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1.
Clin Ophthalmol ; 18: 1191-1206, 2024.
Article in English | MEDLINE | ID: mdl-38711575

ABSTRACT

One of the most recent advancements in the field of cataract surgery is optical biometry. With the advent of optical biometry ocular measurements are now simpler, quicker, and more precise. The devices have made intraocular lens (IOL) power calculations easier in difficult situations too, such as in cases with extremes of axial lengths, silicone filled eyes, cataract surgery in post-keratoplasty eyes, post Laser-Assisted in Situ Keratomileusis (LASIK) eyes, etc. The gold standard for IOL power calculation in the present day is by the use of optical biometry devices. The anatomical measurements by these devices are highly precise and because of these measurements and the incorporation of various IOL power calculation formulas the optical biometry devices give the accurate power and the post-operative visual outcome is highly satisfactory among the patients. The growing use of these devices has made cataract the most commonly performed refractive surgical procedure nowadays. In the current scenario, optical biometry has widespread acceptance in almost all countries and has many advantages over ultrasound or immersion biometry. Cataract surgeons can obtain easy and reliable measurements from these devices. Refractive surprises have also decreased considerably with their use. This article will comprehensively review the principles of the various optical biometry devices, the parameters used in each of the devices, the advantages and disadvantages, and add more like what all this article will add.

2.
Clin Optom (Auckl) ; 16: 107-114, 2024.
Article in English | MEDLINE | ID: mdl-38596476

ABSTRACT

Introduction: Corneal characteristics are unique to each eye and can vary among different levels of refractive errors. However, minimal data are available in the literature on corneal characteristics in myopic Malay school children including the difference between the low myopic group and the moderate myopic group. Therefore, this study aims to determine the corneal characteristics of myopic Malay school children and their associations with axial length. Methods: A total of eighty-four data samples were extracted from forty-two myopic Malay school children. Measurements of the central corneal thickness (CCT), corneal curvature, corneal diameter, and axial length were measured using Lenstar LS900, a non-contact optical biometer. Data were later stratified by the spherical equivalent refraction (SER) into a low myopic group and a moderate myopic group, and paired t-test were employed to determine the differences in the corneal characteristics between these two groups. Univariate and multivariate linear regressions were performed to identify factors that are significantly associated with axial length. Results: There was no significant difference in the CCT, corneal curvature and corneal diameter between the low myopic group and the moderate myopic group (t82=0.015, P=0.99), (t82=-0.802, P=0.43) and (t82=-0.575, P=0.57), respectively. Pearson univariate correlation analysis found that axial length significantly correlated with corneal curvature (r=-0.765, P<0.001) and corneal diameter (r=0.614, P<0.001) but no significant correlation found with CCT (r=0.046, P=0.68). Multiple regression analysis showed that axial length was significantly associated with a flatter corneal curvature (P<0.001), older age (P<0.001) and larger corneal diameter (P=0.02). Conclusion: This study reported the corneal characteristics in myopic Malay school children and its associations with axial length. Results of this study can serve as a reference value for the myopic Malay schoolchild population.

