The effect of religious fasting and dehydration at Ramadan on choroidal thickness and Retinal vessel densities, measured with optical coherence tomography angiography

European Journal of Ophthalmology ◽

10.1177/1120672120958297 ◽

2020 ◽

pp. 112067212095829

Author(s):

Onur Gokmen ◽

Gokhan Ozgur

Keyword(s):

Healthy Subjects ◽

Choroidal Thickness ◽

Retinal Vessel ◽

Vessel Density ◽

Fasting Period ◽

Significant Difference ◽

Density Index ◽

The Mean ◽

Vascular Plexuses ◽

Religious Fasting

Aim: To investigate the effect of religious fasting and dehydration at Ramadan on choroidal thickness and vessel density in the superficial and deep vascular plexuses with OCTA. Methods: The choroidal thickness, and superficial and deep vessel density indices of fasting healthy subjects were measured with an OCTA device, and compared with non-fasting measurements. Results: The study included 70 eyes of 35 healthy subjects with a mean age of 42.86 ± 8.3 years. The measured choroidal thickness, superficial vessel density index and deep vessel density index were 288.89 ± 67 µm, 40.56% and 41.43%, respectively when measured in the fasting period, compared to 284.62 ± 65 µm, 40.41% and 41.41%, respectively when measured in the non-fasting period. The choroidal thickness under the fovea center was found to be significantly higher in the fasting period than in the non-fasting period ( p = 0.014). The mean total choroidal thickness was found to be reduced in the non-fasting period, although not to a statistically significant degree ( p > 0.05). An analysis of the mean total superficial and deep vascular plexuses revealed no statistically significant difference ( p = 0.368, p = 0.938 respectively). Conclusion: Although a significant increase was noted in central choroidal thickness in the fasting period, no significant change due to fasting was observed in the superficial and deep capillary plexuses. The choroidal layer may vary in thickness due to fasting-related metabolic factors, while retinal vessels are more stable against such effects.

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Influence of Fasting followed by Acute Water Ingestion on Subfoveal Choroidal Thickness in Eyes of Healthy Subjects

Ophthalmology Point of Care ◽

10.5301/oapoc.0000013 ◽

2017 ◽

Vol 1 (1) ◽

pp. oapoc.0000013

Author(s):

Rocio Blanco-Garavito ◽

Polina Astroz ◽

Salomon Yves Cohen ◽

Eric H. Souied

Keyword(s):

Healthy Volunteers ◽

Healthy Subjects ◽

Choroidal Thickness ◽

Enhanced Depth Imaging ◽

Hydration Status ◽

Subfoveal Choroidal Thickness ◽

Water Ingestion ◽

Case Series Study ◽

Significant Difference ◽

The Mean

Purpose To investigate the influence of at least 12 hours of fasting followed by acute water ingestion on macular choroidal thickness in eyes of healthy subjects. Methods Prospective case series study including healthy volunteers from April 1, 2015 to May 31, 2015. Macular choroidal thickness was measured on enhanced depth imaging optical coherence tomography (EDI-OCT) and on swept-source (SS)-OCT after 12 hours of fasting, and 60 minutes after acute water ingestion (750 mL in 5 minutes). Results A total of 52 eyes of 26 healthy volunteers were included in this study. The mean age for participants was 32 years old. After 12 hours of fasting, the mean (±SD) subfoveal choroidal thickness was 335.43 (±104.82) μm on EDI-OCT and 286.16 (±80.32) μm on SS-OCT. The mean (±SD) subfoveal choroidal thickness after acute water intake was 352.32 (±120.36) μm and 290.5 (±85.86) μm, respectively. There was no significant difference between the mean subfoveal thickness at baseline and 60 minutes after acute water ingestion for any of the choroidal imaging techniques (p = 0.1386 for EDI-OCT and p = 0.0659 for SS-OCT). Conclusions These results suggest that choroidal circulation can physiologically quickly adapt to systemic vascular changes in healthy eyes. Choroidal thickness did not depend upon the hydration status for the subjects participating in this study.

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The Y-shaped trabecular bone structure in the odontoid process of the axis: a CT scan study in 54 healthy subjects and biomechanical considerations

Journal of Neurosurgery Spine ◽

10.3171/2018.9.spine18396 ◽

2019 ◽

Vol 30 (5) ◽

pp. 585-592 ◽

Cited By ~ 5

Author(s):

Nicola Montemurro ◽

Paolo Perrini ◽

Vittoriano Mangini ◽

Massimo Galli ◽

Andrea Papini

Keyword(s):

