The Experts below are selected from a list of 12261 Experts worldwide ranked by ideXlab platform
Jianhua Wang - One of the best experts on this subject based on the ideXlab platform.
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anterior segment Biometry of the accommodating intraocular lens and its relationship with the amplitude of accommodation
Eye & Contact Lens-science and Clinical Practice, 2017Co-Authors: Lin Leng, Qi Chen, Yimin Yuan, Dexi Zhu, Jianhua Wang, Meixiao ShenAbstract:Objectives:To evaluate the anterior segment Biometry of the Tetraflex accommodating intraocular lens (AIOL) and the contribution of forward movement to the amplitude of accommodation (AMP).Methods:Patients who underwent phacoemulsification with implantation of Tetraflex AIOLs and control nonaccommod
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wavefront derived refraction and full eye Biometry in pseudophakic eyes
PLOS ONE, 2016Co-Authors: Xinjie Mao, Hong Jiang, James T Banta, Che Liu, Jianhua WangAbstract:Purpose To assess wavefront derived refraction and full eye Biometry including ciliary muscle dimension and full eye axial geometry in pseudophakic eyes using spectral domain OCT equipped with a Shack-Hartmann wavefront sensor. Methods Twenty-eight adult subjects (32 pseudophakic eyes) having recently undergone cataract surgery were enrolled in this study. A custom system combining two optical coherence tomography systems with a Shack-Hartmann wavefront sensor was constructed to image and monitor changes in whole eye Biometry, the ciliary muscle and ocular aberration in the pseudophakic eye. A Badal optical channel and a visual target aligning with the wavefront sensor were incorporated into the system for measuring the wavefront-derived refraction. The imaging acquisition was performed twice. The coefficients of repeatability (CoR) and intraclass correlation coefficient (ICC) were calculated. Results Images were acquired and processed successfully in all patients. No significant difference was detected between repeated measurements of ciliary muscle dimension, full-eye Biometry or defocus aberration. The CoR of full-eye Biometry ranged from 0.36% to 3.04% and the ICC ranged from 0.981 to 0.999. The CoR for ciliary muscle dimensions ranged from 12.2% to 41.6% and the ICC ranged from 0.767 to 0.919. The defocus aberrations of the two measurements were 0.443 ± 0.534 D and 0.447 ± 0.586 D and the ICC was 0.951. Conclusions The combined system is capable of measuring full eye Biometry and refraction with good repeatability. The system is suitable for future investigation of pseudoaccommodation in the pseudophakic eye.
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whole eye axial Biometry during accommodation using ultra long scan depth optical coherence tomography
American Journal of Ophthalmology, 2014Co-Authors: Jianguang Zhong, Zhe Xu, Hong Jiang, Yilei Shao, Huicheng Zhang, Jianhua WangAbstract:Purpose To investigate changes of whole eye axial Biometry during accommodation using ultra-long scan depth optical coherence tomography (UL-OCT). Design Prospective, observational case series. Methods Twenty-one adult subjects were enrolled. Using UL-OCT, the left eye of each subject was imaged with relaxed diopters (0 D) and accommodative stimuli (+6 D). Full eye Biometry included central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness, vitreous length, and axial length (AL). Results During accommodation (+6 D), the axial Biometry of the whole eye changed significantly. Compared to the rest state, ACD at the accommodative state decreased significantly from 3.128 ± 0.305 mm to 2.961 ± 0.298 mm (paired t test, P P P P Conclusions During accommodation, whole eye axial Biometry changed, including a decrease in ACD and vitreous length and an increase in lens thickness and AL. UL-OCT provides an alternative method that is suitable for full eye Biometry during accommodation.
