scholarly journals Reference values of the central corneal thickness with different refractive errors for the adult Egyptian population

2020 ◽  
Author(s):  
Amr A. Gab-Alla
Keyword(s):  
Reference Values ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Cross Sectional Study ◽  
Refractive Errors ◽  
Spherical Equivalent ◽  
Sectional Study ◽  
Cross Sectional ◽  
Egyptian Population ◽  
The Mean

Abstract Background: To generate reference values of the central corneal thickness (CCT) with different refractive errors for the adult Egyptian population. Methods: A retrospective, observational, and cross-sectional study of 2200 eyes in 1166 subjects scheduled for LASIK, who came to private refractive eye center, Ismailia, Egypt. The study period was from January 2018 to January 2020. The subjects were divided into a broad range of myopia with spherical equivalent (SE) <-0.5D and hyperopia SE> +0.5D. Then, the myopic eyes divided into low (SE>-3.0D), moderate (SE-3.0D to >-6.0D), and high (SE<-6.0D). Similarly, the hyperopic eyes were divided into low (SE<+3.0 D) and moderate (SE+3.0D to <+6.0D) and high >+6.0D. The refractive error was measured by an auto-refractometer (Topcon, Tokyo Optical Co., Ltd., Japan), and CCT was measured using Sirius (CSO, Florence, Italy). Results: The data of 1100 myopic eyes in 556 subjects (30.5% males and 69.5% females) and 1100 hyperopic eyes in 610 subjects (33.6% males and 66.4% females). The mean+SD of CCT for the total myopic subjects was 531.98+32.92μm, range (406 to 636μm). The mean+SD of SE was -4.1±2.5D, range (-0.5 to -12.0D). The mean+SD of CCT for the total hyperopic subjects was 529±38.8μm, range (448 to 619 μm). The mean+SD of SE was +3.65+1.97D, range (+0.5 to +8.5D).Conclusion: In this study, the mean of CCT of the Egyptian population was 531.9 μm for myopic and 529μm for hyperopic subjects respectively. The myopic and hyperopic subjects show a reduction in CCT with age. Females have a thinner cornea than males, 23.6% of the myopic eyes, and 16.5% of the hyperopic eyes have CCT less than 500μm.

scholarly journals ADULT MYOPES

2018 ◽  
Vol 25 (11) ◽  
pp. 1660-1666
Author(s):  
NuhaMohamed Fath Elrahman ◽  
AbdElaziz Mohamed Elmadina ◽  
Manzoor Ahmad Qureshi ◽  
Adil Mousa Younis ◽  
Muhammad Ijaz Ahmad ◽  
...  
Keyword(s):  
Axial Length ◽  
Corneal Thickness ◽  
Cross Sectional Study ◽  
Age Group ◽  
Spherical Equivalent ◽  
Corneal Curvature ◽  
Sectional Study ◽  
Cross Sectional ◽  
Gender And Age ◽  
The Mean

Objectives: This study aimed to explore the correlation of central cornealthicknesses (CCT), mean keratometry (KM) and axial length (AL) to myopia degree in sphericalequivalent (SE) among Sudanese adults. Study Design: Cross sectional study. Setting:University Eye complex clinic and Makka Eye complex Omdurman. Period: April to October2015. Methods: Central Corneal Thickness (CCT), k-reading (KM), axial length and thedegree of refraction (SE) 0f 200 myopic eyes and 60 emmetropic eyes as a control groupwere measured. Results: Adult Sudanese females (57%) were found greater than males (43%)population; (χ 2 = 109.5, p = 0.000 ), most of the participants’ age was less than 25 years(χ 2 = 109.5, p = 0.000 ), and the mean myopic spherical equivalent (SE) was – 4.79 ± 2.55 D,ranging from -1.00 to -11.00 D. The mean CCT of the myopic group was 542.8 ±11.9 μm,while for the emmetropic group was 538.7 ±12.4 μm. The cornea were steeper in eyes withlonger axial length (r = 0.24, p =0.001). Eyes with higher myopic spherical equivalent hadlonger axial length (r =0.30, p <0.001). Mean keratometrys were steeper with increasing age(r= 0.24, p= 0.001). This study has shown that CCT has no correlation with degree of myopia(p= 0.46), gender (p= 0.99), and age (p= 0.07). The CCT, KM, and AL means for myopicparticipants were found significantly greater than emmetropic participants (p=0.000, 0.000,and 0.044 respectively. Conclusion: The females participants of myopia were higher rate thanmales, early adults’ age group were of higher rate myopic incident; there was no correlationbetween CCT and the degree of myopia, gender, and age. CCT, KM, and AL means for myopicwere found higher than emmetropic participant. Eyes with more myopic spherical equivalenthad longer axial length; corneal curvature mean becomes steeper with increasing age.

