Intra-operative aberrometry versus conventional biometry for intraocular lens power calculation: A prospective observational study from a tertiary referral center

Purpose: To evaluate the per operative intra?ocular lens (IOL) power calculation using intra?operative aberrometry (ORA) and its comparison with conventional methods. Methods: Patients with cataract planned for phacoemulsification by a single surgeon under topical anesthesia were enrolled in this prospective observational study in this prospective observational study. All patients underwent pre?operative biometry (Manual SRK?II and IOLMaster® 500) to determine the intra?ocular lens (IOL) power. Intra?operative aberrometry using ORA was also performed; however, IOL was inserted according to IOLMaster® (SRK/T). Spherical equivalent (SE) was recorded on post?operative days 1, 7, and 30. Patients were divided into three groups based on axial lengths for analysis. Comparative analysis was performed for the calculated IOL powers and prediction errors of ORA with conventional methods. Adjusted IOL power to calculate the emmetropic IOL using the LiHue formula was also determined and was compared with existing methods. A P-value less than 0.05 was considered statistically significant. Results: A total of 115 eyes from 113 patients were included, with a median age of 54.90 ± 14.3 years. The mean axial length was found to be 23.94 ± 2.3 mm. There was good agreement (87%) between ORA and IOLMaster® for calculated IOL powers with a mean difference of 0.047 ± 0.5D between the two (P = 0.33). A positive correlation was found between IOL power calculated using ORA, IOLMaster®, SRK?II, and adjusted IOL. Conclusion: The use of intra?operative aberrometry (ORA) to calculate IOL power in patients undergoing uncomplicated phacoemulsification is non?inferior relative to standard pre?operative measurement and planning.

Comparison of ocular biometry and refractive outcome between ANTERION and IOL Master 700

Purpose: To assess the comparability of ocular biometry measurements and refractive outcomes between ANTERION and IOL Master 700. Methods: This comparative prospective study was conducted from December 2020 to February 2021. A total of 225 patients who had cataracts were enrolled for the study and different parameters such as anterior keratometry (Steep K, Flat K) with axis, Sim K, central corneal thickness (CCT), aqueous depth (AQD), lens thickness (LT), and axial length (AL), white?to?white (WTW) were evaluated in IOL master 700 first and then with ANTERION. Finally, 203 patients completed the 6?week follow?up and the postoperative refraction was done at the 6th week. To assess the agreement between the devices, intraclass coefficient (ICC) and Bland–Altman analysis with 95% limits of agreement (LoA) were used. To analyze the agreement for postoperative residual refractive error between the two devices, Kappa statistics were used. Results: The mean difference for steep K, flat K, and Sim K between ANTERION and IOL Master 700 were ? 0.18 +/?0.26 D, ?0.13+/? 0.28D, ?0.15 +/?0.23, respectively. The CCT, ACD, and LT also showed excellent agreement (ICC > 0.9) but the similarity for the keratometry axis was not up to the mark (ICC = 0.794). For postoperative refractive outcomes, the Kappa value was 0.437, indicating moderate agreement. Conclusion: ANTERION showed a good agreement for the majority of parameters with IOLMaster 700 in measuring ocular biometry, except for the keratometry. The accuracy of the intraocular lens power calculations was clinically acceptable with both biometers though the IOL power given by ANTERION remained slightly on the hypermetropic side.

A comparative study on calculation of intraocular lens power using different formulas between IOLMaster 700 and IOLMaster 500 in cataract eyes / 中华实验眼科杂志

