scholarly journals Comparative Study of Anterior Eye Segment Measurements with Spectral Swept-Source and Time-Domain Optical Coherence Tomography in Eyes with Corneal Dystrophies

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Anna K. Nowinska ◽  
Sławomir J. Teper ◽  
Dominika A. Janiszewska ◽  
Anita Lyssek-Boron ◽  
Dariusz Dobrowolski ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Optical Coherence ◽  
Swept Source ◽  
Corneal Dystrophies ◽  
Epithelial Basement Membrane ◽  
Normal Individuals ◽  
Anterior Eye Segment

Purpose.To compare anterior eye segment measurements and morphology obtained with two optical coherence tomography systems (TD OCT, SS OCT) in eyes with corneal dystrophies (CDs).Methods. Fifty healthy volunteers (50 eyes) and 54 patients (96 eyes) diagnosed with CD (epithelial basement membrane dystrophy, EBMD = 12 eyes; Thiel-Behnke CD = 6 eyes; lattice CD TGFBI type = 15 eyes; granular CD type 1 = 7 eyes, granular CD type 2 = 2 eyes; macular CD = 23 eyes; and Fuchs endothelial CD = 31 eyes) were recruited for the study. Automated and manual central corneal thickness (aCCT, mCCT), anterior chamber depth (ACD), and nasal and temporal trabecular iris angle (nTIA, tTIA) were measured and compared with Bland-Altman plots.Results.Good agreement between the TD and SS OCT measurements was demonstrated for mCCT and aCCT in normal individuals and for mCCT in the CDs group. The ACD, nTIA, and tTIA measurements differed significantly in both groups. TBCD, LCD, and FECD caused increased CCT. MCD caused significant corneal thinning. FECD affected all analyzed parameters.Conclusions.Better agreement between SS OCT and TD OCT measurements was demonstrated in normal individuals compared to the CDs group. OCT provides comprehensive corneal deposits analysis and demonstrates the association of CD with CCT, ACD, and TIA measurements.

scholarly journals Reliability of a New Swept-Source Optical Coherence Tomography Biometer in Healthy Children, Adults, and Cataract Patients

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Jinhai Huang ◽  
Yuyu Zhao ◽  
Giacomo Savini ◽  
Guanshun Yu ◽  
Jinjin Yu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Healthy Children ◽  
Optical Coherence ◽  
Swept Source ◽  
Repeatability And Reproducibility ◽  
Optical Biometer ◽  
Cataract Patients ◽  
Iolmaster 700

Purpose. To comprehensively assess the reliability of a new optical biometer (IOLMaster 700), based on swept-source optical coherence tomography (SS-OCT) and comparison with a standard biometer (IOLMaster 500), in healthy children, adults, and cataract patients. Methods. A total of 301 eyes from 301 consecutive subjects were enrolled prospectively. Two experienced operators measured each eye three times consecutively with the IOLMaster 700. The axial length (AL), keratometry (K), anterior chamber depth (ACD), lens thickness (LT), central corneal thickness (CCT), and white-to-white (WTW) distance were recorded. Intraoperator repeatability and interoperator reproducibility of the IOLMaster 700 were analyzed using the test-retest (TRT), coefficients of variation (CoV), and intraclass correlation coefficients (ICCs). The agreement between the two devices was evaluated using the Bland–Altman method. Results. The repeatability and reproducibility of the SS-OCT optical biometer were high for all ocular biometry parameters in all groups, except for the WTW in cataract patients (TRT, 0.27–0.44 mm; ICC, 0.86–0.95). The reproducibility of averaged measurements from three consecutive readings (TRT : AL = 0.02 mm, CCT = 5.41 μm, ACD = 0.03 mm, LT = 0.03 mm, Km = 0.17 D, and WTW = 0.22 mm) was higher than the reproducibility of single measurements (TRT : AL = 0.04 mm, CCT = 7.43 μm, ACD = 0.06 mm, LT = 0.05 mm, Km = 0.26 D, and WTW = 0.35 mm) in the three groups. The consistency in the data between the two biometers was high, with narrow 95% LoAs in the three groups. Conclusion. Repeatability and reproducibility of the new SS-OCT optical biometer were excellent and consistent with that of the standard biometer with respect to healthy children, healthy adults, and cataract patients.

scholarly journals Comparison of two novel swept-source optical coherence tomography devices to a partial coherence interferometry-based biometer

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tommy C. Y. Chan ◽  
Marco C. Y. Yu ◽  
Vivian Chiu ◽  
Gilda Lai ◽  
Christopher K. S. Leung ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Cross Sectional Study ◽  
Systematic Difference ◽  
Partial Coherence ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Partial Coherence Interferometry