Ct Scan ◽

Healthy Subjects ◽

Bone Structure ◽

Cone Beam Ct ◽

Odontoid Process ◽

Trabecular Structure ◽

Anatomical Entity ◽

Significant Difference ◽

Axial Ct ◽

The Mean

OBJECTIVEOdontoid process fractures are very common in both young and geriatric patients. The axial trabecular architecture of the dens appears to be crucial for physiological and biomechanical function of the C1–2 joint. The aim of this study is to demonstrate the presence of a Y-shaped trabecular structure of the dens on axial CT and to describe its anatomical and biomechanical implications.METHODSFifty-four C2 odontoid processes in healthy subjects were prospectively examined for the presence of a Y-shaped trabecular structure at the odontocentral synchondrosis level with a dental cone beam CT scan. Length, width, and axial area of the odontoid process were measured in all subjects. In addition, measurements of the one-third right anterior area of the Y-shaped structure were taken.RESULTSThe Y-shaped trabecular structure was found in 79.6% of cases. Length and width of the odontoid process were 13.5 ± 0.6 mm and 11.2 ± 0.9 mm, respectively. The mean area of the odontoid process at the odontocentral synchondrosis was 93.5 ± 4.3 mm2, whereas the mean one-third right anterior area of the odontoid process at the same level was 29.3 ± 2.5 mm2. The mean area of the odontoid process and its length and width were similar in men and women (p > 0.05). No significant difference was found in the mean area of the odontoid process in people older than 65 years (94 ± 4.2 mm2) compared to people younger than 65 years (93.3 ± 4.4 mm2; p > 0.05).CONCLUSIONSThe authors identified a new anatomical entity, named the Y-shaped trabecular structure of the odontoid process, on axial CT scans. This structure appears to be the result of bone transformation induced by the elevated dynamic loading at the C1–2 level. The presence of the Y-shaped structure provides new insights into biomechanical responses of C2 under physiological loading and traumatic conditions.

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VESTIBULAR AFFERENTS POPULATION ACTIVATED BY VARIOUS MODES FOR ELICITING OCULAR AND CERVICAL VESTIBULAR-EVOKED MYOGENIC POTENTIALS

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237211002864 ◽

2011 ◽

Vol 23 (06) ◽

pp. 527-532 ◽

Cited By ~ 1

Author(s):

Shou-Jen Wang ◽

Fu-Shan Jaw ◽

Yi-Ho Young

Keyword(s):

Healthy Subjects ◽

Mean Amplitude ◽

Vestibular Evoked Myogenic Potentials ◽

Force Level ◽

Characteristic Parameters ◽

Stimulation Mode ◽

Vestibular Afferents ◽

Significant Difference ◽

The Mean

This study compared cervical and ocular vestibular-evoked myogenic potentials (cVEMPs and oVEMPs) between air-conducted sound (ACS) and bone-conducted vibration (BCV) modes to determine whether these two stimulation modes activate the same population of primary vestibular afferents. Fifteen healthy subjects underwent cVEMP and oVEMP tests using ACS stimuli at 127 dB pe SPL and BCV stimuli at 128 dB force level. The characteristic parameters of cVEMPs and oVEMPs were compared between ACS and BCV modes. The mean p13 and n23 latencies of ACS-cVEMPs were significantly longer than those of BCV-cVEMPs. Likewise, the mean nI and pI latencies for ACS-oVEMPs were also significantly longer than those for BCV-oVEMPs. There was no significant difference in the mean amplitude of cVEMPs between the ACS and BCV modes. However, comparing the oVEMP amplitude, a relationship: (Amplitude of BCV-oVEMP) = 2.3 x (Amplitude of ACS-oVEMP) was demonstrated. In conclusion, the population of primary vestibular afferents activated by ACS and BCV stimuli is similar for cVEMPs. In contrast with oVEMPs, BCV mode activates more number of primary vestibular afferents than ACS mode does. In interpreting oVEMP and cVEMP results, stimulation mode should be checked first.

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The Circadian Rhythm of Copeptin, the C-Terminal Portion of Arginine Vasopressin

Journal of Biomarkers ◽

10.1155/2017/4737082 ◽

2017 ◽

Vol 2017 ◽

pp. 1-5 ◽

Cited By ~ 7

Author(s):

Svetlana Beglinger ◽

Jürgen Drewe ◽

Mirjam Christ-Crain

Keyword(s):