Objective:To compare the accuracy of IOLMaster 700 and IOLMaster 500 in intraocular lens (IOL) power calculation.Methods:A cross-sectional study was conducted.Two hundred and sixty-two eyes of 262 patients who underwent phacoemulsification combined with IOL implantation at the Eye Hospital of Wenzhou Medical University from November 2018 to November 2019 were enrolled.Preoperative biometry for cataract surgery was performed using IOLMaster 700 and IOLMaster 500.IOL power was calculated through the built-in formulas, Haigis, Holladay Ⅰ, Hoffer Q and SRK/T of the two devices.The difference in IOL power calculation between the two devices was analyzed through the prediction error of IOL power calculation using different formulas across different axial length (AL) ranges.This study complied with the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the Eye Hospital of Wenzhou Medical University (No.2020-038-K-33). Written informed consent was obtained from each patient before the surgery.Results:There was no significant difference in mean absolute error (MAE) between IOLMaster 700 and IOLMaster 500 using Haigis, Hoffer Q and SRK/T over the entire AL range (all at P >0.05). The MAE of IOLMaster 500 was 0.47 (0.24, 0.90) D, which was significantly lower than 0.50 (0.28, 0.99) D of IOLMaster 700 using Holladay Ⅰ formula ( Z=-3.120, P=0.002). When AL was <22.0 mm and ≥24.5 mm-<26.0 mm, there was no significant difference in MAE between the two devices using the four formulas (all at P >0.05). When AL was ≥22.0 mm-24.5 mm, there was no significant difference in the MAE between the two devices using Haigis, Hoffer Q and SRK/T (all at P >0.05), but 0.42 (0.18, 0.75) D from IOLMaster 500 was smaller than 0.45 (0.25, 0.79) D from IOLMaster 700 using Holladay Ⅰ, showing a statistically significant difference ( Z=-3.487, P <0.001). But the difference was negligible and therefore was of no clinical significance.When AL was ≥26.0 mm, there was no statistically significant difference in the MAE between the two devices using Haigis, Holladay Ⅰ and SRK/T, but 0.66 (0.38, 1.00) D from IOLMaster 500 was significantly smaller than 0.98 (0.62, 1.32) D from IOLMaster 700 using Hoffer Q ( Z=-3.046, P=0.002). Conclusions:The refractive prediction accuracy of IOLMaster 700 and IOLMaster 500 using Haigis, Hoffer Q and SRK/T is similar over the entire AL range.For patient with long AL, the IOL calculation from IOLMaster 700 using Hoffer Q is significantly larger than that from IOLMaster 500, which requires extra caution in clinical practice.The accuracy of IOLMaster 700 and IOLMaster 500 for IOL prediction is very similar.

Comparison of Ocular Biometry Using New Swept-source Optical Coherence Tomography-based Optical Biometer with Other Devices

PURPOSE: To evaluate the agreement between optical biometry with swept-source optical coherence tomography-based optical biometry (IOLMaster 700) and other devices. METHODS: A total of 137 eyes (78 patients) with cataracts were included in this retrospective study. Axial length (AL), anterior chamber depth (ACD), keratometry, and white-to-white (WTW) distance measured using IOLMaster 700 were compared with results for the following five different biometers: IOLMaster 500, A-scan, automated refractor, manual keratometry, and Galilei G4. Differences and correlations among the devices were assessed using the Bland-Altman plot and intraclass correlation coefficient (ICC). RESULTS: For AL values, the IOLMaster 700, IOLMaster 500, and A-scan measurements showed excellent agreement (all ICC >0.99). For ACD values, ICC of IOLMaster 700 and Galilei G4 was 0.965 but A-scan was poorly correlated with either IOLMaster 700 or Galilei G4. The ICCs of IOLMaster 700 and other devices were all greater than 0.9 for average keratometry, but those of the mean cylinder keratometry were all between 0.7 and 0.8. The mean difference in the WTW distance between the IOLMaster 700 and Galilei G4 was 0.029 mm, but the ICC was 0.525. AL measurements were not possible for 10 eyes with the IOLMaster 500 but were obtained in all eyes with the IOLMaster 700. CONCLUSIONS: In clinical practice, AL, ACD, and average keratometry values of IOLMaster 700 can be used interchangeably with those of the other devices tested. However, the ACD value between IOLMaster 700 and A-scan or the WTW distance between IOLMaster 700 and Galilei G4 are not interchangeable because of clinical and statistical differences in measurements between the devices.

Comparative Efficacy of the New Optical Biometer on Intraocular Lens Power Calculation (AL-Scan versus IOLMaster)

