Czech and Slovak Ophthalmology 249 10.31348/2022/24 Original article The Exactness of Intraocular Lens Power Calculation Formulas for Short Eyes and Correlation Between Method Accuracy and Eyeball Axial Length Stopyra Wiktor https://orcid.org/0000-0002-3919-8339 11 10 2022 5 3

Purpose: To compare the accuracy of intraocular lens power calculation formulas and to examine the correlation of this exactness with the axial length for eyes shorter than 22.00 mm Methods: The data of hyperopic patients who underwent uneventful phacoemulsification between October 2015 and June 2019 were reviewed. The intraocular lens power for each patient was calculated using 6 formulas (Holladay1, SRK/T, Hoffer Q, Holladay 2, Haigis and Barrett Universal II) before cataract surgery. Postoperative refraction was measured, and refractive prediction error was calculated 3 months after phacoemulsification. The correlation between axial length and absolute error was evaluated. Results: Fifty-six patients (62 eyes) whose ocular axial length ranged between 20.58 mm and 21.97 mm were included in the study. The Hoffer Q formula achieved the lowest mean absolute error of 0.09 (±0.08 D). A significant correlation for the Hoffer Q (ρ = -0.329, p = 0.009) and the SRK/T (ρ = 0.321, p = 0.011) formula was observed. Conclusions: 1. The Hoffer Q formula obtained the lowest absolute error and was recommended for intraocular lens power calculation for eyeballs with axial length shorter than 22.0 mm. 2. The correlation between axial length and absolute error is a factor which should be considered when calculating intraocular lens power.

 phacoemulsification hyperopia intraocular lenses Hoffer Q formula References Wang JK, Chang SW. Optical biometry intraocular lens power calculation using different formulas in patients with different axial lengths. Int J Ophthalmol 2013; 6: 150-154. https//doi.org/10.3980/j.issn.2222-3959.2013.02.0810.3980/j.issn.2222-3959.2013.02.08 Lee AC, Quazi MA, Pepose JS. Biometry and intraocular lens power calculation. Curr Opin Ophthalmol 2008 Jan; 19(1):13-7. doi: 10.1097/ICU.0b013e3282f1c5ad10.1097/ICU.0b013e3282f1c5ad Cooke DL, Cooke TL: Comparison of 9 intraocular lens power calculation formulas. J Cataract Refract Surg. 2016;42: 1490-1500. https//dx.doi.org/101016/j.jcrs.2016.06.029 Aristodemou P., Knox Cartwright N., Sparrow J., Johnston R. Formula choice: Hoffer Q, Holladay 1 or SRK/T and refractive outcomes in 8108 eyes after cataract surgery with biometry by partial coherence interferometry. J Cataract Refract Surg. 2011 Jan; 37(1): 63–71. https//doi.org/10.1016/j.jcrs.2010.07.03210.1016/j.jcrs.2010.07.032 Stopyra W. Accurate intraocular lens power calculation formulas for eyeballs with the axial length smaller than 22.0 mm. Okulistyka 3/2017: 29-31. Moschos M, Chatziralli I, Koutsandrea C. Intraocular lens power calculation in eyes with short axial length. Indian J. Ophthalmol. 2014 Jun;62(6):692-694. https//doi.org/10.4103/0301-4738.12979110.4103/0301-4738.129791 Kane JX, Van Heerden A, Atik A, Petsoglou C. Accuracy of 3 new methods for intraocular lens power selection. J Cataract Refract Surg. 2017 Mar;43(3):333-339. https//dx.doi.org/10.1016/j.jcrs.2016.12.02110.1016/j.jcrs.2016.12.021 Gale RP, Saha N, Johnston RL. National biometry audit II. Eye 2006; 20:25-28. Haigis W. Matrix-optical representation of currently used intraocular lens power formulas. J Cataract Refract Surg 2009; 25: 229-234. Hoffer KJ. The Hoffer Q formula: a comparison of theoretic and regression formulas. J Cataract Refract Surg 1993; 19:700-712. Wang Q, Jiang W, Lin T, Wu X, Lin H, Chen W. Meta-analysis of accuracy of intraocular lens power calculation formulas in short eyes. Clin Exp Ophthalmol. 