AbstractTo evaluate the repeatability and agreement of corneal and biometry measurements obtained with two swept-source optical coherence tomography (SSOCT) and a partial coherence interferometry-based device. This is a cross-sectional study. Forty-eight eyes of 48 patients had three consecutive measurements for ANTERION (Heidelberg Engineering, Germany), CASIAII (Tomey, Japan) and IOLMaster500 (Carl Zeiss Meditec, USA) on the same visit. Mean keratometry (Km), central corneal thickness (CCT), anterior chamber depth (ACD) and axial length (AL) were recorded. Corneal astigmatic measurements were converted into vector components—J0 and J45. Intra-device repeatability and agreements of measurements amongst the devices were evaluated using repeatability coefficients (RCs) and Bland–Altman plots, respectively. All devices demonstrated comparable repeatability for Km (p ≥ 0.138). ANTERION had the lowest RC for J0 amongst the devices (p ≤ 0.039). Systematic difference was found for the Km and J0 obtained with IOLMaster500 compared to either SSOCTs (p ≤ 0.010). The ACD and AL measured by IOLMaster500 showed a higher RC compared with either SSOCTs (p < 0.002). Systematic difference was found in CCT and ACD between the two SSOCTs (p < 0.001), and in AL between ANTERION and IOLMaster500 (p < 0.001), with a mean difference of 1.6 µm, 0.022 mm and 0.021 mm, respectively. Both SSOCTs demonstrated smaller test–retest variability for measuring ACD and AL compared with IOLMaster500. There were significant disagreement in keratometry and AL measurements between the SSOCTs and PCI-based device; their measurements should not be considered as interchangeable.

scholarly journals Comparison of Anterior Ocular Biometric Measurements Using Swept-Source and Time-Domain Optical Coherence Tomography

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Sisi Chen ◽  
Rongrong Gao ◽  
Colm McAlinden ◽  
Junming Ye ◽  
Yiran Wang ◽  
...  
Keyword(s):  
Time Domain ◽  
Corneal Thickness ◽  
Intraclass Correlation ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Correlation Coefficients ◽  
Random Order ◽  
Optical Coherence ◽  
Swept Source ◽  
Significant Difference

Purpose. To compare central corneal thickness (CCT), aqueous depth (AQD), and anterior chamber depth (ACD) measurements using the swept-source (CASIA SS-1000, Tomey, Japan) and time-domain (Visante, Carl Zeiss Meditec, USA) anterior segment optical coherence tomographers (OCT) in normal eyes. Methods. Sixty-eight eyes of 68 subjects were included. Three consecutive scans of each subject were obtained using both devices in a random order by one experienced operator. Standard deviation (Sw), coefficient of repeatability (CoR), coefficients of variation (CoV), and intraclass correlation coefficients (ICC) were used to evaluate the intraoperator repeatability. Agreement was assessed using the Bland–Altman plots and 95% limits of agreement (LoA). Results. All measurements of the swept-source OCT (SS-OCT) and time-domain OCT (TD-OCT) showed high repeatability with low CoR (CCT: 2.34 μm and 6.16 μm; AQD: 0.05 mm and 0.09 mm; ACD: 0.06 mm and 0.09 mm), low CoV (CCT: 0.16% and 0.42%; AQD: 0.61% and 0.97%; ACD: 0.53% and 0.83%), and high ICC (>0.98). The mean CCT with SS-OCT was slightly thicker than the results with TD-OCT (difference = 4.55 ± 2.62 μm, P<0.001). There was no statistically significant difference in AQD or ACD measurements between the two devices (0.01 ± 0.05 mm, P=0.111; 0.02 ± 0.05 mm, P=0.022, respectively). The 95% LoA between the SS-OCT and TD-OCT were −0.59 to 9.69 μm for CCT, −0.10 to 0.12 mm for AQD, and −0.09 to 0.12 mm for ACD. Conclusions. High levels of repeatability and agreement were found between the two devices for all three parameters, suggesting interchangeability. SS-OCT demonstrated superior repeatability compared with TD-OCT.

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 Corneal and Epithelial Thickness Mapping: Comparison of Swept-Source- and Spectral-Domain-Optical Coherence Tomography

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Cristina Georgeon ◽  
Ilanite Marciano ◽  
Roxane Cuyaubère ◽  
Otman Sandali ◽  
Nacim Bouheraoua ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Spectral Domain ◽  
Lamellar Keratoplasty ◽  
Optical Coherence ◽  
Swept Source ◽  
Epithelial Thickness ◽  
Spectral Domain Oct ◽  
Anterior Lamellar Keratoplasty ◽  
Sd Oct

