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. 2024 May 25:18:1457-1465.
doi: 10.2147/OPTH.S461195. eCollection 2024.

Comparison of Barrett TK Universal II and Barrett Universal II TCRP Formulas in Power Calculations for 3 Presbyopia-Correcting Intraocular Lenses

Qingchen Li  1   2   3 , Xinyi Liu  1   2 , Jiasong Yang  1   2   4 , Yumeng Dai  1   2 , Wensheng Li  1   2   4
Affiliations

Comparison of Barrett TK Universal II and Barrett Universal II TCRP Formulas in Power Calculations for 3 Presbyopia-Correcting Intraocular Lenses

Qingchen Li et al. Clin Ophthalmol. .

Abstract

Purpose: To compare Barrett TK Universal II and Barrett Universal II TCRP calculations in the power calculations for 3 presbyopia-correcting intraocular lenses (PC-IOL).

Methods: This observational study involved 64 eyes from 64 patients who prepared to undergo extraction of crystalline lenses combined with PC-IOL (Symfony ZXR00, PanOptix TFNT00, or AT LISA tri 839MP) implantation. All eyes underwent ocular biometric measurements with IOLMaster 700 and Pentacam HR, and the interdevice agreement of measurements including total keratometry (TK, IOLMaster 700) and total corneal refractive power (TCRP, Pentacam HR) was evaluated. IOL power calculations were performed using TK-based Barrett TK Universal II and TCRP-based Barrett Universal II calculations, respectively.

Results: Paired t-tests showed that the differences in white-to-white diameter, central corneal thickness, anterior chamber depth, and mean TK between IOLMaster 700 and Pentacam HR were slight but significant (all P<0.05), and the differences in recommended IOL power for emmetropia between two Barrett calculations were also significant in 3 PC-IOLs (all P<0.05). The ROC curve showed that the AUC was 0.917 (95% CI, 0.820-0.971) for the absolute value of the difference between TK and TCRP in discriminating the difference of ≥ ±0.5 D in predicted IOL power with best cutoff values of 0.4 D.

Conclusion: The novel Barrett TK Universal II formula built in IOLMaster 700 is comparable to TCRP-based Barrett Universal II calculation for IOL power calculation of PC-IOLs, and the convenience of using the Barrett TK Universal II formula should be founded on measurement consistency between devices.

Keywords: intraocular lens power calculation; presbyopic corrections; refractive prediction accuracy; scheimpflug tomography; swept-source optical biometer.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Bland–Altman plots showing agreement of the measurements between IOLMaster 700 and Pentacam HR. (A) WTW vs corneal diameter; (B) CCT vs corneal thickness at the apex; (C) ACD vs ACDExt; (D) TSE vs TCRP Km.
Figure 2
Figure 2
Comparison of the recommended IOL power for emmetropia between Barrett TK Universal II and Barrett Universal II TCRP calculations. Bland–Altman plots showing agreement of the recommended IOL power for (A) Symfony ZXR00; (B) PanOptix TFNT00; and (C) AT LISA tri 839MP. (D) Paired t-tests showed that the differences in the recommended IOL power for emmetropia between Barrett TK Universal II and Barrett Universal II TCRP calculations for all three PC-IOLs were significant (* all P < 0.05).
Figure 3
Figure 3
Correlation of the ocular measurements and the absolute value of the difference in the recommended IOL power for emmetropia between Barrett TK Universal II and Barrett Universal II TCRP calculations. (A) AL, r = 0.09, P > 0.05. (B) ACD, r = 0.11, P > 0.05. (C) LT, r = 0.04, P > 0.05. (D) WTW, r = −0.23, P > 0.05. (E) CCT, r = −0.29, P < 0.05. (F) TSE, r = 0.42, P < 0.05.
Figure 4
Figure 4
(A) The correlation of the absolute value of the difference between TSE and TCRP Km and the absolute value of the difference in the recommended IOL power for emmetropia between Barrett TK Universal II and Barrett Universal II TCRP calculations was significantly positive (r = 0.87, P < 0.05). (B) ROC curve of the absolute value of the difference between TSE and mean TCRP in discriminating the absolute value of the difference in the recommended IOL power for emmetropia of ≥ 0.5 D, and the AUC was 0.917 (P < 0.05, 95% CI, 0.820–0.971) with best cutoff values of 0.4 D. (C) Correlation of CCT and the absolute value of the difference between TK and TCRP (r = −0.25, P > 0.05). (D) Correlation of TSE and the absolute value of the difference between TK and TCRP (r = 0.39, P < 0.05).
Figure 5
Figure 5
Stacked histogram comparing the percentages of eyes (N = 64) within differences of 0 D, ±0.5 D, ±1.0 D, and ±1.5 D in IOL power selection between Barrett TK Universal II and Barrett Universal II TCRP calculations among 3 PC-IOLs. More than 70% of cases finally received a difference of ±0.5 D or 0 D in the actually selected IOL power between Barrett TK Universal II and Barrett Universal II TCRP calculations.
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References

    1. Wolffsohn JS, Davies LN. Presbyopia: effectiveness of correction strategies. Prog Retin Eye Res. 2019;68:124–143. doi:10.1016/j.preteyeres.2018.09.004 - DOI - PubMed
    1. Torky MA, Nokrashy AE, Metwally H, Abdelhameed AG. Visual performance following implantation of presbyopia correcting intraocular lenses. Eye. 2022. doi:10.1038/s41433-022-02188-y - DOI - PMC - PubMed
    1. Melles RB, Holladay JT, Chang WJ. Accuracy of intraocular lens calculation formulas. Ophthalmology. 2018;125(2):169–178. doi:10.1016/j.ophtha.2017.08.027 - DOI - PubMed
    1. Chang P, Qian S, Wang Y, et al. Accuracy of new-generation intraocular lens calculation formulas in eyes with variations in predicted refraction. Graefes Arch Clin Exp Ophthalmol. 2023;261(1):127–135. doi:10.1007/s00417-022-05748-w - DOI - PubMed
    1. Li H, Ye Z, Luo Y, Li Z. Comparing the accuracy of the new-generation intraocular lens power calculation formulae in axial myopic eyes: a meta-analysis. Int Ophthalmol. 2023;43(2):619–633. doi:10.1007/s10792-022-02466-4 - DOI - PMC - PubMed