PURPOSE: To evaluate the agreement in axial length (AL), keratometry, and anterior chamber depth measurements between AL-Scan and IOLMaster biometers and to compare the efficacy of the AL-Scan on intraocular lens (IOL) power calculations and refractive outcomes with those obtained by the IOLMaster. METHODS: Medical records of 48 eyes from 48 patients who underwent uneventful phacoemulsification and IOL insertion were retrospectively reviewed. One of the two types of monofocal aspheric IOLs were implanted (Tecnis ZCB00 [n = 34] or CT Asphina 509M [n = 14]). Two different partial coherence interferometers measured and compared AL, keratometry (2.4 mm), anterior chamber depth, and IOL power calculations with SRK/T, Hoffer Q, Holladay2, and Haigis formulas. The difference between expected and actual final refractive error was compared as refractive mean error (ME), refractive mean absolute error (MAE), and median absolute error (MedAE). RESULTS: AL measured by the AL-Scan was shorter than that measured by the IOLMaster (p = 0.029). The IOL power of Tecnis did not differ between the four formulas; however, the Asphina measurement calculated using Hoffer Q for the AL-Scan was lower (0.28 diopters, p = 0.015) than that calculated by the IOLMaster. There were no statistically significant differences between the calculations by MAE and MedAE for the four formulas in either IOL. In SRK/T, ME in Tecnis-inserted eyes measured by AL-Scan showed a tendency toward myopia (p = 0.032). CONCLUSIONS: Measurement by AL-Scan provides reliable biometry data and power calculations compared to the IOLMaster; however, refractive outcomes of Tecnis-inserted eyes by AL-Scan calculated using SRK/T can show a slight myopic tendency.

Comparison of ocular variables obtained from Tomey OA-2000 and IOLMaster / 眼科新进展

Objective To compare the ocular parameters measured by 2 biometry devices Tomey OA-2000 and IOLMaster in cataract eyes.Methods A total of 74 cataract patients (74 eyes) were included in this prospective study.Ocular parameters,including axial length (AL),keratometry (K),anterior chamber depth (ACD) and white to white (WTW),were obtained from Tomey OA-2000 and IOLMaster,respectively.Paired t-test was applied to analyze the differences of ocular parameters from Tomey OA-2000 and IOLMaster,while Bland-Altman plot was used to assess the agreement of these ocular parameters.Results The AL,flat K,steep K,mean K,central corneal thickness (CCT),ACD,lens thickness,pupil diameter and WTW values measured by Tomey OA-2000 were (24.26 ± 2.71) mm,(44.09 ± 1.76) D,(45.01 ± 1.73) D,(44.55 ± 1.72)D,(518.41 ±34.18) μm,(3.07 ±0.48)mm,(4.48 ±0.61)mm,(4.07 ±0.95)mm and (11.50 ± 0.52)mm respectively.Values of AL,flat K,steep K,mean K,ACD and WTW from IOLMaster were (24.33 ± 2.69) mm,(44.21 ± 1.74) mm,(45.15 ± 1.76) D,(44.69 ± 1.74) D,(3.04 ± 0.46)mm and (11.65 ± 0.41) mm respectively.The difference values of AL,flat K,steep K,mean K,ACD and WTW between Tomey OA-2000 and IOLMaster were (-0.07 ±0.10) mm (t =-5.99,P＜0.01),(-0.12 ± 0.21) D (t =-4.14,P＜0.01),(-0.14 ± 0.20)D (t =-5.88,P＜0.01),(-0.12 ±0.13) D (t =-7.44,P＜0.01),(0.03 ±0.14) mm (t=1.99,P=0.05) and (-0.14±0.32) mm (t=-3.73,P＜0.01) respectively.The 95％ limits of agreement (LoA) of the AL,flat K,steep K,mean K,ACD obtained from the two devices was 0.27 mm,0.50 D,0.53 D,0.38 D,0.30 mm,respectively,and the agreement was good;95％ LoA of WTW was 0.78 mm,and the consistency was poor.Conclusion The differences of AL,K values and ACD between Tomey OA-2000 and IOLMaster were small,suggesting the agreement is unified.

Comparison of Ocular Biometry Using Low-Coherence Reflectometry with Other Devices for Intraocular Lens Power Calculation

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.

Discrepancy of sulcus-to-sulcus diameter and its relationship with white-to-white diameter in high myopic eyes / 中华实验眼科杂志

