aberration control with standard rigid gas permeable contact...

2
Aberration control with standard rigid gas permeable Aberration control with standard rigid gas permeable contact lenses contact lenses Results 3.1 Wave Aberrations with and without CL Instituto de Optica, Consejo Superior de Investigaciones Científicas, Madrid, Spain E-mail: [email protected] 2 Methods Background & Purpose 1 Background Why is it interesting? Four different aberration measurements: Total Total Total Total and corneal corneal corneal corneal (anterior), with with with with and without without without without contact lens Spherical wavefront 10 12 19 23 28 Total Aberrations: Laser Ray Tracing A scanning beam samples the pupil. Centroids of retinal spots are used to calculate the wavefront 2,16,17 . Developed at the Inst. of Optics, Madrid. Corneal Aberrations: Videokeratography From elevation maps obtained with a commercial Videokeratographer (Atlas Humphrey, Zeiss) and our own computer algorithms we estimate corneal wave aberrations 1,3,15 (referred to anterior surface aberrations when the lens is on). General Scheme Subjects and lenses 3 1. Aberrometry is a useful tool to understand contact lens fitting. 2. RGP lenses can reduce greatly the amount of aberrations, particularly in eyes with large corneal aberrations. 3. The control of flexure and knowledge of the internal optics can help to improve contact lens optical performance. 4 Conclusions 1. - Barbero S, Marcos S, Merayo-Lloves J, and Moreno-Barriuso E. Validation of the estimation of corneal aberrations from videokeratography In keratoconus. Journal of Refractive Surgery 2002;18:263-270. 2. - Moreno-Barriuso E, Marcos S, Navarro R, and Burns SA. Comparing Laser Ray Tracing, Spatially Resolved Refractometer and Hartmann-Shack sensor to measure the ocular wavefront aberration. Optom & Vis Sci 2001;78:152 - 156. 3. - Barbero S, Marcos S, and Merayo-Lloves JM. Exploring total and corneal aberrations in an unilateral aphakic subject. Journal of Cataract and Refractive Surgery. In press 2002; 4. - Fernandez EJ, Iglesias I, and Artal P. Closed-loop adaptive optics in the human eye. Optics Letters 2001;26:746-748. 5. - Hofer H, Chen L, Yoon G, Singer B, Yamauchi Y, et al. Improvement in retinal image quality with dynamic correction of the eye's aberrations. Opt. Express. http://www.opticsexpress.org/oearchive/source/31887.htm 2001;8:631-643. 6. - Navarro R, Moreno-Barriuso E, Bará S, and Mancebo T. Phase-plates for wave-aberration compensation in the human eye. Optics Letters 2000;25:236 - 238. 7. - N.Lopez-Gil, A.Benito, Castejón-Mochón JF, Marín JM, G.Lo-a-Foe, et al. Aberration Correction using Customized Soft Contact Lenses with Aspheric and Asymmetric Surfaces. Inves Ophtalm and Visual Sci (Suppl.) In press 2002;73: 8. - MacRae SM, Schwiegerling J, and Snyder R. Customized corneal ablation and super vision. Journal of Refractive Surgery 2000;16:230-235. 9. - Mrochen M, Kaemmerer M, and Seiler T. Wavefront-guided Laser in situ Keratomileusis: Early results in three eyes. Journal of Refractive Surgery 2000;16:116-121. 10. - Phillips A and Speedwell L. Contact Lenses. 4th Edition, : Butterworth-Heinemann, 1997. 11. - Griffiths M, Zahner K, Collins M, and Carney L. Masking of irregular corneal topography with contact lenses. CLAO J 1998;24:76-81. 12. - Atchison D. Aberrations associated with rigid contact lenses. J Opt Soc Am A 1995;12:2267-2273. 13. - Collins M, Franklin R, Carney L, Bergiel C, Lagos P, et al. Flexure of Thin Rigid Contact Lenses. Contact Lens and Anterior Eye 2001;24:59-64. 14. - Hong X, Himebaugh N, and Thibos L. On-eye evaluation of optical performance of rigid and soft contact lenses. Optom Vis Sci 2001;78:872-880. 15. - Marcos S, Barbero S, Moreno-Barriuso E, Llorente L, Merayo-Lloves J, et al. Total and corneal aberrations before and after standard LASIK refractive surgery. Investigative Ophthalmology and Visual Science 2001;42 (Suppl.):529. 16. - Navarro R and Losada MA. Aberrations and relative efficiency of light pencils in the living human eye. Optometry and Vision Science 1997;74:540-547. 17. - Navarro R and Moreno-Barriuso E. Laser ray-tracing method for optical testing. Optics Letters 1999;24:1-3. 18. - Corzine J and Klein S. Factors determining rigid contact lens flexure. Optom Vis Sci 1997;74:639-645. 