scholarly journals Usefulness of the Non-Contact Tonometry in Out-Patient Screening

2016 ◽  
Vol 15 (2) ◽  
Author(s):  
Satheesh Solomon T Selvin ◽  
Chris Elsa Samson Jacob ◽  
Thomas Kuriakose
Keyword(s):  
Central Corneal Thickness ◽  
Care Center ◽  
Corneal Thickness ◽  
Tertiary Care ◽  
Cross Sectional Study ◽  
Applanation Tonometry ◽  
Cross Sectional ◽  
Significant Difference ◽  
Iop Measurement ◽  
The Mean

Purpose: Goldmann applanation tonometry (GAT) is considered the gold standard for Intraocular Pressure (IOP) measurement. It has the disadvantages of being a contact device, need for a slit-lamp, non-portability and need of a skilled examiner. Many hospitals are using a Non Contact Tonometry (NCT) as a screening device to save clinician time, however the usefulness is not proved in terms of reliability. This study was aimed to determine the usefulness of the Air-puff tonometer (TONOREF NIDEK II, NIDEK CO., LTD., JAPAN) over a GAT in a tertiary care center. Design: Cross-sectional Study Methods: This was a cross-sectional, non interventional observational study conducted on 224 eyes (right eye) from 224 patients. All patients underwent the IOP measurement with both methods and a central corneal thickness (CCT) measured. The data was analyzed using SPSS 20.0 software. Results: The mean age of the patients was 40.3±11.29 years. There was a statistically significant difference (p<0.001) between the mean NCT and GAT readings which persisted even after correction for central corneal thickness. The correlation between NCT and GAT using Pearson’s correlation coefficient was strong irrespective of the corrections for their corneal thickness (r = 0.751 and 0.718 for uncorrected and corrected values respectively). The correlation of the individual clinicians for the readings varied from moderate to strong. The ROC curve showed the best sensitivity and specificity to occur at around 13 to 14 mmHg. Conclusion: NCT seems to overestimate the IOP at low ranges as compared to the GAT and underestimate at higher ranges. The crossover of the values is seen between 12 to 13 mmHg.  The clinician should do an individualized analysis of his/her GAT measurements to the readings of the NCT machine at the clinic to obtain clinician specific nomogram. 

scholarly journals Refractive Outcomes of  Table-Mounted and HandheldAuto-Refractometers in Children: An Observational Cross-Sectional Study

2021 ◽  
Author(s):  
müjdat karab ◽  
sinem karabulut ◽  
Aylin karalezli
Keyword(s):  
Cross Sectional Study ◽  
Spherical Equivalent ◽  
Sectional Study ◽  
Cross Sectional ◽  
Refractive Outcomes ◽  
Spearman's Rho ◽  
Spearman’S Rho ◽  
The Mean ◽  
Mean Differences ◽  
Cylinder Power

Abstract Background: To compare the refractive results of two autorefractors.Methods: We designed this study as an observational, cross-sectional study. We compared the mean spheric and cylinder power, spherical equivalent, Jackson cross-cylinder values, determined the limits of agreement (LoA), and evaluated reliability.Results: Nidek HandyRef-K autorefractor measured more astigmatism and myopia in terms of the mean cylindrical power (P<.001) and spherical equivalent (P=.024). Nidek HandyRef-K showed significantly more myopic results in subgroups with spherical power more than +1.50 Diopters (D) hyperopia and -3.00 D myopia (P=.031; P=.045; P=.026; respectively) and higher astigmatism in the subgroup with the cylindric power less than -1.00 D (P<.001). The mean differences and 95% LoA were 0.06 D ± 0.47 D (-0.82 D to 0.98 D) in spherical power, 0.08 D ± 0.28 D (-0.47 D to 0.64 D) in cylindrical power, 0.11 D ± 0.47 D (-0.81 D to 1.01 D) in spherical equivalent, 0.02 D ± 0.36 D (-0.73 D to 0.69 D) in Jackson cross-cylinder power at 0°, 0.005 D ± 0.54 D (-1.07 D to 1.06 D) in Jackson cross-cylinder power at 45°. There was a strong correlation for spherical power (Spearman’s rho=0.99, P<.001), cylindrical power (Spearman’s rho=0.88, P<.001), spherical equivalent (Spearman’s rho=0.98, P<.001).Conclusion: Nidek HandyRef-K showed more myopic results regarding spherical equivalent and cylindrical power. Nidek HandyRef-K showed significantly more myopia in spherical power more than +1.50 D hyperopia, -3.00 D myopia, and more prominent astigmatism in cylindrical power less than -1.00 D subgroups.