Background Horizontal sulcus-to-sulcus (STS) and white-to-white diameter are important parameters for designing the proper size of collamer implantable contact lens (ICL).Inappropriate size of ICL may induce the complications postoperatively.Several previous studies compare horizontal STS and white-to-white diameter in normal eyes have been reported,but seldom in high myopic eyes.Objective This study was to investigate the discrepancy of STS diameters in 4 axes and analyze the relationship between horizontal STS diameter and white-towhite diameter in high myopia eyes.Methods The STS diameters in 4 axes (45,90,135 and 180 degrees) and the white-to-white diameters were measured in 48 eyes of 26 high myopia patients using the 50 MHz ultrasound biomicroscopy (UBM),the Orbscan-Ⅱ topography system,and the IOL Master,respectively.The mean spherical was (-12.93±3.87) diopters (D) (-8 to-20 D).Statistical evaluation was performed using the one-way ANOVA for comparison of measurement.The agreement of three devices was assessed using the Bland and Altman method.Results The mean STS diameter at 45,90,135 and 180 degrees was (12.06±0.50) mm,(12.27±0.50)mm,(12.03±0.46) mm and (11.84±0.47)mm,respectively.The 90 degree STS was significantly larger than other STS diameters (all at P＜0.05).The 180 degrees STS was significantly shorter than other STS diameters (all at P＜0.05).However,there was no significant difference between 45 degree STS and 135 degree STS (P=0.817).The mean WTW was (11.56±0.40) mm with Orbscan Ⅱ z topography system and (11.98±0.41) mm with IOLMaster.The WTW measured with Orbscan Ⅱ z was significantly shorter than the 180 degrees STS (t =-4.384,P =0.000).The WTW measured with IOLMaster was significantly larger than the 180 degrees STS (t =2.368,P =0.000).Bland-Altman analysis showed not very well agreement for measurements of WTW,STS between Orbscan Ⅱz and UBM,IOLMaster and UBM,Orbscan Ⅱ z and IOLMaster,the width of 95％ confidence interval (CI) were-0.57 to 1.12 mm,-0.96 to 0.67 mm,-0.73 to-0.13 mm,respectively.Conclusions The STS diameters in 4 different axes are not identical with each other in high myopia eyes.The longest STS is in the vertical meridian,the shortest STS is in the horizontal meridian.The WTW diameter measured with both Orbscan Ⅱ z and IOLMaster are not precise for calculating the horizontal STS in high myopia eyes.Three instruments cannot be interchanged for calculating the size of ICL.

Intraocular Lens Power Calculation Using IOLMaster and Various Formulas in Short Eyes

PURPOSE: To evaluate the predictability of intraocular lens (IOL) power calculations using the IOLMaster and four different IOL power calculation formulas (Haigis, Hoffer Q, SRK II, and SRK/T) for cataract surgery in eyes with a short axial length (AL). METHODS: The present study was a retrospective comparative analysis which included 25 eyes with an AL shorter than 22.0 mm that underwent uneventful phacoemulsification with IOL implantation from July 2007 to December 2008 at Seoul National University Boramae Hospital. Preoperative AL and keratometric power were measured by the IOLMaster, and power of the implanted IOL was determined using Haigis, Hoffer Q, SRK II, and SRK/T formulas. Postoperative refractive errors two months after surgery were measured using automatic refracto-keratometry (Nidek) and were compared with the predicted postoperative power. The mean absolute error (MAE) was defined as the average of the absolute value of the difference between actual and predicted spherical equivalences of postoperative refractive error. RESULTS: The MAE was smallest with the Haigis formula (0.37 +/- 0.26 diopter [D]), followed by those of SRK/T (0.53 +/- 0.25 D), SRK II (0.56 +/- 0.20 D), and Hoffer Q (0.62 +/- 0.16 D) in 25 eyes with an AL shorter than 22.0 mm. The proportion with an absolute error (AE) of less than 1 D was greatest in the Haigis formula (96%), followed by those in the SRK II (88%), SRK-T (84%), and Hoffer Q (80%). CONCLUSIONS: The MAE was less than 0.7 D and the proportion of AE less than 1 D was more than 80% in all formulas. The IOL power calculation using the Haigis formula showed the best results for postoperative power prediction in short eyes.

Comparison of axial length and anterior chamber depth measurements by IOLMaster, Axis- Ⅱ A-scan and ODM 1000A sonograph / 中华实验眼科杂志

