scholarly journals Comparison of Optical versus Ultrasonic Biometry in Keratoconic Eyes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Yasin Çınar ◽  
Abdullah Kürşat Cingü ◽  
Muhammed Şahin ◽  
Alparslan Şahin ◽  
Harun Yüksel ◽  
...  
Keyword(s):  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Demographic Characteristics ◽  
Ophthalmological Examination ◽  
Average Difference ◽  
Bland Altman Method ◽  
Study Population ◽  
Biometric Measurements ◽  
The Difference

Purpose. To compare the measurements of optical versus ultrasonic biometry devices in keratoconic eyes.Materials and Methods. Forty-two eyes of 42 keratoconus (KC) patients enrolled in the study were examined. Clinical and demographic characteristics of the patients were noted, and detailed ophthalmological examination was performed. Following Pentacam measurements, central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), and axial length (AL) were obtained using the Lenstar and US biometer to determine the reproducibility of the measurements between the two devices in keratoconic eyes. The Bland-Altman method was used to describe the agreement between the two devices.Results. The Lenstar could not measure at least one of the biometric properties in one eye and did not automatically give the corrected ACD in 2/3 of our study population. The Lenstar measured CCT (average difference 5.4 ± 19.6 µm; ICC = 0.90; ), LT (average difference 0.13 ± 0.17 mm; ICC = 0.67; ), and AL (average difference 0.10 ± 0.76 mm; ICC = 0.75; ) thinner than US biometer, whereas it measured ACD (average difference 0.18 ± 0.17 mm; ICC = 0.85; ) deeper than US biometer in keratoconic eyes.Conclusion. Although the difference between the measurements obtained using the two devices might be clinically acceptable, US biometry and Lenstar should not be used interchangeably for biometric measurements in KC patients.

Lenstar® LS 900 vs Pentacam®-AXL: Comparative study of ocular biometric measurements and intraocular lens power calculation

2018 ◽  
Vol 28 (6) ◽  
pp. 645-651 ◽  
Author(s):  
Joana Maria Mendes Pereira ◽  
Arminda Neves ◽  
Pedro Alfaiate ◽  
Mónica Santos ◽  
Henrique Aragão ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Intraocular Lens ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
T Test ◽  
Biometric Measurements ◽  
Paired T Test ◽  
Intraocular Lens Calculation

Purpose: Comparison of biometric measurements and calculation of intraocular lens with a new biometer (Pentacam®-AXL, Oculus, Germany) and a reference biometer (Lenstar LS 900®, Haag-Streit AG, Switzerland), in order to assess the agreement between these two devices. Setting: Centro Hospitalar de Leiria, Portugal Materials and methods: Prospective, institutional study, in which measurements of axial length, anterior chamber depth from the corneal epithelium and endothelium to the anterior surface of the lens (anterior chamber depth ext and anterior chamber depth int), central corneal thickness and keratometry readings of the flattest and steepest meridians (K1 and K2) were obtained with the two systems. Intraocular lens calculation was also performed, using the Haigis, SRK/T and HofferQ formulas. Results: The study sample included 136 eyes of 79 patients. Of these, 42 were women and 37 were men. Statistically significant differences were found (p < 0.05, paired T test) in K1, K2 and central corneal thickness between the 2 biometers. Intraocular lens calculation with the Lenstar® and the Pentacam® with Haigis, SRK/T and HofferQ formulas showed statistically significant differences (p < 0.05 Paired T test). Conclusion: Axial length measurements obtained with the Pentacam® and Lenstar® appear to be interchangeable, while measurements of anterior chamber depth, K1 and K2, and central corneal thickness do not appear to be interchangeable between different devices. Statistically significant differences were found in the calculation of intraocular lenses in all formulas used.

scholarly journals Comparing biometry in normal eyes of children with unilateral cataract/corneal disease to age-matched controls

2016 ◽  
Vol 7 (2) ◽  
pp. 108-116
Author(s):  
Adem Gul ◽  
Adnan Cinal ◽  
Cagatay Caglar ◽  
Tekin Yasar ◽  
Adil Kilic
Keyword(s):  
Anterior Chamber ◽  
Axial Length ◽  
Central Corneal Thickness ◽  
Pediatric Patients ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Control Group ◽  
Study Group ◽  
Lens Thickness ◽  
The Difference

