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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< AL ≤30 mm)and 52 eyes in group C(AL >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<0.05), with a difference of AL measured by the two devices: group C>group B>group A. However, there was no statistical significance in LT, Km, and WTW measured by the two instruments(all P>0.05). All biometric parameters measured by the two devices were positively correlated(all r>0.9, P<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>0.05), but the IOL Master 700 calculated a smaller PE than Lenstar LS900(P<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.
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AIM: To evaluate the accuracy of the formulas, including Haigis, SRK/T, Holladay 1, and Holladay 2, in predicting the diopter of the intraocular lens implanted in high myopia cataract patients.METHODS: Prospective study. A total of 168 cases(168 eyes)of age-related cataract with an axial length(AL)≥26 mm who were treated in our hospital from August 2017 to November 2021 were selected. According to the preoperative AL measured by IOL Master 700, the patients were divided into five groups, including 37 cases(37 eyes)in group A with 26 mm≤AL<27 mm, 34 cases(34 eyes)in group B with 27 mm≤AL<28 mm, 42 cases(42 eyes)in group C with 28 mm≤AL<29 mm, 28 cases(28 eyes)in group D with 29 mm≤AL<30 mm, and 27 patients(27 eyes)in group E with AL ≥ 30 mm. Subjective refraction was performed at 3 mo postoperatively, and the mean numerical error(MNE)and mean absolute error(MAE)of each formula for predicting diopters were calculated.RESULTS: The MNE and MAE of the Haigis and Holladay 2 formulas were relatively less in each group, and MNE and MAE did not significantly increase with the growth of the axial length. However, the MAE and MNE of the SRK/T and Holladay 1 formulas significantly increased with the growth of the axial length, with the MNE and MAE of the Holladay 1 formula increasing more significantly in groups C, D, and E.CONCLUSION: For patients with age-related cataract, with an axial length of ≥26 mm, the accuracy of predicting the diopter of the intraocular lens using the Haigis and Holladay 2 formulas were higher.
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AIM:To compare the differences of ocular biometric parameters of age-related cataract between Tibetan and Han ethnic groups, and to analyze the distribution characteristics of ocular biometric parameters in Tibetan cataract patients.METHODS:Retrospective cohort study. A total of 661 patients(1 030 eyes)with age-related cataract confirmed in the hospital between January 2019 and December 2020 were enrolled. The parameters of axial length, anterior chamber depth, keratometry, corneal astigmatism and astigmatic axis were measured by IOL Master 500 in 483 cases(739 eyes)of Tibetan age-related cataract patients and 178 cases(291 eyes)of Han patients.RESULTS:The axial length, anterior chamber depth and corneal astigmatism of the Tibetan patients with age-related cataract were 23.33(22.81, 23.86)mm, 3.04(2.79, 3.30)mm and 0.73(0.47, 1.07)D. The mean keratometry was 43.89±1.35 D. The results indicated that Tibetan cataract patients had shorter axial lengths and smaller keratometry compared to Han patients(all P<0.05). Age in Tibetan patients was negatively correlated with axial length and anterior chamber depth, and positively correlated with keratometry(all P<0.05). Tibetan male patients had longer axial lengths, deeper anterior chambers, and flatter corneas compared to female patients(all P<0.05).CONCLUSION:There were differences in ocular biometric parameters between age-related cataract patients of Tibetan and Han ethnicities. The distribution of ocular biometric parameters in Tibetan cataract patients varied across different age groups and gender groups.