Background Axial length and anterior chamber depth are important parameters for the calculation of diopter of intraocular lens ( IOL ). Objective This study was to investigate and compare the measuring outcomes of axial length and anterior chamber depth with IOLMaster,Axis- Ⅱ A-scan and ODM 1000A sonograph.Methods This a observational study.Axial length and anterior chamber depth were measured in 83 eyes of 48 patients with IOLMaster,Axis-Ⅱ A-scan and ODM 1000A sonograph by the same operator.The measuring results were compared among the three methods.Results The axial length were(25.79±0.85) mm,(25.72± 0.82 )mm and ( 26.00 ±0.83 )mm respectively with Axis- Ⅱ,ODM 1000A sonograph and IOLMaster.The difference between Axis-Ⅱ and DM 1000A sonograph was (0.07 ± 0.35 )mm without statistical difference between them (t=1.711,P =0.091 ).The difference of axial length between IOLMaster and DM 1000A sonograph was ( 0.27 ±0.29) mm with a statistical difference between them ( t =-8.570,P =0.000 ).The difference between IOLMaster and Axis- Ⅱ was (0.21 ±0.32 ) mm and showed a statistical difference ( t =- 5.931,P ＜ 0.01 ).The positive correlations were found in the axial length values by the each other comparison among the three instruments( r=0.916,0.938,0.928,P＜0.01 ).The anterior chamber depth values were ( 3.81 ±0.21 ) mm,( 3.84 ±0.25 ) mm and ( 3.83 ±0.18 )mm respectively with Axis-Ⅱ,0DM 1000A sonograph and IOLMaster.The difference of anterior chamber depth between Axis- Ⅱ and DM 1000A was (0.03 ±0.17 ) mm without statistical difference between them ( t =- 1.324,P =0.189 ).The difference in the anterior chamber depth between IOLMaster and DM 1000A was (0.01 ±0.15 ) mm and that between IOLMaster and Axis-Ⅱ was( 0.01 ±0.12)mm without any statistical differences among them (t =0.815,P=0.417 ;t=-0.900,P=0.371 ).The high correlation between anterior chamber depth measurements were found by the each other comparison in the three instruments ( r =0.735,0.813,0.823,P ＜ 0.01 ).Conclusions ODM 1000A sonograph can provide precise axial length and anterior chamber depth values.However,ODM 1000Asonograph can not substitute for IOLMaster in the measurement of the anterior chamber depth and axial length.

Comparison of corneal curvature, anterior chamber depth and axial length measured by IOLMaster, Orbscan Ⅱ and ultrasound before and after LASIK / 中华实验眼科杂志

BackgroundIt is important to measure the corneal curvature, anterior chamber depth (ACD) and axial length accurately for calculating IOL power. The interchange outcomes from different measuring methods and apparatus will cause unreliable IOL power. ObjectiveThe present study was to compare the differences of corneal curvature, anterior chamber depth (ACD) measured by IOLMaster and Orbscan Ⅱbefore and after laser in situ keratomileusis(LASIK) and further compare the axial length measured by IOLMaster and A-ultrasound. Methods One hundred and thirty eyes from 65 consecutive myopic patients before LASIK and 56 eyes of 28 cases with 1-month follow-up duration after LASIK in Henan Eye Institute were enrolled in this study. The K value, ACD between IOLMaster and Orbscan Ⅱ as well as results of axial length between IOLMaster and A-ultrasound were compared by using paired t test. The agreements of the measured values among IOLMaster, Orbscan Ⅱ and A-ultrasound were evaluated using Bland-Altman plot. ResultsBefore LASIK,the K value measured by IOLMaster,Orbscan Ⅱ were ( 43.32 ± 1.52 ) D and ( 42.99 ± 1.45 ) D respectively with the difference value of( 0. 33 ±0. 03 ) D, showing a significant difference(t=10. 380,P=0.000) and a positive relation between them(r=0.971,P=0.000). After LASIK,the K value measured by IOLMaster, Orbscan Ⅱwere(39. 02±2. 14) D and ( 38.91 ±2. 04) D with the difference value (0. 12±0. 33 ) D, presenting a significant differences between them (t =2.715, P =0.009). Bland-Altman plots indicated the disagreement in K value and uninterchangeable. Before LASIK, the ACD measured by IOLMaster,Orbscan Ⅱ and A-ultrasound were ( 3.72 ± 0. 22 ) mm, ( 3.69 ±0. 22 ) mm and ( 3.75± 0.27 )mm respectively and no significant differences were found between them (P ＞ 0. 05 ). Axial length measured by IOLMaster significantly prolonged in comparison with A-ultrasound(25.59± 1. 01 mm vs 25.22±0.99 mm ) , and the difference was( -0. 37 ±0. 30 ) mm, showing significant difference ( t =- 14. 098, P =0. 000 ) and positive correlation ( r =0. 954, P =0. 000 ). Axial length values measured by IOLMaster were ( 25.54 ± 1.05 ) mm in preoperation and ( 25.48 ± 1.01 ) mm in postoperation with the difference (0.052±0. 412)mm, showing statistically insignificant difference between them (t=0. 946,P=0. 348). ConclusionsKeratometries measured by IOLMaster,Orbscan Ⅱ are much more different. Therefore,these two methods are not recommended to use interchangely. ACD measured by IOLMaster,Orbscan Ⅱ and A ultrasound are proved to obtain the similar results and is clinically interchange. Axial length measured by IOLMaster is longer than that measured by A-ultrasound.