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axial Biometry of the entire eye using ultra long scan depth optical coherence tomography
American Journal of Ophthalmology, 2014Co-Authors: Jianguang Zhong, Hong Jiang, Yilei Shao, Huicheng Zhang, Jianhua WangAbstract:Purpose To assess the repeatability of axial Biometry of the entire eye using ultra-long scan depth optical coherence tomography (OCT) and to investigate the agreement with IOLMaster measurements (Carl Zeiss Meditec). Design Prospective, observational case series. Methods There were 37 adult subjects enrolled in group 1 and 12 adult subjects enrolled in group 2. Using ultra-long scan depth OCT, the left eyes of these groups were measured in 2 separate sessions. The images were processed by a manual method and custom-developed automatic software. A model eye was imaged for verification. The subjects in group 2 were imaged using ultra-long scan depth OCT and using the IOLMaster for axial length measurement comparison. Results All measured parameters of the model eye matched the geometric parameters. In group 1, there were no significant differences in all measured parameters using automatic and manual segmentation methods ( P > .05, paired t test). The percentage of coefficient of repeatability of segments ranged from 0.3% to 3.9%. The corresponding interclass correlation coefficients ranged from 0.946 to 0.999. The correlation between the results using automatic and manual segmentation methods appeared to be strong ( R 2 = 0.999; P R 1 2 = 0.987; P R 2 2 = 0.988; P Conclusions Automatic axial Biometry using ultra-long scan depth OCT successfully measured each segment of the entire eye with good repeatability. With further development of automatic segmentation, ultra-long scan depth OCT seems to be a promising tool in the axial Biometry of the entire eye.
Oliver Findl - One of the best experts on this subject based on the ideXlab platform.
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macular disease detection with a swept source optical coherence tomography based Biometry device in patients scheduled for cataract surgery
Journal of Cataract and Refractive Surgery, 2016Co-Authors: Nino Hirnschall, Christoph Leisser, Stephan Radda, Sophie Maedel, Oliver FindlAbstract:Purpose To assess the sensitivity and specificity for detecting macular disease with a new optical Biometry device with swept-source optical coherence tomography (SS-OCT) used before cataract surgery. Setting Hanusch Hospital, Vienna, Austria. Design Consecutive case series. Methods This study included patients with or without macular disease. All patients were scanned using the new Biometry device (IOLMaster 700), which allows a 1.0 mm central retinal scan using SS-OCT technology. Also, all eyes were assessed using a dedicated retinal OCT device (RTVue) on the same day. Two experienced examiners and 1 ophthalmology resident graded all scans individually. Sensitivity and specificity for detecting macular disease were assessed, as were the receiver operating characteristic curves. Results Of the 125 eyes included, 5 were excluded from the analysis, 65 had a macular disease, and 55 were healthy. The sensitivity of the Biometry device was moderate (between 42% and 68%), and the specificity was high (89% to 98%). Intraobserver reproducibility for assessing the Biometry device was 88.3%. Conclusions The Biometry device with SS-OCT provided useful information concerning the macula, especially for intraretinal fluid and macular holes. However, it cannot replace a macular OCT device. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.
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influence of operator experience on the performance of ultrasound Biometry compared to optical Biometry before cataract surgery
Journal of Cataract and Refractive Surgery, 2003Co-Authors: Oliver Findl, Georg Rainer, Katharina Kriechbaum, Stefan Sacu, Barbara Kiss, Kaija Polak, Johannes Nepp, Gebtraud Schild, Saskia M Maca, Vanessa PetternelAbstract:Abstract Purpose To compare measurements performed with the IOLMaster (Carl Zeiss, Meditec AG) with those obtained by applanation ultrasound (US) and manual keratometry and to evaluate the effect of operator experience on US Biometry. Setting Department of Ophthalmology, University of Vienna, Vienna, Austria. Methods The axial length (696 eyes) and anterior chamber depth (ACD) (462 eyes) were measured in 377 patients with cataract using the IOLMaster and applanation US. To assess the effect of operator experience on the biometric results, the operators were divided into 2 groups: experienced and less experienced in performing US Biometry. The difference in measurements between the methods and the variability of the difference were compared between the 2 groups. Results Applanation US measured axial length and ACD shorter than the IOLMaster; the mean numerical difference was 0.13 mm and 0.19 mm, respectively ( P P P Conclusions Experienced US operators had less difference and lower variability in the difference between applanation US and IOLMaster readings for axial length and ACD measurements. The noncontact optical method, which is essentially operator independent, gave significantly more reliable Biometry before cataract surgery, especially in the case of less experienced operators.