3.
International Eye Science ; (12): 612-617, 2024.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-1012831

ABSTRACT

AIM:To compare the differences, correlations and consistency of IOL Master 700 or Lenstar LS900 in preoperative ocular biometry and the accuracy of intraocular lens(IOL)degree calculation of cataract patients with high myopia.METHODS: Retrospective study. A total of 136 cases(136 eyes)of high myopia and cataract patients who underwent phacoemulsification at the ophthalmology department of Army Medical Center of PLA from March 2021 to March 2023 were collected, with a mean age of 57.38±8.08 years. Patients were divided into 3 groups based on axial length(AL): 41 eyes in group A(26 mm≤ AL ≤28 mm), 43 eyes in group B(28 mm&#x003C; AL ≤30 mm)and 52 eyes in group C(AL &#x003E;30 mm). AL, mean keratometry(Km), anterior chamber depth(ACD), lens thickness(LT)and white-to-white(WTW)were preoperatively measured by two instruments, respectively. Barrett Universal II formula was used to calculate the IOL degrees of all patients, the appropriate reserved diopter was decided individually, and the prediction error(PE)and absolute error(AE)of the two instruments were compared.RESULTS:The AL and ACD of patients in the three groups measured by Lenstar LS900 were higher than the AL measurd by IOL Master 700(all P&#x003C;0.05), with a difference of AL measured by the two devices: group C&#x003E;group B&#x003E;group A. However, there was no statistical significance in LT, Km, and WTW measured by the two instruments(all P&#x003E;0.05). All biometric parameters measured by the two devices were positively correlated(all r&#x003E;0.9, P&#x003C;0.05), and consistent(95% LoA of all groups were narrow). There was no statistically significant difference in AE calculated by the two devices(P&#x003E;0.05), but the IOL Master 700 calculated a smaller PE than Lenstar LS900(P&#x003C;0.05), with lower percentage of hyperopic shift in IOL Master 700.CONCLUSION:In cataract patients with high myopia, AL measured by Lenstar LS900 is longer than that by IOL Master 700, and the differences of AL increase along with the growth of AL. Both devices have a good prediction for IOL calculation, but IOL Master 700 has less refractive error, lower percentage of hyperopic shift, and greater clinical advantages IOL Master 700.

4.
Expert Rev Med Devices ; 20(8): 681-690, 2023.
Article in English | MEDLINE | ID: mdl-37402231

ABSTRACT

BACKGROUND: Due to the increasing use of contact lenses (CL) and the interest in ocular and body size relationships, this study aimed to compare measurements from two biometers (contact ultrasonic EchoScan US-800 and non-contact optical Lenstar LS900) with and without CL and to explore the relationship between ocular and body biometric parameters. DESIGN AND METHODS: This cross-sectional study measured ocular biometry using two biometers along with their body height and right foot length in 50 participants. Differences between biometry data from the two devices were compared and correlations between ocular and body biometric values were analyzed. RESULTS: All parameters showed interbiometric differences (p ≤ 0.030), except crystalline lens thickness during CL wear (p = 0.159). Comparing measurements with and without CL, differences were observed in axial length (p < 0.001), vitreous length measured by optical biometer (p = 0.016), and anterior chamber depth by ultrasonic biometer (p < 0.016). Lens thickness remained unaffected (p ≥ 0.190). Body height and foot length were correlated with anterior chamber depth, vitreous length, and axial length (p ≤ 0.019, r ≥ 0.330). Most biometric parameters were correlated among them using both devices (p ≤ 0.037, r ≥ 0.296). CONCLUSIONS: These biometers are not interchangeable and CL affects measurements. Body height and foot length correlate with ocular dimensions, and most ocular biometric values correlate positively.


Subject(s)
Contact Lenses , Lens, Crystalline , Humans , Anterior Chamber/anatomy & histology , Lens, Crystalline/anatomy & histology , Cross-Sectional Studies , Axial Length, Eye/anatomy & histology , Biometry , Tomography, Optical Coherence/methods , Reproducibility of Results
5.
Clin Ophthalmol ; 17: 2125-2131, 2023.
Article in English | MEDLINE | ID: mdl-37521148

ABSTRACT

Purpose: To compare the refractive accuracy resulting from calculations based on measurements with a swept-source optical coherence tomography (SS-OCT) biometer compared to calculations based on measurements with an optical low coherence reflectometry (OLCR) biometer at one month postoperatively. Methods: This was a retrospective comparative non-interventional study of preoperative biometry and postoperative refraction and visual acuity of 200 eyes. All eyes had preoperative biometry with both the Argos (Movu, a Santec company) and Lenstar LS900 (Haag-Streit AG) devices. Data were collected for mean postoperative prediction error (directional and absolute), preoperative mean K, delta K (corneal astigmatism), axial length, and anterior chamber depth. Results: The mean directional prediction error was -0.15 ± 0.47 D for Argos and -0.31 ± 0.50 D for Lenstar LS900, and there was a statistically significant mean of the differences (0.16 ± 0.24 D; p < 0.001). The mean absolute prediction error was 0.35 ± 0.34 D for Argos and 0.42 ± 0.41 D for Lenstar LS900, and there was a statistically significant mean of the differences (-0.07 ± 0.24 D; p < 0.001). Neither the differences in directional prediction error nor the differences in absolute prediction error were clinically significant. Conclusion: The directional and absolute prediction accuracies were statistically significant, but not clinically different between the Argos and Lenstar LS900 devices. In addition, differences between preoperative K, AL, and ACD measurements were not clinically significant.