Objective. To compare the results and repeatability of the corneal thickness (CT) and epithelial thickness (ET) maps provided by Swept-Source-Optical Coherence Tomography with those of Spectral-Domain-OCT in normal eyes. Methods. 30 normal eyes of 30 patients were assessed by 3 trained operators with SS-OCT and SD-OCT. Results. The central and minimum ET obtained with both devices were correlated: central ET, r = 0.86, p < 0.05 ; minimum ET, r = 0.72, p < 0.05 . Compared with SD-OCT, SS-OCT tended to underestimate these figures by 1.4 and 1.9 μm on average. The central and minimum CT obtained with both devices were strongly correlated: central CT, r = 0.994, p < 0.05 ; minimum CT, r = 0.995, p < 0.05 . SS-OCT tended to overestimate these figures by 11 and 14 μm on average. Repeatability was good for both devices with a mean coefficient of variation of measurements <6% for ET and <2% for CT. Interoperator variability (standard deviation and COV) was significantly higher for SS-OCT than for SD-OCT for all local epithelial thicknesses and significantly lower for the central CT and several local corneal thicknesses, whereas no significant differences between both technologies were found for the central and minimum ET and the minimum CT. Conclusion. SS-OCT and SD-OCT provide reproducible measurements of CT and ET in normal corneas with a strong correlation between both technologies. However, both technologies are not interchangeable when the main thickness parameters (i.e., central and minimum CT and minimum ET) are used for diagnosing early keratoconus or calculating the expected residual stromal bed thickness before corneal refractive surgery or anterior lamellar keratoplasty.

scholarly journals Assessment of anterior chamber configuration changes after phacoemulsification with swept-source optical coherence tomography

2019 ◽  
Author(s):  
Man Hu ◽  
Qian Zheng ◽  
Zhangliang Li ◽  
Pingjun Chang ◽  
Yun-e Zhao
Keyword(s):  
Optical Coherence Tomography ◽  
Cataract Surgery ◽  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Optical Coherence ◽  
Swept Source ◽  
Narrow Angle ◽  
Age Related ◽  
Shallow Anterior Chamber

Abstract Background To assess the changes of anterior chamber angle in patients with shallow anterior chamber and normal anterior chamber after phacoemulsification and intraocular lens implantation (IOL) using anterior segment swept-source optical coherence tomography (AS-SS-OCT). Methods This was a prospective case control study; 60 eyes of 60 patients who underwent cataract surgery. Based on anterior chamber depth (ACD) and gonioscopy findings, the eyes were classified into two groups, shallow anterior chamber group (30 eyes) and normal anterior chamber group (30 eyes). AS-SS-OCT was used to measure ACD and angle parameters angle opening distance (AOD), angle recess area (ARA), trabecular iris space area(TISA), and trabecular iris angle (TIA). Serial changes in each group were measured before and 3 months after phacoemulsification and IOL, and the differences between the two groups were compared. Results All angle parameters including ACD, AOD, ARA, TISA, and TIA in both groups at 3 months after cataract surgery were significantly different from the preoperative values (p<0.01). In addition, we found significant differences of all angle parameters between groups of shallow anterior chamber (SAC) and normal anterior chamber (NAC) (All P< 0.05). Besides, the TISA750 in superior quadrant and anterior chamber volume (ACV) were significantly smaller in the group of SAC than those in the group of NAC (P = 0.041 and 0.002, respectively). Conclusions The parameters of anterior chamber increased significantly in both two groups but not increase to the same extent 3 months after phacoemulsification. Iris thickening may also be one of the narrow angle factors,not just age-related lens thickening.

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 Risk factors and evaluation of keratoconus progression after penetrating keratoplasty with anterior segment optical coherence tomography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Junko Yoshida ◽  
Tetsuya Toyono ◽  
Rika Shirakawa ◽  
Takashi Miyai ◽  
Tomohiko Usui
Keyword(s):  
Risk Factors ◽  
Optical Coherence Tomography ◽  
Penetrating Keratoplasty ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Optical Coherence ◽  
Graft Size ◽  
Corneal Power ◽  
Corneal Thinning

Abstract To determine the risk factors and unique characteristics of keratoconus (KC) progression after penetrating keratoplasty (PK), anterior segment optical coherence tomography parameters were statistically analyzed in comparison with eyes undergoing PK for other diseases as a control. Ninety-one eyes maintaining clear PK grafts for over 10 years were divided into 2 groups according to the primary indication for PK (KC vs Others groups). Corneal thinning indicators (inferior host thinnest corneal thickness/central corneal thickness [IHT/CCT], inferior graft thinnest corneal thickness/CCT [IGT/CCT]), were smaller whereas anterior chamber depth, and steepest corneal power (Ks), and maximum corneal power (Kmax) were larger in the KC group with statistical significance. Graft size, Kmax and Ks correlated with IHT/CCT and IGT/CCT in the KC group. These correlations were not detected in controls. Graft size and postoperative period were selected by multivariate regression analysis as factors for corneal ectatic changes in the KC group. In conclusion, KC eyes long after PK show inferior graft and host corneal thinning, and corneal protrusion. Corneal power parameters such as Kmax or Ks can be used to monitor KC progression after PK. A small graft might lead to KC progression after PK.

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