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An In-Vitro Investigation on the Birefringence of the Human Cornea Using Digital Photoelasticity

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Abstract

Background

Pre and post-operative clinical assessment of the patients is generally based on the corneal tomographic data. However, techniques are required to assess the patient-specific structural and pathological changes for better therapeutic and surgical interventions. The birefringence of the human cornea is the manifestation of mechanics-structure interrelationship and is an important property to quantify corneal abnormalities.

Objective

The present paper aims to understand the mechanics-structure interrelationship of the human cornea.

Methods

For the first time, the birefringence behavior of the human cornea is explored using the digital photoelasticity technique and finite element method. The experimentally obtained phase maps of twenty corneas were analyzed at 0 and 20 mm Hg pressure. Finally, a qualitative comparison of the results from experiments and simulations was carried out.

Results

Features like isotropic points, retardation maps, etc., were extracted from the photoelastic phase maps. The pressure loading did not create a statistically significant change in the average retardation of the central 4 mm cornea. However, the isotropic points were distributed differently in the tested corneas, depicting inter-individual variability in corneal birefringence. The authors found that the steepness or flatness of the corneal curvature decides the location of the isotropic points.

Conclusions

The inter-individual variability in corneal birefringence arises from the complex interplay of the cornea's microstructure, curvature, and stress distribution. The authors foresee the applicability of digital photoelasticity in clinics for diagnostic and monitoring purposes due to its operational simplicity and data accuracy.

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References

  1. Fanjul-Vélez F, Pircher M, Baumann B et al (2010) Polarimetric analysis of the human cornea measured by polarization-sensitive optical coherence tomography. J Biomed Opt 15:056004-1–56010. https://doi.org/10.1117/1.3486540

    Article  Google Scholar 

  2. Donohue DJ, Stoyanov BJ, Mccally RL, Farrell RA (1995) Numerical modeling of the cornea ’ s lamellar structure and birefringence properties. J Opt Soc Am A 12:1425–1438. https://doi.org/10.1364/JOSAA.12.001425

    Article  Google Scholar 

  3. Bone RA, Draper G (2007) Optical anisotropy of the human cornea determined with a polarizing microscope. Appl Opt 46:8351–8357. https://doi.org/10.1364/AO.46.008351

    Article  Google Scholar 

  4. Götzinger E, Pircher M, Sticker M et al (2004) Measurement and imaging of birefringent properties of the human cornea with phase-resolved, polarization-sensitive optical coherence tomography. J Biomed Opt 9:94. https://doi.org/10.1117/1.1629308

    Article  Google Scholar 

  5. Stanworth A, Naylor EJ (1950) The Polarization optics of isolated cornea. B Journal of Opt 34:201–211. https://doi.org/10.1136/bjo.34.4.201

    Article  Google Scholar 

  6. Knighton RW, Huang X-R, Cavuoto LA (2008) Corneal birefringence mapped by scanning laser polarimetry. Opt Express 16:13738. https://doi.org/10.1364/oe.16.013738

    Article  Google Scholar 

  7. Kaplan D, Bettelheim FA (1972) Dynamic Rheooptical Behavior of isolated cornea. Biophys J 12:1630–1641. https://doi.org/10.1016/S0006-3495(72)86186-1

  8. Nyquist GW (1968) Stress-induced birefringence of the cornea. Am J Ophthalmol 65:398–404. https://doi.org/10.1016/0002-9394(68)93090-0

    Article  Google Scholar 

  9. Richhariya A, Verma Y, Rao DK et al (2014) Effect of Intraocular Pressure and Anisotropy on the Optical Properties of the Cornea: A Study Using Polarization Sensitive Optical Coherence Tomography. Asia-Pacific Journal of Ophthalmology 3:348–353. https://doi.org/10.1097/apo.0000000000000015

    Article  Google Scholar 

  10. Misson GP (2007) Circular polarization biomicroscopy: A method for determining human corneal stromal lamellar organization in vivo. Ophthalmic Physiol Opt 27:256–264. https://doi.org/10.1111/j.1475-1313.2007.00482.x

    Article  Google Scholar 

  11. Antony SJ (2015) Imaging shear stress distribution and evaluating the stress concentration factor of the human eye. Sci Rep. https://doi.org/10.1038/srep08899