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AIM:To observe the accuracy of infiltrating B ultrasound guided A-scan segment biometric measurement of axial length in dense cataract.METHODS: Perspective study. A total of 86 patients(90 eyes)with dense cataract were selected from Chengdu Aier Eye Hospital from August 2020 to August 2022. There were 61 males(59 eyes)males and 25 females(31 eyes)females, with an average age of 66.49±14.55 years. The axial length(AL), anterior chamber depth(ACD)(including corneal thickness), corneal curvature(K), lens thickness(LT), central corneal thickness(CCT), and white-to-white(WTW)were measured preoperatively by contact A-scan, infiltrating B ultrasound guided segmented A-scan, and IOL Master 700, respectively. At 1 wk postoperatively, AL was retested by IOL Master 700 in aphakic mode. Furthermore, the agreements and correlations of AL obtained by the three kinds of devices were analyzed.RESULTS:The AL measured by contact A-scan and infiltrating B ultrasound guided segmented A-scan were 23.40(22.63, 23.89)mm and 23.70(23.04, 24.25)mm, respectively, and the AL measured by IOL Master 700 at 1 wk postoperatively was 23.72(23.01, 24.27)mm. There were statistical significant difference in AL measured by the three methods(P=0.018), while there were no statistical significant difference in AL measured by infiltrating B ultrasound guided segmented A-scan and IOL Master 700(P=0.991). Bland-Altman analysis showed that there was a good agreement in AL measured by infiltrating B ultrasound guided segmented A-scan and IOL Master 700(P=0.0809). The AL measured by infiltrating B ultrasound guided segmented A-scan and IOL Master 700 was positively correlated(rs=0.992, P<0.0001), and the AL was positively correlated between preoperative contact A-scan and postoperative IOL Master 700(rs=0.989, P<0.0001).CONCLUSION:For dense cataract, infiltrating B ultrasound guided A-scan segment biometric measurement, which has good correlations and agreement, is closer to the AL measured by IOL Master 700 postoperatively than that measured by contact A-scan.
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AIM: To observe the changes in the Chang-Warning chord(CW chord)before and after cataract surgery using the IOL Master 700 and predict the CW chord using an artificial intelligence prediction model and preoperative measurement data.METHODS: The analysis was conducted on the preoperative and postoperative IOL Master 700 measurements of 304 cataract patients. This included astigmatism vector value, average keratometry, axial length, anterior chamber depth, lens thickness, corneal central thickness, white-to-white, the position of the Purkinje reflex I image relative to the corneal center and pupil center, and the CW chord. A prediction model based on the SVR algorithm and the BP neural network algorithm was established to predict the postoperative CW chord using the preoperative CW chord and ocular biological parameters.RESULTS: The X component of the CW chord showed a slight shift in the temporal direction in both the left and right eyes after cataract surgery, while the Y component changed little. The SVR model, using the preoperative CW chord and other preoperative biometric parameters as input data, was able to predict the X and Y components of the CW chord more accurately than the BP neural network.CONCLUSION: The CW chord can be directly measured with a coaxial fixation light using various biometers, corneal topographers, or tomographers. The use of the SVR algorithm can accurately predict the postoperative CW chord before cataract surgery.
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AIM: To compare the difference and consistency of corneal refractive power and astigmatism measured by CASIA2 and IOL Master 700 in patients with age-related cataract.METHODS: Retrospective study. A total of 153 patients(232 eyes)with age-related cataract admitted to Daping hospital from November to December 2021 were selected. The flat keratometry(Kf), steep keratometry(Ks), mean keratometry(Km), degree and axis of astigmatism(vector representation J0 and J45)of the anterior, posterior surfaces together with the total cornea from cataract patients were measured by CASIA2 and IOL Master 700, respectively. The difference, correlation and consistency of the two instruments were analyzed.RESULTS:There was no significant difference in J45 values of posterior corneal surface measured by CASIA2 and IOL Master 700(-0.006±0.038D vs. -0.005±0.044D, P>0.05), but there were significant differences in other parameters(all P<0.05). All parameters measured by the two instruments were significantly positive correlated(all r/rs>0.7, P<0.001); Bland-Altman analysis showed that the refractive power and astigmatism of the anterior cornea surface measured by the two facilities were in good consistency, while the refractive power of the posterior surface and the whole cornea showed poor consistency.CONCLUSION: CASIA2 and IOL Master 700 showed little differences and good consistency in the refractive power and astigmatism of the anterior, posterior and total corneal surface in cataract patients, which seems interchangeable. However, the refractive power of the posterior surface and the whole cornea has significant differences and poor consistency, which should not be interchange casually.
