To assess the repeatability and reproducibility of 3 rotating Scheimpflug cameras, the Pentacam (Oculus, Wetzlar, Germany), Sirius (Costruzione Strumenti Oftalmici, Florence, Italy), and Galilei ...(Ziemer, Biel, Switzerland), and 1 Fourier-domain optical coherence tomography (FD-OCT) system, the RTvue-100 OCT (Optovue Inc., Fremont, CA), in measuring corneal thickness.
Evaluation of diagnostic test.
Sixty-six right eyes of 66 healthy volunteers, whose mean age ± standard deviation (SD) was 35.39±10.06 years (range, 18-55 years).
Corneal thickness measurements obtained by each system included central corneal thickness (CCT), thinnest corneal thickness (TCT), and midperipheral corneal thickness (MPCT), measured at superior, inferior, nasal, and temporal locations at a distance of 1 and 2.5 mm from the corneal apex. In the first session, 3 consecutive measurements were performed by the same operator to assess intraobserver repeatability and by a second operator to assess interobserver reproducibility. Measurements were repeated in the second session scheduled 1 day to 1 week later. The mean values obtained in the 2 sessions by the first operator were used to investigate the intersession reproducibility.
Intraobserver repeatability and interobserver and intersession repeatability of corneal thickness measurements, as calculated by means of within-subject SD, test-retest repeatability, coefficient of variation (COV), and intraclass correlation coefficients.
The precision of CCT, TCT, CT2 mm (midperipheral corneal thickness MPCT with a distance of 1 mm from the corneal apex), and CT5 mm (midperipheral corneal thickness MPCT with a distance of 2.5 mm from the corneal apex) measurements was high with all 4 systems. The COV was ≤1.16%, 0.94%, and 1.10% for repeatability, interobserver reproducibility, and intersession reproducibility, respectively. The 4 devices offered better interobserver reproducibility than intersession reproducibility for all measurements. The CTsuperior-5 mm (midperipheral corneal thickness MPCT, measured at superior locations with a distance of 2.5 mm from the corneal apex) measurements showed the poorest repeatability and reproducibility. The Galilei revealed the best precision of CCT, TCT, and CT2 mm measurements.
Both Scheimpflug imaging and FD-OCT offer highly repeatable and reproducible measurements of CCT and MPCT. The precision was lower in the midperipheral superior quadrant.
The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Guided bone regeneration (GBR) is widely used in treating oral bone defects to exclude the influence of non-osteogenic tissue on the bone healing process. The traditional method of GBR with a ...titanium mesh to treat large-area bone defects is limited by the deficiency of increased trauma and costs to patients. Herein, a bi-layered scaffold for GBR composed of a fiber barrier layer and a self-healing hydrogel repair layer is successfully fabricated. The barrier layer is a fibrous membrane material with specific porosity constructed by electrospinning, while the functional layer is a self-healing hydrogel material formed by multiple dynamic covalent bonds. The system can provide an osteogenic microenvironment by preventing the infiltration of connective tissue to bone defects, maintain the stability of the osteogenic space through the self-healing property, and regulate the release of bioactive substances in the dynamic physical condition, which is beneficial to osteoblast proliferation, differentiation, and bone regeneration. This study focused on exploring the effects of different crosslinkers and bonding methods on the comprehensive properties of hydrogels. and proved that the hybrid scaffold system has good biocompatibility, cell barrier function and can enhance bone regeneration activity. Thereby it could be a promising clinical strategy for bone regeneration.
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Purpose: To compare the repeatability and reproducibility of central corneal thickness (CCT) measurements by high‐resolution (HR) rotating Scheimpflug imaging and Fourier‐domain optical coherence ...tomography (FD‐OCT). CCT measurements were compared to those determined by ultrasound pachymetry (UP).
Methods: In 35 healthy eyes, intra‐observer repeatability for HR Scheimpflug (Pentacam) and FD‐OCT (RTVue) systems was determined in consecutive images taken by an observer in the shortest time possible. Imaging was repeated again by a second observer to evaluate inter‐observer reproducibility. The CCT measurements were compared among Scheimpflug, FD‐OCT and UP images.
