scholarly journals Determining the mean difference in central corneal thickness measured by applanation ultrasound and oculus Wavelight Occulyzer II

2021 ◽  
Vol 35 (3) ◽  
Author(s):  
Dr Ronak afza Memon ◽  
Dr munira Shakir ◽  
Dr Sahira Wasim
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Mean Difference ◽  
Topical Anesthetic ◽  
Cross Sectional ◽  
Anesthetic Agents ◽  
Department Of Ophthalmology ◽  
The Mean ◽  
Thickness Measurements ◽  
Ultrasound Pachymeter

Abstract Objective: The objective is to determine the mean difference of central corneal thickness measurements by using ultrasound pachymeter and oculus Wavelight Occulyzer II. Patients & Methods: This prospective cross-sectional comparative study was conducted at Department of Ophthalmology, Liaquat National Hospital, Karachi for 6 months duration, after the approval from ethical committee. Patients were included in our study on the basis of inclusion & exclusion criteria. Central corneal thickness measurements was taken by using ultrasound pachymeter & oculus Wavelight Occulyzer II. All the data was collected by single researcher. The results were plotted, compared & analyzed. Results: 130 patients attending ophthalmology department and fulfilling the inclusion criteria were assessed. One eye of each patient was measured (65 were right eye and 65 were left eye). 73(56.2%) were male and 57(43.8%) were females. Mean age of these patients was 33.9 ±8.9 years. The mean ± SD thinnest oculus Wavelight Occulyzer II measurement was 538.61±23.46 ?m and ranged between 476.0 and 619.0 ?m whereas the mean thinnest ultrasound pachymeter measurement was 535.1±21.816?m and ranged between 482 and 601 ?m. There was highly significant correlation of central corneal thickness between both the instruments. (r=0.96, p<0.001)  Conclusion: According to the results of our study there is a highly correlation of central corneal thickness was found between the readings obtained from both UP and oculus Wavelight Occulyzer II. So we concluded that oculus Wavelight Occulyzer II can be used as an alternative technique to ultrasound pachymetry while assessing CCT in clinical settings to  decrease the risk of procedure associated problems with UP like epithelial trauma and infection, to decrease the frequent use of topical anesthetic agents, for early detection and management of glaucoma & in anxious patients also. Keywords: Central corneal thickness, ultrasound pachymeter, oculus Wavelight Occulyzer II  

scholarly journals Difference in Central Corneal Thickness between Applanation Ultrasound and Oculus Wave � 152 Light Occulyzer II

2019 ◽  
Vol 35 (3) ◽  
Author(s):  
Munira Shakir, Ronak Afza Memon Sahira Wasim Shakir Zafar
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Clinical Settings ◽  
Exclusion Criteria ◽  
Cross Sectional ◽  
Ultrasound Pachymetry ◽  
Department Of Ophthalmology ◽  
The Mean ◽  
Thickness Measurements ◽  
Applanation Ultrasound

Purpose: To determine the mean difference of central corneal thickness measurements by using ultrasound Pachymetry and oculus Wave light Occulyzer II. Study Design: Cross-sectional comparative study using non-probability consecutive sampling. Place and Duration of Study: This study was conducted at Department of Ophthalmology, Liaquat National Hospital Karachi from November 2018 to June 2019. Material & Methods: After approval from ethical committee, patients were included in our study on the basis of inclusion & exclusion criteria. Central corneal thickness measurements were taken by using ultrasound Pachymetry & oculus Wave light Occulyzer II. All the data was collected by single researcher. The results were plotted, compared & analyzed. Paired t-test was used for the comparison of quantitative variables. Results: There were 130 patients included in the study out of which 73 (56.2%) were males and 57 (43.8%) were females. Mean age of these patients was 33.9 � 8.9 years. The mean � SD thinnest oculus Wave light Occulyzer II measurement was 538.61 � 23.46 ?m and ranged between 476.0 and 619.0 ?m whereas the mean thinnest ultrasound Pachymetry measurement was 535.1 � 21.816 ?m and ranged between 482 and 601 ?m. There was highly significant correlation of central corneal thickness between both the instruments. (r = 0.96, p < 0.001). Conclusion: There is a high correlation of central corneal thickness between the readings obtained from ultrasound and optical pachymetry machines therefore oculus Wave light Occulyzer II can be used as an alternative technique to ultrasound pachymetry while assessing CCT in clinical settings. Key Words: Central corneal thickness, Ultrasound Pachymetry, Optical Pachymetry.

scholarly journals Central Corneal Thickness in an Adult Non-Glaucomatous Ethnic Population in Nigeria

