Intraocular lens power calculation after myopic laser in situ keratomileusis: Estimating the corneal refractive power

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

Purpose: To derive regression-based formulas and identify essential dependent variables to estimate refractive corneal power after myopic laser in situ keratomileusis (LASIK). Setting: University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA. Methods: A retrospective data review of 30 eyes (23 patients) having myopic LASIK followed by phacoemulsification and posterior chamber intraocular lens (IOL) implantation in the same eye gathered the following: pre-LASIK and post-LASIK refractions and topographies, axial length, IOL type and power, and spherical equivalent (SE) refraction 3 months after phacoemulsification. Using the double-K Holladay 1 formula, the refractive corneal power in each eye was back-calculated. Regression formulas were derived and compared with current corneal power estimation methods. Results: The multiple regression formula based on the average corneal power in the central 3.0 mm area (ACCP3mm) and the change (Δ) in SE (SEpostLASIK - SEpreLASIK) was simplified to ACCPadj = ACCP3mm - 0.16ΔSE, with the highest Pearson correlation coefficient (r = 0.989) and lowest absolute corneal power estimation error (0.30 diopter [D] ± 0.30 (SD)). Regression based on ACCP3mm alone yielded 0.980 and 0.49 ± 0.40 D, respectively. Using SimK with ΔSE resulted in a lower r value (0.971) and larger absolute corneal power estimation error (0.65 ± 0.44 D) (P = .0014). The clinical history methods yielded 0.909 and 1.09 ± 0.868 D, respectively (P = .0005). Conclusion: The regression formula based on ACCP3mm and ΔSE was very accurate in predicting refractive corneal power after myopic LASIK followed by formulas based on ACCP3mm alone and SimK and ΔSE, all of which consolidate the validity of similar previously suggested methods, including EffRPadjusted.

Original languageEnglish (US)
Pages (from-to)1070-1076
Number of pages7
JournalJournal of Cataract and Refractive Surgery
Volume34
Issue number7
DOIs
StatePublished - Jul 2008

Fingerprint

Laser In Situ Keratomileusis
Intraocular Lenses
Phacoemulsification
Intraocular Lens Implantation

ASJC Scopus subject areas

  • Ophthalmology

Cite this

@article{59ba4c6c99fe4e59b460557dd407e9ec,
title = "Intraocular lens power calculation after myopic laser in situ keratomileusis: Estimating the corneal refractive power",
abstract = "Purpose: To derive regression-based formulas and identify essential dependent variables to estimate refractive corneal power after myopic laser in situ keratomileusis (LASIK). Setting: University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA. Methods: A retrospective data review of 30 eyes (23 patients) having myopic LASIK followed by phacoemulsification and posterior chamber intraocular lens (IOL) implantation in the same eye gathered the following: pre-LASIK and post-LASIK refractions and topographies, axial length, IOL type and power, and spherical equivalent (SE) refraction 3 months after phacoemulsification. Using the double-K Holladay 1 formula, the refractive corneal power in each eye was back-calculated. Regression formulas were derived and compared with current corneal power estimation methods. Results: The multiple regression formula based on the average corneal power in the central 3.0 mm area (ACCP3mm) and the change (Δ) in SE (SEpostLASIK - SEpreLASIK) was simplified to ACCPadj = ACCP3mm - 0.16ΔSE, with the highest Pearson correlation coefficient (r = 0.989) and lowest absolute corneal power estimation error (0.30 diopter [D] ± 0.30 (SD)). Regression based on ACCP3mm alone yielded 0.980 and 0.49 ± 0.40 D, respectively. Using SimK with ΔSE resulted in a lower r value (0.971) and larger absolute corneal power estimation error (0.65 ± 0.44 D) (P = .0014). The clinical history methods yielded 0.909 and 1.09 ± 0.868 D, respectively (P = .0005). Conclusion: The regression formula based on ACCP3mm and ΔSE was very accurate in predicting refractive corneal power after myopic LASIK followed by formulas based on ACCP3mm alone and SimK and ΔSE, all of which consolidate the validity of similar previously suggested methods, including EffRPadjusted.",
author = "Awwad, {Shady T.} and Christian Manasseh and Bowman, {Robert W} and Cavanagh, {Harrison D} and Steven Verity and Venkateswara Mootha and McCulley, {James P}",
year = "2008",
month = "7",
doi = "10.1016/j.jcrs.2008.03.020",
language = "English (US)",
volume = "34",
pages = "1070--1076",
journal = "Journal of Cataract and Refractive Surgery",
issn = "0886-3350",
publisher = "Elsevier Inc.",
number = "7",

}

TY - JOUR

T1 - Intraocular lens power calculation after myopic laser in situ keratomileusis

T2 - Estimating the corneal refractive power

AU - Awwad, Shady T.