Circadian Rhythm ◽

Healthy Subjects ◽

Prospective Observational Study ◽

Diagnostic Marker ◽

Early Morning ◽

Fasting Period ◽

Mean Values ◽

The Mean ◽

Salt Homeostasis ◽

Minor Extent

Background. Several studies have investigated copeptin as a prognostic marker of different acute diseases and as a diagnostic marker in disorders of water and salt homeostasis. However, no data of the normal circadian rhythm of copeptin in healthy subjects are available. Aim. To investigate the circadian rhythm of copeptin in healthy subjects under standardized conditions. Methods. 19 healthy volunteers aged 18 to 53 years, male and female, were studied in a prospective observational study. In all 19 participants, blood samples for copeptin were taken in regular intervals of 30 minutes for 24 hours after a fasting period of minimum 8 hours. Results. The mean values of copeptin showed a circadian rhythm, similar to that described for AVP release, with a trend towards higher levels (5.9±1 pmol/L) at night and early morning between 4 am and 6 am and lowest levels (2.3±0.2 pmol/L) in the late afternoon between 5 pm and 7 pm. This finding was only observed in individuals with initial higher copeptin levels, whereas in individuals with lower basal copeptin levels no circadian rhythm was observed. Conclusion. There is evidence for a circadian rhythm in copeptin release during 24 hours, however, of minor extent. These findings suggest that copeptin levels can be determined irrespectively of the time of the day.

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Quantitative assessment of choriocapillaris flow deficits in diabetic retinopathy: A swept-source optical coherence tomography angiography study

PLoS ONE ◽

10.1371/journal.pone.0243830 ◽

2020 ◽

Vol 15 (12) ◽

pp. e0243830

Author(s):

Yining Dai ◽

Hao Zhou ◽

Qinqin Zhang ◽

Zhongdi Chu ◽

Lisa C. Olmos de Koo ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Diabetic Retinopathy ◽

Healthy Subjects ◽

Optical Coherence Tomography Angiography ◽

Optical Coherence ◽

Swept Source ◽

Significant Difference ◽

En Face ◽

The Mean

Purpose To quantitatively assess choriocapillaris (CC) flow deficits in eyes with diabetic retinopathy (DR) using swept-source optical coherence tomography angiography (SS-OCTA). Methods Diabetic subjects with different stages of DR and age-matched healthy subjects were recruited and imaged with SS-OCTA. The en face CC blood flow images were generated using previously published and validated algorithms. The percentage of CC flow deficits (FD%) and the mean CC flow deficit size were calculated in a 5-mm-diameter circle centered on the fovea from the 6×6-mm scans. Results Forty-five diabetic subjects and 27 control subjects were included in the study. The CC FD% in diabetic eyes was on average 1.4-fold greater than in control eyes (12.34±4.14% vs 8.82±2.61%, P < 0.001). The mean CC FD size in diabetic eyes was on average 1.4-fold larger than in control eyes (2151.3± 650.8μm2 vs 1574.4±255.0 μm2, P < 0.001). No significant difference in CC FD% or mean CC FD size was observed between eyes with nonproliferative DR and eyes with proliferative DR (P = 1.000 and P = 1.000, respectively). Conclusions CC perfusion in DR can be objectively and quantitatively assessed with FD% and FD size. In the macular region, both CC FD% and CC FD size are increased in eyes with DR. SS-OCTA provides new insights for the investigations of CC perfusion status in diabetes in vivo.

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CHOROIDAL THICKNESS IN PATIENTS WITH DIABETIC MACULAR EDEMA

Pakistan Armed Forces Medical Journal ◽

10.51253/pafmj.v71i2.3286 ◽

2021 ◽

Vol 71 (2) ◽

pp. 433-37

Author(s):

Amash Aqil ◽

Muhammad Moin ◽

Khadijah Abid ◽

Ahsan Mehmood

Keyword(s):

Diabetic Retinopathy ◽

Macular Edema ◽

Diabetic Macular Edema ◽

Choroidal Thickness ◽

Macular Thickness ◽

Control Group ◽

Central Macular Thickness ◽

Department Of Ophthalmology ◽

Significant Difference ◽

The Mean

Objective: To evaluate central macular thickness and choroidal thickness in patients with macular edema due to diabetic retinopathy versus controls. Study Design: Cross-sectional comparative study. Place and Duration of Study: Department of Ophthalmology, Lahore General Hospital, Lahore, from Jan to Jul 2018. Methodology: A retrospective data of 100 eyes from 50 patients having with diabetic macular edema associated with diabetic retinopathy was extracted from hospital registry. Additionally, 100 eyes of 50 individuals without any preexisting ocular conditions, comprising a control group was included in the study. Choroidal thickness measurements were made from the posterior edge of the retinal pigment epithelium to the choroid/sclera junction at subfoveal level using optical coherence tomography. Central macular thickness was also measured for all the enrolled patients. Results: One hundred patients fulfilling the inclusion criteria were enrolled in our study. The mean age was 56.27 ± 14.41 years. The mean Central macular thickness of all the patients were reported as 270.49 ± 72.38 μm, while the choroidal thickness was 284.89 ± 96.51 μm. There was statistically significant difference in central macular thickness between both healthy and diabetic retinopathy with diabetic macular edema groups (p=0.001), whereas insignificant difference existed between the two groups forchoroidal thickness (p=0.735). Conclusion: In patients with diabetic macular edema no significant change in choroidal thickness was observed compared with healthy controls, while the thickness of the retina was high in patients with macular edema due to diabetes.