6.
J Curr Ophthalmol ; 35(2): 153-158, 2023.
Article in English | MEDLINE | ID: mdl-38250485

ABSTRACT

Purpose: To assess the agreement between biometric parameters measured by a spectral-domain optical coherence tomography optical biometer device (Optopol Revo NX) with a validated swept-source biometer (IOLMaster 700) and a validated optical low-coherence reflectometry biometer (Lenstar LS 900), in cataract surgery candidates. Methods: In this prospective comparative study, 100 patients (100 eyes) who were eligible for cataract surgery were involved. Bland-Altman plots were used to assess agreement between devices for biometric parameters including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), and central corneal thickness (CCT). Results: AL measurements were successful in 82 eyes (82.0%) with Revo NX, in 91 eyes (91.0%) with Lenstar LS 900, and in 97 eyes (97.0%) with IOLMaster 700. When Revo NX was compared to IOL Master 700 and Lenstar LS 900, the mean differences were as follows: -0.02 ± 0.02 mm and -0.02 ± 0.03 mm (P = 0.313, P = 0.525) for AL, 0.01 ± 0.03 mm and 0.10 ± 0.03 mm (P = 0.691, P = 0.002) for ACD, -0.15 ± 0.03 mm and 0.001 ± 0.04 mm (P < 0.001, P = 0.95) for LT, and -2.29 ± 0.92 µm, and 0.73 ± 1.43 µm (P = 0.015, P = 0.612) for CCT. Three devices were highly correlated for AL, ACD, LT, and CCT (interclass correlation coefficient > 0.75). Bland-Altman plots showed a narrower 95% limit of agreement (-0.35 to 0.31) between Revo NX and IOLMaster 700 in measuring AL. Conclusions: Despite the higher measurement failure rate in eyes with cataract, the Revo NX showed very good agreement with the IOLMaster 700 and Lenstar LS 900 optical biometers in measuring AL, ACD, LT, and CCT. However, ACD and LT measurements cannot be considered interchangeable between these devices.

7.
Int Ophthalmol ; 42(11): 3541-3546, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35543852

ABSTRACT

PURPOSE: To test whether some biometry measurements provided by the Lenstar LS900 compared well with the AL-Scan, Pentacam rotating Scheimpflug camera, Ultrasound Biomicroscopy (UBM) and Tomey EM-3000. METHODS: Two hundred and one patients having routine cataract surgery had standard preoperative assessment. In this clinical study, the axis length (AL) and lens thickness (LT) were taken by Lenstar LS900 and AL-Scan; anterior chamber depth (ACD) was taken by Lenstar LS900, A-Scan, Pentacam and UBM; central corneal thickness (CCT) was taken by Lenstar LS900, Pentacam and Tomey EM-3000. The results were compared using a Wilcoxon-Mann-Whitney U test and Pearson correlation calculations. Agreement was assessed through intraclass correlation coefficients and Bland-Altman plots. RESULTS: The highest correlation was found between Lenstar and AL-Scan for AL (r = 0.975; P < 0.001). For LT measurements, the correlation between these two devices was also good (r = 0.699; P < 0.001). Excellent correlations were showed between Lenstar and Pentacam or UBM for ACD (r = 0.948, 0.704, respectively, both P < 0.001), but not between Lenstar and AL-Scan (r = 0.453, P < 0.001). The correlations of CCT between Lenstar and Pentacam or Tomey EM-3000 were both excellent (r = 0.817, 0.882, respectively, both P < 0.001). CONCLUSIONS: In phakic eyes of cataract patients, measurements of AL, LT, ACD and CCT from Lenstar LS900 yielded results that correlated very well with other clinical instruments.