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refractive outcome of cataract surgery using partial coherence interferometry and ultrasound Biometry clinical feasibility study of a commercial prototype ii
Journal of Cataract and Refractive Surgery, 2002Co-Authors: Barabara Kiss, Wolfgang Drexler, Christoph K. Hitzenberger, Oliver Findl, Rupert Menapace, Georg Rainer, Vanessa Petternel, Matthias Wirtitsch, Michael Georgopoulos, Adolf Friedrich FercherAbstract:Abstract Purpose: To evaluate the refractive outcome of cataract patients 3 months postoperatively using optical Biometry obtained with a prototype version (axial length measurement, ALM, Carl Zeiss Jena) of the commercial partial coherence interferometry (PCI) instrument (IOLMaster, Carl Zeiss Jena). Setting: Department of Ophthalmology, Vienna General Hospital, and Institute of Medical Physics, University of Vienna, Austria. Methods: Forty-five patients with age-related cataract in both eyes were scheduled for bilateral cataract surgery. Axial length was measured preoperatively with a prototype (ALM) of the commercial PCI instrument as well as with immersion ultrasound (IUS). Immersion US was performed by a single experienced investigator. In each patient, the first eye was randomly assigned to receive an intraocular lens (IOL) using the Holladay IOL power formula based on ALM or IUS Biometry. The other biometric technique was used in the contralateral eye. Subjective refractive outcome was assessed 3 months postoperatively. Results: Refractive outcomes with the 2 techniques did not differ significantly ( P = .28). The mean numerical error (MNE) (the difference between the refractive outcome 3 months postoperatively and the predicted spherical equivalent) was 0.13 diopter (D) and 0.03 D for the ALM and IUS, respectively. The mean absolute error (MAE) (the absolute value of MNE) was 0.48 D (range 0.00 to 1.58 D) and 0.46 D (range 0.01 to 1.92 D) with the ALM and IUS, respectively. By recalculating the surgeon factor retrospectively to correct the Holladay formula to obtain a postoperative MNE of zero, a theoretical MAE of 0.46 D was obtained with both Biometry techniques. Conclusions: Refractive outcome in cataract patients using PCI Biometry was as good as that achieved with optimized IUS. However, the difference in axial length measured by the ALM compared to that measured by IUS must be considered when using the IOL A-constants supplied by the manufacturers.
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improved prediction of intraocular lens power using partial coherence interferometry
Journal of Cataract and Refractive Surgery, 2001Co-Authors: Oliver Findl, Wolfgang Drexler, Christoph K. Hitzenberger, Rupert Menapace, Harald Heinzl, Adolf Friedrich FercherAbstract:Abstract Purpose To evaluate the feasibility of using a new optical Biometry technique, dual-beam partial coherence interferometry (PCI), to improve intraocular lens (IOL) power prediction in cataract surgery. Setting Department of Ophthalmology, Vienna General Hospital, and Institute of Medical Physics, University of Vienna, Vienna, Austria. Methods Preoperative axial length (AL) data obtained with PCI Biometry and applanation ultrasound (US) Biometry in 77 eyes of 51 patients was applied to 4 commonly used IOL power formulas. The refractive outcome and the mean absolute error (MAE) were calculated for each formula using both Biometry methods. A linear multiple-regression model based on preoperative PCI Biometry data was derived to predict the postoperative anterior chamber depth (ACD). The predictive power of this regression model was assessed by adding the predicted ACD to the SRK/T formula. Predicted residuals were calculated to evaluate the feasibility and stability of this modified IOL power formula. Results Using PCI instead of US Biometry significantly improved the refractive outcome with all 4 IOL power formulas. The Holladay I and SRK/T formulas yielded an MAE of 0.44 diopter (D) using PCI AL data and 0.56 D and 0.57 D, respectively, using US Biometry data. The SRK/T formula combined with the PCI regression model for postoperative ACD prediction performed slightly better (MAE 0.42 D) than the conventional SRK/T formula alone. Predicted residuals revealed an MAE of 0.46 D, proving the predictive performance of the new formula. Conclusions Partial coherence interferometry Biometry applied to several widely used IOL power formulas yielded significantly better IOL power prediction and therefore refractive outcome in cataract surgery than US Biometry. Further improvement can be achieved by applying PCI to a modified SRK/T formula that predicts the postoperative ACD using PCI Biometry data.
