Age-Related Differences in Central Corneal Thickness Alterations Caused by Short-Term Hypobaric Hypoxia

Cornea ◽  
2009 ◽  
Vol 28 (2) ◽  
pp. 136-139 ◽  
Author(s):  
Remzi Karadag ◽  
Ahmet Sen ◽  
Haydar Golemez ◽  
Hikmet Basmak ◽  
Nilgun Yildirim ◽  
...  
Keyword(s):  
Hypobaric Hypoxia ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Short Term ◽  
Age Related

scholarly journals Analysis of Lens Thickness Distribution Based on Swept-Source Optical Coherence Tomography (SS-OCT)

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Xi Feng ◽  
Yong Wang ◽  
Jianheng Liang ◽  
Yali Xu ◽  
Julio Ortega-Usobiaga ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Negative Correlation ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Biometric Data ◽  
Swept Source ◽  
Age Related ◽  
Cataract Patients

Objective. This study aimed to analyze the distribution of lens thickness (LT) and its associations in age-related cataract patients based on swept-source optical coherence tomography (SS-OCT). Methods. This cross-sectional study included 59,726 Chinese age-related cataract patients. Only right-eye data were included in the study. Repeated measures of ocular parameters were performed using an IOL Master 700 device. The distributions of ocular biometric data including anterior chamber depth (ACD), LT, axial length (AL), central corneal thickness (CCT), white-to-white (WTW), and mean keratometry (MK) and their associations with age were assessed. The anterior segment (AS) was measured as the sum of CCT, ACD, and LT, while the vitreous chamber depth (VCD) was calculated as the difference between AL and AS. The values of LT : AL, AS : AL, and VCD : AL in different AL groups and their changes are the main outcome measures used to observe the proportion of the anterior and posterior segments of the eye. Results. Biometric data were available for 59,726 individuals. The mean age was 68.81 years (range = 40–100); 40.62% were male and 59.38% were female. Mean anterior chamber depth (ACD) was 3.02 ± 0.44 mm, mean LT was 4.51 ± 0.44 mm, mean axial length (AL) was 23.89 ± 1.92 mm, mean central corneal thickness (CCT) was 0.53 ± 0.03 mm, mean white-to-white (WTW) was 11.64 ± 0.44 mm, and mean keratometry (MK) was 44.27 ± 1.65 diopter. Female patients had shorter AL, shallower ACD, smaller CCT and WTW, decreased LT, and steeper corneas ( p  < 0.005). ACD revealed the strongest negative correlation ( p  ≤ 0.001, r = –0.682) with LT. Age ( p  ≤ 0.001, r = 0.348) showed a moderate positive correlation, whereas MK ( p  ＜ 0.05, r = 0.011), CCT ( p  ≤ 0.001, r = 0.041) had a weak positive correlation and WTW ( p  ≤ 0.001, r = –0.034) had a weak negative correlation with LT. A nonlinear correlation was found between LT and AL. LT increased with age in both males and females. LT changed variably in eyes with AL less than 27 mm, LT decreased as AL increased, then LT gradually increased as AL increased in extremely long and extra-long eyes ( p  ≤ 0.001). LT : AL and AS : AL decreased as AL increased, VCD : AL gradually increased as AL increased in highly myopic eyes, and VCD : AL increased by about 0.01 for every 1 mm increase in AL. Conclusions. Among Chinese age-related cataract patients, we found LT to have the strongest relation with ACD. The lens was thicker in elderly patients and women. The correlation between LT and AL is not a simple negative correlation; with the increase of age, LT decreases first and then increases. The proportion of VCD is constantly rising with the elongation of AL.

scholarly journals Correlation between corneal thickness, keratometry, age, and differential pressure difference in healthy eyes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ahmet Colakoglu ◽  
Iffet Emel Colakoglu ◽  
Cemile Banu Cosar
Keyword(s):  
Pressure Difference ◽  
Central Corneal Thickness ◽  
Dynamic Range ◽  
Linear Regression Analysis ◽  
Corneal Thickness ◽  
Positive Association ◽  
Differential Pressure ◽  
Corneal Curvature ◽  
Age Related ◽  
Department Of Ophthalmology

