scholarly journals Interocular biometric parameters comparison measured with swept-source technology

2021 ◽  
Author(s):  
César Albarrán-Diego ◽  
Francisco Poyales ◽  
Esther López-Artero ◽  
Nuria Garzón ◽  
María García-Montero
Keyword(s):  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Crystalline Lens ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Swept Source ◽  
Biometric Parameters ◽  
Chord Distance ◽  
Lens Power ◽  
Almost All

Abstract Purpose In the event that any ocular parameter involved in the calculation of intraocular lens power could not be properly measured in one eye, it is important to know whether clinically relevant differences between both eyes can be expected. The aim of this work is to evaluate the symmetry of interocular biometric parameters. Methods This was a prospective, cross-sectional study involving 4090 subjects. Patients underwent consecutive swept-source optical biometry performed with an IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany). The biometric parameters that were evaluated were: axial length (AL), mean anterior curvature (Rm), anterior chamber depth (ACD), crystalline lens thickness (LT), central corneal thickness (CCT) and white-to-white (WTW). The Chang–Waring chord distance (CWC-D) and the Chang–Waring chord angle (CWC-A) were also evaluated. Results There is an excellent correlation between both eyes for almost all the biometric parameters under study, with the exception of the CWC. Agreement for AL was better for eyes shorter than 24 mm. The linearity of the OD-vs-OS relationship can be correctly assumed for all parameters (Cusum test: p > 0.05 in all cases). Conclusion There are no clinically significant interocular differences for the biometric parameters under study, although for all of them, except the LT, statistically significant differences did arise. In the case of AL, moderate differences can be expected in eyes larger than 24 mm.

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 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 Lens Biometry in Congenital Lens Deformities: A Swept-Source Anterior Segment OCT Analysis

2021 ◽  
Vol 8 ◽  
Author(s):  
Ze-xu Chen ◽  
Wan-Nan Jia ◽  
Yong-Xiang Jiang
Keyword(s):  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Crystalline Lens ◽  
Maximum Diameter ◽  
Swept Source ◽  
Biometric Parameters ◽  
Projection Length ◽  
Lens Surface ◽  
Lens Radius

Aims: To investigate the lens biometric parameters in congenital lens deformities, using a novel technique of swept-source anterior segment optical coherence tomography (SS-ASOCT).Methods: This prospective study included patients with microspherophakia (MSP), coloboma lentis (CL), and posterior lenticonus (PL). For this cohort, 360-degree high-resolution lens images were obtained using the latest SS-ASOCT (CASIA2, Tomey Corp, Nagoya, Japan). The lens biometric parameters were calculated by the CASIA2 built-in software for anterior lens radius (ALR), posterior lens radius (PLR), anteroposterior distance (APD), anterior chamber depth (ACD), equatorial diameter (Eq Dia), rear projection length (RPL), and maximum diameter of the lesion (MDL).Results: This study included two eyes each with MSP and CL and one eye with PL. The lens of MSP was spherical and posteriorly dislocated, with decreased ALR and PLR, Eq Dia, but increased APD. In patients with CL, the coloboma was isolated, bilateral, inferior, and located toward the maldeveloped ciliary body. High astigmatism was mainly lenticular, and this was calculated by the ALR and PLR. Regarding the site of coloboma, a significant decrease in ALR was observed, while the PLR and APD were not affected. The PL eyes had a cone-shaped protrusion of the posterior lens surface with a subtle cataractous region around the apex. An extremely high posterior surface curvature was observed with a mean PLR of 1.67 mm. The RPL and MDL were about 1.80 and 0.4 mm, respectively, which were homogenous at different sections.Conclusions: The CASIA2 is a valuable option for in vivo crystalline lens measurement for congenital lens deformities, enabling the accurate diagnosis and providing illuminating insights into the pathogenesis of MSP, CL, and PL

scholarly journals Assessment of Full-Eye Response to Osmotic Stress in Mouse Model In Vivo Using Optical Coherence Tomography

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yang Ni ◽  
Baisheng Xu ◽  
Lan Wu ◽  
Chixin Du ◽  
Bo Jiang ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Osmotic Stress ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Crystalline Lens ◽  
Angle Closure ◽  
Optical Coherence ◽  
Ocular Disorders ◽  
Almost All

NaCl based solutions were applied as osmotic stress agents to alter the hydration state of the mouse eye. Full-eye responses to these osmotic challenges were monitored in vivo using a custom-built optical coherence tomography (OCT) with an extended imaging range of 12.38 mm. Dynamic changes in the mouse eye were quantified based on the OCT images using several parameters, including the central corneal thickness (CCT), the anterior chamber depth (ACD), the crystalline lens thickness (LT), the cornea-retina distance (CRD), the iris curvature (IC), and the lens scattering intensity (LSI). Apparent but reversible changes in the morphology of almost all the ocular components and the light transparency of the lens are exhibited. Particularly, the ocular dehydration induced by the hypertonic challenges resulted in a closing of the iridocorneal angle and an opacification of the lens. Our results indicated that the ocular hydration is an important physiological process which might be correlated with various ocular disorders, such as dry eye, cataract, and angle-closure glaucoma, and would affect the biometry and imaging of the eye. OCT uniquely enables the comprehensive study of the dynamic full-eye responses to the ocular hydration in vivo.

