Weicong Lu

Efficacy Comparison of 16 Interventions for Myopia Control in Children: A Network Meta-analysis

PURPOSE To determine the effectiveness of different interventions to slow down the progression of myopia in children. METHODS We searched MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, World Health Organization International Clinical Trials Registry Platform, and ClinicalTrials.gov from inception to August 2014. We selected randomized controlled trials (RCTs) involving interventions for controlling the progression of myopia in children with a treatment duration of at least 1 year for analysis. MAIN OUTCOME MEASURES The primary outcomes were mean annual change in refraction (diopters/year) and mean annual change in axial length (millimeters/year). RESULTS Thirty RCTs (involving 5422 eyes) were identified. Network meta-analysis showed that in comparison with placebo or single vision spectacle lenses, high-dose atropine (refraction change: 0.68 [0.52-0.84]; axial length change: -0.21 [-0.28 to -0.16]), moderate-dose atropine (refraction change: 0.53 [0.28-0.77]; axial length change: -0.21 [-0.32 to -0.12]), and low-dose atropine (refraction change: 0.53 [0.21-0.85]; axial length change: -0.15 [-0.25 to -0.05]) markedly slowed myopia progression. Pirenzepine (refraction change: 0.29 [0.05-0.52]; axial length change: -0.09 [-0.17 to -0.01]), orthokeratology (axial length change: -0.15 [-0.22 to -0.08]), and peripheral defocus modifying contact lenses (axial length change: -0.11 [-0.20 to -0.03]) showed moderate effects. Progressive addition spectacle lenses (refraction change: 0.14 [0.02-0.26]; axial length change: -0.04 [-0.09 to -0.01]) showed slight effects. CONCLUSIONS This network analysis indicates that a range of interventions can significantly reduce myopia progression when compared with single vision spectacle lenses or placebo. In terms of refraction, atropine, pirenzepine, and progressive addition spectacle lenses were effective. In terms of axial length, atropine, orthokeratology, peripheral defocus modifying contact lenses, pirenzepine, and progressive addition spectacle lenses were effective. The most effective interventions were pharmacologic, that is, muscarinic antagonists such as atropine and pirenzepine. Certain specially designed contact lenses, including orthokeratology and peripheral defocus modifying contact lenses, had moderate effects, whereas specially designed spectacle lenses showed minimal effect.

Evaluation of a new optical biometry device for measurements of ocular components and its comparison with IOLMaster

Objective To assess the reliability of ocular component measurements with a new optical biometry device (AL-Scan; Nidek) and compare these measurements with those of the IOLMaster (Carl Zeiss Meditec) in patients with cataract. Methods Sixty-eight cataractous eyes of 68 patients were included in the prospective study. To assess AL-Scan repeatability and reproducibility, central corneal thickness, anterior chamber depth (ACD), keratometry (K) over 2.4 mm and 3.3 mm diameter, axial length (AL), white to white (WTW), and pupil distance (PD) values were measured by two operators. ACD, K, AL and WTW were also measured with the IOLMaster to investigate the level of agreement. Calculations of intraocular lens (IOL) power were compared between the two devices. Results AL-Scan measurements were highly repeatable and reproducible, except for WTW and PD. Bland–Altman analysis showed good agreement between devices for AL, ACD and most K values. Compared with the IOLMaster, AL-Scan-derived K values using a diameter of 2.4 mm showed a narrower 95% limit of agreement (LoA) than those obtained with a diameter of 3.3 mm. However, poor agreement of WTW measurements was found. The 95% LoAs between devices for IOL calculations were smaller when based on AL-Scan K measurements using a diameter of 2.4 mm rather than 3.3 mm. Conclusions The repeatability and reproducibility of AL-Scan was excellent for all parameters, except WTW and PD. Excluding WTW, good agreement was found between the AL-Scan and IOLMaster. The 2.4-mm diameter K value may be the most reliable choice for calculation of IOL power with the AL-Scan.

