Multiple regression and vector analyses of laser situ keratomileusis for myopia and astigmatism

David Huang, R. Doyle Stulting, Jonathan D. Carr, Keith P. Thompson, George O. Waring

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

PURPOSE: To construct a quantitative model relating refractive results to laser settings and other factors. METHODS: A prospective clinical trial was performed, including 14 surgeons and 523 eyes of 278 patients who desired correction of myopia from -1.00 to -16.00 D (mean, -6.20 D) and astigmatism up to 6.00 D (mean, 1.10 D). Myopia and astigmatism were corrected by laser in situ keratomileusis (LASIK) with sequential spherical and cylindrical ablations using a 5.5-mm ablation zone and a transition zone to 7.0 mm. The Nidek EC-5000 excimer laser and the Chiron Automated Corneal Shaper were used. RESULTS: Surgically induced refractive changes 3 months after surgery were measured. Spherical ablation by LASIK produced a 19% greater refractive change than that predicted by the Nidek PRK algorithm. The laser setting needed to achieve each 1.00 D of cylinder correction induced 1.30 D change in spherical equivalent refraction (0.80 D more than expected). Patient age and nonlinear effects had small but statistically significant influences on refractive outcome. Sex, left/right eye, and surgeon were not significant factors. Residual variations in spherical equivalent refraction included a 0.50-D constant plus 9% of the predicted spherical equivalent change. Residual variations in the parallel and orthogonal components of cylinder correction were, respectively, 28% and 13% of the predicted cylinder change plus a 0.30-D constant component. The standard deviation of axis alignment error for cylinder ablation was 3.7°. CONCLUSIONS: Cylindrical ablation produced a spherical change that was larger than expected. To compensate for this, spherical ablation should be reduced in eyes with astigmatism. Variability in the correction of astigmatism was proportionally larger than that for spherical correction and was primarily due to magnitude rather than axis error.

Original languageEnglish (US)
Pages (from-to)538-549
Number of pages12
JournalJournal of Refractive Surgery
Volume15
Issue number5
StatePublished - Sep 1999
Externally publishedYes

Fingerprint

Astigmatism
Myopia
Lasers
Regression Analysis
Laser In Situ Keratomileusis
Excimer Lasers
Clinical Trials
Surgeons

ASJC Scopus subject areas

  • Ophthalmology

Cite this

Huang, D., Stulting, R. D., Carr, J. D., Thompson, K. P., & Waring, G. O. (1999). Multiple regression and vector analyses of laser situ keratomileusis for myopia and astigmatism. Journal of Refractive Surgery, 15(5), 538-549.

Multiple regression and vector analyses of laser situ keratomileusis for myopia and astigmatism. / Huang, David; Stulting, R. Doyle; Carr, Jonathan D.; Thompson, Keith P.; Waring, George O.

In: Journal of Refractive Surgery, Vol. 15, No. 5, 09.1999, p. 538-549.

Research output: Contribution to journalArticle

Huang, D, Stulting, RD, Carr, JD, Thompson, KP & Waring, GO 1999, 'Multiple regression and vector analyses of laser situ keratomileusis for myopia and astigmatism', Journal of Refractive Surgery, vol. 15, no. 5, pp. 538-549.
Huang, David ; Stulting, R. Doyle ; Carr, Jonathan D. ; Thompson, Keith P. ; Waring, George O. / Multiple regression and vector analyses of laser situ keratomileusis for myopia and astigmatism. In: Journal of Refractive Surgery. 1999 ; Vol. 15, No. 5. pp. 538-549.
@article{bd50672ee2bc434f991e8d40a0ad1ce2,
title = "Multiple regression and vector analyses of laser situ keratomileusis for myopia and astigmatism",
abstract = "PURPOSE: To construct a quantitative model relating refractive results to laser settings and other factors. METHODS: A prospective clinical trial was performed, including 14 surgeons and 523 eyes of 278 patients who desired correction of myopia from -1.00 to -16.00 D (mean, -6.20 D) and astigmatism up to 6.00 D (mean, 1.10 D). Myopia and astigmatism were corrected by laser in situ keratomileusis (LASIK) with sequential spherical and cylindrical ablations using a 5.5-mm ablation zone and a transition zone to 7.0 mm. The Nidek EC-5000 excimer laser and the Chiron Automated Corneal Shaper were used. RESULTS: Surgically induced refractive changes 3 months after surgery were measured. Spherical ablation by LASIK produced a 19{\%} greater refractive change than that predicted by the Nidek PRK algorithm. The laser setting needed to achieve each 1.00 D of cylinder correction induced 1.30 D change in spherical equivalent refraction (0.80 D more than expected). Patient age and nonlinear effects had small but statistically significant influences on refractive outcome. Sex, left/right eye, and surgeon were not significant factors. Residual variations in spherical equivalent refraction included a 0.50-D constant plus 9{\%} of the predicted spherical equivalent change. Residual variations in the parallel and orthogonal components of cylinder correction were, respectively, 28{\%} and 13{\%} of the predicted cylinder change plus a 0.30-D constant component. The standard deviation of axis alignment error for cylinder ablation was 3.7°. CONCLUSIONS: Cylindrical ablation produced a spherical change that was larger than expected. To compensate for this, spherical ablation should be reduced in eyes with astigmatism. Variability in the correction of astigmatism was proportionally larger than that for spherical correction and was primarily due to magnitude rather than axis error.",
author = "David Huang and Stulting, {R. Doyle} and Carr, {Jonathan D.} and Thompson, {Keith P.} and Waring, {George O.}",
year = "1999",
month = "9",
language = "English (US)",
volume = "15",
pages = "538--549",
journal = "Journal of Refractive Surgery",
issn = "0883-0444",
publisher = "Slack Incorporated",
number = "5",