2018 May;46(4):356-363. https//doi. org/10.1111/ceo.1305810.1111/ceo.13058 Wang Q, Jiang W, Lin T, Zhu Y, Chen C, Lin H. Accuracy of intraocular lens power calculation formulas in long eyes: a systemic review and meta-analysis. Clin. Exp. Ophthalmology 2018; 46:738-749. https//doi.org/10.1111/ceo.1318410.1111/ceo.13184 Gökce S, Zeiter J, Weikert M, Koch D, Hill W, Wang L. Intraocular lens power calculation in short eyes using 7 formulas. J. Cataract Refract. Surg. 2017 Jul;43(7):892-897. https//dx.doi.org/10.1016/j. jcrs.2017.07.00410.1016/j Carifi G, Aiello F, Zygoura V, Kopsachilis N, Maurino V. Accuracy of the refractive prediction determined by multiple currently available intraocular lens power calculation formulas in small eyes. Am J Ophthalmol. 2015 Mar;159(3):577-583. https//doi.org/10.1016/j. ajo.2014.11.03610.1016/j Batkov E, Pashtayev N, Mikhaylova V. Calculation of intraocular lens power in surgical treatment of extreme hyperopia. Vestn. Oftalmol. 2019;135(1):21-27. https//doi.org/10.17116/oftalma20191350112110.17116/oftalma201913501121 Hoffer KJ, Savini G. IOL power calculation in short and long eyes. Asia Pac. J. Ophthalmol. (Phila). 2017 Jul-Aug:6(4):330-331. https// doi.org/10.22608/APO.201733810.22608/APO.2017338 Roh Y, Lee S,Han Y, Kim M, Wee W, Lee J. Intraocular lens power calculation using IOLMaster and various formulas in short eyes. Korean J. Ophthalmol. 2011 Jun; 25(3):151-155. https//doi.org/10.3341/ kjo.2011.25.3.151 Carmona-González D, Castillo-Gόmez A, Palomino-Bautista C, Romero-Dominguez M, Gutiérez-Moreno MÁ. Comparison of the accuracy of 11 intraocular lens power calculation formulas. Eur J Ophthalmol 2020 Oct 15;1120672120962030. https//doi. org/10.1177/112067212096203010.1177/1120672120962030 Tang KS, Tran EM, Chen AJ, Rivera DR, Rivera JJ, Greenberg PB. Accuracy of biometric formulae for intraocular lens power calculation in a teaching hospital. Int J Ophthalmol. 2020 Jan 18;13(1):61- Darcy K, Gunn D, Tavassoli S, Sparrow J, Kane JX. Assesment of the accuracy of new and updated intraocular lens power calculation formulas in 10930 eyes from the UK National Health Service. J Catarcact Refract Surg. 2020 Jan;46(1):2-7. Doshi D, Limdi P, Parekh N, Gohil N. A Comparative Study to Assess the Predictability of Different IOL Power Calculation Formulas in Eyes of Short and Long Axial Length. J Clin Diagn. Res. 2017 Jan; 11(1):NC01-NC04. https//doi.org/10.7860/JCDR/2017/22095.913610.7860/JCDR/2017/22095.9136 Chen C, Xu X, Miao Y, Zheng G, Sun Y, Xu X. Accuracy of Intraocular Lens Power Formulas Involving 148 Eyes with Long Axial Lengths: A Retrospective Chart-Review Study. J. Ophthalmol. 2015; 2015:976847. https//doi.org/10.1155/2015/97684710.1155/2015/976847 Karabela Y, Eliacik M, Kava F. Performance of the SRK/T formula using A-Scan ultrasound biometry after phacoemulsification in eyes with short and long axial lengths. BMC Ophthalmol. 2016 Jul 8;16:96. https//doi.org/10.1186/s12886-016-0271-810.1186/s12886-016-0271-8 Gavin EA, Hammond CJ. Intraocular lens power calculation in short eyes. Eye. 2008; 22: 935-938. https//doi.org/10.1038/ sj.eye.6702774 Eom Y, Kang S-Y, Song J-S, Kim HM. Use of corneal power-specific constants to improve the accuracy of the SRK/T formula. Ophthalmology 2013; 120: 477-481. https//doi.org/10.1016/j. ophtha.2012.09.00810.1016/j https//doi.org/10.18240/ijo.202001.0910.18240/ijo.202001.09