scholarly journals Corneal Analysis with Swept Source Optical Coherence Tomography in Patients with Coexisting Cataract and Fuchs Endothelial Corneal Dystrophy

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 223
Author(s):  
Anna Nowińska ◽  
Edyta Chlasta-Twardzik ◽  
Michał Dembski ◽  
Klaudia Ulfik-Dembska ◽  
Edward Wylęgała
Keyword(s):  
Optical Coherence Tomography ◽  
Corneal Thickness ◽  
Preoperative Assessment ◽  
Corneal Dystrophy ◽  
Cross Sectional Study ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Significant Area ◽  
Characteristic Features

This study focused on defining the characteristic features of keratometry and pachymetry elevation maps based on swept source optical coherence tomography (SS OCT) in Fuchs endothelial corneal dystrophy (FECD) eyes with a coexisting cataract. 70 eyes of 35 patients diagnosed with FECD and a coexisting cataract and 70 control eyes were included in this prospective, controlled, observational, cross-sectional study. Features characteristic of intermediately affected eyes included an increased corneal thinnest thickness (CTT) (p = 0.01), 3 and 6 mm asymmetry (p < 0.0001), higher order Fourier indices (p < 0.05 and p ≤ 0.0001, respectively), chord µ, and a posterior Ectasia Screening Index (pESI) (p < 0.01). The lack of agreement between the anterior and posterior elevation map and a significant area of negative values in the posterior map were detected. In advanced FECD eyes, our study additionally revealed decreased posterior keratometry steep (Ks), keratometry flat (Kf), keratometry average (AvgK), eccentricity (Ecc), an increased corneal apex thickness (CAT), and decreased 3 and 6 mm posterior spherical indices (p < 0.0001 for all of the above). Characteristic features of subclinical FECD, independent of the corneal thickness, can be detected by SS OCT and should be considered during the preoperative assessment of patients with a coexisting cataract.

scholarly journals Comparison of Two Novel Swept-Source Optical Coherence Tomography Devices to A Partial Coherence Interferometry-Based Biometer

2020 ◽  
Author(s):  
Tommy Chan ◽  
Marco Yu ◽  
Vivian Chiu ◽  
Gilda Lai ◽  
Christopher Leung ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber Depth ◽  
Cross Sectional Study ◽  
Systematic Difference ◽  
Partial Coherence ◽  
Optical Coherence ◽  
Cross Sectional ◽  
Swept Source ◽  
Partial Coherence Interferometry ◽  
Significant Disagreement

Abstract Purpose To evaluate the repeatability and agreement of cornea and biometry measurements obtained with two swept-source optical coherence tomography (SSOCT) and a partial coherence interferometry-based device.METHODS 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 cornea 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. RESULTS 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, 0.022mm and 0.021 mm, respectively. CONCLUSIONS 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 but the disagreement could be refined by readjustment of intraocular lens constant in clinical practice.

scholarly journals Peripheral Anterior Chamber Depth and Screening Techniques for Primary Angle Closure Disease in Community Elderly Chinese

2020 ◽  
Author(s):  
Wenwen Xue ◽  
Qin Luo ◽  
Yin Yuan ◽  
Chaowei Fu ◽  
Jiangnan He ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Multivariate Logistic Regression Analysis ◽  
Population Based ◽  
Cross Sectional Study ◽  
Angle Closure ◽  
Cross Sectional ◽  
Primary Angle Closure ◽  
Elderly Chinese

Abstract Purpose To investigate the distribution of peripheral anterior chamber depth (ACD) and the relationship between peripheral ACD and gonioscopy compared to other ocular parameters (peripheral ACD, spherical equivalent [SE], intraocular pressure [IOP]) for primary angle closure disease (PACD) screening in an elderly Chinese community. Methods Cross-sectional study. Adults 50 and older were enrolled from a population-based study using cluster random sampling in Pudong New District, Shanghai. Remote ocular screening was performed with digital anterior eye structure photography. Van Herrick measurements were used to evaluate the peripheral ACD, the depth of the peripheral anterior chamber, and corneal thickness (CT), and the ACD to CT ratio was calculated. Subjects with peripheral ACD less than 0.5 CT were made follow-up appointments for clinical examination with gonioscopy. Receiver operating characteristic curves (ROC) were generated to show the performance of different tests in screening for primary angle closure disease (PACD). Results 2528 adults participated in the study with 91 patients diagnosed with PACD. 2463 subjects had valid data in the right eye available for analysis. The mean peripheral ACD values for men and women were significantly different: 1.04±0.46 (range 0.11-2.93) CT and 0.87±0.41 (range 0.12-2.96) CT respectively (t=-4.18; P<0.0001). Multivariate logistic regression analysis reveals that peripheral ACD declined by 0.31 CT (P<0.0001) per diopter of SE and was 0.19 CT (P<0.0001) shallower in women than in men (r2=0.1304, P<0.0001). Peripheral ACD performed best in screening for PACD. Conclusions Peripheral ACD measurement is recommended for PACD screening in community elderly Chinese.