Subject(s)
Cataract Extraction , Cataract , Lens, Crystalline , Humans , Tomography, Optical Coherence , Biometry , Lens, Crystalline/diagnostic imaging , Cataract/diagnosis , Reproducibility of Results , Anterior Chamber/diagnostic imaging , Cornea/diagnostic imaging
8.
Eur J Ophthalmol ; 32(1): 213-220, 2022 Jan.
Article in English | MEDLINE | ID: mdl-33653160

ABSTRACT

OBJECTIVES: To describe the pattern and mutual relationships between basic biometric characteristics of the eye in a Central European Caucasian population. METHODS: A single-centre retrospective study of 2340 patients (965 males, 1375 females) scheduled for cataract surgery between 2014 and 2016. Measurements using laser interferometry included AL (axial length), K (average corneal curvature), ACD (anterior chamber depth), LT (lens thickness), CCT (central corneal thickness), AST (astigmatism) and WTW (white to white). Subjects were stratified by gender and controlled for age. Descriptive, correlation and regression analyses were performed on the data. RESULTS: The mean AL was 23.33 ± 1.01 mm - higher in males (23.59 ± 0.99 mm), in comparison to females (23.15 ± 0.99 mm). The elderly had lower ACD and higher LT, while males had higher AL independent of age. Furthermore, LT and K decreased with AL, while ACD decreased with LT and increased with AL independent of age and gender. CONCLUSIONS: The estimates of the biometrics are obtained on a large sample of subjects and can serve as normative values for Lenstar LS900 in the Central European Caucasian population.


Subject(s)
Cataract , Lens, Crystalline , Aged , Anterior Chamber , Axial Length, Eye , Biometry , Cataract/diagnosis , Cornea , Female , Humans , Male , Retrospective Studies , Tomography, Optical Coherence
9.
Semin Ophthalmol ; 37(1): 63-66, 2022 Jan 02.
Article in English | MEDLINE | ID: mdl-33818277

ABSTRACT

PURPOSE: To compare on-axis measurements of the axial length (AL) with off-axis measurements in the paracentral horizontal and vertical positions using the Lenstar LS 900 biometer. METHODS: In this, the samples were selected from patients scheduled for cataract surgery using a systematic randomization method. After applying the exclusion criteria, all subjects underwent optometric examinations and AL measurement using the Lenstar. Five consecutive, non-cycloplegic measurements were done on the right eye centrally, 10° temporally, 10° nasally, 10° superiorly and 10° inferiorly on the retina by the same examiner. RESULTS: Two hundred and seven eyes were examined in this study, of which 126 (60%) were for female patients. The mean age of the participants was 64.32 ± 10.77 years (range: 34-91 years). The mean central, superior, inferior, temporal, and nasal axial AL was 23.22 ± 1.02, 23.21 ± 1.02, 23.21 ± 1.02, 23.21 ± 1.02, 23.20 ± 1.03, respectively. Comparison of these readings using repeated measures ANOVA showed a statistically significant difference in the AL value among these positions. According to the post-hoc results, superior and nasal AL was statistically significantly lower compared to the central AL. CONCLUSION: If on-axis biometry is not available, AL can be measured in an off-axis manner in the paracentral temporal, superior and inferior positions. Considering the marked difference in AL measurement between central and nasal positions, off-axis measurement is not recommended in the nasal part because it may be associated with a marked hyperopic shift after cataract surgery.


Subject(s)
Cataract Extraction , Cataract , Lens, Crystalline , Lenses, Intraocular , Adult , Aged , Aged, 80 and over , Anterior Chamber , Axial Length, Eye , Biometry , Eye , Female , Humans , Interferometry , Middle Aged , Reproducibility of Results
10.
Indian J Ophthalmol ; 69(9): 2469-2474, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34427246