Objective: To compare ocular biometry and central corneal thickness of unaffected healthy eyes of pediatric patients with monocular cataracts/corneal opacities and age- matched controls.Materials and methods: We studied 329 eyes of 329 children who were between 1 and 12 years old. The study group (n: 164) consisted of healthy fellow eyes of children operated for unilateral congenital/traumatic cataract and corneal laceration. Axial length, anterior chamber depth, lens thickness, vitreous chamber depth, and central corneal thickness were measured by ultrasound biometry/ pachymetry. Results: Axial length was 22.16 mm in the study group and 21.99 mm in the control group. Anterior chamber depth, lens thickness, and vitreous chamber depth results were 3.35; 3.64 and 15.20 in the treatment group and 3.20; 3.63, and 15.15 mm in the control group, respectively. The axial length and all the components, i.e. anterior chamber depth, lens thickness, and vitreous chamber depth are higher in the unaffected healthy eyes of the pediatric patients than that of the control group but only the difference in the anterior chamber depth was statistically significant. The central corneal thickness was 548 microns and 559 microns in the study and the control groups, respectively, and the difference was found to be significant. Conclusion: Greater anterior chamber depth was chiefly responsible for the overall increase in the axial length in the study group. The central corneal thickness was significantly thinner in the study group than that of the control group. 

scholarly journals Intraocular Pressure Changes Following Different Keratoplasty Techniques and Association with Cornea Parameters and anterior Chamber Depth

2021 ◽  
Author(s):  
Gülşah Gümüş ◽  
cigdem altan ◽  
yusuf yildirim ◽  
nilay kandemir besek ◽  
selim genç ◽  
...  
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Early Postoperative Period ◽  
Lamellar Keratoplasty ◽  
Deep Anterior Lamellar Keratoplasty ◽  
Anterior Lamellar Keratoplasty ◽  
The Difference ◽  
Pressure Changes

Abstract Purpose To evaluate early intraocular pressure (IOP) changes following different keratoplasty techniques and to investigate the relationship between corneal thickness (CT), keratometry values, anterior chamber depth (ACD) and IOP changes. Methods We included patients who underwent penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK) and Descemet membrane endothelial keratoplasty (DMEK). ACD, CT, and keratometry measurements were repeated postoperatively at hour 24, week 1, and month 1. IOP measurements were repeated at postoperative hours 6 and 24, week 1, and month 1 by Tono-Pen XL. Results Twenty-two patients underwent PK, 12 patients underwent DALK, and 19 patients underwent DMEK. The difference between the IOP preoperatively and 6 hours postoperatively and between the IOP preoperatively and 24 hours postoperatively were statistically significant in the three types of surgery (p < 0.05 for each). The difference between preoperative and postoperative week 1 IOP was statistically significant only in the PK group (p = 0.023). When the IOP was compared between the three types of surgeries, the IOP at postoperative week 1 in the PK group was significantly higher than the DALK and DMEK groups (p = 0.021). There was no correlation between ACD, corneal thickness, K values, and IOP in any group. Conclusion IOP may increase in all types of keratoplasty during the first hours after surgery, but PK has a risk of high IOP longer in the early postoperative period. PK patients should be followed more carefully during postoperative week 1 to check for an increase in IOP.

scholarly journals Repeatability and Agreement of Central Corneal Thickness and Keratometry Measurements between Four Different Devices

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Laszlo Kiraly ◽  
Jana Stange ◽  
Kathleen S. Kunert ◽  
Saadettin Sel
Keyword(s):  
Clinical Practice ◽  
Statistical Analysis ◽  
Correlation Coefficient ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Intraclass Correlation ◽  
Bland Altman Method ◽  
Significant Difference ◽  
Healthy Eyes ◽  
Iolmaster 700

Background.To estimate repeatability and comparability of central corneal thickness (CCT) and keratometry measurements obtained by four different devices in healthy eyes.Methods.Fifty-five healthy eyes from 55 volunteers were enrolled in this study. CCT (IOLMaster 700, Pentacam HR, and Cirrus HD-OCT) and keratometry readings (IOLMaster 700, Pentacam HR, and iDesign) were measured. For statistical analysis, the corneal spherocylinder was converted into power vectors (J0, J45). Repeatability was assessed by intraclass correlation coefficient (ICC). Agreement of measurements between the devices was evaluated by the Bland-Altman method.Results.The analysis of repeatability of CCT data of IOLMaster 700, Pentacam HR, and Cirrus HD-OCT showed high ICCs (range 0.995 to 0.999). The comparison of CCT measurements revealed statistically significant differences between Pentacam HR versus IOLMaster 700 (p<0.0001) and Pentacam HR versus Cirrus HD-OCT (p<0.0001), respectively. There was no difference in CCT measurements between IOLMaster 700 and Cirrus HD-OCT (p=0.519). The repeatability of keratometry readings (J0 and J45) of IOLMaster 700, Pentacam HR, and iDesign was also high with ICCs ranging from 0.974 to 0.999. The Pentacam HR revealed significantly higher J0 in comparison to IOLMaster 700 (p=0.009) and iDesign (p=0.041); however, no significant difference was between IOLMaster 700 and iDesign (p=0.426). Comparison of J45 showed no significant difference between IOLMaster 700, Pentacam HR, and iDesign. These results were in accordance with Bland-Altman plots.Conclusion.In clinical practice, the devices analyzed should not be used interchangeably due to low agreement regarding CCT as well as keratometry readings.

