Accuracy of Formulas for Intraocular Lens Power Calculation After Myopic Refractive Surgery
Abstract
PURPOSE:
To assess the accuracy of the following intraocular lens (IOL) power formulas: Barrett True-K No History (BTKNH), Emmetropia Verifying Optical 2.0 Post Myopic LASIK/PRK (EVO 2.0), Haigis-L, American Society of Cataract and Refractive Surgery (ASCRS) average, and Shammas, designed for patients who have undergone previous myopic refractive surgery, independent of preexisting clinical history and corneal tomographic measurements.
METHODS:
Data from 302 eyes of 302 patients who previously underwent myopic refractive surgery and had cataract surgery done by a single surgeon with only one IOL type inserted were included. The predicted refraction was calculated for each of the formulas and compared with the actual refractive outcome to give the prediction error. Subgroup analysis based on the axial length and mean keratometry was performed.
RESULTS:
On the basis of mean absolute prediction error (MAE), the formulas were ranked as follows: Haigis-L (0.61 diopters [D]), ASCRS average (0.63 D), BTKNH (0.67 D), EVO 2.0 (0.68 D), and Shammas (0.69 D). The Haigis-L had a statistically significant lower MAE compared with all formulas (P < .05) except the ASCRS average. Hyperopic mean prediction errors were seen in all formulas for axial lengths of greater than 30 mm or mean keratometry values of 35.00 diopters or less.
CONCLUSIONS:
The Haigis-L and the ASCRS average formulas provided the most accurate results in the overall population evaluated in this study. Moreover, according to data observed, it is important to be careful handling very long eyes and very flat corneas because hyperopic refractions could be more common.
[J Refract Surg. 2022;38(7):443–449.]
- 1. . New options for IOL calculations after refractive surgery. J Cataract Refract Surg. 2006; 32(3):371–372.
10.1016/j.jcrs.2006.01.034 PMID:16631027 > Crossref MedlineGoogle Scholar - 2. . Intraocular lens power calculation after previous laser refractive surgery. J Cataract Refract Surg. 2009; 35(4):759–765.
10.1016/j.jcrs.2009.01.005 PMID:19304101 > Crossref MedlineGoogle Scholar - 3. . Intraocular lens calculation after refractive surgery for myopia: Haigis-L formula. J Cataract Refract Surg. 2008; 34(10):1658–1663.
10.1016/j.jcrs.2008.06.029 PMID:18812114 > Crossref MedlineGoogle Scholar - 4. . Intraocular lens power calculation after laser in situ keratomileusis for myopia and hyperopia: a standardized approach. Cornea. 2001; 20(8):792–797.
10.1097/00003226-200111000-00003 PMID:11685053 > Crossref MedlineGoogle Scholar - 5. . Measuring corneal power for intraocular lens power calculation after refractive surgery: comparison of methods. J Cataract Refract Surg. 2002; 28(11):1932–1938.
10.1016/S0886-3350(02)01438-4 PMID:12457665 > Crossref MedlineGoogle Scholar - 6. . Correcting the corneal power measurements for intraocular lens power calculations after myopic laser in situ keratomileusis. Am J Ophthalmol. 2003; 136(3):426–432.
10.1016/S0002-9394(03)00275-7 PMID:12967794 > Crossref MedlineGoogle Scholar - 7. . Keratometry for intraocular lens power calculation using Orbscan II in eyes with laser in situ keratomileusis. J Refract Surg. 2005; 21(4):365–368.
10.3928/1081-597X-20050701-11 PMID:16128334 > LinkGoogle Scholar - 8. . Reliability of a new correcting factor in calculating intraocular lens power after refractive corneal surgery. J Cataract Refract Surg. 2005; 31(5):1020–1024.
10.1016/j.jcrs.2004.10.055 PMID:15975473 > Crossref MedlineGoogle Scholar - 9. . Simple regression formula for intraocular lens power adjustment in eyes requiring cataract surgery after excimer laser photoablation. J Cataract Refract Surg. 2006; 32(3):430–434.
10.1016/j.jcrs.2005.12.106 PMID:16631051 > Crossref MedlineGoogle Scholar - 10. . Estimation of true corneal power after keratorefractive surgery in eyes requiring cataract surgery: BESSt formula. J Cataract Refract Surg. 2006; 32(12):2004–2014.
10.1016/j.jcrs.2006.08.037 PMID:17137976 > Crossref MedlineGoogle Scholar - 11. . New factor to improve reliability of the clinical history method for intraocular lens power calculation after refractive surgery. J Cataract Refract Surg. 2010; 36(12):2123–2128.