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Changes in Vessel Density of the Patients with Narrow Antenior Chamber after an Acute Intraocular Pressure Elevation Observed by OCT Angiography

10.21203/rs.2.368/v3 ◽

2019 ◽

Author(s):

ziwei Ma ◽

WENHAN QIU ◽

DANNI ZHOU ◽

WEIHUA YANG ◽

XUEFENG PAN ◽

...

Keyword(s):

Intraocular Pressure ◽

Retinal Vessel ◽

Vessel Density ◽

Significant Difference ◽

Intraocular Pressure Elevation ◽

Acute Elevation ◽

Group A ◽

Prospective Comparative Study ◽

Iop Elevation ◽

Group B

Abstract Background:Although the pathogenesis of glaucoma is not fully understood ,an elevated intraocular pressure (IOP) is a major factor contributing to its development and progression. The aim of this study was to investigate the changes in the vessel densities of the macula and optic nerve head (ONH) after an acute elevation in the intraocular pressure (IOP) observed using optical coherence tomography angiography (OCTA). Methods: This was a prospective comparative study of subjects with narrow anterior chamber angles who underwent laser peripheral iridotomies (LPIs). The IOP was measured before and one hour after the LPI. The retinal vessel densities of the macula and ONH were measured using OCTA at the baseline and one hour after the LPI. Results: A total of 64 eyes of 51 individuals were enrolled in this study, and 58 eyes of 43 individuals finally completed the study with a mean IOP rise of 10.5 ± 7.6 mmHg after the LPI. Based on the magnitude of the rise in the IOP, we divided the subjects into three groups: group A = IOP rise ≤ 10 mmHg, group B = 10 mmHg < IOP rise ≤ 20 mmHg, and group C = IOP rise > 20 mmHg. The vessel density did not differ after the acute IOP elevation in either the macular region or papillary region in group A or group B (p > 0.05), but there was a significant difference in group C (p < 0.05). However, when the subjects were not separated into groups, the vessel densities of the ONH and macular region did not differ between the measurements obtained at the baseline and one hour after the LPI (p>0.05). The correlation existed in peripapillary and macular vessel density (p < 0.05). Conclusion: In these subjects with narrow antenior chamber, an acute mild or moderate IOP elevation for one hour after the LPI did not affect the vessel density in the macula or ONH, as examined using OCTA. However, when the IOP rise was greater than 20 mmHg, the macular and papillary vessel density decreased significantly.

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Subfoveal Choroidal Thickness and Treatment Outcomes of Intravitreal Aflibercept for Branch Retinal Vein Occlusion

Life ◽

10.3390/life11060572 ◽

2021 ◽

Vol 11 (6) ◽

pp. 572

Author(s):

Yoshihito Sakanishi ◽

Syu Morita ◽

Keitaro Mashimo ◽

Kazunori Tamaki ◽

Nobuyuki Ebihara

Keyword(s):

Treatment Outcomes ◽

Retinal Vein Occlusion ◽

Branch Retinal Vein Occlusion ◽

Choroidal Thickness ◽

Foveal Thickness ◽

Subfoveal Choroidal Thickness ◽

Vein Occlusion ◽

Significant Difference ◽

Intravitreal Aflibercept ◽

The Mean

We aimed to investigate the relationship between subfoveal choroidal thickness (SCT) and treatment outcomes of intravitreal aflibercept (IVA) for macular edema (ME) due to branch retinal vein occlusion (BRVO). We retrospectively evaluated 46 patients with treatment-naive BRVO-ME who underwent IVA treatment between March 2016 and February 2017. There was no significant difference in visual acuity within 6 months (0.29 ± 0.20 vs. 0.27 ± 0.19, p = 0.338), the mean central foveal thickness improvement (332.0 ± 162.2 μm vs. 303.9 ± 166.6 μm, p = 0.492), and the mean number of IVA injections (1.7 ± 0.7 vs. 1.6 ± 0.7 times, p = 0.658) between the SCT thickened (n = 26 patients, 26 eyes) and SCT non-thickened groups (n = 20 patients, 20 eyes). The rate of ME recurrence was significantly lower in the SCT decreased group (6/17 eyes (35.2%) vs. 19/30 eyes (63.3%); p = 0.038). In conclusion, pretreatment choroidal thickening does not affect the therapeutic effect of IVA for BRVO, but ME recurrence was lower in cases of treatment-related choroidal thinning. Thus, changes in SCT may be a therapeutic indicator of IVA for acute BRVO.

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