2021 ◽  
Author(s):  
Nkechinyere Judith Uche ◽  
Nkiru Kizor karaiwe ◽  
Suhanya Okeke ◽  
Jude Shiweobi
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Cross Sectional Study ◽  
Ethnic Population ◽  
Topical Anesthetic ◽  
Cross Sectional ◽  
Southeastern Nigeria ◽  
The Mean ◽  
Sub Saharan ◽  
The Relationship

Abstract Purpose: To determine the mean central corneal thickness (CCT) of healthy adult Nigerians from the Igbo ethnic population in southeastern Nigeria which has the highest prevalence of glaucoma and to evaluate the relationship if any between mean CCT and patients’ demographics.Methods: A cross sectional study conducted at an eye screening center in Enugu Southeastern Nigeria. Subjects with healthy eyes from the Igbo ethnic population were recruited. Central corneal thickness was measured with ultrasound pachymetry (Sonomed PacScan plus, model 300AP+) on eligible subjects. Topical anesthetic was instilled and 3 measurements of corneal thickness were taken. The average thickness for each eye was calculated and the relationship between mean CCT, age and gender were studied.Results: 706 eyes of 353 participants were examined. 52.7% of the subjects were females while 47.3% were males. The mean age of participants was 50.29 ± 16.58 years. The mean central corneal thickness (CCT) for RE was 527.68 ± 36.88μm (95% CI: 523.83 –531.55μm) and 527.45 ± 38.01μm for LE (95% CI: 523.47 – 531.43μm). There was a decrease in CCT values with increasing age (p= 0.016, p= 0.05 for RE and left eyes respectively). Males had a significantly higher CCT compared to females for both right and left eyes (p=0.004, p=0.007).Conclusion: Central corneal thickness values in the Igbo ethnic population of Southeast Nigeria, an ethnic group with the reported highest prevalence of glaucoma in Nigeria from our study is thinner than those reported from other regions both within Nigeria as well as some Sub-Saharan populations, Caucasians, Asians, and Hispanics but it is however comparable with values reported among Cameroonians and African Americans. CCT among Nigerian Igbos, seems to decrease with age and appears thicker in males compared with females.

scholarly journals Corneal Biomechanical Parameters and Central Corneal Thickness in Glaucoma Patients, Glaucoma Suspects, and a Healthy Population

2021 ◽  
Vol 10 (12) ◽  
pp. 2637
Author(s):  
Mª. Ángeles del Buey-Sayas ◽  
Elena Lanchares-Sancho ◽  
Pilar Campins-Falcó ◽  
María Dolores Pinazo-Durán ◽  
Cristina Peris-Martínez
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Mean Difference ◽  
The Other ◽  
Control Group ◽  
Healthy Population ◽  
Diagnostic Categories ◽  
Significant Difference ◽  
Biomechanical Parameters ◽  
The Mean

Purpose: To evaluate and compare corneal hysteresis (CH), corneal resistance factor (CRF), and central corneal thickness (CCT), measurements were taken between a healthy population (controls), patients diagnosed with glaucoma (DG), and glaucoma suspect patients due to ocular hypertension (OHT), family history of glaucoma (FHG), or glaucoma-like optic discs (GLD). Additionally, Goldmann-correlated intraocular pressure (IOPg) and corneal-compensated IOP (IOPcc) were compared between the different groups of patients. Methods: In this prospective analytical-observational study, a total of 1065 patients (one eye of each) were recruited to undergo Ocular Response Analyzer (ORA) testing, ultrasound pachymetry, and clinical examination. Corneal biomechanical parameters (CH, CRF), CCT, IOPg, and IOPcc were measured in the control group (n = 574) and the other groups: DG (n = 147), FHG (n = 78), GLD (n = 90), and OHT (n = 176). We performed a variance analysis (ANOVA) for all the dependent variables according to the different diagnostic categories with multiple comparisons to identify the differences between the diagnostic categories, deeming p < 0.05 as statistically significant. Results: The mean CH in the DG group (9.69 mmHg) was significantly lower compared to controls (10.75 mmHg; mean difference 1.05, p < 0.001), FHG (10.70 mmHg; mean difference 1.00, p < 0.05), GLD (10.63 mmHg; mean difference 0.93, p < 0.05) and OHT (10.54 mmHg; mean difference 0.84, p < 0.05). No glaucoma suspects (FHG, GLD, OHT groups) presented significant differences between themselves and the control group (p = 1.00). No statistically significant differences were found in the mean CRF between DG (11.18 mmHg) and the control group (10.75 mmHg; mean difference 0.42, p = 0.40). The FHG and OHT groups showed significantly higher mean CRF values (12.32 and 12.41 mmHg, respectively) than the DG group (11.18 mmHg), with mean differences of 1.13 (p < 0.05) and 1.22 (p < 0.001), respectively. No statistically significant differences were found in CCT in the analysis between DG (562 μ) and the other groups (control = 556 μ, FHG = 576 μ, GLD = 569 μ, OHT = 570 μ). The means of IOPg and IOPcc values were higher in the DG patient and suspect groups than in the control group, with statistically significant differences in all groups (p < 0.001). Conclusion: This study presents corneal biomechanical values (CH, CRF), CCT, IOPg, and IOPcc for diagnosed glaucoma patients, three suspected glaucoma groups, and a healthy population, using the ORA. Mean CH values were markedly lower in the DG group (diagnosed with glaucoma damage) compared to the other groups. No significant difference was found in CCT between the DG and control groups. Unexpectedly, CRF showed higher values in all groups than in the control group, but the difference was only statistically significant in the suspect groups (FHG, GLD, and OHT), not in the DG group.