Results: Mean coefficients of repeatability were 0.48% for Scheimpflug and 0.26% for FD‐OCT. For Scheimpflug, the coefficient of inter‐operator reproducibility was 0.87%. For FD‐OCT, the coefficient of inter‐operator reproducibility was 0.45%. The CCT measurements by Scheimpflug, OCT and UP images were (mean ± standard deviation) 521.7 ± 27.6 μm, 510.8 ± 28.6 μm and 516.5 ± 27.6 μm, respectively. The differences between instruments were statistically significant. The 95% limits of agreement in CCT were −0.7 to 22.5 μm for Pentacam‐OCT, −13.4 to 24.0 μm for Pentacam‐UP and −26.7 to 15.4 μm for OCT‐UP. There was a high degree of correlation between CCT measured by all 3 methods.
Conclusion: Noncontact measurements of CCT with HR Scheimpflug and FD‐OCT systems yielded excellent repeatability and reproducibility and can be used interchangeably. Although both devices were comparable with UP; in clinical practice, the measurements acquired by optical modalities are not directly interchangeable with UP measurements.
Abstract Purpose To compare a new swept source optical coherence tomography (SS-OCT) based biometer (OA-2000) with the IOLMaster v5.4 (partial coherence interferometry) and Aladdin (optical ...low-coherence interferometry) biometers in terms of axial length measurement and failure rate in eyes with cataract. Design Reliability study Methods A total of 377 eyes of 210 patients were scanned with the three biometers in a random order. For each biometer, the number of unobtainable axial length measurements was recorded and grouped as per the type and severity of cataract based on the Lens Opacities Classification System III by the same experienced ophthalmologist. The Bland-Altman limits of agreement (LoA) method was used to assess the agreement in axial length measurements between the three biometers. Results The failure rate was 0 eyes (0%) with the OA-2000, 136 eyes (36.07%) with the IOLMaster and 51 eyes (13.53%) with the Aladdin. Chi-squared analyses indicated a significant difference in failure rate between all three devices (P<0.001). Logistic regression analysis highlighted a statistically significant trend of higher failure rates with increasing severity of nuclear, cortical and posterior subcapsular cataracts. Bland-Altman statistics indicated small mean differences and narrow LoA (OA-2000 versus IOLMaster -0.09 to 0.08mm; OA-2000 versus Aladdin -0.10 to 0.07mm; IOLMaster versus Aladdin -0.05 to 0.04mm). Conclusions The OA-2000, a new SS-OCT based biometer, outperformed both the IOLMaster and Aladdin biometers in very advanced cataracts of various morphologies. The use of SS-OCT technology may be the reason for the improved performance of the OA-2000 and may lead to this technology becoming the gold standard for the measurement of axial length.
To evaluate axial length (AL) measurement failure rate with the IOLMaster (Carl Zeiss AG, Germany) and Lenstar LS 900 (Haag-Streit AG, Switzerland) in eyes with cataract.
Two hundred and ninety-six ...eyes of 170 patients with cataract were enrolled. Cataract type and severity were graded using the Lens Opacities Classification System III (LOCS III) and AL measurements were attempted with IOLMaster (version 5.4) and Lenstar LS 900 (version 1.1). Chi-squared analysis was used to assess if the difference in AL measurement acquisition rate was statistically significant between the two devices. The association of the different cataract types and severity with the AL measurement acquisition rate was evaluated with logistic regression analysis.
AL measurements were obtained in 184 eyes (62.16%) using the IOLMaster and 191 eyes (64.53%) using the Lenstar, which corresponds to a failure rate of 37.84% and 35.47% respectively. Chi-square analysis indicated no significant difference between the Lenstar and IOLMaster for AL measurement failure rate (x2 = 0.356, P = 0.550). Logistic regression analysis indicated no association between acquisition rates and cortical or nuclear cataracts with either device. There was a statistically significant association between acquisition rates and increasing severity of posterior subcapsular cataracts with the IOLMaster (β = -1.491, P<0.001) and Lenstar LS 900 (β = -1.507, P<0.001).