ABSTRACT

PURPOSE: There is a considerable lack of awareness of slit-lamp measurement of anterior chamber depth (ACD) by the Redmond Smith method (SACD) in present day-to-day clinical practice, which may provide rapid assessment in pseudoexfoliation (PXF) when assessing for angle closure and planning for cataract surgery. This assumes importance not only in outreach clinics but also in the ongoing pandemic caused by the highly contagious novel coronavirus, where social distancing is advocated to contain the spread. We aimed to compare the axial ACD in PXF and normal patients by SACD, and its agreement with the anterior segment optical coherence tomography (ASOCT) and LenstarLS-900. METHODS: A prospective comparative observational study was done at a tertiary eye care hospital. A PXF group and a normal group of controls were recruited. All eyes were phakic with normal cornea. Any eye with previous intraocular/refractive surgery and cause of other secondary or uncontrolled glaucoma was excluded. SACD was measured clinically via slit-lamp method and also via ASOCT and Lenstar; agreement between the methodologies was plotted. RESULTS: Fifty patients were recruited in each group. Mean age was 66.82 ± 4.88 years in PXF patients and 65 ± 5.46 years in controls (P = 0.2). ACD was found to be greater in controls compared with the PXF patients; this difference was statistically significant (P < 0.001) across all methodologies. A good agreement with narrow 95% limits of agreement was found between these methodologies. CONCLUSION: Redmond Smith slit-lamp methodology of estimating the axial ACD is recommended as a rapid, quantifiable, noncontact screening technique during routine examination, especially in primary outreach centers, and is also advantageous during the ongoing pandemic by reducing expendable investigations.


Subject(s)
COVID-19 , Tomography, Optical Coherence , Aged , Anterior Chamber/diagnostic imaging , Humans , Middle Aged , Prospective Studies , SARS-CoV-2
11.
Clin Exp Optom ; 103(2): 192-196, 2020 03.
Article in English | MEDLINE | ID: mdl-30924211

ABSTRACT

BACKGROUND: To evaluate the angle kappa and pupil barycentre configuration in patients with myopic tilted disc syndrome (TDS). METHODS: Thirty-five eyes of 35 patients with TDS were included in the study. Thirty-five eyes of 35 age- and sex-matched healthy subjects were enrolled in the control group. All measurements were performed with the Lenstar LS 900. Angle kappa was calculated according to Pythagorean theorem using the x and y co-ordinates of the pupil centre. Pupil dx and pupil dy values (pupil dx: x co-ordinate of pupil centre relative to corneal apex, pupil dy: y co-ordinate of pupil centre relative to corneal apex) were used to evaluate the pupil barycentre configuration. Central corneal thickness, white to white (cornea diameter), pupil diameter, anterior chamber depth, lens thickness, and axial length were also measured. RESULTS: The calculated mean angle kappa distance was 0.27 ± 0.15 mm in the TDS group and 0.29 ± 0.23 mm in the control group (p = 0.42). The mean pupil dx was -0.01 ± 0.24 mm in the TDS group and -0.17 ± 0.14 mm in the control group (p = 0.006). The mean pupil dy was -0.02 ± 0.13 mm in the TDS group and -0.05 ± 0.22 mm in the control group (p = 0.65). CONCLUSIONS: The pupil barycentre in TDS cases was statistically significantly closer to the corneal vertex on the horizontal plane compared to the control group. However, there was no statistically significant differences in terms of angle kappa and pupil dy values between the groups. According to our results, refractive surgery can be performed safely with respect to complications related to decentration of ablation zone and decentration of multifocal intraocular lenses in these groups of patients.


Subject(s)
Diagnostic Techniques, Ophthalmological , Myopia/diagnosis , Optic Disk/diagnostic imaging , Pupil/physiology , Visual Acuity , Adult , Cross-Sectional Studies , Female , Humans , Male , Myopia/physiopathology , Retrospective Studies , Syndrome
12.
Ophthalmologe ; 116(3): 253-260, 2019 Mar.
Article in German | MEDLINE | ID: mdl-29372303

ABSTRACT

BACKGROUND: Modern cataract surgery not only consists of a minimally invasive lens extraction but also of the implantation of a suitable intraocular lens. OBJECTIVE: The aim of this prospective trial was a comparison of the predicted refractive error of two optical biometers, the IOLMaster 500 and LenStar LS 900 for intraocular lens power calculation in cataract surgery. MATERIAL AND METHODS: This was a prospective, analytical, comparative, non-masked study. A total of 86 eyes of 86 patients were examined and measured with both instruments before and after uneventful cataract surgery. Primary outcome measures were the differences of the predicted refractive error of both instruments. The predicted refractive error was calculated with different formulas. The results were compared to each other, to the desired target refraction as well as to the postoperative spherical equivalent. RESULTS: The mean differences in predicted refractive error of both instruments varied between 0.9 ± 0.19 (standard deviation) diopters (D) and 0.18 ± 0.30 D depending on the chosen formula. The IOLMaster 500 predicted less difference to the desired target refraction as well as to the spherical equivalent than the LenStar LS 900 with nearly all formulas. CONCLUSION: Both devices generated reproducible exact data with only a small deviation from the desired target refraction and from the postoperative spherical equivalent. There were statistically significant differences based on the chosen a­constants as well as the utilized measurement methods of both instruments.