19. - J. Perrigin, D. Perrigin, S. Quintero, and T. Grosvenor. Silicone-acrylate contact lenses for myopia control: 3-year results. Optom Vis Sci. 67, 764-769 (1990). 20. - A.Ho, F.Manns, T.Pham, S.Farrar. The Effect of RGP Lens Decentration on Aberration: the Influence of the Tear Lens. Inves Ophtalm and Visual Sci (Suppl.) In press 2002;73: References 5 Acknowledgements: CAM 08.7/0010./2000 & Carl Zeiss, S.A. Spain CVS Symposium 2002: Engineering the Eye Carlos Dorronsoro, Sergio Barbero, Lourdes Llorente & Susana Mar Carlos Dorronsoro, Sergio Barbero, Lourdes Llorente & Susana Marcos cos Conclusions 4 3.2 Aberration Coefficients (Zernike) 3.3 Aberration correction with RGP CLs 3.4 What happens to spherical aberration? 3.5 Tear lens aberration map Pupil Monitoring LRT Measures: pupil dilation by tropicamide 1%. S1: High correction: high corneal aberrations and low flexure (conformity) S2 & S3: Low correction: corneal aberrations but high flexure (conformity) S4: No correction: corneal aberrations partially compensating internal optics Each aberration term can be numerically tracked for every subject and every optical element (anterior surface of the lens, tear lens, cornea, internal optics (crystalline lens)) Goal : To measure on-eye aberrations of standard rigid gas permeable contact lenses 1. To measure the capability of standard RGP lenses to correct aberrations 2. To evaluate the possibilities of aberrometry as a new tool to assist the contact lens fitting Aberrations degrade retinal image quality. Some methods for correcting aberrations have been proposed recently : adaptive optics 4,5 , phase plates 6 , custom CLs 7 , customized ablations 8,9 RGP lenses are expected to correct corneal irregularities 11 , and thus improve optical quality 14 . Psychophysical experiments have shown that RGP contact lenses can improve visual performance 10 . Computer simulations try to understand contact lens fitting and tear lens optical properties 12,20 . Flexure of RGP lenses is a relevant factor 13,18 . RGP CL has been proposed to control myopia 19 . 4 eyes from 4 subjects, long term and satisfied RGP contact lens wearers with their own lenses Sph. error: -4.5 D to -8 D, Ages: 18 to 33 No ocular condition except for myopia Additional measurements: Autorefractometry, keratometry & optical biometry. Pupil diameter: 5 mm Measures done with stabilized lens and tear. Careful contact lens and pupil monitorization. + = = + Total (LRT) (Crystalline + ...) (Tear Lens + Crystalline + ...) Without Contact Lens With Contact Lens Aberration Correction Flexure Study Tear Lens Study Internal Anterior (Videokeratography) Total (LRT) Internal Corneal (Videokeratography) Best case: S1 1.36 0.46 µm (RMS no tilt & defocus) 0.77 0.39 µm (RMS no tilt & def & astigmatism) Worst case: S4 No correction of total aberrations (minor increase). Slight correction of corneal aberrations. The amount of corneal aberration correction and the degree of flexure (conformity of the lens to the cornea) can be assessed by correlating corneal Zernike coefficients to the on-eye RGP lens anterior surface coefficients. Slopes and R close to 1 are indicative of low correction and high flexure. While there is important intersubject variability in corneal and internal spherical aberration, we found similar spherical aberration values for all anterior lens surfaces (as they all are spherical lenses). Total spherical aberration with the lens is close to zero, suggesting some compensatory effect by the tear lens. While this measurement is noisy and indirect (estimated as the difference of internal aberration maps) we found very systematically negative spherical aberration values. An alternative to fluorescein analysis? TOTAL CORNEAL With Astigmatism Without Astigmatism Without CL With CL Without CL With CL S1 1.36 0.77 1.29 0.57 0.67 0.42 0.46 0.39 TOTAL CORNEAL With Astigmatism Without Astigmatism Without CL With CL Without CL With CL S2 1.00 0.70 0.77 0.92 0.18 0.25 0.24 0.51 TOTAL CORNEAL With Astigmatism Without Astigmatism Without CL With CL Without CL With CL S3 0.89 0.91 0.69 0.98 0.23 0.18 0.16 0.30 TOTAL CORNEAL With Astigmatism Without Astigmatism Without CL With CL Without CL With CL S4 0.37 0.51 0.46 0.46 0.13 0.24 0.24 0.36 INTERNAL WITHOUT CL TEAR LENS S2 INTERNAL WITH CL S1 S3 Corneal Corneal S1 S3 Total Total 3.3 Effects of flexure