The IOLMaster and Lenstar LS 900 have similar AL measurement failure rates (35-38%) for Chinese public hospital cataract patients. Increasing severity of posterior subcapsular cataracts was problematic for both devices.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To assess the repeatability of common measurements with the Sirius Scheimpflug-Placido topographer and Lenstar LS900 optical low-coherence reflectometry (OLCR) biometer and the limits of agreement ...(LoA) between the devices.
Eye Hospital of Wenzhou Medical College, Wenzhou, China.
Comparative evaluation of a diagnostic test or technology.
One randomly healthy eye of subjects was scanned 3 times with both devices. The parameters assessed were central corneal thickness (CCT), anterior chamber depth (ACD) from the corneal epithelium and from the endothelium, mean keratometry (K), and white-to-white (WTW) corneal diameter. The repeatability of scans was calculated using the within-subject standard deviation after 1-way analysis of variance was performed. The agreement between devices was assessed using the Bland-Altman LoA method, which equals the mean difference between devices ± 1.96 × standard deviation of the differences. The mean of 3 scans of each device was used to assess the LoA.
Forty subjects were evaluated. The repeatability of the Scheimpflug-Placido topographer and OLCR biometer was 3.10 μm and 3.32 μm for CCT, 0.04 mm and 0.05 mm for WTW corneal diameter, and 0.17 D and 0.10 D for mean K, respectively. The repeatability for both devices was 0.02 mm for the ACD from the corneal epithelium and the ACD from the corneal endothelium. On Bland-Altman LoA analysis, all parameters were within clinically acceptable limits.
Both devices had excellent repeatability for all parameters assessed. Good LoAs were found between the 2 devices, indicating they can be used interchangeably for the parameters assessed.
Purpose To determine the repeatability, reproducibility, and agreement of anterior chamber depth (ACD) measurements obtained with 3 Scheimpflug cameras and an anterior segment optical coherence ...tomography (AS-OCT) device. Setting Eye Hospital of Wenzhou Medical University, Zhejiang, China. Design Observational cross-sectional study. Methods Two observers took 3 consecutive measurements in healthy right eyes using each device to assess intraoperator repeatability. The mean values obtained at different sessions by the first operator were used to determine the intersession reproducibility. Three consecutive measurements obtained by the first operator at the first session were averaged and used to assess agreement. Results The ACD measurements obtained by 2 observers in 71 eyes were highly repeatable using the 4 devices, with a test–retest repeatability of 0.04 to 0.07 mm for intraoperator repeatability. The interoperator and intersession reproducibility of ACD measurements were high, and the test–retest repeatability ranges of interoperator and intersession reproducibility were 0.06 to 0.07 mm and 0.05 to 0.08 mm, respectively. The ACD measurements of the 4 systems were sorted from the thickest to the thinnest (Galilei G2 > Visante > Sirius > Pentacam). The differences in the measurements were statistically significant except between the ACD measurements obtained by the Sirius device and the Visante device. However, good agreement with narrow 95% limits of agreement was found between these devices. Conclusions The 4 devices provided high intraoperator repeatability and interoperator and intersession reproducibility for ACD measurements. Good agreement in ACD measurements was found between the devices in healthy eyes. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.
To evaluate the safety, efficacy, and predictability of IntraLase (Abbott Medical Optics) femtosecond laser-assisted compared to microkeratome-assisted myopic LASIK.
A comprehensive literature search ...of Cochrane Library, PubMed, and EMBASE was conducted to identify relevant trials comparing LASIK with IntraLase femtosecond laser to LASIK with microkeratomes for the correction of myopia. Meta-analyses were performed on the primary outcomes (loss of ≥2 lines of corrected distance visual acuity CDVA, uncorrected distance visual acuity UDVA 20/20 or better, manifest refraction spherical equivalent MRSE within ±0.50 diopters D, final refractive SE, and astigmatism), and secondary outcomes (flap thickness predictability, changes in higher order aberrations HOAs, and complications).
