The Impact of Migraine on Posterior Ocular Structures

Purpose. To investigate the thickness of the retinal nerve fiber layer (RNFL) and choroid in patients who have migraines in comparison to healthy controls.Methods. This study included 76 eyes and patients in the migraine group, 36 with aura (MWA group) and 40 without (MWoA group), and 38 eyes as control subjects. The RNFL and macular thicknesses were analysed with standard OCT protocol while choroidal thickness was analysed with EDI protocol in all subjects. Choroidal thickness was measured at the fovea, 1500 µm nasal and 1500 µm temporal to the fovea in a horizontal section.Results. The mean RNFL thickness for nasal and nasal inferior sectors was significantly thinner (P≤0.018) in the migraineurs’ eyes than in those of the controls, as was the mean choroid thickness at the fovea and measured points (P<0.0001). However, the mean macular thickness was not significantly different between the groups.Conclusions. This study suggests that migraine leads to a reduction in the peripapillary RNFL thickness and to thinning in choroidal structures. These findings can be explained by a chronic ischemic insult related to migraine pathogenic mechanisms and these findings are considered supportive of the relationship between glaucoma and migraine.

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Choroidal thickness and retinal nerve fiber layer analysis in acute systemic brucellosis

European Journal of Inflammation ◽

10.1177/20587392211040666 ◽

2021 ◽

Vol 19 ◽

pp. 205873922110406

Author(s):

Kürşad Ramazan Zor ◽

Tuğba Arslan Gülen ◽

Gamze Yıldırım Biçer ◽

Erkut Küçük ◽

Ayfer İmre ◽

...

Keyword(s):

Nerve Fiber ◽

Retinal Nerve Fiber Layer ◽

Choroidal Thickness ◽

Control Group ◽

Fiber Layer ◽

Subfoveal Choroidal Thickness ◽

Nerve Fiber Layer ◽

Rnfl Thickness ◽

The Mean ◽

Retinal Nerve Fiber

Introduction This study aims to detect changes in choroidal thickness and retinal nerve fiber layer (RNFL) thickness in acute stage brucellosis. Methods Fnewly diagnosed patients with acute brucellosis and 19 healthy individuals as control group were included in the study. Choroidal thickness and RNFL thickness were measured using the Spectral Domain Cirrus OCT Model 400 (Carl Zeiss Meditec, Jena, Germany) for each participant in the patient and control group. Results In the brucella group, in the right eyes, the mean nasal choroidal thickness was 272.77 ± 50.26 μm ( p = 0.689), the mean subfoveal choroidal thickness was 321.14 ± 33.08 μm ( p = 0.590), the mean temporal choroidal thickness was 278.86 ± 48.84 μm ( p = 0.478), and the mean RNFL thickness was 90.43 ± 8.93 μm ( p = 0.567). In the left eyes, the mean nasal choroidal thickness was 282.29 ± 48.93 μm ( p = 0.715), the mean subfoveal choroidal thickness was 316.79 ± 39.57 μm ( p = 0.540), the mean temporal choroidal thickness was 284.93 ± 50.57 μm ( p = 0.392), and the mean RNFL thickness was 92.64 ± 8.95 μm ( p = 0.813). Conclusion No difference was found between the control and the brucella groups regarding to all choroidal regions and RNFL thickness.

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Choroidal Thickness and Structural Glaucoma Parameters in Glaucomatous, Preperimetric Glaucomatous, and Healthy Eyes using Swept-Source OCT

European Journal of Ophthalmology ◽

10.5301/ejo.5000926 ◽

2017 ◽

Vol 27 (5) ◽

pp. 548-554 ◽

Cited By ~ 5

Author(s):

Handan Akil ◽

Mayss Al-Sheikh ◽

Khalil Ghasemi Falavarjani ◽

Brian Francis ◽

Vikas Chopra

Keyword(s):