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partial coherence interferometry a novel approach to Biometry in cataract surgery
American Journal of Ophthalmology, 1998Co-Authors: Wolfgang Drexler, Christoph K. Hitzenberger, Oliver Findl, Rupert Menapace, Georg Rainer, Clemens Vass, Adolf Friedrich FercherAbstract:Abstract PURPOSE: To compare Biometry performed by an enhanced version of dual beam partial coherence interferometry and applanation ultrasound in a prospective study of 85 cataract eyes to improve refractive outcome of cataract surgery due to a more accurate calculation of intraocular lens power. METHODS: The SRK II formula using ultrasound Biometry data was employed. Three months after surgery, partial coherence interferometry Biometry was repeated and refractive outcome was determined. Preoperative partial coherence interferometry Biometry data were used to determine the refractive power of the intraocular lenses retrospectively and to calculate the possible refractive outcome. RESULTS: Precision of partial coherence interferometry Biometry was more than 10 times better than that of ultrasound. Therefore, the possible mean absolute error for postoperative refraction achieved with partial coherence interferometry Biometry was 0.49 diopters (compared with 0.67 diopters with ultrasound Biometry), resulting in an improvement of 27%. Axial eye length measured with the two techniques differed by a mean of 460 μm. The difference in lens thickness measured with partial coherence interferometry and ultrasound significantly correlated with cataract grade. A mean shortening of 120 μm of axial eye length following cataract surgery was also detected by partial coherence interferometry. CONCLUSIONS: The enhanced version of partial coherence interferometry offers Biometry with unprecedented precision (
Yilei Shao - One of the best experts on this subject based on the ideXlab platform.
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whole eye axial Biometry during accommodation using ultra long scan depth optical coherence tomography
American Journal of Ophthalmology, 2014Co-Authors: Jianguang Zhong, Zhe Xu, Hong Jiang, Yilei Shao, Huicheng Zhang, Jianhua WangAbstract:Purpose To investigate changes of whole eye axial Biometry during accommodation using ultra-long scan depth optical coherence tomography (UL-OCT). Design Prospective, observational case series. Methods Twenty-one adult subjects were enrolled. Using UL-OCT, the left eye of each subject was imaged with relaxed diopters (0 D) and accommodative stimuli (+6 D). Full eye Biometry included central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness, vitreous length, and axial length (AL). Results During accommodation (+6 D), the axial Biometry of the whole eye changed significantly. Compared to the rest state, ACD at the accommodative state decreased significantly from 3.128 ± 0.305 mm to 2.961 ± 0.298 mm (paired t test, P P P P Conclusions During accommodation, whole eye axial Biometry changed, including a decrease in ACD and vitreous length and an increase in lens thickness and AL. UL-OCT provides an alternative method that is suitable for full eye Biometry during accommodation.
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axial Biometry of the entire eye using ultra long scan depth optical coherence tomography
American Journal of Ophthalmology, 2014Co-Authors: Jianguang Zhong, Hong Jiang, Yilei Shao, Huicheng Zhang, Jianhua WangAbstract:Purpose To assess the repeatability of axial Biometry of the entire eye using ultra-long scan depth optical coherence tomography (OCT) and to investigate the agreement with IOLMaster measurements (Carl Zeiss Meditec). Design Prospective, observational case series. Methods There were 37 adult subjects enrolled in group 1 and 12 adult subjects enrolled in group 2. Using ultra-long scan depth OCT, the left eyes of these groups were measured in 2 separate sessions. The images were processed by a manual method and custom-developed automatic software. A model eye was imaged for verification. The subjects in group 2 were imaged using ultra-long scan depth OCT and using the IOLMaster for axial length measurement comparison. Results All measured parameters of the model eye matched the geometric parameters. In group 1, there were no significant differences in all measured parameters using automatic and manual segmentation methods ( P > .05, paired t test). The percentage of coefficient of repeatability of segments ranged from 0.3% to 3.9%. The corresponding interclass correlation coefficients ranged from 0.946 to 0.999. The correlation between the results using automatic and manual segmentation methods appeared to be strong ( R 2 = 0.999; P R 1 2 = 0.987; P R 2 2 = 0.988; P Conclusions Automatic axial Biometry using ultra-long scan depth OCT successfully measured each segment of the entire eye with good repeatability. With further development of automatic segmentation, ultra-long scan depth OCT seems to be a promising tool in the axial Biometry of the entire eye.
