scholarly journals Correlation between Central Corneal Thickness and Degree of Myopia among Malaysian Patients Undergoing Laser Keratorefractive Surgery

2020 ◽  
pp. 52-58
Author(s):  
Sagili Chandrasekhara Reddy ◽  
Mohd Mansor Shariff ◽  
Aina Malindri Dasrilsyah
Keyword(s):  
Optical Coherence Tomography ◽  
Refractive Surgery ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Military Hospital ◽  
Moderate Degree ◽  
Optical Coherence ◽  
Corneal Refractive Surgery ◽  
The Mean

Purpose: To determine the central corneal thickness in myopic adult patients scheduled for laser corneal refractive surgery and to explore its correlation with degree of refractive error. Materials and Methods: The case records of 130 myopic patients who underwent laser corneal refractive surgery in a military hospital over a period of two years were reviewed to determine the central corneal thickness. All patients had 6/6 vision with best correction, and did not have any other anterior segment or fundus diseases in both eyes. The central corneal thickness was measured with Visante Carl Zeiss anterior segment optical coherence tomography instrument.                                                                                                                        Results: Out of 130 patients, males were more (73, 56.2%); mean age of patients was 33.8 years (range 18-60 years) and majority were Malays (110, 84.6%).  The spherical power of myopia ranged from – 0.5 to – 10.00 D, and the cylindrical power ranged from – 0.25 to – 3.25 D. The mean central corneal thickness of both eyes was 528.2 µm (range 331- 615 µm); in the mild degree of myopia (- 0.50 to - 2.00 D) 527.9 µm, moderate degree (- 2.25 to -5.00 D) 529.4 µm, and high degree (-5.25 to -11.00 D) 523.9 µm. Conclusion: The anterior segment optical coherence tomography provides noncontact, rapid, pachymetry mapping of the corneal thickness. In Malaysian patients, the mean central corneal thickness of both eyes in myopia was 528.1 µm (range 331- 615 µm). There was no correlation between the mean central corneal thickness and degree of myopia, different genders, age groups, ethnic groups and two eyes.

scholarly journals Indications of Optical Coherence Tomography in Keratoplasties: Literature Review

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Thiago Trindade Nesi ◽  
Daniel Amorim Leite ◽  
Fábio Medina Rocha ◽  
Marco Antônio Tanure ◽  
Pedro Paulo Reis ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Literature Review ◽  
Early Identification ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Secondary Glaucoma ◽  
Optical Coherence

Optical coherence tomography (OCT) of the anterior segment, in particular corneal OCT, has become a reliable tool for the cornea specialist, as it provides the acquisition of digital images at high resolution with a noncontact technology. In penetrating or lamellar keratoplasties, OCT can be used to assess central corneal thickness and pachymetry maps, as well as precise measurements of deep stromal opacities, thereby guiding the surgeon to choose the best treatment option. OCT has also been used to evaluate the keratoplasty postoperative period, for early identification of possible complications, such as secondary glaucoma or donor disc detachments in endothelial keratoplasties. Intraoperatively, OCT can be used to assess stromal bed regularity and transparency in anterior lamellar surgeries, especially for those techniques in which a bare Descemet’s membrane is the goal. The purpose of this paper is to review and discuss the role of OCT as a diagnostic tool in various types of keratoplasties.

scholarly journals Comparison of Central Corneal Thickness Measurements between Angiovue Optical Coherence Tomography, Ultrasound Pachymetry and Ocular Biometry

2020 ◽  
pp. 1-9
Author(s):  
E. Pateras ◽  
A. I. Kouroupaki
Keyword(s):  
Optical Coherence Tomography ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Repeated Measurements ◽  
Optical Coherence ◽  
Swept Source ◽  
Ocular Biometry ◽  
Significant Linear Correlation ◽  
Ultrasound Pachymetry ◽  
The Mean

Purpose: To compare central corneal thickness (CCT) measurements and their reproducibility when taken by Ultrasound Pachymetry, Ocular Biometry and Angiovue Optical Coherence Tomography (OCT). Methods: Twenty-five healthy volunteers were recruited creating a sample size of 50 eyes. All subjects had pachymetric measurements by Ultrasound pachymetry (PachPen Handheld Pachymeter, Keeler Instruments Inc), Ocular biometry (IOL Master 700 Swept Source Biometry, Zeiss) and Angiovue Optical Coherence Tomography (Optovue Avanti RTVue XR Angiovue). The measurements of central corneal thickness for the three devices were taken by the same examiner twice for more accuracy. Results: The average measurements of central corneal thickness by Ultrasound pachymetry (PachPen Handheld Pachymeter, Keeler Instruments Inc), Ocular biometry (IOL Master 700 Swept Source Biometry, Zeiss) and Angiovue Optical Coherence Tomography (Optovue Avanti RTVue XR Angiovue) were 547.26 μm, 551.36 μm, and 536.42 μm, respectively. The mean standard deviation (SD) of repeated measurements by Ocular biometry was 48.87 μm, which was greater than the mean SD of 44.24 μm and 40.35 μm (P < 0.001) by ultrasound pachymetry and Angiovue optical coherence tomography, respectively. There were statistically significant differences in the measurement results among the 3 methods (Ultrasound pachymetry vs. Ocular biometry P = 0.019; Ultrasound pachymetry vs. Angiovue Optical Coherence Tomography; P < 0.001; Ocular biometry vs. Angiovue Optical Coherence Tomography P < 0.001). There was a significant linear correlation between the Ultrasound pachymetry and Ocular biometry (r = 0.945, P<0.001), Ultrasound pachymetry and Angiovue Optical Coherence Tomography (r = 0.895, P<0.001), and Ocular biometry and Angiovue Optical Coherence Tomography (r = 0.902, P<0.001). Conclusion: Central corneal thickness readings were comparable between PachPen Handheld Pachymeter, IOL Master 700 Biometry and Angiovue Optical Coherence Tomography; Angiovue optical coherence tomography gave significantly smaller values. The measurements of the 3 methods showed significant linear correlations with one another. All methods provided acceptable repeatability of measurements.