    Article  Google Scholar 

  12. Sobczak M, Asejczyk M (2021) Birefringent properties of the cornea measured by a Mueller type polarimeter in healthy adults and children. Biomed Opt Express 12:7872. https://doi.org/10.1364/BOE.440274

    Article  Google Scholar 

  13. Zandman F (1966) Photoelastic effect of the living eye. Exp Mech 6:19A-22A. https://doi.org/10.1007/bf02327314

    Article  Google Scholar 

  14. Ramesh K, Ramakrishnan V (2016) Digital photoelasticity of glass: A comprehensive review. Opt Lasers Eng 87:59–74. https://doi.org/10.1016/j.optlaseng.2016.03.017

    Article  Google Scholar 

  15. Zhang Y, Chen Y (2021) Topography-guided corneal surface laser ablation combined with simultaneous accelerated corneal collagen cross-linking for treatment of keratoconus. BMC Ophthalmol 21:1–9. https://doi.org/10.1186/s12886-021-02042-x

    Article  Google Scholar 

  16. Vinciguerra P, Epstein D, Albè E et al (2007) Corneal topography-guided penetrating keratoplasty and suture adjustment: New approach for astigmatism control. Cornea 26:675–682. https://doi.org/10.1097/ICO.0b013e3180553bb2

    Article  Google Scholar 

  17. Gururani H, Richhariya A, Ramji M, Chinthapenta V (2021) Implications of the structure-property relationship on the optomechanical characterization of the cornea : A review. Optik (Stuttg) 232:166529. https://doi.org/10.1016/j.ijleo.2021.166529

    Article  Google Scholar 

  18. Nakagawa T, Maeda N, Kosaki R et al (2009) Higher-order aberrations due to the posterior corneal surface in patients with keratoconus. Invest Ophthalmol Vis Sci 50:2660–2665. https://doi.org/10.1167/iovs.08-2754

    Article  Google Scholar 

  19. Pallikaris IG, Kymionis GD, Astyrakakis NI (2001) Corneal ectasia induced by laser in situ keratomileusis. J Cataract Refract Surg 27:1796–1802. https://doi.org/10.1016/S0886-3350(01)01090-2

    Article  Google Scholar 

  20. Roberts CJ, Dupps WJ (2014) Biomechanics of corneal ectasia and biomechanical treatments. J Cataract Refract Surg 40:991–998. https://doi.org/10.1016/j.jcrs.2014.04.013

    Article  Google Scholar 

  21. Greenfield DS, Knighton RW (2001) Stability of Corneal Polarization Axis Measurements for Scanning Laser Polarimetry. Ophthalmology 108:1065–1069. https://doi.org/10.1016/S0161-6420(01)00569-3

  22. Timoshenko S, Goodier JN (1934) Theory of elasticity

  23. Ru F (2005) White-to-White Corneal Diameter Normal Values in Healthy Humans Obtained With the Orbscan II Topography System 24:259–261

    Google Scholar 

  24. Ramji M, Ramesh K (2010) Adaptive quality guided phase unwrapping algorithm for whole-field digital photoelastic parameter estimation of complex models. Strain 46:184–194. https://doi.org/10.1111/j.1475-1305.2008.00431.x

    Article  Google Scholar 

  25. Petrucci G (1997) Full-field automatic evaluation of an isoclinic parameter in white light. Exp Mech 37:420–426. https://doi.org/10.1007/BF02317308

    Article  Google Scholar 

  26. Zhang Y, Wang S, Ji G, Dong Z (2014) an Improved Quality Guided Phase Unwrapping Method and Its Applications To Mri. Progress In Electromagnetics Research 145:273–286. https://doi.org/10.2528/pier14021005

    Article  Google Scholar 

  27. Ramesh K, Yadav AK, Pankhawalla VA (1995) Plotting of fringe contours from finite element results. Commun Numer Methods Eng 11:839–847. https://doi.org/10.1002/cnm.1640111008

    Article  MATH  Google Scholar 

  28. Abass A, Hayes S, White N et al (2015) Transverse depth-dependent changes in corneal collagen lamellar orientation and distribution. J R Soc Interface 12:20140717–20140717. https://doi.org/10.1098/rsif.2014.0717

    Article  Google Scholar 

  29. Li LY, Tighe B (2006) The anisotropic material constitutive models for the human cornea. J Struct Biol 153:223–230. https://doi.org/10.1016/j.jsb.2005.10.014

