance imaging (rs-fMRI) utilizing graph theory, a data driven and hypothesis free approach, to model functional networks of the brain. Results. Comparing whole brain network properties using graph theory we observed globally affected network topologies with increasing pathlength in SAD. Nodal changes, however, were highly restricted to bilateral inferior occipital cortex. Interestingly, we found a lateralization where hyper-connectedness was restricted to right inferior occipital cortex and hyper-efficiency was found in the left inferior occipital cortex. Furthermore, we found these nodes became more "hub like" in patients, suggesting a greater functional role. Conclusions. Our work stresses the importance of abnormal intrinsic processing during rest, primarily affecting visual areas and subsequently changing whole brain networks, and thus providing an important hint towards potential future therapeutic approaches.
    The World Journal of Biological Psychiatry 11/2014; 16(2):1-12. DOI:10.3109/15622975.2014.966144 · 4.18 Impact Factor
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    • "The available experimental data are not sufficient to determine which of these two assumptions is correct. Low electrooculographic (EOG) ratios have been consistently demonstrated in SAD, suggesting abnormal retinal pigment epithelium in winter (Lam et al., 1991; Ozaki et al., 1995). "
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    ABSTRACT: The purpose of this study was to investigate the effects of light therapy on visual contrast sensitivity in patients with seasonal affective disorder (n=10) and healthy control subjects (n=10). Static and dynamic visual contrast sensitivity was measured using a Venus system before and after 4 weeks of light therapy (10,000 lux, 30 min, 5 times a week). Light therapy increased static visual contrast sensitivity in the patients. We found no significant difference between the patients and controls either before or after light therapy. These results raise the possibility that light therapy induces retinal sensitization in seasonal affective disorder.
    Psychiatry Research 05/2004; 126(1):15-21. DOI:10.1016/j.psychres.2003.12.013 · 2.47 Impact Factor
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    • "Similarly to some works which indicated changing of the so called EoG-ratio after phototherapy [6], we introduce parameters characterising changes of the fractal dimension during eyes-opening (∆ o ) and eyes-closing (∆ c ) in EEG, and we define ∆ o /∆ c as open-/closed-eyes ratio (FD-ratio). "
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    ABSTRACT: : We propose a new method, based on fractal analysis of EEG signal, of asessing phototherapy results in patients with Seasonal Affective Disorder (SAD). We demonstrate that the changes of the proposed parameter
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