AbstractTo determine the use of differential pressure difference (DPD), in air-puff differential tonometry, as a potential biomechanical measure of the cornea and elucidate its relationship with the intraocular pressure (IOP), central corneal thickness, corneal curvature, and age. This study comprised 396 eyes from 198 patients and was conducted at Acibadem University, School of Medicine, Department of Ophthalmology, Istanbul, Turkey. The central corneal curvature and refraction of the eyes were measured using an Auto Kerato-Refractometer (KR-1; Topcon Corporation, Tokyo, Japan). IOP and central corneal thickness were measured using a tono-pachymeter (CT-1P; Topcon Corporation, Tokyo, Japan), wherein two separate readings of IOP were obtained using two different modes: 1–30 and 1–60. The difference between these two readings was recorded as the DPD. The factors affecting the DPD were determined by stepwise multiple linear regression analysis. DPD varied over a dynamic range of − 3.0 to + 5.0 mmHg and was weakly correlated with the central corneal thickness (r = 0.115, p < 0.05). DPD showed no significant correlation with IOP 1–30 (p > 0.05). A weak but statistically significant (p < 0.05) positive correlation of DPD was observed with age (r = 0.123), Kavg (r = 0.102), and the CCT (r = 0.115). There was a significant correlation between DPD and Kavg, CCT, and age. There was no significant correlation between DPD and IOP 1–30. Age-related changes in the corneal ultrastructure may be a plausible explanation for the weak positive association between age and DPD. The proposed method may prove a valid non-invasive tool for the evaluation of corneal biomechanics and introduce DPD in the decision-making of routine clinical practice.

scholarly journals Short-term variation of central corneal thickness and axial anterior chamber depth of healthy eyes using Scheimpflug photography via the Oculus Pentacam*

2009 ◽  
Vol 68 (1) ◽  
Author(s):  
S. D. Mathebula
Keyword(s):  
Anterior Chamber ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Small Variation ◽  
Short Term ◽  
Corneal Scarring ◽  
Term Variation ◽  
Standard Deviations ◽  
The Individual

The purpose of this study was to investigate short-term variation and intra-subject repeatabil-ity of  human central corneal thickness (CCT) and axial anterior chamber depth (AACD) measure-ments obtained using the Oculus Pentacam. Forty consecutive images of the right eye of the anteriorsegment of 10 young and healthy individuals were measured with the Pentacam. Measurements of CCT and AACD were ob-tained from these images and means, standard deviations,variances and repeatability of the measurements were investigated. Both parameters (CCTand AACD) showed small variation with good orexcellent repeatability for all eyes. The inter-subject or overall means and standard deviations for CCT and AACD of the 10 right eyes were 0.555 ±0.05 millimeters (or 555 ± 50 microns) and 3.206± 0.04 millimeters, respectively. The individual or intra-subject averages for samples of CCT and AACD measurements are also provided in this paper. Univariate normality of the data was explored with Kolmogorov-Smirnov, Lilliefors and ShapiroWilks tests and we found that generally the data was normally distributed although there were some exceptions. Based on the results of this study, the Oculus Pentacam appears to provide repeatable and reliable measures for both CCT and AACD in young,normal eyes. Further research is, however, needed to determine short-term variation and repeatability of CCT and AACD with the Pentacam in more com-plicated eyes with, say, corneal scarring or ectasia or where refractive surgery may be an issue.

scholarly journals Short-term variation of central corneal thickness measurements in keratoconus using the Tono- Pachymeter NT530P (Tonopachy™)

2012 ◽  
Vol 71 (3) ◽  
Author(s):  
K. P. Mashige ◽  
O. A. Oduntan ◽  
N. M. Gcabashe
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Short Term ◽  
Mean Values ◽  
Term Variation ◽  
Kolmogorov Smirnov ◽  
Good Repeatability ◽  
Standard Deviations ◽  
The Right ◽  
Thickness Measurements

Repeatability of values is a crucial reliability index in any instrument used to measure ocular parameters. The purpose of this study was to investigate short-term variability of central corneal thickness (CCT) measurements in keratoconic eyes. The Tono-Pachymeter NT530P (Tonopachy™) was used to take fifty successive automatic measurements of CCT of the right eyes of ten keratoconic subjects(six females and four males), aged 19 to 41 years (mean = 30.4 ± 6.8 years). The means, standard deviations and variances of the measurements showed little variation with good repeatability. Theinter-subject or overall mean values and standard deviations of the measurements were 452.1 ± 30.3 μm. The Kolmogorov-Smirnov (K-S), Lilliefors and Shapiro-Wilks (S-W) tests showed that gener-ally the data was normally distributed, with a few exceptions. The results of this study suggest that over short periods of time, the Tonopachy™ provides repeatable measures of CCT in keratoconic corneas. (S Afr Optom 2012 71(3) 102-108)