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 The pattern of central corneal thickness in patients attending a Tertiary Hospital in Dar-Es-Salaam

2021 ◽  
Vol 9 (2) ◽  
pp. 127-133
Author(s):  
Annamary Stanislaus ◽  
Ntsilane Susan Mosenene ◽  
Celina Mhina ◽  
John Stanslaus Kisimbi ◽  
Frederick Robert Burgess ◽  
...  
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Dar Es Salaam ◽  
Applanation Tonometry ◽  
P Value ◽  
Muhimbili National Hospital ◽  
National Hospital ◽  
Cross Sectional ◽  
Significant Difference ◽  
The Mean

Background: Central Corneal Thickness (CCT) is an indicator of corneal health status as well as being an essential tool in assessment and management of corneal diseases. It is an important factor in the diagnosis and management of glaucoma as it affects the measurement of intraocular pressure. However, the pattern of central corneal thickness in our population is not known. Our study aimed to describe the CCT measurements and their variation with age and sex among patients attending the eye clinic at Muhimbili National Hospital (MNH), in Dar es Salaam, Tanzania. Methodology: A hospital-based descriptive, cross-sectional study used convenient sampling to recruit adult patients aged 18 years and above, presenting to the MNH between August 2016 and January 2017.Visual acuity assessment, Goldman applanation tonometry and CCT assessment using an ultrasound pachymeter were performed. Patients with previous intraocular surgery were excluded. Results: A total of 398 patients (208 males and 190 females) were recruited. The mean CCT was 526.64±38.30 µm; being 523.99±38.20 µm for males and 529.7±38.3 µm for females. 226 (56.85%) had CCT of less than 520 µm.There was no statistically significant difference in CCT between gender. The proportion of patients with thinner CCT increased with increasing age from 25.8% in those < 30 years to 75% in those aged 71years and above. The mean CCT decreased with increasing age with P-value<0.001. Conclusion: The average CCT in patients attending Muhimbili National Hospital is 526.64 µm (SD 38.30) which is generally thin, inversely proportion to age and similar that of other Africans and African-Americans. This finding has implications for the management of glaucoma in this population.

scholarly journals Measurements of Corneal Thickness in Eyes with Pseudoexfoliation Syndrome: Comparative Study of Different Image Processing Protocols

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Katarzyna Krysik ◽  
Dariusz Dobrowolski ◽  
Katarzyna Polanowska ◽  
Anita Lyssek-Boron ◽  
Edward A. Wylegala
Keyword(s):  
Time Domain ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Imaging Systems ◽  
Pressure Measurements ◽  
Swept Source ◽  
Swept Source Oct ◽  
The Mean ◽  
Thickness Measurements ◽  
Cataract Patients

Purpose. Comparative analysis of central and peripheral corneal thickness in PEX patients using three different imaging systems: Pentacam-Scheimpflug device, time-domain optical coherence tomography (OCT) Visante, and swept-source OCT Casia. Materials and Methods. 128 eyes of 80 patients with diagnosed PEX were examined and compared with 112 normal, non-PEX eyes of 72 cataract patients. The study parameters included 5 measured zones: central and 4 peripheral (superior, inferior, nasal, and temporal). Results. The mean CCT in eyes with PEX syndrome measured with all three instruments was thicker than that in normal eyes. Corneal thickness measurements in the PEX group were statistically significantly different between Pentacam and OCT Casia: central corneal thickness (p=0.04), inferior corneal zone (p=0.01), and nasal and temporal corneal zones (p<0.01). Between Pentacam and OCT Visante inferior, nasal and temporal corneal zones were statistically significantly different (p<0.01). Between OCT Casia and OCT Visante, there were no statistically significant differences in measured parameters values. Conclusion. The central corneal thickness in eyes with PEX syndrome measured with three different independent methods is higher than that in the non-PEX group, and despite variable peripheral corneal thickness, this one parameter is still crucial in intraocular pressure measurements.

scholarly journals Mean difference of visual acuity with auto refraction and subjective refraction.

