scholarly journals Comparative analysis of two optical biometry devices: high wavelength swept source OCT versus partial coherence interferometry

Author(s):  
Eszter Szalai ◽  
Adrienne Csutak

Abstract Purpose To study the reproducibility of measurements performed with a recently developed multimodal high resolution swept source optical coherence tomography (SSOCT) and to make comparisons with a partial coherence interferometry (PCI) biometer. Methods One hundred and fifty-two eyes of 152 subjects were involved in this study with a mean age of 65.71 ± 13.86 years (26–85 years). Anterior surface keratometry (K), anterior chamber depth (ACD), white-to-white (WTW) and axial length (AL) values were recorded by the SSOCT (ANTERION, Heidelberg Engineering Ltd, Germany) and PCI (IOLMaster 500, version 5.5, Carl Zeiss Meditec, Germany). Intraocular lens (IOL) power was calculated based on ANTERION and IOLMaster keratometry values by using five traditional vergence formulas. Results Anterior surface simulated keratometry values did not differ significantly between the IOLMaster and ANTERION (P > 0.05). AL measurements were successful in 95% of the cases both with the SSOCT and PCI. No significant difference was disclosed between the two instruments (P = 0.229). For WTW measurements, a significant difference was observed between the two optical biometers (P < 0.0001). The difference between PCI and SSOCT in IOL powers was statistically significant for SRK/T, Hoffer and Holladay formulas (P < 0.001). Conclusion Our results implicated an overall good reproducibility of anterior keratometry, AL, ACD and WTW measurements for IOLMaster and ANTERION. The discrepancies between their measurements resulted in significant difference in the calculated IOL power for SRK/T, Hoffer and Holladay formulas, but not for Haigis formula.

2020 ◽  
pp. bjophthalmol-2020-316193
Author(s):  
Giacomo Savini ◽  
Marco Di Maita ◽  
Kenneth J Hoffer ◽  
Kristian Næser ◽  
Domenico Schiano-Lomoriello ◽  
...  

Background/aimsTo compare the accuracy of 13 formulas for intraocular lens (IOL) power calculation in cataract surgery.MethodsIn this retrospective interventional case series, optical biometry measurements were entered into these formulas: Barrett Universal II (BUII) with and without anterior chamber depth (ACD) as a predictor, EVO 2.0 with and without ACD as a predictor, Haigis, Hoffer Q, Holladay 1, Holladay 2AL, Kane, Næser 2, Pearl-DGS, RBF 2.0, SRK/T, T2 and VRF. The mean prediction error (PE), median absolute error (MedAE), mean absolute error and percentage of eyes with a PE within ±0.25, ±0.50, ±0.75 and ±1.00 diopters (D) were calculated.ResultsTwo hundred consecutive eyes were enrolled. With all formulas, the mean PE was zero. The BUII with no ACD had the lowest standard deviation (±0.343 D), followed by the T2 (0.347 D), Kane (0.348 D), EVO 2.0 with no ACD (0.348 D) and BUII with ACD (0.353 D) formulas. The difference among the MedAEs of all formulas was statistically significant (p<0.0001); the lowest values were achieved with the Kane (0.214 D), RBF 2.0 (0.215 D), BUII with and without ACD (0.218 D) and SRK/T (0.223 D). A percentage ranging from 80% to 88.5% of eyes showed a PE within ±0.50 D and all formulas achieved more than 50% of eyes with a PE within ±0.25 D.ConclusionAll investigated formulas achieved good results; there was a tendency towards better outcomes with newer formulas. Traditional formulas can still be considered an accurate option.


2020 ◽  
Author(s):  
Tommy Chan ◽  
Marco Yu ◽  
Vivian Chiu ◽  
Gilda Lai ◽  
Christopher Leung ◽  
...  