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Page 1: Aberration control with standard rigid gas permeable contact …moreno-barriuso.com/carlos/handout_CVS_2002_RGP.pdf · Aberration control with standard rigid gas permeable contact

Aberration control with standard rigid gas permeable Aberration control with standard rigid gas permeable contact lensescontact lenses

Results3.1 Wave Aberrations with and without CL

Instituto de Optica, Consejo Superior de Investigaciones Científicas, Madrid, SpainE-mail: [email protected]

2 Methods

Background & Purpose1BackgroundWhy is it interesting?

Four different aberration measurements:TotalTotalTotalTotal and cornealcornealcornealcorneal (anterior), withwithwithwith and withoutwithoutwithoutwithout contact lens

Spherical wavefront

1012

19

2328

Total Aberrations: Laser Ray TracingA scanning beam samples the pupil. Centroids of retinal spots are used to calculate the wavefront2,16,17.Developed at the Inst. of Optics, Madrid.Corneal Aberrations: Videokeratography

From elevation maps obtained with a commercial Videokeratographer (AtlasHumphrey, Zeiss) and our own computer algorithms we estimate corneal wave aberrations1,3,15 (referred to anterior surface aberrations when the lens is on).

General SchemeSubjects and lenses

3

1. Aberrometry is a useful tool to understand contact lens fitting.2. RGP lenses can reduce greatly the amount of aberrations, particularly in eyes with

large corneal aberrations. 3. The control of flexure and knowledge of the internal optics can help to improve

contact lens optical performance.