Jianguang Zhong - One of the best experts on this subject based on the ideXlab platform.
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whole eye axial Biometry during accommodation using ultra long scan depth optical coherence tomography
American Journal of Ophthalmology, 2014Co-Authors: Jianguang Zhong, Zhe Xu, Hong Jiang, Yilei Shao, Huicheng Zhang, Jianhua WangAbstract:Purpose To investigate changes of whole eye axial Biometry during accommodation using ultra-long scan depth optical coherence tomography (UL-OCT). Design Prospective, observational case series. Methods Twenty-one adult subjects were enrolled. Using UL-OCT, the left eye of each subject was imaged with relaxed diopters (0 D) and accommodative stimuli (+6 D). Full eye Biometry included central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness, vitreous length, and axial length (AL). Results During accommodation (+6 D), the axial Biometry of the whole eye changed significantly. Compared to the rest state, ACD at the accommodative state decreased significantly from 3.128 ± 0.305 mm to 2.961 ± 0.298 mm (paired t test, P P P P Conclusions During accommodation, whole eye axial Biometry changed, including a decrease in ACD and vitreous length and an increase in lens thickness and AL. UL-OCT provides an alternative method that is suitable for full eye Biometry during accommodation.
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axial Biometry of the entire eye using ultra long scan depth optical coherence tomography
American Journal of Ophthalmology, 2014Co-Authors: Jianguang Zhong, Hong Jiang, Yilei Shao, Huicheng Zhang, Jianhua WangAbstract:Purpose To assess the repeatability of axial Biometry of the entire eye using ultra-long scan depth optical coherence tomography (OCT) and to investigate the agreement with IOLMaster measurements (Carl Zeiss Meditec). Design Prospective, observational case series. Methods There were 37 adult subjects enrolled in group 1 and 12 adult subjects enrolled in group 2. Using ultra-long scan depth OCT, the left eyes of these groups were measured in 2 separate sessions. The images were processed by a manual method and custom-developed automatic software. A model eye was imaged for verification. The subjects in group 2 were imaged using ultra-long scan depth OCT and using the IOLMaster for axial length measurement comparison. Results All measured parameters of the model eye matched the geometric parameters. In group 1, there were no significant differences in all measured parameters using automatic and manual segmentation methods ( P > .05, paired t test). The percentage of coefficient of repeatability of segments ranged from 0.3% to 3.9%. The corresponding interclass correlation coefficients ranged from 0.946 to 0.999. The correlation between the results using automatic and manual segmentation methods appeared to be strong ( R 2 = 0.999; P R 1 2 = 0.987; P R 2 2 = 0.988; P Conclusions Automatic axial Biometry using ultra-long scan depth OCT successfully measured each segment of the entire eye with good repeatability. With further development of automatic segmentation, ultra-long scan depth OCT seems to be a promising tool in the axial Biometry of the entire eye.
Hong Jiang - One of the best experts on this subject based on the ideXlab platform.