A comparative study about axial length measurement between IOLMaster and adjusted A-scan ultrasound methods in silicone-filled eyes / 中华实验眼科杂志

Background Combination of cataractopiesis with intraocular lens (IOL) is believed to improve the patient' s quality of life. However, 1OL power and axial length measured by traditional method in silicone-filled eye is normally bias to the actual levels. The optical coherence biometry technology has been widely used in the measurement of IOL, but little studies have been conducted to demonstrate the IOL power difference between those methods. Objective This study was to evaluate the predictability of IOL power calculations using the IOLMaster and adjusting contact ultrasound A-scan method in silicone oil-filled eyes. Methods Forty-four silicone-filled eyes of 42 patients were divided into 2 groups according to the intraocular pressure (IOP) ( group A: ≥ 10 mmHg group,29 eyes;group B:＜10 mmHg group, 15 eyes). IOLMaster and ocular ultrasonic measurement were used to measure the axis length before and after silicone oil was removed. The preoperatively measured eye axis and cornea curve were used to calculate the theoretical IOL. Results In normal IOP group ( T≥ 10 mmHg,29 eyes), the precision and stability of IOLMaster for axial length ( AL ) measurements and IOL power calculations were better than adjusted ultrasound A-scan( ZIOLMasterdependent = -2. 236, P = 0. 025 ), although in low IOP group ( T＜ 10 mmHg, 15 eyes),there were too much differences in axial length mesurement and IOL power calculation between the IOLMaster and adjusted ultrasound A-scan, so the post-operative imformation was not predicted accurately. Conclusion For anticipatory normal postoperative IOP eyes, the refractive outcome in cataract surgery in silicone oil-filled eyes can be predicted reliably and accurately with IOLMaster. But for complicated or anticipatory unstable postoperative IOP eyes,secondary implantation of IOL would be better.

Evaluation of ocular refraction in silicone oil temponade eyes by the IOL-Master system / 眼科研究

Background The combination procedure of the removal of silicon oil and cataract extraction+intraocular lens (IOL) implantation is the main method of treating cataract in silicone oil tamponade eye.However,the conventional measuring method of the IOL power is limiting in eyes with silicone oil tamponade.The IOL-Master system is confirmed to be an ideal non-contact optical measuring instrument in vivo.Objective The aim of this study is to measure the preoperative IOL power,evaluate the accuracy of biometry with the IOL-Master system and compare the relationship between different factors and refractive error.Methods IOL power was measured in 29 silicone oil tamponade eyes of 29 patients prior to the silicone oil removal combining IOL implantation with the IOL-Master system according to different factors such as placement time,axis oculi,complications and so on.The reasons of visual acuity recovery and measurement error were discussed.Results Postoperative visual acuity was improved in all of the patients.The average predictive refractive error was 0.329±0.846 (-1.5--2D).Classified factors for the cause of disease for axis oculi included rhegmatogenous retinal detachment (RRD)(t=0.478,P=0.637),macular hole(t=0.135,P=0.895),myopia(t=0.435,P=0.667)and oil-placed time (good for less than 1 year).These factors showed an indirect relationship with errors.Conclusion Silicone oil removal combined with IOL implantation can improve visual acuity.The IOL-Master biometry is accurate,safe and convenient in measuring the IOL power in silicon oil temponade eye,but future research should be performed to decrease the measuring error.