Precision of a new Scheimpflug and Placido-disk analyzer in measuring corneal thickness and agreement with ultrasound pachymetry

Purpose To assess the precision of corneal thickness measurements obtained by a new Scheimpflug camera combined with Placido‐disk corneal topography (Sirius) and compare the measured values with those obtained by ultrasound (US) pachymetry. Setting Eye Hospital of Wenzhou Medical College, Wenzhou, China. Design Comparative evaluation of a diagnostic test or technology. Methods Eyes of healthy subjects were examined with the Scheimpflug–Placido topographer. Central (CCT) and thinnest (TCT) corneal thickness were recorded after 3 consecutive measurements. For US pachymetry, only CCT was measured. Measurements were repeated within 1 week. The within‐subject standard deviation (Sw), test–retest repeatability, coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated to evaluate intrasession repeatability and intersession reproducibility. Interdevice comparison was analyzed with paired t tests and Bland‐Altman plots. Results The intrasession repeatability of Scheimpflug–Placido measurements was high, with test–retest and CoV close to 9 μm and 0.6% for CCT and TCT, respectively. The intersession test–retest and CoV were close to 10 μm and 0.7%, respectively. The ICC was higher than 0.98 for repeatability and reproducibility. High agreement was found between Scheimpflug–Placido and US pachymetry measurements, with narrow 95% limits of agreement. Conclusions The Scheimpflug–Placido instrument showed excellent intrasession repeatability and intersession reproducibility of CCT and TCT measurements in healthy eyes. High agreement and lack of statistically significant difference suggest that the instruments TCT and the US pachymetry–CCT measurements can be used interchangeably in subjects with normal corneal thickness. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Comparison and evaluation of central corneal thickness using 2 new noncontact specular microscopes and conventional pachymetry devices.

Purpose: The aim of this study was to evaluate the repeatability of central corneal thickness (CCT) measurements in normal eyes using 2 new noncontact specular microscopes (NCSMs) EM-3000 (Tomey, Japan) and SP-02 (CSO, Italy) and to compare the results with those obtained from an SP-3000P NCSM (Topcon, Japan) and ultrasound pachymetry (USP). Methods: Seventy subjects were enrolled in a prospective study. A single experienced ophthalmologist performed tests with each of the 4 instruments. Measurements were obtained in the right eye during the same session. The testing sequence of the NCSM was randomly selected. After performing noncontact examinations, the USP was performed to derive the CCT measurements. Intraoperator repeatability was analyzed using within-subject coefficient of variation and intraclass correlation coefficients. The agreement between NCSMs or NCSM and USP was assessed with Bland–Altman plots and 95% limits of agreement (LoA). Results: The mean CCT values measured by SP-3000P, EM-3000, SP-02, and USP were 513.66 ± 33.14 &mgr;m, 529.12 ± 33.22 &mgr;m, 549.06 ± 40.27 &mgr;m, and 539.01 ± 35.73 &mgr;m, respectively. All coefficients of variation were <1.3%, and the intraclass correlation coefficients were >0.95. There were statistically significant differences between any 2 devices as determined by CCT measurements. The mean difference between paired comparisons was >9 &mgr;m. The 95% LoA ranges were broad, and the greatest 95% LoA was found to exist between SP-3000P and SP-02. Conclusions: The new NCSMs and USP all show a high intraoperator repeatability for CCT measurements in normal eyes. However, interdevice agreement was poor and prevented the comparison of CCT measurements taken with different instruments.

Evaluation of corneal thickness using a Scheimpflug–Placido disk corneal analyzer and comparison with ultrasound pachymetry in eyes after laser in situ keratomileusis

Purpose To evaluate the repeatability and reproducibility of corneal thickness measurements in post‐laser in situ keratomileusis (LASIK) eyes using a rotating Scheimpflug camera combined with a Placido disk corneal topographer (Sirius) and compare the results with those of ultrasound (US) pachymetry. Setting Eye Hospital of Wenzhou Medical College, Wenzhou, China. Design Comparative evaluation of a diagnostic test or technology. Methods Patients were examined 3 times with the Scheimpflug–Placido topographer by 2 examiners. The central pupil corneal thickness (CTpupil), apical corneal thickness (CTapex), and thinnest corneal thickness (CTthinnest) were recorded. After noncontact examinations, US pachymetry was used to obtain the central corneal thickness (CCT). Results The Scheimpflug–Placido topographer showed high intraoperator repeatability as indicated by a test–retest repeatability of less than 8.5 &mgr;m for CTpupil, CTapex, and CTthinnest, The coefficients of variation (CoV) were less than 0.7%, and the intraclass correlation coefficient was higher than 0.99. Excellent results were also obtained for interoperator reproducibility. All CoVs were less than 0.5%. The 95% limits of agreement between the Scheimpflug–Placido measurement and the US pachymetry measurements were narrow (−16.62 to 12.44 &mgr;m for CTpupil versus US pachymetry CCT; −17.49 to 12.16 &mgr;m for CTapex versus US pachymetry CCT; −18.59 to 10.90 &mgr;m for CTthinnest versus US pachymetry CCT). Conclusions The Scheimpflug–Placido topographer showed excellent intraoperator repeatability and interoperator reproducibility of CTpupil, CTapex, and CTthinnest measurements in post‐LASIK eyes. The CCT measurements obtained using the device were in high agreement with those obtained by US pachymetry, suggesting that the 2 devices are interchangeable. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Repeatability and interobserver reproducibility of a new optical biometer based on swept-source optical coherence tomography and comparison with IOLMaster