scholarly journals Role of anterior segment optical coherence tomography in the evaluation of microbial keratitis

2021 ◽  
Vol 7 (3) ◽  
pp. 548-553
Author(s):  
Isha Chaturvedi ◽  
Kamaljeet Singh ◽  
Jagriti Rana ◽  
Kshama Dwivedi ◽  
Reena Sachan
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Morphological Characteristics ◽  
Objective Evaluation ◽  
Response To Treatment ◽  
Optical Coherence ◽  
Microbial Keratitis ◽  
The Mean

Anterior segment optical coherence tomography (AS-OCT) is a newer technology that provides two-dimensional images of corneal infiltration. This study was undertaken to assess whether AS-OCT can aid objective evaluation and response to treatment in resolving microbial keratitis. This prospective study was performed on 17 patients of who underwent slit lamp and AS-OCT examination at presentation and follow up on days 3, 7, 14, 28 and 6 weeks. A standardized scanning protocol was used to measure the corneal thickness (CT) and infiltrate thickness (IT) using the caliper tool of a commercially available AS-OCT device. The mean CT in the infiltrated area and mean IT, both were thickest at presentation (710.88 um and 288.76 um respectively). The mean CT decreased to 665.12 µm, 650.24 µm, 584.35 µm, 549 µm, 507.47 µm on days 3, 7, 14, 28 and 6 weeks respectively. Similarly, the mean IT decreased to 287.24 µm, 244.41 µm, 197 µm, 174.59 µm and 154.82 µm. Paired t- test was used to calculate the statistical change in CT and IT, which was significant (p&#60;0.0001) at 6 weeks, at the rate of 0.67% and 1.01% per day. AS-OCT can show morphological characteristics of microbial keratitis and give quantitative assessment at every follow up.

scholarly journals Anterior Segment Eye Assessment of Refractive Surgery Candidates in the Southeast of Iran

2016 ◽  
Vol 8 (12) ◽  
pp. 133 ◽  
Author(s):  
Neda Nakhjavanpour ◽  
Abolfazl Payandeh ◽  
Majid Rajabi ◽  
Vahid Shoja
Keyword(s):  
Anterior Chamber ◽  
Refractive Surgery ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Weather Conditions ◽  
Capital City ◽  
Linear Regression Models ◽  
Corneal Refractive Surgery

<p>Anterior segment eye parameters are essential factors in diagnosis, screening and management of abnormal ocular conditions. Based on the previous studies, they might differ from one race or population to another. Sistan-and-Baluchestan province, the southeast of Iran, has special weather conditions and race, plus lack of research on these diagnostic factors. Hence, the objective of the present study was to assess anterior segment parameters using pentacam in this area. 800 eyes of subjects which had been referred to the Al-Zahra eye hospital of Zahedan, the capital city of the province, for corneal refractive surgery from October 2014 to March 2015 participated in this research. 95% confidence limits for mean of central corneal thickness, anterior chamber depth and volume were (536.02, 541.20), (3.13, 3.18) and (187.63, 192.58) respectively. Multiple linear regression models showed a lower mean central corneal thickness, and maximum/minimum of keratometry, for males than females, adjusting for age and spherical equivalent. Inversely, anterior chamber depth, and volume were more in males. In order to diagnosis and treating ocular diseases which have effect on retinal thickness, precisely specification of predictive factors is highly needed.</p>

scholarly journals Morphometric evaluation and measurements of primary pterygium by anterior segment optical coherence tomography and its relation with astigmatism

2021 ◽  
Vol 13 ◽  
pp. 251584142110201
Author(s):  
Anuradha Raj ◽  
Renu Dhasmana ◽  
Harsh Bahadur
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Cross Sectional Study ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Horizontal Length ◽  
The Mean ◽  
The Relationship ◽  
Primary Pterygium