Central Corneal Thickness in Patients With Neovascular Age-Related Macular Degeneration

Cornea ◽  
2007 ◽  
Vol 26 (2) ◽  
pp. 182-184 ◽  
Author(s):  
George D Kymionis ◽  
Theoni D Panagiotoglou ◽  
Sonia H Yoo ◽  
Nikolaos S Tsiklis ◽  
Emmanouel Christodoulakis ◽  
...  
Keyword(s):  
Macular Degeneration ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Age Related Macular Degeneration ◽  
Age Related

scholarly journals Effect of short-term orthokeratology lens or ordinary frame glasses wear on corneal thickness, corneal endothelial cells and vision correction in adolescents with low to moderate myopia

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Shuyi Yuan ◽  
Shuxian Zhang ◽  
Yanglin Jiang ◽  
Lihua Li
Keyword(s):  
Endothelial Cells ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Control Group ◽  
Corneal Curvature ◽  
Corneal Endothelial Cells ◽  
Short Term ◽  
Naked Eye ◽  
Vision Correction ◽  
Experimental Group

Abstract Background We aimed to investigate the effect of short-term orthokeratology lens or frame glasses wear on corneal thickness, corneal endothelial cells and vision correction in adolescents with low to moderate myopia. Methods Data of 100 adolescents with low to moderate myopia were retrospectively analyzed. The patients were assigned into two groups. The experimental group were treated with night-wear orthokeratology lens, and control group were treated with ordinary frame glasses. Follow up was carried out at the 3rd, 6th and 12th months of treatment. The naked-eye vision, diopter, corneal curvature, intraocular pressure, axial length, endothelial cell count and central corneal thickness were examined. Complications within 12 months were observed, and corneal fluorescein staining was graded. Results The naked-eye vision of the experimental group was significantly higher than that of the control group at the 3rd, 6th and 12th months, while the diopter of the experimental group was significantly lower than that of the control group at these time points. The corneal curvature of the experimental group was significantly decreased when comparing with that of the control group at the above 3 time points. The increase of axial length in the experimental group was significantly less than that in the control group at the 6th and 12th months. Conclusions Short-term orthokeratology lens wear can effectively improve the naked-eye vision in adolescents with low to moderate myopia without significant impact on the central corneal thickness and corneal endothelial cells. It is a relatively safe method to correct myopia.

scholarly journals Age-Related Variations of Rabbit Corneal Geometrical and Clinical Biomechanical Parameters

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Haixia Zhang ◽  
Xiao Qin ◽  
Xiaomeng Cao ◽  
Di Zhang ◽  
Lin Li
Keyword(s):  
Intraocular Pressure ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Curvature Radius ◽  
Geometrical Parameters ◽  
Corneal Curvature ◽  
Corneal Resistance Factor ◽  
Upward Trend ◽  
Age Related ◽  
Biomechanical Parameters

Purpose. To study the variations in corneal clinical biomechanical parameters (CCBP) and corneal geometrical parameters of rabbit in relation to age. Methods. Rabbits aged 3, 7, 12, 18, and 24 months were enrolled. Each eye of the rabbits was tested with Ocular Response Analyzer (ORA), Optical Coherence Tomography (OCT), and Pachymeter to obtain the intraocular pressure (IOP): Goldmann-correlated IOP (IOPg) and Corneal Compensated Intraocular Pressure (IOPcc); CCBP: Corneal Hysteresis (CH) and Corneal Resistance Factor (CRF); corneal geometric parameters: corneal curvature radius (CCR) and central corneal thickness (CCT). Results. The IOP of the rabbits changes slightly from 3 to 7 months of age, while it significantly decreases from 7 to 18 months of age and increases from 18 to 24 months of age; CH and CRF decrease with the increase of age; CCT increases from 7 to 18 months and decreases from 3 to 7 months of age and from 18 to 24 months of age; CCR presents an upward trend from 3 to 18 months and a significant decrease between 18 and 24 months of age. Conclusion. CH and CRF are negatively correlated with age. CCT and CCR are positively correlated with age.

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