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wavefront derived refraction and full eye Biometry in pseudophakic eyes
PLOS ONE, 2016Co-Authors: Xinjie Mao, Hong Jiang, James T Banta, Che Liu, Jianhua WangAbstract:Purpose To assess wavefront derived refraction and full eye Biometry including ciliary muscle dimension and full eye axial geometry in pseudophakic eyes using spectral domain OCT equipped with a Shack-Hartmann wavefront sensor. Methods Twenty-eight adult subjects (32 pseudophakic eyes) having recently undergone cataract surgery were enrolled in this study. A custom system combining two optical coherence tomography systems with a Shack-Hartmann wavefront sensor was constructed to image and monitor changes in whole eye Biometry, the ciliary muscle and ocular aberration in the pseudophakic eye. A Badal optical channel and a visual target aligning with the wavefront sensor were incorporated into the system for measuring the wavefront-derived refraction. The imaging acquisition was performed twice. The coefficients of repeatability (CoR) and intraclass correlation coefficient (ICC) were calculated. Results Images were acquired and processed successfully in all patients. No significant difference was detected between repeated measurements of ciliary muscle dimension, full-eye Biometry or defocus aberration. The CoR of full-eye Biometry ranged from 0.36% to 3.04% and the ICC ranged from 0.981 to 0.999. The CoR for ciliary muscle dimensions ranged from 12.2% to 41.6% and the ICC ranged from 0.767 to 0.919. The defocus aberrations of the two measurements were 0.443 ± 0.534 D and 0.447 ± 0.586 D and the ICC was 0.951. Conclusions The combined system is capable of measuring full eye Biometry and refraction with good repeatability. The system is suitable for future investigation of pseudoaccommodation in the pseudophakic eye.
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whole eye axial Biometry during accommodation using ultra long scan depth optical coherence tomography
American Journal of Ophthalmology, 2014Co-Authors: Jianguang Zhong, Zhe Xu, Hong Jiang, Yilei Shao, Huicheng Zhang, Jianhua WangAbstract:Purpose To investigate changes of whole eye axial Biometry during accommodation using ultra-long scan depth optical coherence tomography (UL-OCT). Design Prospective, observational case series. Methods Twenty-one adult subjects were enrolled. Using UL-OCT, the left eye of each subject was imaged with relaxed diopters (0 D) and accommodative stimuli (+6 D). Full eye Biometry included central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness, vitreous length, and axial length (AL). Results During accommodation (+6 D), the axial Biometry of the whole eye changed significantly. Compared to the rest state, ACD at the accommodative state decreased significantly from 3.128 ± 0.305 mm to 2.961 ± 0.298 mm (paired t test, P P P P Conclusions During accommodation, whole eye axial Biometry changed, including a decrease in ACD and vitreous length and an increase in lens thickness and AL. UL-OCT provides an alternative method that is suitable for full eye Biometry during accommodation.
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axial Biometry of the entire eye using ultra long scan depth optical coherence tomography
American Journal of Ophthalmology, 2014Co-Authors: Jianguang Zhong, Hong Jiang, Yilei Shao, Huicheng Zhang, Jianhua WangAbstract:Purpose To assess the repeatability of axial Biometry of the entire eye using ultra-long scan depth optical coherence tomography (OCT) and to investigate the agreement with IOLMaster measurements (Carl Zeiss Meditec). Design Prospective, observational case series. Methods There were 37 adult subjects enrolled in group 1 and 12 adult subjects enrolled in group 2. Using ultra-long scan depth OCT, the left eyes of these groups were measured in 2 separate sessions. The images were processed by a manual method and custom-developed automatic software. A model eye was imaged for verification. The subjects in group 2 were imaged using ultra-long scan depth OCT and using the IOLMaster for axial length measurement comparison. Results All measured parameters of the model eye matched the geometric parameters. In group 1, there were no significant differences in all measured parameters using automatic and manual segmentation methods ( P > .05, paired t test). The percentage of coefficient of repeatability of segments ranged from 0.3% to 3.9%. The corresponding interclass correlation coefficients ranged from 0.946 to 0.999. The correlation between the results using automatic and manual segmentation methods appeared to be strong ( R 2 = 0.999; P R 1 2 = 0.987; P R 2 2 = 0.988; P Conclusions Automatic axial Biometry using ultra-long scan depth OCT successfully measured each segment of the entire eye with good repeatability. With further development of automatic segmentation, ultra-long scan depth OCT seems to be a promising tool in the axial Biometry of the entire eye.