Purpose: To evaluate the relationship between measurements and various morphometric parameters of primary pterygium on anterior segment optical coherence tomography(AS-OCT) and refractive and keratometric astigmatism. Methods: In this cross-sectional study, patients with primary pterygium were included. The AS-OCT parameters of pterygium consisting of epithelial thickness near apex(µm), apical or head thickness(µm), its thickness at limbus(µm), horizontal length of pterygium(mm), central corneal thickness (µm) and maximum pterygium thickness(mm) were evaluated. Results: Sixty three patients comprising of 63 eyes with a primary pterygium were studied. The mean keratometric and refractive astigmatism were 1.69 ± 3.15 Diopter(D) and0.5 ± 1.4D, respectively. There was a significant association between pterygium grade and stocker’s line with keratometric astigmatism ( p = 0.02, 0.00) respectively. Vertical and horizontal length on slit lamp and horizontal length on AS-OCT showed significant association with keratometric astigmatism ( p = 0.05, 0.00,0.00), respectively. Limbal thickness on AS-OCT showed significant positive correlation with refractive astigmatism ( r = 0.29, p = 0.02). Conclusion: The pterygium grade influences the keratometric astigmatism. Increased limbal thickness of pterygium on AS-OCT leads to more refractive astigmatism.

scholarly journals Comparison between a New Optical Biometry Device and an Anterior Segment Optical Coherence Tomographer for Measuring Central Corneal Thickness and Anterior Chamber Depth

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Jinhai Huang ◽  
Weicong Lu ◽  
Giacomo Savini ◽  
Hao Chen ◽  
Chengfang Wang ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Normal Subjects ◽  
Optical Coherence ◽  
Limits Of Agreement ◽  
Mean Values ◽  
The Mean

Purpose.To compare between a new optical biometer (AL-Scan, Nidek Co., Aichi, Japan) and an anterior segment optical coherence tomographer (Visante AS-OCT, Carl Zeiss Meditec, Dublin, USA) for measuring central corneal thickness (CCT), anterior chamber depth (ACD), and aqueous depth (AD).Methods.Sixty-three eyes of 63 normal subjects were examined with AL-Scan and Visante AS-OCT in this prospective study. One eye per subject was measured three times with both devices to record their CCT, ACD, and AD. All procedures were performed by the same operator. Agreement between the two devices was assessed using pairedt-tests, Bland-Altman plots, and 95% limits of agreement (LoA).Results.The mean CCT, ACD, and AD measured by AL-Scan were538.59±27.37 μm,3.70±0.30 mm, and3.16±0.30 mm, respectively. The mean values obtained by the Visante OCT were536.14±26.61 μm for CCT,3.71±0.29 mm for ACD, and3.17±0.29 mm for AD. The mean CCT by the AL-Scan was higher than that obtained by the Visante AS-OCT (difference =2.45±6.07 μm,P<0.05). The differences in ACD and AD measurements were not statistically significant. The 95% LoA of CCT, ACD, and AD were between −9.44 and 14.35 μm, −0.15 and 0.12 mm, and −0.15 and 0.12 mm, respectively.Conclusions.Since these two devices were comparable for measuring CCT, ACD, and AD, their results can be interchangeably used in the clinic.

Central Corneal Thickness: Ultrasound Pachymetry Verus Anterior Segment Optical Coherence Tomography

2021 ◽  
Vol 37 (4) ◽  
Author(s):  
Waqas Ali ◽  
Munira Shakir ◽  
Sahira Wasim ◽  
Ronak Afza
Keyword(s):  
Optical Coherence Tomography ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Mean Difference ◽  
P Value ◽  
Optical Coherence ◽  
Ultrasound Pachymetry ◽  
Group A ◽  
Group B

Purpose: To determine the mean difference in central corneal thickness between ultrasound pachymetry and anterior segment optical coherence tomography in patients visiting tertiary care hospital of Karachi Study design: Cross sectional study Place and Duration of Study: Department of Ophthalmology, Liaquat National Hospital, Karachi from 27th December 2018 to 26th June 2019. Methods: Total 216 eyes of 108 patients were divided into two groups. Central corneal thickness was measured using ultrasound pachymeters in group A and with anterior segment optical coherence tomography in group B. Data was collected and analyzed using SPSS version 21. Mean central corneal thickness was compared between the two methods. Stratification was done on gender, age and post-stratification independent sample t-test was applied for mean difference CCT and P-value ? 0.05 was taken as significant. Results: Total 108 patients were equally divided into two groups. Mean age was 48.70±7.82 years in group A and 50.66±6.88 years in group B. In group A, there were 74.1% males and 25.9% females while in group B, there were 75.9% males and 24.1% females. There was statistically significant difference between the mean central corneal thickness of group A and group B for right and left eyes (p<0.001). Mean difference was also compared for gender and age groups. We found statistically significant differences in central corneal thickness in between the two methods in both age groups (?45 years and > 45 years). Conclusion: Central corneal thickness was more with pachymeters as compared to the AS-OCT (p value < 0.05) Key Words: Central Corneal Thickness, Anterior Segment Optical Coherence Tomography, Ultrasound Pachymetry.

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