}

TY - JOUR

T1 - Multiple regression and vector analyses of laser situ keratomileusis for myopia and astigmatism

AU - Huang, David

AU - Stulting, R. Doyle

AU - Carr, Jonathan D.

AU - Thompson, Keith P.

AU - Waring, George O.

PY - 1999/9

Y1 - 1999/9

N2 - PURPOSE: To construct a quantitative model relating refractive results to laser settings and other factors. METHODS: A prospective clinical trial was performed, including 14 surgeons and 523 eyes of 278 patients who desired correction of myopia from -1.00 to -16.00 D (mean, -6.20 D) and astigmatism up to 6.00 D (mean, 1.10 D). Myopia and astigmatism were corrected by laser in situ keratomileusis (LASIK) with sequential spherical and cylindrical ablations using a 5.5-mm ablation zone and a transition zone to 7.0 mm. The Nidek EC-5000 excimer laser and the Chiron Automated Corneal Shaper were used. RESULTS: Surgically induced refractive changes 3 months after surgery were measured. Spherical ablation by LASIK produced a 19% greater refractive change than that predicted by the Nidek PRK algorithm. The laser setting needed to achieve each 1.00 D of cylinder correction induced 1.30 D change in spherical equivalent refraction (0.80 D more than expected). Patient age and nonlinear effects had small but statistically significant influences on refractive outcome. Sex, left/right eye, and surgeon were not significant factors. Residual variations in spherical equivalent refraction included a 0.50-D constant plus 9% of the predicted spherical equivalent change. Residual variations in the parallel and orthogonal components of cylinder correction were, respectively, 28% and 13% of the predicted cylinder change plus a 0.30-D constant component. The standard deviation of axis alignment error for cylinder ablation was 3.7°. CONCLUSIONS: Cylindrical ablation produced a spherical change that was larger than expected. To compensate for this, spherical ablation should be reduced in eyes with astigmatism. Variability in the correction of astigmatism was proportionally larger than that for spherical correction and was primarily due to magnitude rather than axis error.

AB - PURPOSE: To construct a quantitative model relating refractive results to laser settings and other factors. METHODS: A prospective clinical trial was performed, including 14 surgeons and 523 eyes of 278 patients who desired correction of myopia from -1.00 to -16.00 D (mean, -6.20 D) and astigmatism up to 6.00 D (mean, 1.10 D). Myopia and astigmatism were corrected by laser in situ keratomileusis (LASIK) with sequential spherical and cylindrical ablations using a 5.5-mm ablation zone and a transition zone to 7.0 mm. The Nidek EC-5000 excimer laser and the Chiron Automated Corneal Shaper were used. RESULTS: Surgically induced refractive changes 3 months after surgery were measured. Spherical ablation by LASIK produced a 19% greater refractive change than that predicted by the Nidek PRK algorithm. The laser setting needed to achieve each 1.00 D of cylinder correction induced 1.30 D change in spherical equivalent refraction (0.80 D more than expected). Patient age and nonlinear effects had small but statistically significant influences on refractive outcome. Sex, left/right eye, and surgeon were not significant factors. Residual variations in spherical equivalent refraction included a 0.50-D constant plus 9% of the predicted spherical equivalent change. Residual variations in the parallel and orthogonal components of cylinder correction were, respectively, 28% and 13% of the predicted cylinder change plus a 0.30-D constant component. The standard deviation of axis alignment error for cylinder ablation was 3.7°. CONCLUSIONS: Cylindrical ablation produced a spherical change that was larger than expected. To compensate for this, spherical ablation should be reduced in eyes with astigmatism. Variability in the correction of astigmatism was proportionally larger than that for spherical correction and was primarily due to magnitude rather than axis error.

UR - http://www.scopus.com/inward/record.url?scp=0032847436&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032847436&partnerID=8YFLogxK

M3 - Article

C2 - 10504078

AN - SCOPUS:0032847436

VL - 15

SP - 538

EP - 549

JO - Journal of Refractive Surgery

JF - Journal of Refractive Surgery

SN - 0883-0444

IS - 5

ER -