Objective To evaluate the precision of the measurements in healthy subjects obtained with a new optical biometer (OA-2000, Tomey, Nagoya, Japan) using swept-source optical coherence tomography (SS-OCT) and compare these measurements with those provided by the IOLMaster v5.4 (Carl Zeiss Meditec AG, Jena, Germany) using partial coherence interferometry (PCI). Methods Axial length (AL), keratometry (K) over 2.5 mm and 3.0 mm diameters, anterior chamber depth (ACD) (corneal epithelium to lens), lens thickness (LT), central corneal thickness and corneal diameter (CD) were measured with SS-OCT by two experienced operators. Intraobserver repeatability and interobserver reproducibility were assessed. AL, ACD, K and CD were also measured with PCI for agreement analysis using Bland-Altman plots. Results Sixty-five eyes of 65 normal subjects were enrolled in the prospective study. The SS-OCT measurements revealed high repeatability and reproducibility with low test-retest repeatability, low within-subject coefficient of variation (CoV) and high intraclass correlation coefficients. Bland-Altman analysis showed narrow 95% limits of agreement for most parameters indicating excellent agreement for AL (−0.05 mm to 0.07 mm), K values both at 2.5 mm (−0.42 D to 0.20 D) and 3.0 mm (−0.42 D to 0.08 D) and ACD (−0.19 mm to 0.22 mm) except for the CD (−1.11 mm to −0.01 mm). Conclusions The repeatability and reproducibility of SS-OCT were excellent for all parameters including AL, K, ACD, LT and CD values. High agreement was shown between SS-OCT and PCI for most biometrical parameters.

Precision and agreement of corneal power measurements obtained using a new corneal topographer OphthaTOP.

Purpose To evaluate repeatability and reproducibility of anterior corneal power measurements obtained with a new corneal topographer OphthaTOP (Hummel AG, Germany) and agreement with measurements by a rotating Scheimpflug camera (Pentacam HR, Oculus, Germany) and an automated keratometer (IOLMaster, Carl Zeiss Meditec, Germany). Methods The right eyes of 79 healthy subjects were prospectively measured three times with all three devices. Another examiner performed three additional scans with the OphthaTOP in the same session. Within one week, the first examiner repeated the measurements using the OphthaTOP. The flat simulated keratometry (Kf), steep K (Ks), mean K (Km), J0, and J45 were noted. Repeatability and reproducibility of measurements were assessed by within-subject standard deviation (Sw), repeatability (2.77 Sw), coefficient of variation (CoV), and intraclass correlation coefficient (ICC). Agreement between devices was assessed using 95% limits of agreement (LoA). Results Intraobserver repeatability and interobserver and intersession reproducibility of all measured parameters showed a 2.77 Sw of 0.29 diopter or less, a CoV of less than 0.24%, and an ICC of more than 0.906. Statistically significant differences (P<0.001) were found between the parameters analyzed by the three devices, except J0 and J45. The mean differences between OphthaTOP and the other two devices were small, and the 95% LoA was narrow for all results. Conclusions The OphthaTOP showed excellent intraobserver repeatability and interobserver and intersession reproducibility of corneal power measurements. Good agreements with the other two devices in these parameters were found in healthy eyes.

Corneal Power Measurement Obtained by Fourier-Domain Optical Coherence Tomography: Repeatability, Reproducibility, and Comparison With Scheimpflug and Automated Keratometry Measurements.