scholarly journals Comparing School-Aged Refraction Measurements Using the 2WIN-S Portable Refractor in Relation to Cycloplegic Retinoscopy: A Cross-Sectional Study

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Ziming Liu ◽  
Emmanuel Eric Pazo ◽  
Hong Ye ◽  
Cui Yu ◽  
Ling Xu ◽  
...  
Keyword(s):  
Gold Standard ◽  
Intraclass Correlation ◽  
Cross Sectional Study ◽  
Mean Value ◽  
Spherical Equivalent ◽  
Sectional Study ◽  
Altman Analysis ◽  
Cross Sectional ◽  
Bland Altman Analysis ◽  
The Mean

Purpose. To assess the repeatability and agreement of refractive measurements using 2WIN-S photoscreening with the gold-standard cycloplegic retinoscope refraction. Design. Single centre, cross-sectional study. Methods. Spherical, cylindrical, axis, and spherical equivalent of 194 bilateral eyes of 97 children were assessed using a retinoscope and 2WIN-S. One week later, another operator repeated the 2WIN-S measurements. The primary outcome measures were to assess the repeatability and agreement between spherical equivalent, J0, and J45 readings of 2WIN-S. The repeatability of measurements was assessed by the within-subject standard deviation (2.77 Sw) and intraclass correlation coefficient (ICC). The agreement between devices was assessed using 95% limits of agreement. The extent of the agreement between cycloplegic retinoscopy and noncycloplegic 2WIN-S measurements was assessed using Bland–Altman analysis. Results. The mean age ± SD was 10.3 ± 2.46 year (range, 4–14 years). The sphere, cylinder, and spherical equivalent measurements were found to be consistent with both apparatus (r value >0.86). ICC for SE, J0, and J45 was 0.900, 0.666, and 0.639, respectively; Sw for SE, J0, and J45 was 0.61D, 0.30D, and 0.31D, respectively; Bland–Altman analysis of retinoscopy with cycloplegia and 2WIN-S for SE was 184/194 (95%) in 95% confidence interval, and the mean value was 0.46. J0 was 184/194 (95%), and the mean value is −0.04. J45 was 181/194 (93%), and the mean value is −0.15. Conclusion. The objective refractive measurement of 2WIN-S had good reliability and high agreement with the gold-standard retinoscopy refraction in children and adolescents. While consistency was observed, it is essential to take into consideration that it is a screening tool.

Central corneal thickness and normal tension glaucoma: A cross-sectional study

2006 ◽  
Vol 77 (3) ◽  
pp. 134-140 ◽  
Author(s):  
Michael Sullivan-Mee ◽  
Kathy D. Halverson ◽  
Mollie C. Saxon ◽  
Glenn B. Saxon ◽  
Clifford Qualls
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Normal Tension Glaucoma ◽  
Cross Sectional Study ◽  
Sectional Study ◽  
Cross Sectional

scholarly journals Predictive model for early diagnosis of keratoconus

2020 ◽  
Author(s):  
GRACIA CASTRO-LUNA ◽  
ANTONIO PÉREZ-RUEDA
Keyword(s):  
Early Diagnosis ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Cross Sectional Study ◽  
Bivariate Analysis ◽  
Diagnostic Model ◽  
Sectional Study ◽  
Cross Sectional ◽  
Recorded Data ◽  
Topographic Parameters

Abstract Background To describe the topographic, pachymetric and aberrometry characteristics in patients with keratoconus, subclinical keratoconus/forme fruste and normal corneas. Calculate a diagnostic model of subclinical keratoconus/forme fruste. Methods The design was a cross-sectional study. It included 205 eyes from 188 patients distributed in 82 normal corneas, 40 subclinical keratoconus/forme fruste and 83 established keratoconus The topographic, pachymetric and aberrometry variables obtained by rotary Scheimpflug camera (Pentacam® type) were analyzed. A descriptive and bivariate analysis of the recorded data was performed. A diagnostic model of subclinical keratoconus/forme fruste was calculated. Results Statistically significant differences were obtained when comparing normal corneas with subclinical keratoconus/forme fruste in variables of vertical asymmetry and corneal thickness.The regression model was calculated with the minimum corneal thickness and the anterior coma to 90º and posterior coma to 90º. Conclusions The diagnosis of subclinical keratoconus/forme fruste depends on the central corneal thickness, and two aberrometric topographic parameters the anterior coma to 90º and posterior coma to 90º.

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