Ocular Outcomes in Healthy Subjects Undergoing a Short-Term Head-Down Tilt Test

2021 ◽  
Vol 92 (8) ◽  
pp. 619-626
Author(s):  
Bahadr zelbaykal ◽  
Gkhan retmenolu ◽  
. Hakk Tunez
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Healthy Subjects ◽  
Corneal Thickness ◽  
Age Groups ◽  
Vessel Density ◽  
Tilt Test ◽  
Short Term ◽  
Disc Area ◽  
Before And After

PURPOSE: This study aimed to examine the effect of head-down tilt (HDT) on vascular autoregulation in different age groups anddetermine its effects on intraocular pressure (IOP) and central corneal thickness (CCT).METHODS: Included were 43 eyes of 23 men. The optic nerve head and parafoveal vascular densities were measured by optical coherence tomography angiography before and after 20 min 10 HDT. Also, the study comprised an examination of theIOP and CCT in a subset of 8 participants (14 eyes) in the sitting position and during 15 min of 10 HDT.RESULTS: Grid-based inside disc all-vessel density (GBID) was statistically significantly lower after the HDT test in subjects under 30 yr (1.26). Whole image and peripapillary capillary vessel density (WICVD, PCVD), and whole image and peripapillary all-vessel density (WIAVD, PAVD) were significantly higher after the HDT test in subjects ages 3039 yr (1.34, 2.16, 1.05, 1.72, respectively). Inside disc capillary, all-vessel density (IDCVD, IDAVD) and GBID were significantly higher after HDT in subjects over 40 yr (2.48, 2.15, 1.52, respectively). In a subset of eight participants, IOP was significantly higher (3.7 mmHg) and CCT was unchanged after 15 min of HDT.CONCLUSION: Our study showed that simulated microgravity induced optic nerve head vessel density at the inside disc area, especially in persons over 40 years. In addition, IOP was increased by HDT, although no change in CCT was observed.zelbaykal B, retmenolu G, Tunez H. Ocular outcomes in healthy subjects undergoing a short-term head-down tilt test. Aerosp Med Hum Perform. 2021; 92(8):619626.

Short-term effect of weight loss after bariatric surgery on IOP, RNFL thickness, and the optic nerve head blood flow measured by OCTA

2021 ◽  
pp. 112067212110483
Author(s):  
Malak I ElShazly ◽  
Kareem B Elessawy ◽  
Marwa M Salama
Keyword(s):  
Bariatric Surgery ◽  
Blood Flow ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Weight Reduction ◽  
Vessel Density ◽  
Ganglion Cell Complex ◽  
Obese Patients ◽  
Short Term ◽  
Rnfl Thickness

Purpose: To study the influence of weight reduction after bariatric surgery on the intraocular pressure (IOP), retinal nerve fiber layer (RNFL) thickness, and blood flow of optic nerve head by optical coherence tomography angiography (OCTA). Methods: This prospective observational cohort study included 60 obese patients. Body mass index (BMI), IOP, RNFL, and ganglion cell complex (GCC) thickness, rim area, and radial peripapillary capillary (RPC) vessel density were assessed before and 3 months after bariatric surgery. Results: The BMI and the IOP showed significant postoperative reduction to 40.45 ± 4.3 kg/m2 and 14.83 ± 2.5 mmHg while the preoperative results were 51.13 ± 4.83 kg/m2 and 16.95 ± 4.2 mm ( p < 0.0001), respectively. No statistically significant change was detected in the RNFL, GCC thickness, rim area, or the RPC vessel density ( p > 0.05). No statistically significant correlation was detected between the BMI changes and changes in the IOP, RNFL thickness, rim area, GCC thickness, or RPC vessel density. Conclusion: No significant effect of bariatric surgery on the RNFL thickness and the optic nerve head blood flow measured by OCTA despite a significant IOP reduction 3 months post-surgical. OCTA can be a useful tool to assess the short-term influence of significant weight reduction on the retinal microcirculation. Summary: Despite a significant BMI and IOP reduction following bariatric surgery in obese patients, the vascular flow of the ONH, measured by OCTA, and the RNFL thickness were not significantly affected. The former might be attributed to the complex autoregulatory mechanisms related to the ONH and its microcirculation.