Nerve Fiber ◽

Choroidal Thickness ◽

Wide Field ◽

Inner Plexiform Layer ◽

Fiber Layer ◽

Swept Source ◽

Nerve Fiber Layer ◽

Rnfl Thickness ◽

The Mean ◽

Healthy Eyes

Purpose To evaluate choroidal thickness (CT) and its relationship with retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer thickness (GCIPLT) in glaucomatous, preperimetric glaucomatous, and healthy eyes using swept-source optical coherence tomography (SS-OCT). Methods Fifty eyes with primary open-angle glaucoma, 20 eyes with preperimetric glaucoma, and 20 age-matched healthy eyes were enrolled. Three-dimensional wide-field (12 × 9 mm) images were obtained using a SS-OCT instrument. Peripapillary CT and RNFL thickness, as well as macular CT and GCIPLT, were recorded. The correlation of the CT with nerve fiber layer and GCIPLT measurements was assessed. The association between CT and potential confounding variables including age, sex, axial length, intraocular pressure, and central corneal thickness was also examined. Results Mean peripapillary CTs were 111.7 ± 41.7, 127.7 ± 40.1, and 120.8 ± 35.4 μm in glaucomatous, preperimetric glaucomatous, and normal eyes, respectively. There was statistically significant but weak correlation for the mean RNFL and mean peripapillary CT in glaucomatous subjects (r = 0.341, p = 0.04). There was a significant correlation between RNFL thickness and peripapillary CT in 1, 2, 5, and 6 clock hours of glaucomatous eyes (r = 0.410, p = 0.005; r = 0.316, p = 0.03; r = 0.346, p = 0.02; r = 0.35, p = 0.04, respectively). Mean macular CT was 181.5 ± 70.5, 187.4 ± 65.5, and 185.4 ± 76.4 μm in glaucomatous, preperimetric glaucomatous, and healthy eyes, respectively (p = 0.7). There was no statistically significant correlation between the mean GCIPLT and mean macular CT in all subjects (p>0.05). Conclusions Choroidal thinning and its correlation with other parameters in patients with glaucoma should be further investigated with the proprietary software of SS-OCT.

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Can the coronavirus disease 2019 (COVID-19) cause choroiditis and optic neuropathy?

European Journal of Inflammation ◽

10.1177/20587392211059060 ◽

2021 ◽

Vol 19 ◽

pp. 205873922110590

Author(s):

Kürşad Ramazan Zor ◽

Gamze Yıldırım Biçer ◽

Nesrin Tutaş Günaydın ◽

Erkut Küçük ◽

Uğur Yılmaz

Keyword(s):

Choroidal Thickness ◽

Cross Sectional Study ◽

Control Group ◽

Fiber Layer ◽

Cross Sectional ◽

Subfoveal Choroidal Thickness ◽

Rnfl Thickness ◽

Significant Difference ◽

The Mean ◽

The Right

Objectives: We aim to investigate the involvement of the choroid and retinal nerve fiber layer (RNFL) in COVID-19 patients using spectral domain optical coherence tomography. Methods: This cross-sectional study was conducted between April and June 2020. 40 patients (23 female and 17 male) with COVID-19 and 42 healthy individuals (26 female and 16 male) were included in the study. The OCT scans were performed 4 weeks after the COVID-19 diagnosis. Results: In the COVID-19 group, in the right eyes, the mean nasal choroidal thickness was 295.70 ± 7,046 μm ( p = 0.017), mean subfoveal choroidal thickness was 333.25 ± 6,353 μm ( p = 0.003), mean temporal choroidal thickness was 296.63 ± 6,324 μm ( p = 0.039), and mean RNFL was 89.23 ± 1.30 μm ( p = 0.227). In the left eyes, mean nasal choroidal thickness was 287.88 ± 9,033 μm ( p = 0.267), mean subfoveal choroidal thickness was 333.80 ± 9,457 μm ( p = 0.013), mean temporal choroidal thickness was 298.50 ± 9,158 μm ( p = 0.079), and mean RNFL was 89.48 ± 1,289 μm ( p = 0.092). Compared with the control group, the patient group had significant thickening of the choroidal thickness in all quadrants of the right eyes, and significant thickening of the subfoveal choroidal thickness in the left eyes. There was no significant difference in the RNFL thickness between groups ( p > 0.05). Conclusion: COVID-19 may cause a subclinical involvement in the choroidal layer.

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Subfoveal choroidal thickness and peripapillary retinal nerve fiber layer thickness in young obese males

European Journal of Ophthalmology ◽

10.1177/1120672120982899 ◽

2020 ◽

pp. 112067212098289

Author(s):

Ceylan Uslu Dogan ◽

Damla Culha

Keyword(s):