Purpose: To assess the repeatability and reproducibility of corneal power values obtained by a Fourier-domain optical coherence tomography (FD-OCT) system (RTVue) and to compare them with the values obtained by a Scheimpflug camera system (Pentacam HR) and by automated keratometry (IOL Master). Methods: Thirty-two eyes from 32 healthy subjects were included in this prospective study. Two experienced observers measured each eye 3 consecutive times with the Pentacam, IOLMaster, and RTVue centered on either the pupil or corneal vertex. The conventional keratometry equivalent (CKE) and anterior (Ka), posterior (Kp), and net (Kn) corneal power values were determined. Results: The corneal power values obtained by the RTVue showed high repeatability (all intraclass correlation coefficient >0.96) and reproducibility (coefficient of variation <1.0%). Pupil-centered FD-OCT performed slightly better than corneal vertex-centered FD-OCT. Mean corneal values had higher reproducibly than any of the individual values. CKE, Ka, Kp, and Kn obtained by FD-OCT were 0.62 to 0.68 diopters (D), 0.70 to 0.76 D, 0.11 to 0.13 D, and 0.93 to 0.94 D higher than those obtained by the Pentacam HR, respectively. CKE and Ka obtained with the RTVue were also 0.60 to 0.74 D higher than those obtained with the IOLMaster, respectively. Conclusions: The corneal power measurements obtained by the RTVue FD-OCT system showed high repeatability and reproducibility. Measurements obtained by FD-OCT with pupil centration were more reproducible than those obtained by FD-OCT with corneal vertex centration. We recommend that pupil-centered FD-OCT be used in clinical applications. Neither RTVue versus Pentacam HR nor RTVue versus IOLMaster can be used interchangeably.

Comparison of Anterior Segment Measurements with Scheimpflug/Placido Photography-Based Topography System and IOLMaster Partial Coherence Interferometry in Patients with Cataracts

Purpose. To assess the consistency of anterior segment measurements obtained using a Sirius Scheimpflug/Placido photography-based topography system (CSO, Italy) and IOLMaster partial coherence interferometry (Carl Zeiss Meditec, Germany) in eyes with cataracts. Methods. A total of 90 eyes of 90 patients were included in this prospective study. The anterior chamber depth (ACD), keratometry (K), corneal astigmatism axis, and white to white (WTW) values were randomly measured three times with Sirius and IOLMaster. Concordance between them was assessed by calculating 95% limits of agreement (LoA). Results. The ACD and K taken with the Sirius were statistically significantly higher than that taken with the IOLMaster; however, the Sirius significantly underestimated the WTW values compared with the IOLMaster. Good agreement was found for Km and ACD measurements, with 95% LoA of −0.20 to 0.54 mm and −0.16 to 0.34 mm, respectively. Poor agreement was observed for astigmatism axis and WTW measurements, as the 95% LoA was −23.96 to 23.36° and −1.15 to 0.37 mm, respectively. Conclusion. With the exception of astigmatism axis and WTW, anterior segment measurements taken by Sirius and IOLMaster devices showed good agreement and may be used interchangeably in patients with cataracts.

Precision of Corneal Thickness Measurements Obtained Using the Scheimpflug-Placido Imaging and Agreement with Ultrasound Pachymetry

Purpose. To assess the reliability and comparability of measuring central corneal thickness (CCT) and thinnest corneal thickness (TCT) using a new Scheimpflug-Placido analyzer (TMS-5, Japan) and ultrasound (US) pachymetry. Methods. Seventy-six healthy subjects were prospectively measured 3 times by 1 operator using the TMS-5, 3 additional consecutive scans were performed by a second operator, and ultrasound (US) pachymetry measurements were taken. The test-retest repeatability (TRT), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated to evaluate intraoperator repeatability and interoperator reproducibility. Agreement among the devices was assessed using Bland-Altman plots and 95% limits of agreement (LoA). Results. The intraoperators TRT and CoV were <19 μm and 2.0%, respectively. The interoperators TRT and CoV were <12 μm and 1.0%, respectively, and ICC was >0.90. The mean CCT and TCT measurements using the TMS-5 were 15.97 μm (95% LoA from −26.42 to −5.52 μm) and 20.32 μm (95% LoA from −30.67 to −9.97 μm) smaller, respectively, than those using US pachymetry. Conclusions. The TMS-5 shows good repeatability and reproducibility for measuring CCT and TCT in normal subjects but only moderate agreement with US pachymetry results. Caution is warranted before using these techniques interchangeably.