Comparison of ocular biometric parameters between concomitant exotropic and orthotropic eyes

2020 ◽  
Author(s):  
Weifen Gong ◽  
Fan Yang ◽  
Shibin Lin ◽  
Geng Wang
Keyword(s):  
Strong Correlation ◽  
Partial Correlation ◽  
Pearson Correlation ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Correlation Coefficients ◽  
Cross Sectional Study ◽  
Spherical Equivalent ◽  
Cross Sectional ◽  
Cover Test

Abstract PurposeTo compare the biometric characteristics between concomitant exotropia (XT) and orthotropia (OT) with OA2000.MethodThis cross-sectional study collected 4–18 years old children. All subjects underwent a comprehensive ophthalmic examination and prism alternate cover test for ocular alignment measurement. Included subjects had no any eye surgery, structural ocular anomalies, amblyopia of either eyes, ptosis, cataract and nystagmus. OA-2000 was used for the measurement of ocular biological parameters. Spherical equivalent (SE, spherical power + (cylindrical power)/2), keratometry, central corneal thickness (CCT), white to white distance (WTW), pupil diameter (PD), anterior chamber depth (ACD), lens thickness (LT), axial lengths (AL) and intereye differences in SE, keratometry, CCT, WTW, PD, ACD, LT and AL were analyzed by independent sample t-tests. Pearson correlation was used for correlations assessment. Partial correlation was used to control for intereye differences in SE.ResultsA total of 156 subjects (79 XT and 77 OT) were collected. Intereye differences in spherical equivalent (SE) (t 2.369, P 0.019), AL (t 3.423, P 0.001), ACD (t 3.782, P < 0.001), LT (t 3.136, P 0.002) and PD (t 3.229, P 0.002) were significantly larger in XT patients than OT patients. The correlation coefficient of XT with SE asymmetry was 0.187 (P 0.020), 0.265 with AL asymmetry (P 0.001), 0.289 with ACD asymmetry (P < 0.001), 0.251 with PD asymmetry (P 0.002) and 0.243 with LT asymmetry (P 0.002). Strong correlation (r 0.875) was found between anisometropia and AL asymmetry. After controlling the effect of anisometropia, the correlation coefficients slightly reduced between XT patients and intereye differences in AL (reduced to 0.213), ACD (reduced to 0.266), PD (reduced to 0.230) and LT (reduced to 0.230). Strong correlation (r 0.855) was found between intereye differences in ACD and LT.ConclusionCompared with OT subjects, intereye differences in SE, AL, ACD, LT and PD were significantly larger in XT patients and had positive correlation with XT and may be associated with the pathogenesis of XT.

Lens power in Iranian schoolchildren: a population-based study

2017 ◽  
Vol 102 (6) ◽  
pp. 779-783 ◽  
Author(s):  
Hassan Hashemi ◽  
Reza Pakzad ◽  
Rafael Iribarren ◽  
Mehdi Khabazkhoob ◽  
Mohammad Hassan Emamian ◽  
...  
Keyword(s):  
Anterior Chamber Depth ◽  
Multiple Linear Regression Model ◽  
Population Based ◽  
Cross Sectional Study ◽  
Cluster Sampling ◽  
Cross Sectional ◽  
Total Study Population ◽  
Study Population ◽  
The Mean ◽  
Lens Power

AimsTo evaluate lens power (LP) in schoolchildren aged 6–12 years.MethodsThis cross-sectional study was conducted in Shahroud, northeast Iran. The students were selected through random cluster sampling and underwent the measurements of biometry, uncorrected and corrected visual acuity, non-cycloplegic and cycloplegic refraction. The LP was calculated using the Bennett formula.ResultsOf 6624 invited children, 5620 (84.8%) participated in the study and data of 4870 children were finally analysed. The mean age of the participants was 9.7 years and 2277 participants (46.02%) were girls. The mean LPs were 22.86 dioptres (D) in total study population, 23.91 D in 6 and 22.10 D in 12-year-old children. The mean LP was higher in girls than boys (23.48 D vs 22.34 D), in rural children than urban children (23.17 D vs 22.83 D) and in children with hyperopia (23.25 D) than children with myopia or emmetropia (22.64 D and 22.86 D, respectively). In the multiple linear regression model, lens thickness (β=1.59, p<0.001), anterior chamber depth (β=2.21, p<0.001) and female sex (β=0.016, p=0.015) were associated with an increase in the LP, while axial length (AL) (β=−4.41, p<0.001), corneal power (CP) (β=−1.47, p<0.001), spherical equivalent (SE) (β=−1.50, p<0.001) and age (β=−0.005, p=0.001) were associated with a decrease in the LP. AL and sex had the highest and lowest impact on LP, respectively.ConclusionLP decreased with age between 6 and 12 years and was associated with a shorter AL, deeper ACD, higher SE, thicker lens and lower CP.

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