Fifteen articles describing a total of 3679 eyes were identified. No significant differences were identified between the two groups in regards to a loss of ≥2 lines of CDVA (P=.44), patients achieving UDVA 20/20 or better (P=.24), final UDVA (P=.12), final mean refractive SE (P=.74), final astigmatism (P=.27), or changes in HOAs. The IntraLase group had more patients who were within ±0.50 D of target refraction (P=.05) compared to the microkeratome group, and flap thickness was more predictable in the IntraLase group (P<.0001). The microkeratome group had more epithelial defects (P=.04), whereas the IntraLase group had more cases of diffuse lamellar keratitis (P=.01).
According to the available data, LASIK with the IntraLase femtosecond laser offers no significant benefits over LASIK with microkeratomes in regards to safety and efficacy, but has potential advantages in predictability.
The purpose of the current study was to compare the measurements between a new optical biometer based on swept-source optical coherence tomography (SS-OCT), the OA-2000 (Tomey, Japan), and an optical ...biometer based on optical low coherence reflectometry (OLCR), the Lenstar (Haag-Streit, Switzerland). Ninety-nine eyes of 99 healthy subjects were included. The axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), aqueous depth (AD), lens thickness (LT), keratometry (K) readings, including flat K (Kf), steep K (Ks), mean K (Km), astigmatism vectors J
, J
at diameters of 2.5 and 3.0 mm, and white-to-white diameter (WTW) were measured three times each using both biometer in normal eyes by random sequence. Bland-Altman analysis showed good agreement between the SS-OCT and OLCR devices for AL, AD, ACD, LT, with narrow 95% LoA (-0.05 to 0.07 mm, -0.09 to 0.10 mm, -0.10 to 0.09 mm, and -0.06 to 0.22 mm, respectively), and the P values of ACD were both >0.05. The CCT, Kf, Ks, Km, J
, J
and WTW values provided by the OA-2000 were in good agreement with the Lenstar, and statistically significant differences were detected for some of them but not clinical differences. The agreement was excellent especially for AL.
To comprehensively assess the precision and agreement of anterior corneal power measurements using 8 different devices.
Thirty-five eyes from 35 healthy subjects were included in the prospective ...study. In the first session, a single examiner performed on each subject randomly measurements with the RC-5000 (Tomey Corp., Japan), KR-8000 (Topcon, Japan), IOLMaster (Carl Zeiss Meditec, Germany), E300 (Medmont International, Australia), Allegro Topolyzer (Wavelight AG, Germany), Vista (EyeSys, TX), Pentacam (Oculus, Germany) and Sirius (CSO, Italy). Measurements were repeated in the second session (1 to 2 weeks later). Repeatability and reproducibility of corneal power measurements were assessed based on the intrasession and intersession within-subject standard deviation (Sw), repeatability (2.77Sw), coefficient of variation (COV), and intraclass correlation coefficient (ICC). Agreement was evaluated by 95% limits of agreement (LoA).
All devices demonstrated high repeatability and reproducibility of the keratometric values (2.77Sw<0.36D, COV<0.3%, ICC>0.98). Repeated-measures analysis of variance with Bonferroni post test showed statistically significant differences (P<0.01) among mean keratometric values of most instruments; the largest differences were observed between the EyeSys Vista and Medmont E300. Good agreement (i.e., 95%LoA within ± 0.5D) was found between most instruments for flat, steep and mean keratometry, except for EyeSys and Medmont. Repeatability and reproducibility of vectors J(0) and J(45) was good, as the ICCs were higher than 0.9, except J(45) of Medmont and Pentacam. For the 95% LoAs of J(0) and J(45), they were all ≤ ± 0.31 among any two paired devices.
The 8 devices showed excellent repeatability and reproducibility. The results obtained using the RC-5000, KR-8000, IOLMaster, Allegro Topolyzer, Pentacam and Sirius were comparable, suggesting that they could be used interchangeably in most clinical settings. Caution is warranted with the measurements of the EyeSys Vista and Medmont E300, which should not be used interchangeably with other devices due to lower agreement.
ClinicalTrials.gov NCT01587287.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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