    Article  Google Scholar 

  30. Pandolfi A, Holzapfel GA (2008) Three-dimensional modeling and computational analysis of the human cornea considering distributed collagen fibril orientations. J Biomech Eng 130:061006-1–61012. https://doi.org/10.1115/1.2982251

    Article  Google Scholar 

  31. Ramesh K (2002) Digital Photoelasticity: Advanced Techniques and Applications. Springer

  32. Jaronski JW, Kasprzak HT (2003) Linear birefringence measurements of the in vitro human cornea. Ophthalmic Physiol Opt 23:361–369. https://doi.org/10.1046/j.1475-1313.2003.00128.x

    Article  Google Scholar 

  33. van Blokland GJ, Verhelst SC (1987) Corneal polarization in the living human eye explained with a biaxial model. J Opt Soc Am A 4:82–90. https://doi.org/10.1364/JOSAA.4.000082

    Article  Google Scholar 

  34. Farrell RA, Rouseff D, McCally RL (2005) Propagation of polarized light through two- and three-layer anisotropic stacks. J Opt Soc Am A 22:1981. https://doi.org/10.1364/JOSAA.22.001981

    Article  Google Scholar 

  35. Wilson A, Jones J, Tyrer JR, Marshall J (2020) An interferometric ex vivo study of corneal biomechanics under physiologically representative loading, highlighting the role of the limbus in pressure compensation. Eye and Vision 7:43. https://doi.org/10.1186/s40662-020-00207-1

    Article  Google Scholar 

  36. Mangal SK, Ramesh K (1999) Determination of characteristic parameters in integrated photoelasticity by phase-shifting technique. Opt Lasers Eng 31:263–278. https://doi.org/10.1016/S0143-8166(99)00027-5

    Article  Google Scholar 

  37. Simonini I, Pandolfi A (2015) Customized finite element modelling of the human cornea. PLoS ONE 10:1–23. https://doi.org/10.1371/journal.pone.0130426

    Article  Google Scholar 

  38. Liu X, Wang L, Ji J et al (2014) A Mechanical model of the cornea considering the crimping morphology of collagen fibrils. Invest Ophthalmol Vis Sci 55:2739–2746. https://doi.org/10.1167/iovs.13-12633

    Article  Google Scholar 

  39. Meek KM, Boote C (2004) The organization of collagen in the corneal stroma. Exp Eye Res 78:503–512. https://doi.org/10.1016/j.exer.2003.07.003

    Article  Google Scholar 

Download references

Acknowledgements

This study was funded by the intramural funds of LV Prasad Eye Institute (LVPEI), Hyderabad; and partially supported under Prime Minister Doctoral Research Fellowship grant (to author HG) by the Department of Science and Technology, India, Science, and Engineering Research Board, India, Confederation of Indian Industries, India, the Government of India & LVPEI. The author HG acknowledges Dr. Ashutosh Richhariya & Utkarsha Dasmantarao for providing insights in optics and Jagadeesh Rao for load cell calibration.

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Authors and Affiliations

  1. Micro-Mechanics Lab, IIT Hyderabad, Kandi, Sangareddy, 502284, India

    H. Gururani, S. N. S. H. Chittajallu & V. Chinthapenta

  2. Centre for Technology Innovation, LV Prasad Eye Institute, Hyderabad, 500034, India

    S. N. S. H. Chittajallu

  3. Engineering Optics Lab, IIT Hyderabad, Kandi, Sangareddy, 502284, India

    M. Ramji

  4. The Cornea Institute and Prof. Brien Holden Eye Research Centre, L V Prasad Eye Institute, Hyderabad, 500034, India

    S. Basu

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  1. H. Gururani
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Corresponding author

Correspondence to V. Chinthapenta.

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Ethical Declaration

The current study is performed with the ethical approval from the institutional review board of L V Prasad Eye Institute, Hyderabad (Ethics. Ref. No. 05–19-260, Dt. 14 May 2019), Institutional Ethics committee of IIT Hyderabad, Hyderabad (IEC Protocol No. IITH/IEC/2019/05/14, Dt. 2 May 2019).

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Gururani, H., Chittajallu, S.N.S.H., Ramji, M. et al. An In-Vitro Investigation on the Birefringence of the Human Cornea Using Digital Photoelasticity. Exp Mech 63, 205–219 (2023). https://doi.org/10.1007/s11340-022-00910-1

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