Comparison of IOLMaster(R) and A-Scan Ultrasound: Change in Axial Length After Vitrectomy in Macular Disease

PURPOSE: To evaluate the differences between IOLMaster(R) and A-scans in changes in axial length after vitrectomy in patients with macular disease. METHODS: Using IOLMaster(R) and A-scans, we measured preoperative and postoperative axial length in 12 eyes with epiretinal membranes (ERM) and in 8 eyes with macular holes (MH). The relationship between the absolute error in axial length after vitrectomy and both methods was assessed using Mann-Whitney U test. The correlation to central macular thickness was evaluated by Spearman's correlation coefficient. RESULTS: In eyes with ERM and MH, preoperative and postoperative axial lengths obtained with both methods had no significant difference (p>0.05). The absolute error in axial length after vitrectomy was not significant using IOLMaster(R) (ERM: 0.07+/-0.05 mm, MH: 0.04+/-0.02 mm, p>0.05) but was significant using A-scan (ERM: 0.20+/-0.11 mm, MH: 0.30+/-0.07 mm, p0.05, MH; correlation coefficient = -0.054, p>0.05, A-scan: ERM; correlation coefficient = -0.210, p>0.05, MH; correlation coefficient = -0.156, p>0.05). CONCLUSIONS: The IOLMaster(R) is more useful than the A-scan when measuring axial length without refractive errors after vitrectomy in eyes with macular disease.

Comparison of IOLMaster(R) and A-Scan Ultrasound: Change in Axial Length After Vitrectomy in Macular Disease

PURPOSE: To evaluate the differences between IOLMaster(R) and A-scans in changes in axial length after vitrectomy in patients with macular disease. METHODS: Using IOLMaster(R) and A-scans, we measured preoperative and postoperative axial length in 12 eyes with epiretinal membranes (ERM) and in 8 eyes with macular holes (MH). The relationship between the absolute error in axial length after vitrectomy and both methods was assessed using Mann-Whitney U test. The correlation to central macular thickness was evaluated by Spearman's correlation coefficient. RESULTS: In eyes with ERM and MH, preoperative and postoperative axial lengths obtained with both methods had no significant difference (p>0.05). The absolute error in axial length after vitrectomy was not significant using IOLMaster(R) (ERM: 0.07+/-0.05 mm, MH: 0.04+/-0.02 mm, p>0.05) but was significant using A-scan (ERM: 0.20+/-0.11 mm, MH: 0.30+/-0.07 mm, p0.05, MH; correlation coefficient = -0.054, p>0.05, A-scan: ERM; correlation coefficient = -0.210, p>0.05, MH; correlation coefficient = -0.156, p>0.05). CONCLUSIONS: The IOLMaster(R) is more useful than the A-scan when measuring axial length without refractive errors after vitrectomy in eyes with macular disease.

Comparison of Formulas for Intraocular Lens Power Calculation Installed in a Partial Coherence Interferometer

PURPOSE: To evaluate the accuracy of various formulas installed in IOLMaster software which uses partial coherence interferometry for axial length measurement. METHODS: This retrospective comparative study included 81 eyes of consecutive patients who had uneventful cataract surgery with implantation of Acrysof single piece (SA60AT) IOL. Axial length was measured with IOLMaster and IOL power was calculated using various formulas, including SRK II, SRK/T, Holladay 1, Haigis, and Hoffer Q. Subjects were stratified by axial length into Groups A (axial length or = 25.00 mm). Target refractions of the five formulas were compared to the postoperative manifest refraction at 1 month. RESULTS: The five formulas showed no difference in predicting postoperative refractive errors among all of the groups. CONCLUSIONS: Five formulas installed in IOLMaster software provided equivalent predictions of postoperative refractive error regardless of axial length.

Axial Length and Anterior Chamber Depth by IOL-Master, A-scan according to Viscosity of Silicone Oil

PURPOSE: To evaluate differences between partial coherence laser interferometry (IOL-Master, Zeiss) and A-scan measurement of axial length and anterior chamber depth in silicone oil-filled eyes according to viscosity. METHODS: Using IOL-Master and A-scan, axial length and anterior chamber depth in silicone oil-filled eyes (n=54) and normal eyes (control, n=54) were measured and analyzed. In silicone oil-filled eyes, calculated axial lengths by A-scan using conversion factors, axial length multiplied by 0.71, and vitreous cavity multiplied by 0.64 (classic method) were compared with those calculated by IOL-Master. Anterior chamber depths were also analyzed., and axial lengths and anterior chamber depths were compared according to the viscosities of silicone oil for measurement by A-scan. RESULTS: Axial length and anterior chamber depth using IOL-Master were shorter than those using A-scan by 9.45+/-1.81 mm (p<0.05) and 0.11+/-1.29 mm, respectively. In normal eyes, axial length and anterior chamber depth using IOL-Master and A-scan were not significantly different. In silicone oil-filled eyes, axial length using IOL-Master and conversion factor was also not significantly different. At the highest silicone oil viscosity the difference in measured axial length was greatest (p<0.05) while the difference in anterior chamber depths was smallest. CONCLUSIONS: In silicone oil-filled eyes, axial length by IOL-Master was more accurate than that by A-scan, regardless of silicone oil viscosity. Thus, IOL-Master is more useful than A-scan when measuring axial length in silicone oil-filled eyes.