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Purpose: To evaluate the repeatability of biometry and intraocular lens (IOL) power using Galilei G6 and to determine the agreement of its measurements with those of IOL Master 700 and IOL Master 500. Methods: Hundred mature cataract eyes were examined twice with Galilei G6 and the results were compared with those of other two devices. Axial length (AL), minimum (K1), maximum (K2), and mean keratometry, anterior chamber depth (ACD), white-to-white (WTW) diameter, lens thickness (LT), and the calculated IOL power were the studied parameters. The correlation coefficient, within-subject standard deviation (Sw), Bland–Altman method, and 95% limits of agreement (LoA) were used for statistical analysis. Results: The intraclass correlation coefficient (ICC) was above 0.9 for all indices, and the LoA ranged from a minimum of 0.08 mm for AL to a maximum of 0.50 D for K1. Sw also ranged between a minimum of 0.02 for AL, ACD, and WTW and a maximum of 0.13 for K1. In the Galilei G6–IOL Master 700 pair, the narrowest and widest LoA were calculated for AL (0.07 mm) and K2 (0.49 D), respectively. In the Galilei G6–IOL Master 500 pair, the narrowest and widest widths of LoA were calculated for AL (0.17 mm) and K2 (0.92 D), respectively. In the first pair, the LoA of IOL power (0.57 D) were the best for Haigis formula and in the second pair, the best agreement (LoA: 0.35 D) was observed for Holladay-1. Conclusion: Galilei G6 provided repeatable biometric measurements. The agreement between biometry and IOL power calculation was better in the Galilei G6–IOL Master 700 pair compared to the Galilei G6–IOL Master 500
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@#AIM: To investigate the difference and consistency among iTrace, IOL Master 700 and Pentacam HR in measuring corneal astigmatism before cataract surgery.<p>METHODS: Across-sectional study. From May 2020 to May 2021, a total of 149 cataract patients(181 eyes)were collected in our hospital. Presurgery, steep keratometry(Ks), flat keratometry(Kf), mean keratometry(Km), astigmatism magnitude(Cyl), and steep astigmatic axis values measured by the three instruments of the iTrace, IOL Master 700 and the Pentacam HR. The difference and consistency of the measurement indexes of the three instruments were analyzed.<p>RESULTS: Statistical differences existed in Ks, Kf, Km among the three instruments(<i>F</i>=4.912, 3.514, 4.873, all <i>P</i><0.05)and there was no difference in Cyl and Axis(<i>F</i>=0.523, 0.128, all <i>P</i>>0.05). Bland-Altman analysis showed the outcomes revealed that the Ks and Kf measured by iTrace and the other two instruments have poor consistency, and the consistency of Cyl and Axis was good. But the difference of Axis is not clinically acceptable. There were no statistically differences between the iTrace and the other two devices among the low astigmatism(50 eyes), moderate astigmatism(34 eyes)and high astigmatism(18 eyes)groups(all <i>P</i>>0.05). <p>CONCLUSION: In the preoperative measurement of cataract patients except for the good consistency of astigmatism, the iTrace, IOL Master 700 and Pentacam HR showed different Ks and Kf, and the Axis difference exceeded the clinically acceptable range, especially in the highly astigmatism group. The measurement of corneal astigmatism before cataract surgery should be evaluated by multiple measurement methods and make comprehensive planning for the surgical plan.
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AIM:To evaluate the accuracy of A-ultrasound combined with corneal topography measurement in clinical application by analyzing the ocular-related biometric parameters and refractive error and comparing with those of IOL Master 700 in cataract patients. METHODS: A prospective study. Clinical data were collected from 113 patients(122 eyes)who underwent phacoemulsification in the First Affiliated Hospital of Soochow University from July 2020 to July 2021. The axial length(AL), anterior chamber depth(ACD), lens thickness(LT)and corneal curvature(Km)were measured respectively by IOL Master 700 and A-ultrasound combined with corneal topography measurement and the 3mo after the surgery of the refractive error was analyzed.RESULTS: There were differences in AL(24.09±1.65, 23.81±1.62mm), ACD(3.11±0.42, 2.97±0.43mm)and Km(44.12±1.59, 44.06±1.54D)measured by IOL Master 700 and A-ultrasound combined with corneal topography(P<0.05), while there was no difference in LT(4.34±0.46, 4.30±0.59mm)(P>0.05). The postoperative mean absolute refractive error(MAE)of intraocular lens(IOL)diopter calculation formulas with different measurement methods was significantly different(P<0.001). The Barrett Universal II formula MAE of the IOL Master 700 measuring instrument was different from the Holladay I, Haigis and SRK/T formulas(P<0.01), at the same time, compared with the A-ultrasound combined with corneal topography calculation formula SRK/T and Barrett Universal II formula, they were also different(P<0.01). However, there was no difference among the Holladay Ⅰ, Haigis, SRK/T formula MAE which come from the IOL Master 700 measuring instrument and the A-ultrasound combined with corneal topography calculation formula SRK/T formula(P>0.05). In addition, the Barrett Universal II formula of the IOL Master 700 measuring instrument has the smallest median absolute refractive error(MedAE)(0.260D), and the A-ultrasound combined with corneal topography calculation formula Barrett Universal II formula MedAE is the largest(0.765D).CONCLUSION: The values of AL, ACD and Km measured by A-ultrasound combined with corneal topography were smaller than those of IOL Master 700. When the SRK/T formula was used to calculate the IOL diopter, the results of the two group were similar. However, when using the Barrett Universal Ⅱ formula, the refractive error of the A-ultrasound combined with corneal topography group was large, resulting in hyperopia drift.