Subject(s)
Cataract Extraction , Lenses, Intraocular , Phacoemulsification , Biometry , Humans , Prospective Studies , Refraction, Ocular
13.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-607215

ABSTRACT

Objective To evaluate the repeatability and agreement of two optical biometers (Lenstar LS900 (R) and SW-9000) for ocular biometry in Chinese adolescents.Methods A prospective study was conducted which included 65 ametropic patients,with an average age of (11.45 ± 2.67) years (age ranging from 8 to 18 years).The ocular biometry for right eyeball was performed with Lenstar LS900 (R) and SW-9000 respectively,followed by evaluation of the repeatability of the two biometers using one-way analysis of variance,and the agreement of the two instruments using the Bland-Altman plot.Results The repeatability of parameters measured by Lenstar LS900 (R),including axial length (AL),K value in the flattest meridian (K1),K value in the steepest meridian (K2),central corneal thickness (CCT),anterior depth (AD),lens thickness (LT),pupil diameter (PD),was well,and all intraclass correlation coefficient (ICC) > 0.9;the repeatability of white to white (WTW) was inferior to other parameters,but it was still >0.88.The repeatability of AL,K1,K2,CCT measured by SW-9000 was good,with their ICC > 0.9,but the repeatability of other parameters was poor.The parameters with good repeatability including AL,K1,K2,CCT measured by SW-9000 and Lenstar LS900 (R) were compared respectively,and the results showed that AL and CCT examined by SW-9000 were slightly longer than those measured by Lenstar LS900 (R),and the difference was statistically significant (all P < 0.05).However,there was no significant difference about K1,K2 (all P>0.05).Moreover,the AL,K1,K2 and CCT measured by the two instruments had close linear correlation (all r >0.97,all P <0.01).The BlandAltman plot showed that 95% LoA (limits of agreement) of AL was (-0.057 to 0.133) mm,K1 was (-0.456 to 0.369) D,K2 was (-0.388 to 0.549) D and CCT was (-3.483 to 8.016) μm.Conclusion Biometric parameters including AL,K1,K2,CCT measured by Lenstar LS900 (R) and SW-9000 have good repeatability in the adolescents aged 8-18 years and they are highly correlated;meanwhile,the agreement of AL,K1,K2,CCT measured by SW-9000 with Lenstar LS900 (R) is acceptable in clinical practices.

14.
Article in Chinese | WPRIM (Western Pacific) | ID: wpr-511131

ABSTRACT

Objective To analyze the reproducibility of keratometry and astigmatism measured by the VERION Digital Guidance System and the comparability of VERION with iTrace,Lenstar LS900 and manual keratometer.Methods The keratometry of 62 cataract patients were measured using four different devices.The steep keratometry (Ks),flat keratometry (Kf),astigmatic magnitude,astigmatic axis,cylinder at 0-degree meridian (vector component,J0) and cylinder at 45-degree meridian (vector component,J45) from each machine were recorded and analyzed.The three repeated measurements and the results of VERION system with other three devices were compared to analyze the reproducibility and comparability of VERION system.Results Reproducibility:Intraclass correlation coefficients and Cronbach's alpha values were higher than 0.9 for Ks,Kf,astigmatic magnitude,astigmatic axis,J0 and J45 measured by the VERION system (all P < 0.001).Comparability:The results of Ks and magnitude of astigmatism of VERION were larger than the iTrace (all P < 0.05) in the paired-samples t test.There was no statistical difference for the rest of parameters (all P > 0.05).The Bland-Altman graphs revealed the 95% limits of agreement (LOA) of J0,J45 and the astigmatic axis between VERION and iTrace were (-0.31-0.35) D,(-0.25-0.31) D and-13.5 °-12.3 °,respectively;There was no statistical differences for all parameters except for J45 in the paired-samples t test between the VERION and Lenstar LS900 (all P > 0.05).The Bland-Altman graphs revealed the 95% LOA of J0,J45 and the astigmatic axis were (-0.25-0.31)D,(-0.27-0.36) D and-13.5°-11.0°,respectively;There were statistical differences for the results of Kf and magnitude of astigmatism between the VERION and manual keratometer (all P < 0.05).The Bland-Altman graphs revealed the 95% LOA of J0,J45 and the astigmatic axis between VERION and manual keratometer were (-0.38-0.35) D,(-0.41-0.42) D,-12.6°-16.4°,respectively.Conclusion The VERION system is a reliable system for the measurement of keratometry and astigmatism.The keratometry and astigmatic magnitude of the VERION system have a good agreement with the iTrace,Lenstar LS900 and manual keratometer.However,the astigmatic axis measurements are significantly different among the four devices.