AU - Manasseh, Christian

AU - Bowman, Robert W

AU - Cavanagh, Harrison D

AU - Verity, Steven

AU - Mootha, Venkateswara

AU - McCulley, James P

PY - 2008/7

Y1 - 2008/7

N2 - Purpose: To derive regression-based formulas and identify essential dependent variables to estimate refractive corneal power after myopic laser in situ keratomileusis (LASIK). Setting: University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA. Methods: A retrospective data review of 30 eyes (23 patients) having myopic LASIK followed by phacoemulsification and posterior chamber intraocular lens (IOL) implantation in the same eye gathered the following: pre-LASIK and post-LASIK refractions and topographies, axial length, IOL type and power, and spherical equivalent (SE) refraction 3 months after phacoemulsification. Using the double-K Holladay 1 formula, the refractive corneal power in each eye was back-calculated. Regression formulas were derived and compared with current corneal power estimation methods. Results: The multiple regression formula based on the average corneal power in the central 3.0 mm area (ACCP3mm) and the change (Δ) in SE (SEpostLASIK - SEpreLASIK) was simplified to ACCPadj = ACCP3mm - 0.16ΔSE, with the highest Pearson correlation coefficient (r = 0.989) and lowest absolute corneal power estimation error (0.30 diopter [D] ± 0.30 (SD)). Regression based on ACCP3mm alone yielded 0.980 and 0.49 ± 0.40 D, respectively. Using SimK with ΔSE resulted in a lower r value (0.971) and larger absolute corneal power estimation error (0.65 ± 0.44 D) (P = .0014). The clinical history methods yielded 0.909 and 1.09 ± 0.868 D, respectively (P = .0005). Conclusion: The regression formula based on ACCP3mm and ΔSE was very accurate in predicting refractive corneal power after myopic LASIK followed by formulas based on ACCP3mm alone and SimK and ΔSE, all of which consolidate the validity of similar previously suggested methods, including EffRPadjusted.

AB - Purpose: To derive regression-based formulas and identify essential dependent variables to estimate refractive corneal power after myopic laser in situ keratomileusis (LASIK). Setting: University of Texas Southwestern Medical Center at Dallas, Dallas, Texas, USA. Methods: A retrospective data review of 30 eyes (23 patients) having myopic LASIK followed by phacoemulsification and posterior chamber intraocular lens (IOL) implantation in the same eye gathered the following: pre-LASIK and post-LASIK refractions and topographies, axial length, IOL type and power, and spherical equivalent (SE) refraction 3 months after phacoemulsification. Using the double-K Holladay 1 formula, the refractive corneal power in each eye was back-calculated. Regression formulas were derived and compared with current corneal power estimation methods. Results: The multiple regression formula based on the average corneal power in the central 3.0 mm area (ACCP3mm) and the change (Δ) in SE (SEpostLASIK - SEpreLASIK) was simplified to ACCPadj = ACCP3mm - 0.16ΔSE, with the highest Pearson correlation coefficient (r = 0.989) and lowest absolute corneal power estimation error (0.30 diopter [D] ± 0.30 (SD)). Regression based on ACCP3mm alone yielded 0.980 and 0.49 ± 0.40 D, respectively. Using SimK with ΔSE resulted in a lower r value (0.971) and larger absolute corneal power estimation error (0.65 ± 0.44 D) (P = .0014). The clinical history methods yielded 0.909 and 1.09 ± 0.868 D, respectively (P = .0005). Conclusion: The regression formula based on ACCP3mm and ΔSE was very accurate in predicting refractive corneal power after myopic LASIK followed by formulas based on ACCP3mm alone and SimK and ΔSE, all of which consolidate the validity of similar previously suggested methods, including EffRPadjusted.

UR - http://www.scopus.com/inward/record.url?scp=45549094643&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=45549094643&partnerID=8YFLogxK

U2 - 10.1016/j.jcrs.2008.03.020

DO - 10.1016/j.jcrs.2008.03.020

M3 - Article

C2 - 18571071

AN - SCOPUS:45549094643

VL - 34

SP - 1070

EP - 1076

JO - Journal of Cataract and Refractive Surgery

JF - Journal of Cataract and Refractive Surgery

SN - 0886-3350

IS - 7

ER -