Peripapillary and optic nerve head vessel density of glaucoma and healthy subjects from Afro-Caribbean and European descent: A pilot study

2021 ◽  
Author(s):  
L. Salazar-Quiñones ◽  
C. Yu-Wai-Man ◽  
A. De Antonio Ramirez ◽  
C.D. Méndez-Hernández ◽  
A. Daas ◽  
...  
Keyword(s):  
Pilot Study ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Healthy Subjects ◽  
Vessel Density ◽  
European Descent

scholarly journals P1277EFFECT OF HEMODIALYSIS ON PERIPAPILLARY CHOROIDAL THICKNESS AND OPTIC NERVE HEAD PARAMETERS MEASURED BY SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY

2020 ◽  
Vol 35 (Supplement_3) ◽  
Author(s):  
Won June Lee ◽  
Yong Un Shin ◽  
Mincheol Seong
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Choroidal Thickness ◽  
Optical Coherence ◽  
Swept Source ◽  
Peripapillary Choroidal Thickness ◽  
Disc Area ◽  
Software Changes ◽  
Before And After ◽  
End Stage

Abstract Background and Aims To investigate the effect of hemodialysis (HD) on peripapillary choroidal thickness (PCT) and optic nerve head (ONH) parameters by swept-source optical coherence (SS-OCT) and other ophthalmologic parameters in patients with end-stage kidney disease (ESKD). Method A prospective observational study was performed on 29 patients who underwent HD for ESKD. Detailed ophthalmologic examinations and SS-OCT were performed immediately before and after HD. The PCT were measured using the modification tool in the built-in OCT image viewer program. The ONH parameters including rim area (RA) and vertical cup-to-disc ratio (VCDR) were obtained using built-in software. Changes in PCT, and ONH parameters before and after HD were statistically analyzed. Results Average PCT significantly decreased from 127.3 ± 49.2 before HD to 117.1 ± 50.9 after HD (P&lt;0.001). The RA increased and VCDR decreased significantly after HD (P=0.001 and P=0.027, respectively). Disc area did not show significant change after HD (P=0.648). Significant correlation was found between changes in PCT and changes in macular choroidal thickness (rho=0.547, P=0.002). Conclusion We observed significant decrease in PCT and significant changes in ONH parameters after HD. Our study suggest that HD can give influence on the ONH and its surrounding structure.

Optic Nerve Head Perfusion Before and After Intravitreal Antivascular Growth Factor Injections Using Optical Coherence Tomography-based Microangiography

2019 ◽  
Vol 28 (3) ◽  
pp. 188-193 ◽  
Author(s):  
Joanne C. Wen ◽  
Chieh-Li Chen ◽  
Kasra A. Rezaei ◽  
Jennifer R. Chao ◽  
Atma Vemulakonda ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Nerve ◽  
Growth Factor ◽  
Optic Nerve Head ◽  
Optical Coherence ◽  
Before And After

Subcellular localization-dependent decrements in skeletal muscle glycogen and mitochondria content following short-term disuse in young and old men

2010 ◽  
Vol 299 (6) ◽  
pp. E1053-E1060 ◽  
Author(s):  
Joachim Nielsen ◽  
Charlotte Suetta ◽  
Lars G. Hvid ◽  
Henrik D. Schrøder ◽  
Per Aagaard ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Glycogen ◽  
Vastus Lateralis ◽  
Age Groups ◽  
Quadriceps Muscle ◽  
Fiber Types ◽  
Short Term ◽  
Skeletal Muscle Glycogen ◽  
Before And After ◽  
Old Men

Previous studies have shown that skeletal muscle glycogen and mitochondria are distributed in distinct subcellular localizations, but the role and regulation of these subcellular localizations are unclear. In the present study, we used transmission electron microscopy to investigate the effect of disuse and aging on human skeletal muscle glycogen and mitochondria content in subsarcolemmal (SS), intermyofibrillar (IMF), and intramyofibrillar (intra) localizations. Five young (∼23 yr) and five old (∼66 yr) recreationally active men had their quadriceps muscle immobilized for 2 wk by whole leg casting. Biopsies were obtained from m. vastus lateralis before and after the immobilization period. Immobilization induced a decrement of intra glycogen content by 54% ( P < 0.001) in both age groups and in two ultrastructurally distinct fiber types, whereas the content of IMF and SS glycogen remained unchanged. A localization-dependent decrease ( P = 0.03) in mitochondria content following immobilization was found in both age groups, where SS mitochondria decreased by 33% ( P = 0.02), superficial IMF mitochondria decreased by 20% ( P = 0.05), and central IMF mitochondria remained unchanged. In conclusion, our findings demonstrate a localization-dependent adaptation to immobilization in glycogen and mitochondria content of skeletal muscles of both young and old individuals. Specifically, this suggests that short-term disuse preferentially affects glycogen particles located inside the myofibrils and that mitochondria volume plasticity can be dependent on the distance to the fiber border.