4 Conclusions1. - Barbero S, Marcos S, Merayo-Lloves J, and Moreno-Barriuso E. Validation of the estimation of corneal aberrations from videokeratography In keratoconus. Journal of Refractive Surgery 2002;18:263-270.2. - Moreno-Barriuso E, Marcos S, Navarro R, and Burns SA. Comparing Laser Ray Tracing, Spatially Resolved Refractometer and Hartmann-Shack sensor to measure the ocular wavefront aberration. Optom & Vis Sci 2001;78:152 - 156.3. - Barbero S, Marcos S, and Merayo-Lloves JM. Exploring total and corneal aberrations in an unilateral aphakic subject. Journal of Cataract and Refractive Surgery. In press 2002;4. - Fernandez EJ, Iglesias I, and Artal P. Closed-loop adaptive optics in the human eye. Optics Letters 2001;26:746-748.5. - Hofer H, Chen L, Yoon G, Singer B, Yamauchi Y, et al. Improvement in retinal image quality with dynamic correction of the eye's aberrations. Opt. Express. http://www.opticsexpress.org/oearchive/source/31887.htm 2001;8:631-643.6. - Navarro R, Moreno-Barriuso E, Bará S, and Mancebo T. Phase-plates for wave-aberration compensation in the human eye. Optics Letters 2000;25:236 - 238.7. - N.Lopez-Gil, A.Benito, Castejón-Mochón JF, Marín JM, G.Lo-a-Foe, et al. Aberration Correction using Customized Soft Contact Lenses with Aspheric and Asymmetric Surfaces. Inves Ophtalm and Visual Sci (Suppl.) In press 2002;73:8. - MacRae SM, Schwiegerling J, and Snyder R. Customized corneal ablation and super vision. Journal of Refractive Surgery 2000;16:230-235.9. - Mrochen M, Kaemmerer M, and Seiler T. Wavefront-guided Laser in situ Keratomileusis: Early results in three eyes. Journal of Refractive Surgery 2000;16:116-121.10. - Phillips A and Speedwell L. Contact Lenses. 4th Edition, : Butterworth-Heinemann, 1997.11. - Griffiths M, Zahner K, Collins M, and Carney L. Masking of irregular corneal topography with contact lenses. CLAO J 1998;24:76-81.12. - Atchison D. Aberrations associated with rigid contact lenses. J Opt Soc Am A 1995;12:2267-2273.13. - Collins M, Franklin R, Carney L, Bergiel C, Lagos P, et al. Flexure of Thin Rigid Contact Lenses. Contact Lens and Anterior Eye 2001;24:59-64.14. - Hong X, Himebaugh N, and Thibos L. On-eye evaluation of optical performance of rigid and soft contact lenses. Optom Vis Sci 2001;78:872-880.15. - Marcos S, Barbero S, Moreno-Barriuso E, Llorente L, Merayo-Lloves J, et al. Total and corneal aberrations before and after standard LASIK refractive surgery. Investigative Ophthalmology and Visual Science 2001;42 (Suppl.):529.16. - Navarro R and Losada MA. Aberrations and relative efficiency of light pencils in the living human eye. Optometry and Vision Science 1997;74:540-547.17. - Navarro R and Moreno-Barriuso E. Laser ray-tracing method for optical testing. Optics Letters 1999;24:1-3.18. - Corzine J and Klein S. Factors determining rigid contact lens flexure. Optom Vis Sci 1997;74:639-645.19. - J. Perrigin, D. Perrigin, S. Quintero, and T. Grosvenor. Silicone-acrylate contact lenses for myopia control: 3-year results. Optom Vis Sci. 67, 764-769 (1990).20. - A.Ho, F.Manns, T.Pham, S.Farrar. The Effect of RGP Lens Decentration on Aberration: the Influence of the Tear Lens. Inves Ophtalm and Visual Sci (Suppl.) In press 2002;73:

References5

Acknowledgements:CAM 08.7/0010./2000& Carl Zeiss, S.A. Spain

CVS Symposium 2002: Engineering the Eye

Carlos Dorronsoro, Sergio Barbero, Lourdes Llorente & Susana MarCarlos Dorronsoro, Sergio Barbero, Lourdes Llorente & Susana Marcoscos

Conclusions4

3.2 Aberration Coefficients (Zernike)

3.3 Aberration correction with RGP CLs

3.4 What happens to spherical aberration?

3.5 Tear lens aberration map

Pupil Monitoring

LRT Measures: pupil dilation by tropicamide 1%.