Nerve Fiber ◽

Retinal Nerve Fiber Layer ◽

Choroidal Thickness ◽

Obese Group ◽

Fiber Layer ◽

Subfoveal Choroidal Thickness ◽

Young Males ◽

Rnfl Thickness ◽

Patient Groups ◽

Temporal Quadrant

Objective: Regarding the effect of obesity on subfoveal choroidal thickness (CT) and peripapillary retinal nerve fiber layer (RNFL) thickness, controversial results have been reported in different patient groups. This study aimed to evaluate the effect of obesity on these parameters among young male subjects in comparison with age-matched non-obese healthy males. Methods: This prospective, cross-sectional study included both eyes of 50 obese young males and 50 healthy non-obese young males. The obese and the non-obese groups included subjects with a BMI of ⩾30 and ⩽25 kg/m², respectively. Subfoveal choroidal thickness and RNFL analyses were conducted by spectral domain optical coherence tomography (SD-OCT). Results: Subfoveal choroidal thickness (321.0 ± 46.7 vs 338.4±35.3, p = 0.002) and RNFL thickness at temporal quadrant (73.4 ± 9.9 vs 76.4 ± 9.3, p = 0.008) was significantly lower in the obese group when compared to the non-obese group. The groups did not differ regarding peripapillary RNFL thickness at other quadrants (superior, inferior, or nasal) or regarding mean peripapillary RNFL thickness. Conclusion: Findings of this study demonstrated a negative correlation of obesity with subfoveal choroidal thickness and temporal quadrant peripapillary RNFL thickness. Larger studies on different patient groups with longer-term follow-up are warranted to better elucidate the ophthalmological effects of obesity.

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Heart Rate and Neurological Outcomes in Patients Undergoing Targeted Temperature Management

Journal of Intensive Care Medicine ◽

10.1177/0885066620982502 ◽

2020 ◽

pp. 088506662098250

Author(s):

Chad M. Conner ◽

William H. Perucki ◽

Andre Gabriel ◽

David M. O’Sullivan ◽

Antonio B. Fernandez

Keyword(s):

Heart Rate ◽

Positive Association ◽

Targeted Temperature Management ◽

Temperature Management ◽

Neurological Outcomes ◽

Neurologic Outcomes ◽

Resuscitation Guidelines ◽

The Mean ◽

The Impact ◽

The Relationship

Introduction: There is a paucity of data evaluating the impact of heart rate (HR) during Targeted Temperature Management (TTM) and neurologic outcomes. Current resuscitation guidelines do not specify a HR goal during TTM. We sought to determine the relationship between HR and neurologic outcomes in a single-center registry dataset. Methods: We retrospectively studied 432 consecutive patients who completed TTM (33°C) after cardiac arrest from 2008 to 2017. We evaluated the relationship between neurologic outcomes and HR during TTM. Pittsburgh Cerebral Performance Categories (CPC) at discharge were used to determine neurological recovery. Statistical analysis included chi square, Student’s t-test and Mann-Whitney U. A logistic regression model was created to evaluate the strength of contribution of selected variables on the outcome of interest. Results: Approximately 94,000 HR data points from 432 patients were retrospectively analyzed; the mean HR was 82.17 bpm over the duration of TTM. Favorable neurological outcomes were seen in 160 (37%) patients. The mean HR in the patients with a favorable outcome was lower than the mean HR of those with an unfavorable outcome (79.98 bpm vs 85.67 bpm p < 0.001). Patients with an average HR of 60-91 bpm were 2.4 times more likely to have a favorable neurological outcome compared to than HR’s < 60 or > 91 (odds ratio [OR] = 2.36, 95% confidence interval [CI] 1.61-3.46, p < 0.001). Specifically, mean HR’s in the 73-82 bpm range had the greatest rate of favorable outcomes (OR 3.56, 95% CI 1.95-6.50), p < 0.001. Administration of epinephrine, a history of diabetes mellitus and hypertension all were associated with worse neurological outcomes independent of HR. Conclusion: During TTM, mean HRs between 60-91 showed a positive association with favorable outcomes. It is unclear whether a specific HR should be targeted during TTM or if heart rates between 60-91 bpm might be a sign of less neurological damage.

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Comparative Analysis of Retinal Nerve Fiber Layer Thickness between Normal and Mild to Moderately Myopic Eyes

Pakistan Journal of Ophthalmology ◽

10.36351/pjo.v37i4.1219 ◽

2021 ◽

Vol 37 (4) ◽

Author(s):

Gul Nasreen ◽

Shaheer Suhail Sarwar ◽

Irfana Bibi ◽

Muhammad Arslan Ashraf

Keyword(s):