The Effect of beta-Thalassemia Minor on the Optic Nerve Head Analysis.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3831-3831 ◽  
Author(s):  
Turker Cetin ◽  
Fatih M. Mutlu ◽  
Ferit Avcu ◽  
Tarkan Mumcuoglu ◽  
Oral Nevruz ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Optic Nerve Head ◽  
Beta Thalassemia ◽  
Fiber Layer ◽  
Topographic Analysis ◽  
Nerve Fiber Layer Thickness ◽  
Neuroretinal Rim ◽  
Thalassemia Minor ◽  
Disc Area ◽  
Area And Volume

Abstract Background: A variety of ophthalmologic findings have been reported in patients with anemia. Aim: To determine the effect of beta-thalassemia minor on the optic nerve head topographic analysis. Methods: A total of 39 beta-thalassemia minor patients were divided into 2 groups. Patients with iron, folic acid, or vitamin B12 deficiency were ruled out. Group 1 comprised 20 patients with anemia, and group 2 comprised 19 patients without anemia. One eye of each patient was included into the study. All subjects underwent complete ocular examination. Optic nerve head topographic analysis was performed by using a confocal scanning laser ophthalmoscope type Heidelberg retina tomograph (HRT). The following stereometric parameters were evaluated: disc area, area and volume of cup, area and volume of neuroretinal rim, measure of cup shape, and mean retinal nerve fiber layer thickness. Results: The mean age of group 1 and 2 were 26.8±7.6 and 25.6±4.5 years, respectively (P=0.91). Their mean disc areas were 2.01±0.3 mm2 and 2.53±0.6 mm2, respectively (P =0.009). The differences between groups for area and volume of cup, area and volume of neuroretinal rim, cup shape measure, and mean retinal nerve fiber layer thickness were insignificant (p>0.05). There was no significant difference between mean intraocular pressure of both groups (p=0.93). Conclusion: In beta-thalassemia minor, patients with anemia, optic disc area showed a statistically significant reduction compared to the patients without anemia. Further clinical trials on ocular blood flow and optic nerve oxygenation changes may highlight the role anemia in the optic nerve head of the beta-thalassemia minor patients.

scholarly journals Short-Term Changes in the Anterior Segment and Retina after Small Incision Lenticule Extraction

2020 ◽  
Author(s):  
Yanwei Chen ◽  
Huaping Liao ◽  
Yue Sun ◽  
Xi Shen
Keyword(s):  
Layer Thickness ◽  
Optic Disc ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Vessel Density ◽  
Small Incision Lenticule Extraction ◽  
Short Term ◽  
Small Incision ◽  
Lenticule Extraction

Abstract Background: To analyse short-term changes in the anterior segment and retina after small incision lenticule extraction (SMILE).Methods: Patients with myopia scheduled for SMILE were recruited from Ruijin Hospital, Shanghai, China. Basic patient information such as age, sex, and refractive errors was recorded. Ocular measurements were taken before surgery, and 1 day and 1 week after surgery; they included axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), white to white (WTW), pupil diameter (PD), macular thickness (MT), ganglion cell layer thickness (GCL), retinal nerve fiber layer thickness (RNFL), choroidal thickness (CT), macular vessel density, and optic disc vessel density.Results: Sixty-one eyes of 31 patients were selected for this study. AL, CCT, ACD, and postoperative PD were significantly reduced (p<0.05), while LT was thickened after surgery (p<0.05). MT at the fovea decreased 1 day and 1 week after surgery (p<0.05). GCL showed no significant changes after surgery. RNFL was unchanged 1 day after surgery, but the inferior sector was thickened 1 week after surgery. CT was thicker at the fovea 1 day after surgery and 1.0 mm from the fovea in the nasal sector 1 week after surgery. Macular vessel density was significantly decreased 1 day after surgery and most recovered in 1 week. Optic disc vessel density decreased at the peripapillary part 1 day after surgery and recovered after 1 week. 𝜟ACD and 𝜟LT showed no significant correlation 1 day after surgery. 𝜟ACD was negatively correlated with 𝜟LT and sphere 1 week after surgery (r=-0.847, p<0.000; r=-0.398, p=0.002). 𝜟LT was positively correlated with the sphere 1 week after surgery (r=0.256, p=0.048).Conclusion: The anterior segment was the most affected, while the retina also underwent changes with regard to MT, RNFL, CT, macular vessel density, and peripapillary vessel density.

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