15.
Article in Korean | WPRIM (Western Pacific) | ID: wpr-65426

ABSTRACT

PURPOSE: To compare axial length (AL) and keratometry (K) using optical low-coherence reflectometry (OLCR, Lenstar LS900(R), Haag-Streit, Bern, Switzerland) with current ocular biometry devices and evaluate the accuracy of intraocular lens (IOL) power calculation. METHODS: In this prospective, comparative observational study of eyes with cataracts, AL and K were measured using an OLCR device (Lenstar LS900(R), Haag-Streit), partial coherence interferometry (PCI, IOL Master(R), Carl Zeiss, Jena, Germany), A-scan (Eyecubed) and automated keratometry (KR-7100, Topcon, Tokyo, Japan). IOL power calculation was performed using the Sanders-Retzlaff-Kraff (SRK/T) formula. The IOL prediction error (PE) was calculated by subtracting the predicted IOL power from the postoperative (PO) IOL power (PO 4 weeks, PO 12 weeks). RESULTS: A total of 50 eyes of 39 patients with cataracts (mean age 67.12 +/- 8.51 years) were evaluated in this study. AL and K were not significantly different between the OLCR device and other devices (analysis of variance [ANOVA], p = 0.946, 0.062, respectively). The mean PE in IOL power calculation was -0.22 +/- 0.50D with the OLCR device, 0.08 +/- 0.45D with the PCI device and -0.01 +/- 0.48D with A-scan and automated keratometry (ANOVA, p = 0.006). The highest percentage of eyes with PE smaller than +/- 0.5D was IOL Master(R) followed by Eyecubed and then Lenstar LS900(R). The mean absolute PE was not statistically significant among the 3 devices (ANOVA, p = 0.684). CONCLUSIONS: Ocular biometry measurements were comparable between the OLCR device and the PCI ultrasound device. However, the IOL power prediction showed significant differences among the 3 devices. Therefore, the differences in application of these devices should be considered.


Subject(s)
Humans , Biometry , Cataract , Glycyrrhetinic Acid , Interferometry , Lenses, Intraocular , Observational Study , Prospective Studies , Ultrasonography
16.
Article in Korean | WPRIM (Western Pacific) | ID: wpr-45165

ABSTRACT

PURPOSE: To compare axial length, anterior chamber depth, and keratometric measurements of an optical low-coherence reflectometry device with those of other ocular biometry devices and evaluate the accuracy of predicting postoperative refraction. METHODS: A total of 32 eyes in 32 patients who received cataract surgery were included in the present study. The axial length, anterior chamber depth, and keratometry were measured by optical low-coherence reflectometry (Lenstar LS900(R)), partial coherence interferometry (IOL master(R)), and ultrasound. The SRK/T formula was used to calculate IOL power, and predictive error that subtracts predictive refraction from postoperative refraction was compared among ocular biometry devices. RESULTS: Axial length, anterior chamber depth, and keratometry had a strong correlation and demonstrated no statistically significant differences between Lenstar LS900(R) and other devices. The Bland-Altman plots showed a high degree of agreement between Lenstar LS900(R) and other devices. The mean absolute prediction errors in Lenstar LS900(R) and IOL master(R) were not significantly different. CONCLUSIONS: The ocular biometric measurements and prediction of postoperative refraction using Lenstar LS900(R) were as accurate as IOL master(R) and ultrasound.


Subject(s)
Humans , Anterior Chamber , Biometry , Cataract , Eye , Interferometry
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