S1: High correction:high corneal aberrationsand low flexure (conformity)

S2 & S3: Low correction:corneal aberrations buthigh flexure (conformity)

S4: No correction:corneal aberrations partially compensating internal optics

Each aberration term can be numerically tracked for every subject and every optical element (anterior surface of the lens, tear lens, cornea, internal optics (crystalline lens))

Goal : To measure on-eye aberrations of standard rigid gas permeable contact lenses1. To measure the capability of standard RGP

lenses to correct aberrations 2. To evaluate the possibilities of aberrometry

as a new tool to assist the contact lens fitting

Aberrations degrade retinal image quality. Some methods for correcting aberrations have been proposed recently : adaptive optics4,5, phase plates6, custom CLs7, customized ablations8,9

RGP lenses are expected to correct corneal irregularities11, and thus improve optical quality14.

• Psychophysical experiments have shown that RGP contact lenses can improve visual performance10.• Computer simulations try to understand contact lens fitting and tear lens optical properties12,20. • Flexure of RGP lenses is a relevant factor13,18.• RGP CL has been proposed to control myopia19.

4 eyes from 4 subjects, long term and satisfied RGP contact lens wearers with their own lensesSph. error: -4.5 D to -8 D, Ages: 18 to 33No ocular condition except for myopiaAdditional measurements: Autorefractometry, keratometry & optical biometry.

Pupil diameter: 5 mmMeasures done with stabilized lens and tear. Careful contact lens and pupil monitorization.

+

=

=

+

Total (LRT)

(Crystalline + ...)

(Tear Lens + Crystalline + ...)

Without Contact

Lens

With Contact

Lens

Aberration Correction

Flexure Study

Tear Lens Study

Internal Anterior (Videokeratography)

Total (LRT) Internal Corneal (Videokeratography)

Best case: S11.36 →→→→ 0.46 µµµµm (RMS no tilt & defocus)0.77 →→→→ 0.39 µµµµm (RMS no tilt & def & astigmatism)Worst case: S4No correction of total aberrations (minor increase). Slight correction of corneal aberrations.

The amount of corneal aberration correction and the degree of flexure (conformity of the lens to the cornea) can be assessed by correlating corneal Zernike coefficients to the on-eye RGP lens anterior surface coefficients. Slopes and R close to 1 are indicative of low correction and high flexure.

While there is important intersubject variability in corneal and internal spherical aberration, we found similar spherical aberration values for all anterior lenssurfaces (as they all are spherical lenses).Total spherical aberration with the lens is close to zero, suggesting some compensatory effect by the tear lens.

While this measurement is noisy and indirect (estimated as the difference of internal aberration maps) we found very systematically negative spherical aberration values.An alternative to fluorescein analysis?

TOTAL CORNEAL

With

Ast

igm

atis

mW

ithou

t Ast

igm

atis

m

WithoutCL

WithCL

WithoutCL

WithCL

S1

1.36

0.77

1.29

0.57

0.67

0.42

0.46

0.39

TOTAL CORNEAL

With

Ast

igm

atis

mW

ithou

t Ast

igm

atis

m

WithoutCL

WithCL

WithoutCL

WithCL

S2

1.00

0.70

0.77

0.92

0.18 0.25

0.24 0.51

TOTAL CORNEAL

With

Ast

igm

atis

mW

ithou

t Ast

igm

atis

m

WithoutCL

WithCL

WithoutCL

WithCL

S3

0.89 0.91

0.69 0.98

0.23 0.18

0.16 0.30

TOTAL CORNEAL

With

Ast

igm

atis

mW

ithou

t Ast

igm

atis

m

WithoutCL

WithCL

WithoutCL

WithCL

S4

0.37 0.51

0.46 0.46

0.13 0.24

0.24 0.36

INTERNALWITHOUT CL

TEAR LENSS2 INTERNALWITH CL

bris

sonl

eis.

opto

met

ry.n

et

S1 S3Corneal Corneal

S1 S3Total Total

3.3 Effects of flexure

Page 2: Aberration control with standard rigid gas permeable contact …moreno-barriuso.com/carlos/handout_CVS_2002_RGP.pdf · Aberration control with standard rigid gas permeable contact