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Objetivo: Comparar las mediciones biométricas realizadas con el IOL Master 700 y el Pentacam AXL en pacientes miopes con cirugía fotoablativa previa. Métodos: Se realizó un estudio transversal en 103 ojos de 103 pacientes miopes con cirugía fotoablativa previa, atendidos en el período de enero 2019 a enero 2020, en el Instituto Cubano de Oftalmología "Ramón Pando Ferrer". Las variables estudiadas fueron: edad, sexo, equivalente esférico y características biométricas posoperatorias (longitud axial, profundidad de la cámara anterior y queratometrías), así como su relación, aportadas automáticamente por el IOL master 700 y el pentacam AXL para evitar los factores dependientes del operador, tres meses después de la cirugía. El análisis estadístico se realizó con la prueba t para datos pareados, utilizando una significación del 95 por ciento. Resultados: La edad promedio fue de 25,72 ± 4,26 años. Se analizaron 53 ojos derechos y 50 izquierdos, todos tratados con láser de superficie. El equivalente esférico medio fue de -0,06 ± 0,34 dioptrías y el tiempo entre la cirugía y los exámenes fue de 6,32 ± 3,56 meses. No hubo diferencia estadísticamente significativa (p > 0,05) entre la longitud axial y la profundidad de la cámara anterior; mientras que sí la hubo (p < 0,01) con las queratometrías obtenidas con el IOL Master 700, en comparación con los del pentacam AXL. Conclusión: En pacientes miopes con cirugía fotoablativa previa, el IOL Master 700 y el pentacam AXL proveen mediciones biométricas similares, como la longitud axial y la profundidad de la cámara anterior, no así con la queratometría, la cual es diferente(AU)
Objective: Compare the biometric measurements taken with IOL Master 700 and Pentacam AXL in myopic patients with previous photoablative surgery. Methods: A cross-sectional study was conducted of 103 eyes of 103 myopic patients undergoing photoablative surgery at Ramón Pando Ferrer Cuban Institute of Ophthalmology from January 2019 to January 2020. The variables analyzed were age, sex, spherical equivalent and preoperative biometric characteristics (axial length, anterior chamber depth and keratometries) and the relationship to one another, automatically supplied by IOL Master 700 and Pentacam AXL to avoid operator-dependent factors. The analysis was performed three months after surgery. Statistical analysis was based on the paired Student's t-test with a significance level of 95 percent. Results: Mean age was 25.72 ± 4.26 years. Fifty-three right eyes and 50 left eyes were studied, all of them treated with surface laser. Mean spherical equivalent was -0.06 ± 0.34 diopters; the time elapsed between surgery and the tests was 6.32 ± 3.56 months. No statistically significant differences (p > 0.05) were found between axial length and anterior chamber depth, but statistically significant differences (p < 0.01) were observed between the keratometries obtained with IOL Master 700 and Pentacam AXL. Conclusion: IOL Master 700 and Pentacam AXL provide similar biometric measurements for axial length and anterior chamber depth in myopic patients with previous photoablative surgery, but keratometric measurements are different(AU)