10.1016/j.jcrs.2010.07.017 PMID:21111316 > Crossref MedlineGoogle Scholar - 12. . Intraocular lens power calculation by ray-tracing after myopic excimer laser surgery. Am J Ophthalmol. 2014; 157(1):150–153.e1.
10.1016/j.ajo.2013.08.006 PMID:24099275 > Crossref MedlineGoogle Scholar - 13. . Corneal ray tracing versus simulated keratometry for estimating corneal power changes after excimer laser surgery. J Cataract Refract Surg. 2014; 40(7):1109–1115.
10.1016/j.jcrs.2013.11.032 PMID:24874768 > Crossref MedlineGoogle Scholar - 14. . Accuracy of the Barrett True-K formula for intraocular lens power prediction after laser in situ keratomileusis or photorefractive keratectomy for myopia. J Cataract Refract Surg. 2016; 42(3):363–369.
10.1016/j.jcrs.2015.11.039 PMID:27006324 > Crossref MedlineGoogle Scholar - 15. . Corneal power evaluation after myopic corneal refractive surgery using artificial neural networks. Biomed Eng Online. 2016; 15(1):121.
10.1186/s12938-016-0243-5 PMID:27846894 > Crossref MedlineGoogle Scholar - 16. . New algorithm for intraocular lens power calculations after myopic laser in situ keratomileusis based on rotating Scheimpflug camera data. J Cataract Refract Surg. 2015; 41(2):339–347.
10.1016/j.jcrs.2014.05.040 PMID:25661127 > Crossref MedlineGoogle Scholar - 17. . Optical coherence tomography-based corneal power measurement and intraocular lens power calculation following laser vision correction (an American Ophthalmological Society thesis). Trans Am Ophthalmol Soc. 2013; 111:34–45. PMID:
24167323 > MedlineGoogle Scholar - 18. . A new central-peripheral corneal curvature method for intraocular lens power calculation after excimer laser refractive surgery. Acta Ophthalmol. 2013; 91(2):e133–e139.
10.1111/aos.12007 PMID:23289447 > Crossref MedlineGoogle Scholar - 19. . Intraocular lens power formulas, biometry, and intraoperative aberrometry: a review. Ophthalmology. 2021; 128(11):e94–e114. doi:
10.1016/j.ophtha.2020.08.010 > Crossref MedlineGoogle Scholar - 21. . Intraocular lens power calculation in eyes with previous excimer laser surgery for myopia: a report by the American Academy of Ophthalmology. Ophthalmology. 2021; 128(5):781–792.
10.1016/j.ophtha.2020.10.031 PMID:33500124 > Crossref MedlineGoogle Scholar - 22. . Comparison of three newer generation freely available intraocular lens power calculation formulae across all axial lengths. Indian J Ophthalmol. 2021; 69(3):580–584.
10.4103/ijo.IJO_943_20 PMID:33595478 > Crossref MedlineGoogle Scholar - 23. . Pursuing perfection in intraocular lens calculations: III. Criteria for analyzing outcomes. J Cataract Refract Surg. 2017; 43(8):999–1002.
10.1016/j.jcrs.2017.08.003 PMID:28917430 > Crossref MedlineGoogle Scholar - 24. . Intraocular lens prediction accuracy after corneal refractive surgery using K values from 3 devices. J Cataract Refract Surg. 2013; 39(11):1640–1646.
10.1016/j.jcrs.2013.04.045 PMID:24160380 > Crossref MedlineGoogle Scholar - 25. . Outcomes of the Haigis-L formula for calculating intraocular lens power in Asian eyes after refractive surgery. J Cataract Refract Surg. 2015; 41(3):607–612.
10.1016/j.jcrs.2014.06.034 PMID:25701484 > Crossref MedlineGoogle Scholar - 26. . Comparison of newer intraocular lens power calculation methods for eyes after corneal refractive surgery. Ophthalmology. 2015; 122(12):2443–2449.
10.1016/j.ophtha.2015.08.037 PMID:26459996 > Crossref MedlineGoogle Scholar - 27. . Comparison of intraocular lens power calculation methods following myopic laser refractive surgery: new options using a rotating Scheimpflug camera. Korean J Ophthalmol. 2018; 32(6):497–505.
10.3341/kjo.2018.0008 PMID:30549474 > Crossref MedlineGoogle Scholar - 28. . Comparison of intraocular lens power formulas according to axial length after myopic corneal laser refractive surgery. J Cataract Refract Surg. 2021; 47(3):297–303.
10.1097/j.jcrs.0000000000000445 PMID:32991505 > Crossref MedlineGoogle Scholar