Optical Coherence Tomography ◽

Nerve Fiber ◽

Layer Thickness ◽

Retinal Nerve Fiber Layer ◽

Fiber Layer ◽

Nerve Fiber Layer ◽

Nerve Fiber Layer Thickness ◽

Rnfl Thickness ◽

The Mean ◽

Retinal Nerve Fiber

Purpose: To determine the difference between mean retinal nerve fiber layer (RNFL) thickness in myopic eyes (up to -6.00D) and normal eyes. Study Design: Descriptive observational study. Place and Duration of the Study: Eye department of Mayo hospital Lahore, from February 2019 to April 2019. Methods: We compared the mean RNFL between 58 myopic eyes (up to -6.00 D) and age matched 60 normal eyes. The age of the participants was between 12 to 42 years. Complete ocular examination was done and RNFL thickness was measured by using Optical coherence tomography (NIDEX RS-33.0, software-ex 1.5.2).Data was analyzed by independent sample t-test by using SPSS; with P < .05 as significant. Results: The mean difference among these groups was 5.852 µm with (SE: 1.929). Mean RNFL thickness in myopic group was (95.93 ± 10.158µm) with (SE: 1.334). The result for mean RNFL thickness in myopic eyes was distributed normally as P < .03. Mean RNFL in normal group was (101.78 ± 10.774 µm) with (SE: 1.391), and the result of mean RNFL thickness measured in normal eyes was not distributed normally as P < .20. The results showed that there is a statistically significant difference between mean RNFL thickness measured in normal versus myopic eyes as (P < .003). Conclusion: There is a significance difference between mean RNFL thickness between myopic eyes and normal eyes as measured by OCT. Careful interpretation of RNFL data in myopic eyes is recommended to avoid misdiagnosis with glaucoma. Key Words: Retinal Nerve Fiber Layer thickness, Myopia, Optical Coherence Tomography.

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Analyzing the Effect of the Senior Management’s Support on the Relationship between Factors Affecting and Employees’ Performance in the Al-Zawiya University of Libya

Asian Social Science ◽

10.5539/ass.v13n3p42 ◽

2017 ◽

Vol 13 (3) ◽

pp. 42

Author(s):

Nasreddin Ramadhan Dukhan ◽

Norhisham Mohamad ◽

Asbi B Ali

Keyword(s):

Likert Scale ◽

Factors Affecting ◽

The Mean ◽

Multiple Groups ◽

Strongly Agree ◽

The Impact ◽

The Relationship ◽

Variable Performance

This study aims to test the influence of the senior management’s support as a moderating variable on the relationship between the independent factors (Training, Empowerment, Motivation and Communication) and the dependent variable (Performance of Employees). (SEM-AMOS) is used to test the impact of the moderating variable. Where it is depended on the method of sampling or analysis of what is known as multiple-groups analysis. The paragraphs of the senior management’s support variable are collected and divided into two groups according to the mean of the total paragraphs. In addition, according to the relative weights given to the paragraphs of the questionnaire, using a five- point’s Likert scale: 1= strongly disagree to 5 = strongly agree. The first group consisted of the grades less than the mean and it is considered as the group which is non-supporters of the existence of support. While the second group consisted of the grades higher than the mean and considered as the group which is a supporter of the existence of support. The study found that the model of study in the presence of the support of the senior management’s is appropriate for the second group and inappropriate in light of the lack of support by the senior management’s support for the first group.

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Impact of Valsalva Maneuver on Central Choroid, Central Macula, and Disk Fiber Layer Thickness Among High Myopic and Hyperopic Patients

European Journal of Ophthalmology ◽

10.5301/ejo.5000834 ◽

2016 ◽

Vol 27 (3) ◽

pp. 331-335 ◽

Cited By ~ 1

Author(s):

Isil Kurultay-Ersan ◽

Sinan Emre

Keyword(s):