Abstract Purpose To evaluate the repeatability and agreement of cornea and biometry measurements obtained with two swept-source optical coherence tomography (SSOCT) and a partial coherence interferometry-based device.METHODS This is a cross-sectional study. Forty-eight eyes of 48 patients had three consecutive measurements for ANTERION (Heidelberg Engineering, Germany), CASIAII (Tomey, Japan) and IOLMaster500 (Carl Zeiss Meditec, USA) on the same visit. Mean keratometry (Km), central cornea thickness (CCT), anterior chamber depth (ACD) and axial length (AL) were recorded. Corneal astigmatic measurements were converted into vector components – J0 and J45. Intra-device repeatability and agreements of measurements amongst the devices were evaluated using repeatability coefficients (RCs) and Bland-Altman plots, respectively. RESULTS All devices demonstrated comparable repeatability for Km (p≥0.138). ANTERION had the lowest RC for J0 amongst the devices (p≤0.039). Systematic difference was found for the Km and J0 obtained with IOLMaster500 compared to either SSOCTs (p≤0.010). The ACD and AL measured by IOLMaster500 showed a higher RC compared with either SSOCTs (p<0.002). Systematic difference was found in CCT and ACD between the two SSOCTs (p<0.001), and in AL between ANTERION and IOLMaster500 (p<0.001), with a mean difference of 1.6 µm, 0.022mm and 0.021 mm, respectively. CONCLUSIONS Both SSOCTs demonstrated smaller test-retest variability for measuring ACD and AL compared with IOLMaster500. There were significant disagreement in keratometry and AL measurements between the SSOCTs and PCI-based device; their measurements should not be considered as interchangeable but the disagreement could be refined by readjustment of intraocular lens constant in clinical practice.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tommy C. Y. Chan ◽  
Marco C. Y. Yu ◽  
Vivian Chiu ◽  
Gilda Lai ◽  
Christopher K. S. Leung ◽  
...  

AbstractTo evaluate the repeatability and agreement of corneal and biometry measurements obtained with two swept-source optical coherence tomography (SSOCT) and a partial coherence interferometry-based device. This is a cross-sectional study. Forty-eight eyes of 48 patients had three consecutive measurements for ANTERION (Heidelberg Engineering, Germany), CASIAII (Tomey, Japan) and IOLMaster500 (Carl Zeiss Meditec, USA) on the same visit. Mean keratometry (Km), central corneal thickness (CCT), anterior chamber depth (ACD) and axial length (AL) were recorded. Corneal astigmatic measurements were converted into vector components—J0 and J45. Intra-device repeatability and agreements of measurements amongst the devices were evaluated using repeatability coefficients (RCs) and Bland–Altman plots, respectively. All devices demonstrated comparable repeatability for Km (p ≥ 0.138). ANTERION had the lowest RC for J0 amongst the devices (p ≤ 0.039). Systematic difference was found for the Km and J0 obtained with IOLMaster500 compared to either SSOCTs (p ≤ 0.010). The ACD and AL measured by IOLMaster500 showed a higher RC compared with either SSOCTs (p < 0.002). Systematic difference was found in CCT and ACD between the two SSOCTs (p < 0.001), and in AL between ANTERION and IOLMaster500 (p < 0.001), with a mean difference of 1.6 µm, 0.022 mm and 0.021 mm, respectively. Both SSOCTs demonstrated smaller test–retest variability for measuring ACD and AL compared with IOLMaster500. There were significant disagreement in keratometry and AL measurements between the SSOCTs and PCI-based device; their measurements should not be considered as interchangeable.


2020 ◽  
Author(s):  
Moonjung Kim ◽  
Eui Seok Han

Abstract Background: To evaluate the agreement between the biometers measured by optical low-coherence interferometry (OLCI, Aladdin) and those measured by Scheimpflug imaging combined with partial coherence interferometry (Scheimpflug-PCI, Pentacam AXL) in cataract patients.Methods: The axial length (AL), corneal power (keratometry, K), anterior chamber depth (ACD), and corneal astigmatism were measured with the two devices in patients with cataracts. The difference and correlation were evaluated with a paired t-test (p) and Pearson’s correlation coefficient (r), respectively.Results: One hundred sixty-four eyes of 95 patients were analyzed. The mean AL taken by OLCI was longer with excellent correlation (OLCI 23.25 mm, Scheimpflug-PCI 23.23 mm, p = < 0.0001, r = 0.9990). OLCI measured the ACD 0.08 mm shallower than Scheimpflug-PCI (p = 0.0003, r = 0.7386). The difference was statistically significant for flat K (p = 0.0428). The mean K and steep K were not significantly different. Vector analysis showed no statistically significant difference in the magnitude of astigmatism and the oblique vector between the two devices (p = 0.1441 and p = 0.4147, respectively). Only the cardinal vector was different (p = 0.0087).Conclusions: Although OCLI and Scheimpflug-PCI showed strong correlations for AL, K, ACD, and corneal astigmatism in cataract patients, there were small but statistically significant differences in the AL, ACD, flat K, and cardinal vector. The two devices are not interchangeable for calculating intraocular lens power.