Comparison of Central Corneal Thickness, Thinnest Corneal Thickness, Anterior Chamber Depth, and Simulated Keratometry Using Galilei, Pentacam, and Sirius Devices

Cornea ◽  
2014 ◽  
Vol 33 (6) ◽  
pp. 582-586 ◽  
Author(s):  
Mustafa A. Anayol ◽  
Emre Güler ◽  
Ramazan Yağc ◽  
Mehmet A. Şekeroğlu ◽  
Meltem Ylmazoğlu ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth

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 Comparison of Axial Ocular Measurements with Contact and Non-contact Biometry

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Muhammad Arslan Ashraf ◽  
Muhammad Suhail Sarwar ◽  
Muhammad Awais Afzal ◽  
Imran Khalid ◽  
Sehrish Shahid
Keyword(s):  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Cross Sectional Study ◽  
P Value ◽  
Cross Sectional ◽  
Kappa Test ◽  
Parametric Data ◽  
Significant Difference ◽  
The Difference ◽  
Graphical Presentation

Purpose:  To compare between non-contact and contact biometry for measurements of central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and axial length (AL). Study Design: Descriptive Cross Sectional Study. Place and Duration of Study:  Mayo Hospital, Lahore from June 2018 to December 2018. Material and Methods:  Eighty-four subjects, (168 non-pathological eyes) visiting the eye outpatients department were recruited by non-probability convenience sampling. Patients with high refractive errors and suffering from any ocular pathology were excluded from the study. CCT, ACD, LT and AL were measured with non-contact Biometer (HAAG Streit) followed by Contact Biometer (Ultrasound) after taking consent from the patient. Data was entered and analyzed by using SPSS-21 and Medcalc software. Normality of quantitative data was checked with Shapiro Wilk test. Independent sample t test was used for parametric variable and Mann Whitney-U test was used for non-parametric data. For the agreement between two techniques Cohen’s Kappa test used and Bland-Altman plot was drawn for graphical presentation. P-value equal or less than 0.05 was taken as significant. Results:  Mean age of 84 subject (female: 45.24% and male: 54.76%) was 53.05 ± 13.56 years. The AL was significantly longer for the non-contact measurement with the difference of 0.53 ± 0.32 mm (p < 0.001). Contact pachymetry was significantly higher with the difference of 8.67 ± 20.83 µm (p = 0.046). ACD was significantly deeper for non-contact measurements with the difference of 0.51 ± 0.32 mm (p < 0.001). Contact ultrasound A-scan measured LT significantly thicker with the difference of 0.59 ± 0.56 mm (p < 0.001). Conclusion:  There is significant difference of axial ocular measurements (CCT, ACD, LT and AL) between contact (ultrasound A-scan) and non-contact (HAAG Streit) biometry (p < 0.05).

scholarly journals The Study of Ocular Parameters in Low to Moderate Myopic Chinese Children Age Between Eight to Eighteen-Year-Old

2021 ◽  
Author(s):  
Zhengxuan Li ◽  
Lu Sun ◽  
Hongxin Song
Keyword(s):  
Retrospective Study ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Corneal Endothelial Cell ◽  
Spherical Equivalent ◽  
Corneal Endothelial Cell Density ◽  
The Mean ◽  
Beijing China ◽  
Corneal Diameter

Abstract Purpose: The primary aim of this study was to analyze the distribution of ocular parameters of children aged from eight to eighteen-year-old with low to moderate myopia as well as offer useful information for the design and clinical fitting of ortho-k lens in China.Methods: In this retrospective study, we collected data of 300 subjects (600 eyes) age between eight to eighteen-year-old from the myopic control outpatient clinic at Beijing Tongren Hospital, Beijing, China. The spherical equivalent (SE), axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), corneal endothelial cell density (CECD)，corneal diameter (CD), simulated K (Sim K) were collected from all the subjects and analyzed. Results: The mean of SE for all subjects was -3.12 ± 1.21D, the median was -3.16D. The mean of AL for all subjects was 24.72 ± 0.83 mm, the median was 24.72 mm. The mean of CCT for all subjects was 537.8 ± 29.82 μm, the median was 538.17 μm. The mean of CECD for all subjects was 3340.3 ± 352.6 cells/mm2, the median was 3357.77 cells/mm2. The mean of ACD for all subjects was 3.71 ± 0.21 mm, the median was 3.69 mm. The mean of CD for all subjects was 12.15 ± 1.67 mm, the median was 12.05 mm. The mean of flat K was 42.80 ± 1.29, the median was 42.81. The mean of steep K was 43.76 ± 1.37, the median was 43.76.Conclusions: This study provided the distribution of ocular parameters to offer useful information for diagnosis of many eye conditions. Meanwhile, the distribution of ocular parameters of children aged from eight to eighteen-year-old with low to moderate myopia is beneficial to make the application of overnight orthokeratology lens more appropriate and effective.

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