Czech and Slovak Ophthalmology 202 10.31348/2021/22 Original article The Effect of Pharmacological Pupil Dilation on Intraocular Lens Power Calculation in Patients Indicated for Cataract Surgery Autrata Daniel https://orcid.org/0000-0003-0729-936X Chrapek Oldřich https://orcid.org/0000-0002-1403-4936 Drahorád Stanislav 15 8 2021 4 4

Purpose: To evaluate the influence of pupil dilation on ocular parameters measured by optical biometry and the influence of pupil dilation on intraocular lens (PC IOL) power calculation by using the third-generation (SRK/T) and the fourth-generation (Haigis) formula. Methods: 40 eyes of patients indicated for cataract surgery were included in this study. Each patient was examined by optical biometer firstly without artificial mydriasis (AM) and then after AM, which was achieved using local application of short-term acting mydriatics. Biometric data were measured by Lenstar LS 900 optical biometer, we recorded axial length of the eye (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT) and corneal astigmatism and optical power of cornea. These data we measured were used for calculation of the PC IOL optical power using both the SRK/T and the Haigis formula. The target postoperative refraction was set to emmetropia. Statistical analysis was performed for evaluation of influence of AM on each ocular parameter and influence of AM on the recommended PC IOL power calculated by the SRK/T and the Haigis formula. Results: No statistically significant effect of AM on AL, LT and keratometry was demonstrated. On the contrary we demonstrated significant effect on CCT and ACD. No effect of AM on the PC IOL power calculation using the SRK/T formula was proved – the PC IOL optical power before AM and after AM did not differ in any case. When using the Haigis formula for the PC IOL power calculation, the recommended optical power of the PC IOL changed by +0.5 Dpt in 9 eyes, i.e., 22.5 % of the whole group, but statistical analysis did not show this change as statistically significant. Conclusion: Pharmacological dilation of the pupil significantly affects some intraocular parameters measured by optical biometer and in the case of using the Haigis formula it can influence recommended power of the PC IOL. Conversely, when using the SRK/T formula, pharmacological dilation of pupil does not affect the recommended PC IOL power.

 mydriasis optical biometry intraocular lens calculation SRK/T formula Haigis formula keratometry axial length anterior chamber depth cataract surgery References Čech R, Utíkal T, Juhászová J. Srovnání optické a ultrazvukové biometrie a zhodnocení užívání obou metod v praxi. [Comparison of optical and ultrasound biometry and assessment of using both methods in practice]. Cesk Slov Oftalmol. 2014;70(1):3-9. Czech. Schelenz J, Kamman J. Comparison of contact and immersion technique for axial lenght measurement and implant power calculation. J Cataract Refract Surg. 1989;15:425-428. Hřebcová J, Skorkovská Š, Vašků A. Srovnání kontaktní a imerzní ultrazvukové biometrie s ohledem na cílovou pooperační refrakci. [Comparison of contact and immersion techniques of ultrasound biometry in terms of target postoperative refraction]. Cesk Slov Oftalmol. 2007;63(1):36-41. Czech. Hřebcová J, Vašků A. Srovnání kontaktní a imerzní ultrazvukové biometrie. [Comparison of contact and immersion techniques of ultrasound biometry]. Cesk Slov Oftalmol. 2008;64(1):16-18. Czech. Turczynowska M, Koźlik-Nowakowska K, Gaca-Wysocka M, et al. Effective ocular biometry and intraocular lens power calculation. Eur Opthtalm Rev. 2016;10(2):94-100. Olsen T. Calculation of intraocular lens power: a review. Acta Ophthalmol Scand. 2007;85:472-485. Dang MS, Sunder-Raj PP. SRK II formula in the calculation of intraocular lens power. Br J Ophthalmol. 1989;73:823-826. Falhar M. Vzorce pro výpočet optické mohutnosti intraokulárních čoček. [Formulas for intraocular lens power calculation]. Jemná mechanika a optika. 2008;53(2):35-40. Czech. Kuchynka P, et al. Oční lékařství. 2. vydání. Praha: Grada Publishing; 2016. 936. Drexler W, Findl O, Menapace R, et al. Partial coherence interferometry: a novel approach to biometry in cataract surgery. Am J Ophthalmol. 1998;126:524-534. Srivannaboon S, Chirapapaisan C, Chonpimai P, et al. Comparison of ocular biometry and intraocular lens power using a new biometer and a standard biometer. J Cataract Refract Surg. 2014;40:709-715. Kielhorn I, Rajan MS, Tesha PM, et al. Clinical assessment of the Zeiss IOLMaster. J Cataract Refract Surg. 2003;29:518-522. Wang X, Dong J, Tang M, et al. Effect of pupil dilation on biometric measurements and intraocular lens power calculations in schoolchildren. PloS One. 2018;13(9): e0203677 [cit.2020-12-15]. doi. org/10.1371/journal.pone.020367710.1371/journal.pone.0203677 Olsen T. Sources of error in intraocular lens power calculation. J Cataract Refract Surg. 1992;18(2):125-129. Zeng Y, Gao JH. Effects of Mydrin eye-drops on central corneal thickness values in adult patients with myopia. Clin Exp Optom. 2017;100:151-154. Rodriguez-Raton A, Jimenez-Alvarez M, Arteche-Limousin L, et al. Effect of pupil dilation on biometry measurements with partial coherence interferometry and its effect on IOL power formula calculation. Eur J Ophthalmol. 2015;25(4):309-314. Saitoh K, Yoshida K, Hamatsu Y, et al. Changes in the shape of the anterior and posterior corneal surfaces caused by mydriasis and miosis: detailed analysis. J Cataract Refract Surg. 2004;30:1024- 1030. Bakbak B, Koktekir BE, Gedik S, et al. Effect of pupil dilation on biometric parameters of the Lenstar 900. Cornea. 2013;32:e21-e24. Arriola-Villalobos P, Díaz-Valle D, Garzón N, et al. Effect of pharmacologic pupil dilation on OLCR optical biometry measurements for IOL predictions. Eur J Ophthalmol. 2014;24:53-57. Marchini G, Babighian S, Tosi R, et al. Comparative study of the effects of 2% ibopamine, 10% phenylephrine and 1% tropicamide on the anterior segment. Invest Ophthalmol Vis Sci. 2003;44:281- 289. Read SA, Collins MJ, Woodman EC, et al. Axial length changes during accommodation in myopes and emmetropes. Optom Vis Sci. 2010;87:656-662. Khambhiphant B, Chatbunchachai N, Pongpirul K. The effect of pupillary dilatation on IOL power measurements by using the IOL- Master. Int Ophthalmol. 2015;35:853-859. Teshigawara T, Meguro A, Mizuki N. Influence of pupil dilation on predicted postoperative refraction and recommended IOL to obtain target postoperative refraction calculated by using thirdand fourth-generation calculation formulas. Clin Ophthalmol. 2018;12:1913-1919. Hegazy SH. Effect of pharmacological pupil dilation on ocular biometric parameters and intraocular lens power calculation using the AL-Scan optical biometer. Al-Azhar Assiut Med J. 2015;13(3):208- 217. Adler G, Shahar J, Kesner R, et al. Effect of pupil size on biometry measurements using the IOLMaster. Am J Ophthalmol. 2015;159(5):940-944.