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)

scholarly journals Short-term variation in central corneal thick- ness and intraocular pressure using the Tono-Pachymeter NT530P (Tonopachy™)

2012 ◽  
Vol 71 (1) ◽  
Author(s):  
R. M. Mashige ◽  
N. Rampersad
Keyword(s):  
Statistical Tests ◽  
Corneal Thickness ◽  
Short Term ◽  
Individual Measurement ◽  
Mean Values ◽  
Term Variation ◽  
Kolmogorov Smirnov ◽  
Ocular Pressure ◽  
Standard Deviations ◽  
The Right

Measurements of central corneal thickness (CCT) and intra-ocular pressure (IOP) are important for both diagnostic and therapeutic purposes. The aim of this study was to investigate the short-term variation and intra-subject repeatability of CCT and IOP measurements made with the Tono-Pachymeter NT530P (Tonopachy™). Fifty one consecutive automatic measurements of CCT and IOP were taken for the right eyes of 15 subjects (11 females and 4 males) aged 20 to 57 years (mean = 32.3 ± 13.5 years). The measured values (CCT and IOP) were compared against each other to establish the intra-subject repeatability and bias of each individual measurement with respect to the means, standard deviations and variances. Three different  statistical tests of normality: Kolmogorov-Smirnov (K-S),Lilliefors and Shapiro-Wilks (SW) tests suggested that most of the data was normally distributed,with a few exceptions. The inter-subject or overall mean values and standard deviations for the CCT and IOP samples were 528.2 ± 27.4 μm and 14.4 ±4.3 mmHg respectively. Although possible outliers increased the variability of the measurements of both parameters (CCT and IOP), the data generally showed good repeatability. The results of this study suggest that over short periods of time, the Tonopachy™ gives precise and repeatable measures of CCT and IOP. (S Afr Optom 2012 71(1)12-21) 

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 Assessment of corneal biomechanics, tonometry and pachymetry with the Corvis ST in myopia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaorui Wang ◽  
Colm McAlinden ◽  
Hongbing Zhang ◽  
Jie Yan ◽  
Dan Wang ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Poor Agreement ◽  
Limits Of Agreement ◽  
Corvis St ◽  
Good Repeatability ◽  
Mean Differences ◽  
Repeatability Limit ◽  
The Right

AbstractTo evaluate the repeatability of Corvis ST corneal biomechanical, tonometry and pachymetry measurements, and agreement of pachymetry measures with the Pentacam HR and RTVue OCT. Three consecutive measurements of the right eye of 238 myopic subjects were acquired with the Corvis ST, Pentacam HR, and RTVue OCT. Repeatability of Corvis ST was evaluated by within-subject standard deviation [Sw] and repeatability limit [r]. The agreement of central corneal thickness (CCT) measurements were compared among the three instruments using the Bland–Altman limits of agreement. Comparisons were further stratified by CCT (Corneathin ≤ 500 µm; Corneanormal = 500–550 µm; Corneathick > 550 µm). Sw was below 1 mmHg in Corneathin, Corneanormal, and Corneathick groups for IOP and bIOP. Sw for SP-A1 were 4.880, 6.128, 7.719 mmHg/mm respectively. Sw for CBI were 0.228, 0.157, 0.076, and correspondingly Sw for TBI and SSI were 0.094 and 0.056, 0.079 and 0.053, 0.070 and 0.053. The Bland–Altman plots for CCT implied poor agreement with mean differences of 29.49 µm between Corvis and OCT, 9.33 µm between Pentacam and OCT, and 20.16 µm between Corvis and Pentacam. The Corvis ST showed good repeatability with the exception of CBI in the various CCT groups. The CCT measured by Corvis ST was not interchangeable with Pentacam HR and RTVue OCT.

scholarly journals Reproducibility of Central Corneal Thickness Measurements in Healthy and Glaucomatous Eyes

2017 ◽  
Vol 26 (9) ◽  
pp. 787-791 ◽  
Author(s):  
Tony Realini ◽  
Matthew J. Gurka ◽  
Robert N. Weinreb
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Thickness Measurements

scholarly journals Effect of Desonide 0.25% Ophthalmic Solution on Central Corneal Thickness and Intraocular Pressure of Patients with Allergic Conjunctivitis

1970 ◽  
Vol 12 (3) ◽  
pp. 156-158
Author(s):  
Ozlem Gurses Sahin
Keyword(s):  
Intraocular Pressure ◽  
Allergic Conjunctivitis ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Ophthalmic Solution ◽  
Applanation Tonometry ◽  
Goldmann Applanation Tonometry ◽  
Mean Values ◽  
Conjunctival Hyperaemia ◽  
Significant Difference

Aim: To evaluate whether a significant difference exists between the initial and final mean central corneal thickness that might affect Goldmann applanation tonometer recordings of patients with allergic conjunctivitis treated with desonide 0.25% ophthalmic solution, and to determine the effect of desonide on intraocular pressure by using adjusted intraocular pressure values.Methods: This double-blind randomised placebo-controlled trial enrolled 30 patients (60 eyes) with allergic conjunctivitis. Patients were randomly assigned to receive desonide to 1 eye (study eye) and preservative-free tear supplement (Tears Naturale Free®) to the other eye (control eye) 3 times daily for 3 weeks. Goldmann applanation tonometry and central corneal thickness of both eyes were recorded on the day of presentation and 3 weeks later.Results: Regression of itching, tearing, conjunctival hyperaemia, and tarsal conjunctival papillary reaction were noted in the study eyes after 3 weeks of treatment. The control eyes showed mild regression of pruritis, tearing, conjunctival hyperaemia, and tarsal conjunctival papillary reaction after 3 weeks. There was a significant difference between the initial and final mean central corneal thickness values for the study eyes (p = 0.003). There were no statistically significant differences between the initial and final mean values of Goldmann applanation tonometry and adjusted intraocular pressure for the study eyes. No statistically significant differences were found between the initial and final mean values of any of the parameters for the control eyes.Conclusion: Inflammation-induced increase in central corneal thickness of patients with allergic conjunctivitis treated with desonide showed statistically significant regression. However, this regression did not significantly affect Goldmann applanation tonometry and adjusted intraocular pressure values of the treated eyes.

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