2021 ◽  
Vol 10 (3) ◽  
pp. 542
Author(s):  
Yakov Vega ◽  
Assaf Gershoni ◽  
Asaf Achiron ◽  
Raimo Tuuminen ◽  
Yehonatan Weinberger ◽  
...  

Purpose: To examine the contribution of anterior chamber depth (ACD), lens thickness (LT), and white-to-white (WTW) measurements to intraocular lens (IOL) power calculations using the Barrett Universal II (BUII) formula. Methods: Measurements taken with the IOLMaster 700 (Carl Zeiss, Meditec AG, Jena, Germany) swept-source biometry of 501 right eyes of 501 consecutive patients undergoing cataract extraction surgery between January 2019 and March 2020 were reviewed. IOL power was calculated using the BUII formula, first through the inclusion of all measured variables and then by using partial biometry data. For each calculation method, the IOL power targeting emmetropia was recorded and compared for the whole cohort and stratified by axial length (AL) of the measured eye. Results: The mean IOL power calculated for the entire cohort using all available parameters was 19.50 ± 5.11 diopters (D). When comparing it to the results obtained by partial biometry data, the mean absolute difference ranged from 0.05 to 0.14 D; p < 0.001. The optional variables (ACD, LT, WTW) had the least effect in long eyes (AL ≥ 26 mm; mean absolute difference ranging from 0.02 to 0.07 D; p < 0.001), while the greatest effect in short eyes (AL ≤ 22 mm; mean absolute difference from 0.10 to 0.21 D; p < 0.001). The percentage of eyes with a mean absolute IOL dioptric power difference more than 0.25 D was the highest (32.0%) among the short AL group when using AL and keratometry values only. Conclusions: Using partial biometry data, the BUII formula in small eyes (AL ≤ 22 mm) resulted in a clinically significant difference in the calculated IOL power compared to the full biometry data. In contrast, the contribution of the optional parameters to the calculated IOL power was of little clinical importance in eyes with AL longer than 22 mm.


2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Sisi Chen ◽  
Rongrong Gao ◽  
Colm McAlinden ◽  
Junming Ye ◽  
Yiran Wang ◽  
...  

Purpose. To compare central corneal thickness (CCT), aqueous depth (AQD), and anterior chamber depth (ACD) measurements using the swept-source (CASIA SS-1000, Tomey, Japan) and time-domain (Visante, Carl Zeiss Meditec, USA) anterior segment optical coherence tomographers (OCT) in normal eyes. Methods. Sixty-eight eyes of 68 subjects were included. Three consecutive scans of each subject were obtained using both devices in a random order by one experienced operator. Standard deviation (Sw), coefficient of repeatability (CoR), coefficients of variation (CoV), and intraclass correlation coefficients (ICC) were used to evaluate the intraoperator repeatability. Agreement was assessed using the Bland–Altman plots and 95% limits of agreement (LoA). Results. All measurements of the swept-source OCT (SS-OCT) and time-domain OCT (TD-OCT) showed high repeatability with low CoR (CCT: 2.34 μm and 6.16 μm; AQD: 0.05 mm and 0.09 mm; ACD: 0.06 mm and 0.09 mm), low CoV (CCT: 0.16% and 0.42%; AQD: 0.61% and 0.97%; ACD: 0.53% and 0.83%), and high ICC (>0.98). The mean CCT with SS-OCT was slightly thicker than the results with TD-OCT (difference = 4.55 ± 2.62 μm, P<0.001). There was no statistically significant difference in AQD or ACD measurements between the two devices (0.01 ± 0.05 mm, P=0.111; 0.02 ± 0.05 mm, P=0.022, respectively). The 95% LoA between the SS-OCT and TD-OCT were −0.59 to 9.69 μm for CCT, −0.10 to 0.12 mm for AQD, and −0.09 to 0.12 mm for ACD. Conclusions. High levels of repeatability and agreement were found between the two devices for all three parameters, suggesting interchangeability. SS-OCT demonstrated superior repeatability compared with TD-OCT.


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