1. - Barbero S, Marcos S, Merayo-Lloves J, and Moreno-Barriuso E. Validation of the estimation of corneal aberrations from videokeratography In keratoconus. Journal of Refractive Surgery 2002;18:263-270.2. - Moreno-Barriuso E, Marcos S, Navarro R, and Burns SA. Comparing Laser Ray Tracing, Spatially Resolved Refractometer and Hartmann-Shack sensor to measure the ocular wavefront aberration. Optom & Vis Sci 2001;78:152 - 156.3. - Barbero S, Marcos S, and Merayo-Lloves JM. Exploring total and corneal aberrations in an unilateral aphakic subject. Journal of Cataract and Refractive Surgery. In press 2002;4. - Fernandez EJ, Iglesias I, and Artal P. Closed-loop adaptive optics in the human eye. Optics Letters 2001;26:746-748.5. - Hofer H, Chen L, Yoon G, Singer B, Yamauchi Y, et al. Improvement in retinal image quality with dynamic correction of the eye's aberrations. Opt. Express. http://www.opticsexpress.org/oearchive/source/31887.htm 2001;8:631-643.6. - Navarro R, Moreno-Barriuso E, Bará S, and Mancebo T. Phase-plates for wave-aberration compensation in the human eye. Optics Letters 2000;25:236 - 238.7. - N.Lopez-Gil, A.Benito, Castejón-Mochón JF, Marín JM, G.Lo-a-Foe, et al. Aberration Correction using Customized Soft Contact Lenses with Aspheric and Asymmetric Surfaces. Inves Ophtalm and Visual Sci (Suppl.) In press 2002;73:8. - MacRae SM, Schwiegerling J, and Snyder R. Customized corneal ablation and super vision. Journal of Refractive Surgery 2000;16:230-235.9. - Mrochen M, Kaemmerer M, and Seiler T. Wavefront-guided Laser in situ Keratomileusis: Early results in three eyes. Journal of Refractive Surgery 2000;16:116-121.10. - Phillips A and Speedwell L. Contact Lenses. 4th Edition, : Butterworth-Heinemann, 1997.11. - Griffiths M, Zahner K, Collins M, and Carney L. Masking of irregular corneal topography with contact lenses. CLAO J 1998;24:76-81.12. - Atchison D. Aberrations associated with rigid contact lenses. J Opt Soc Am A 1995;12:2267-2273.13. - Collins M, Franklin R, Carney L, Bergiel C, Lagos P, et al. Flexure of Thin Rigid Contact Lenses. Contact Lens and Anterior Eye 2001;24:59-64.14. - Hong X, Himebaugh N, and Thibos L. On-eye evaluation of optical performance of rigid and soft contact lenses. Optom Vis Sci 2001;78:872-880.15. - Marcos S, Barbero S, Moreno-Barriuso E, Llorente L, Merayo-Lloves J, et al. Total and corneal aberrations before and after standard LASIK refractive surgery. Investigative Ophthalmology and Visual Science 2001;42 (Suppl.):529.16. - Navarro R and Losada MA. Aberrations and relative efficiency of light pencils in the living human eye. Optometry and Vision Science 1997;74:540-547.17. - Navarro R and Moreno-Barriuso E. Laser ray-tracing method for optical testing. Optics Letters 1999;24:1-3.18. - Corzine J and Klein S. Factors determining rigid contact lens flexure. Optom Vis Sci 1997;74:639-645.19. - J. Perrigin, D. Perrigin, S. Quintero, and T. Grosvenor. Silicone-acrylate contact lenses for myopia control: 3-year results. Optom Vis Sci. 67, 764-769 (1990).20. - A.Ho, F.Manns, T.Pham, S.Farrar. The Effect of RGP Lens Decentration on Aberration: the Influence of the Tear Lens. Inves Ophtalm and Visual Sci (Suppl.) In press 2002;73:

References5