The measurement of anterior chamber depth and axial length with the IOLMaster compared with contact ultrasonic axial scan / 国际眼科杂志(Guoji Yanke Zazhi)

· AIM: To compare the measurement of anterior chamber depth (ACD) and axial length (AL) by IOLMaster and contact ultrasonic (US) axial scan (A-scan).· METHODS: Measurements of ACD and AL were prospectively obtained in 137 eyes of 121 subjects with the IOLMaster compared with measurements with the US.· RESULTS: There was an excellent correlation between IOLMaster and US measurements for the ACD (r=0.823;P＜0.001) and AL (r=0.996;P＜0.001). The mean values of the parameters measured by IOLMaster and US were,respectively, as follows: ACD, 2.94±0.49mm, 2.58±0.51mm;AL, 24.37±3.04mm, 23.81±2.83mm. The mean differences of ACD and AL values between IOLMaster and US measurements were 0.36 ±0.30mm, 0.56 ±0.34 mm respectively, and they proved to be statistically significant (P＜0.001), With the 95%limits of agreement (LoA) from -0.08mm to +0.38mm for ACD and from -0.09mm to +0.69mm for AL.· CONCLUSION: As noncontact biometry, IOLMaster provides accurate values. A high degree of agreement between US and IOLMaster was noted. It not only has the advantage of performing noncontact examinations, but also produces various additional data simultaneously and may thus obviate the need for multiple examinations. Further studies are needed to assess the interchangeability of measurements in clinical practice.

Accuracy of Partial Coherence Interferometry in Intraocular Lens Power Calculation

PURPOSE: To evaluate the accuracy and the influencing factors of partial coherence interferometry in intraocular lens (IOL) power calculation for cataract surgery. METHODS: In 86 eyes of 69 patients who had undergone cataract surgery, we measured axial length using both IOLMaster and contact type ultrasonography, calculated the target refraction with SRK II formula and compared the result with the measured value after operation. We also evaluated the factors influencing the accuracy of the power calculation such as age, sex, type of cataract, severity of nucleosclerosis, corneal power, and preoperative refraction. RESULTS: In IOLMaster and contact type ultrasonography, the mean axial lengths were 23.70 +/- 1.27 mm and 23.55 +/- 1.28 mm (p<0.01), and the mean absolute errors (MAE) of refraction were 0.53 +/- 0.26D and 0.66 +/- 0.39D (p<0.01) respectively. The eyes of longer axial length showed larger MAE than those of shorter axial length (p=0.02). CONCLUSIONS: Partial coherence interferometry was more accurate than contact type ultrasonography in IOL power calculation. The factor associated with the accuracy of partial coherence interferometry was the axial length.

The Accuracy of Axial Length Measurement Using Partial Coherence Interferometrys

PURPOSE: IOLMaster(R), a non-contact device using partial coherence interferometry, serves as a new optical method for axial length determination. The accuracy of this device was analyzed by comparing the measurements from IOLMaster(R) and A-scan. METHODS: We measured the axial lengths in 150 eyes of 80 patients with IOLMaster(R) and A-scan. Then, we examined the difference of measurements between the IOLMaster(R) and A-scan according to the patients' age, refractive error, type of cataract, and existence of cataract. RESULTS: Axial length could not be measured with IOLMaster(R) in 12 eyes, which all had severe cataract. The measurements from IOLMaster(R) in both, the cataract group and the normal group, resulted 0.02mm longer than those from A-scan, but did not differ significantly (p>0.1). Also, there was no statistical difference of measurements between IOLMaster(R) and A-scan according to the patients' age, refractive error, and types of cataract (p>0.05). CONCLUSIONS: Axial length measurement with IOLMaster(R) shows no significant difference from A-scan measurement. Therefore, IOLMaster(R) can be a new clinical method of axial length measurement except for cases of a severe cataract.