Axial Length ◽

Choroidal Thickness ◽

Valsalva Maneuver ◽

Significant Negative Correlation ◽

Macular Thickness ◽

Enhanced Depth Imaging ◽

Central Macular Thickness ◽

Fiber Layer ◽

Rnfl Thickness ◽

Before And After

Purpose To evaluate the alterations in mean central choroidal, central macular, and disk retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) during Valsalva maneuver among patients with high refractive errors. Methods A total of 60 high myopic (≥-6.0 D) and 50 high hyperopic (≥ + 3.0 D) eyes of 58 patients aged 19-65 years with visual acuity of 20/20 and without any ophthalmologic or systemic diseases were evaluated by OCT before and after the Valsalva maneuver. The choroidal thickness was measured with enhanced depth imaging OCT method. Central macular thickness, disk RNFL thickness, and axial length were also assessed. Results Mean choroidal thickness increased significantly from 275.0 ± 27.2 μm at rest to 279.8 ± 31.6 μm after Valsalva maneuver in high myopic patients, and from 308.2 ± 27.3 μm to 313.6 ± 28.5 μm in high hyperopic patients (p<0.01 for each). A significant negative correlation of the choroidal thickness was noted with axial length (r = -0.509, p<0.01) and age (r = -0.224, p = 0.01) in the overall study population. Mean central macular thickness was 242.9 ± 44.4 μm and 254.0 ± 22.8 μm, while mean disk RNFL thickness was 81.6 ± 12.4 μm and 98.4 ± 13.3 μm in high myopic and hyperopic patients, respectively. Valsalva maneuver was not associated with significant change in central macular or disk RNFL thickness. Conclusions Significant association of Valsalva maneuver with an increase in choroidal thickness was noted among patients with high degree of myopia and hyperopia. Our findings emphasize the likelihood of increase in choroidal volume due to venous distension to be responsible for the increase observed in choroidal thickness after Valsalva maneuver.

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THE LUCK IN “TALENT VERSUS LUCK” MODELING

Advances in Complex Systems ◽

10.1142/s0219525920500071 ◽

2020 ◽

Vol 23 (03) ◽

pp. 2050007

Author(s):

SEAN ELVIDGE

Keyword(s):

Mean Value ◽

Maximum Amount ◽

Random Numbers ◽

Individual Parameter ◽

Input Parameters ◽

The Mean ◽

Model Variability ◽

The Impact ◽

The Relationship

This paper further investigates the Talent versus Luck (TvL) model described by [Pluchino et al. Talent versus luck: The role of randomness in success and failure, Adv. Complex Syst. 21 (2018) 1850014] which models the relationship between ‘talent’ and ‘luck’ on the impact of an individuals career. It is shown that the model is very sensitive to both random sampling and the choice of value for the input parameters. Running the model repeatedly with the same set of input parameters gives a range of output values of over 50% of the mean value. The sensitivity of the inputs of the model is analyzed using a variance-based approach based upon generating Sobol sequences of quasi-random numbers. When using the model to look at the talent associated with an individual who has the maximum capital over a model run it has been shown that the choice for the standard deviation of the talent distribution contributes to 67% of the model variability. When investigating the maximum amount of capital returned by the model the probability of a lucky event at any given epoch has the largest impact on the model, almost three times more than any other individual parameter. Consequently, during the analysis of the model results one must keep in mind the impact that only small changes in the input parameters can have on the model output.

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Modelling patterns of parasite aggregation in natural populations: trichostrongylid nematode–ruminant interactions as a case study

Parasitology ◽

10.1017/s0031182000075867 ◽

1995 ◽

Vol 111 (S1) ◽

pp. S135-S151 ◽

Cited By ~ 97

Author(s):

B. T. Grenfell ◽

K. Wilson ◽

V. S. Isham ◽

H. E. G. Boyd ◽

K. Dietz

Keyword(s):

Population Biology ◽

Negative Binomial ◽

Natural Populations ◽

Parasite Load ◽

Host Immunity ◽

Moment Closure ◽

The Mean ◽

Parasite Aggregation ◽

The Impact ◽

The Relationship

SUMMARYThe characteristically aggregated frequency distribution of macroparasites in their hosts is a key feature of host–parasite population biology. We begin with a brief review of the theoretical literature concerning parasite aggregation. Though this work has illustrated much about both the sources and impact of parasite aggregation, there is still no definitive analysis of both these aspects. We then go on to illustrate the use of one approach to this problem – the construction of Moment Closure Equations (MCEs), which can be used to represent both the mean and second moments (variances and covariances) of the distribution of different parasite stages and phenomenological measures of host immunity. We apply these models to one of the best documented interactions involving free-living animal hosts – the interaction between trichostrongylid nematodes and ruminants. The analysis compares patterns of variability in experimental infections of Teladorsagia circumcincta in sheep with the equivalent wildlife situation – the epidemiology of T. circumcincta in a feral population of Soay sheep on St Kilda, Outer Hebrides. We focus on the relationship between mean parasite load and aggregation (inversely measured by the negative binomial parameter, k) for cohorts of hosts. The analysis and empirical data indicate that k tracks the increase and subsequent decline in the mean burden with host age. We discuss this result in terms of the degree of heterogeneity in the impact of host immunity or parasite-induced mortality required to shorten the tail of the parasite distribution (and therefore increase k) in older animals. The model is also used to analyse the relationship between estimated worm and egg counts (since only the latter are often available for wildlife hosts). Finally, we use these results to review directions for future work on the nature and impact of parasite aggregation.

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