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Shakeel Ahmad ◽  
Rashida RIaz ◽  
Muhammad Haseeb ◽  
Hafiza Ammara Rasheed ◽  
Samia Iqbal
Keyword(s):  
Visual Acuity ◽  
Demographic Data ◽  
Anterior Segment ◽  
Cross Sectional Study ◽  
Mean Difference ◽  
P Value ◽  
Cross Sectional ◽  
Department Of Ophthalmology ◽  
The Mean ◽  
Cylindrical Axis

Purpose: To compare the mean difference of visual acuity as measured by auto refraction and subjective refraction. Study Design:  Descriptive cross-sectional study. Place and Duration of Study:  Department of ophthalmology, Services hospital Lahore from November 2013 to April 2014. Material and Methods:  Using non-probability consecutive sampling 300 eyes of 300 patients fulfilling inclusion criteria were recruited through OPD registration slip. Demographic data including age and gender was recorded. Complete ophthalmic examination was performed. This included measurement of refractive error by auto-refraction as well as subjective refraction. Detailed anterior segment examination with slit lamp and dilated fundus examination with indirect ophthalmoscopy was performed. The collected data was analyzed by using software SPSS version 17. Results:  The mean age of patients was 34.71 ± 7.45 years. There were 156 (52%) males and 144 (48%) females. There were 263 (87.69%) patients who had visual acuity of 6/6 and 37 (12.33%) had 6/9. Mean spherical auto-refraction and subjective refraction was 0.0290 ± 2.58 and -0.2842 ± 2.37 D with mean difference of -0.3133 ± 1.27 D. The mean cylindrical auto and subjective refraction in this study was -.9742 ± 0.78 D and -0.7500 ± 0.81 D and mean difference was 0.2242 ± 0.74 D. The mean cylindrical axis of auto and subjective refraction was 114.88 ± 49.75 and 115.60 ± 49.70 with mean difference as 0.72 ± 3.02 D (p-value < 0.05). Conclusion:  Difference of spherical, cylindrical and cylindrical axis in auto and subjective refraction was significantly different.

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 Comparison of central corneal thickness measurements with three different optical devices

2021 ◽  
Vol 13 ◽  
pp. 251584142199563
Author(s):  
Mehmet Barış Üçer ◽  
Erdinç Bozkurt
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Correlation Coefficients ◽  
Limits Of Agreement ◽  
The Mean ◽  
Mean Differences ◽  
High Level ◽  
Thickness Measurements

Purpose: The purpose of this study was to compare and evaluate the agreement of central corneal thickness (CCT) values obtained with three different devices working according to optical principle in healthy eyes. Methods: 60 eyes of 60 individuals (30 men and 30 women) were enrolled in this study. CCT measurements performed with Scheimpflug–Placido topographer (Sirius), spectral-domain optical coherence tomography (RTVue) with an anterior segment module, and optical biometer (AL-Scan) were compared. Bland–Altman analysis was used to demonstrate agreement between methods. Results: The mean age was 30.07 ± 7.313 years (range, 18–47 years). The mean CCT values obtained by RTVue, Sirius, and AL-Scan were 518.25 ± 36.38 µm, 526.08 ± 36.33 µm, and 513.50 ± 39.09 µm, respectively. The mean differences in CCT were 7.83 ± 14.15 µm between Sirius and RTVue, 12.58 ± 11.87 µm between Sirius and AL-Scan, and 4.75 ± 4.50 µm between RTVue and AL-Scan. The mean CCT was statistically different among the three groups ( p < 0.05). All three modalities of CCT measurements correlated closely with each other, with Pearson’s correlation coefficients ranging from 0.924 to 0.961. The 95% limits of agreement were −19.90 to 35.56 µm between Sirius and RTVue, −10.69 to 35.85 µm between Sirius and AL-Scan, and −4.07 to 13.58 µm between RTVue and AL-Scan. Conclusion: Different results could be obtained through different noncontact devices in CCT measurements. Although the measurement values obtained by these devices show a high level of correlation, it would be a more correct approach to not use them directly interchangeably in clinical practice. Evaluation and follow-up of CCT should be performed using the same device.

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