Portal de Periódicos da CAPES

Organization of Collagen Fibrils in the Corneal Stroma in Relation to Mechanical Properties and Surgical Practice

1999; Slack Incorporated (United States); Volume: 15; Issue: 6 Linguagem: Inglês

10.3928/1081-597x-19991101-18

1938-2391

Keith M. Meek, Richard Newton,

Intraocular Surgery and Lenses

Organization of Collagen Fibrils in the Corneal Stroma in Relation to Mechanical Properties and Surgical Practice Keith M Meek, PhD, , and , PhD Richard H Newton, PhD, , PhD Keith M Meek, PhD and Richard H Newton, PhD Journal of Refractive Surgery, 2013;15(6):695–699Published Online:November 01, 1999https://doi.org/10.3928/1081-597X-19991101-18Cited by:68PDFView Full Text ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinkedInRedditEmail SectionsMoreAbstractABSTRACTWe have used synchrotron x-ray diffraction to obtain quantitative information about the precise orientation of the collagen fibrils in the human cornea and sclera, and how these fuse at the limbus. We have shown that the human corneal stroma has preferred collagen orientation in the inferiorsuperior and nasal-temporal directions. At the limbus, however, the preferred orientation is tangential to the cornea. We demonstrated that these limbal fibrils are in the form of a circum-corneal annulus and quantified how this annulas varies with position. We have also started to unravel how the corneal collagen fibrils fuse with the collagen in the annulus. The results have both mechanical and surgical implications. Keratoplasty is performed without considering the preferred directions of the collagen fibrils. Surgery is increasingly used to correct astigmatism and myopia. The site and direction of an incision during, for example, cataract surgery, can influence the eventual level of astigmatism. X-ray diffraction helps our understanding of the underlying structural and hence mechanical reasons for refractive problems following surgery. [J Refract Surg 1999;15:695-699]1. Maurice DM. The cornea and sclera. In: Davson H, ed. The Eye, VoJume 1. New York and London: Academic Press; 1969:489-600. Google Scholar2. Fischer E. Die konstruktive Anordnung der kollagenen Fasern in der Sklera und den Sehnervenscheiden des Rinderauges. Z ges Anat 1993:101:168-210. Google Scholar3. Ischreyt G. Anatomische und physikalische Untersuchungen der Rindersklera. ? Graefes Arch Ophthal 1899;48:384-419. Google Scholar4. Kokott W. Ueber mechanisch - funktionelle Strukturen des Auges, v. Graefes Arch Ophthal 1938;138:424-485. Google Scholar5. Komai Y. Ushiki T. The three-dimensional organization of collagen fibrils in the human cornea and sclera. Invest Ophthal Vis Sci 1991;32:2244-2258. Google Scholar6. Haustein J. On the ultrastructure of the developing and adult mouse corneal stroma. Anat Embryol 1983;168:291-305. Google Scholar7. Jakus M. Studies on the cornea. Am J Ophthalmol 1954:38:40-53. Google Scholar8. Thale A, Tillman B. The collagen architecture of the sclera - SEM and immunohistochemical studies. Ann Anat 1993;175:215-220. Google Scholar9. Newton RH. Meek KM. Circumcorneal annulus of collagen fibrils in the human limbus. Invest Ophthalmol Vis Sci 1998;39:1125-1134. Google Scholar10. Meek KM. Blamires T. Elliot GF. Gyi TJ, Nave C. The organisation of collagen fibrils in the human corneal stroma: a synchrotron x-rav diffraction study. Curr Eye Res 1987;6:841-846. Google Scholar11. Newton RH. Meek KM. The integration of the corneal and limbal fibrils in the human eye. Biophys J 1998:75:2508-2512. Google Scholar12. Van Buskirk EM. The anatomy of the limbus. Eye 1989;3:101-108. Google Scholar13. Kohnen T. Corneal shape changes and astigmatic aspects of scleral and corneal tunnel incisions. J Cataract Refract Surg 1987;23:301-302. Google Scholar14. Deschenes J, Jovkar S. Balazsi G. Thompson R Photorefractive keratectomy for correction of astigmatism after penetrating keratoplasty. Int Ophthalmol Clin 1997;36:113-118. Google Scholar15. Merrimam JC. Zheng L. Analysis of surgically induced astigmatism after ECCE and three small incisions for phacoemulsification. Invest Ophthalmol Vis Sci 1998; 39( suppl I.S50. Google Scholar16. Deutsch TA, Gaynes BI. Refractive astigmatism after oblique clear-corneal phacoemulsification cataract incision. Invest Ophthalmol Vis Sci 1998;39? suppl ):S49. Google Scholar17. Kershner RM. Clear corneal catarct surgery and the correction of myopia, hyperopia and astigmatism. Ophthalmology 1997;104:381-389. Google Scholar18. Wibelauer C, Anders N, Pham DT, Wollensak J. Effect of incision location on preoperative oblique astigmatism after scleral tunnel incision. J Cataract Refract Surg 1997:23: 365-371. Google Scholar19. Rapuano CJ. Dana MR, Gomes JAP. Laibson PR. Astigmatic effect of graft alignment in penetrating keratoplasty. Invest Ophthalmol Vis Sci 1995:361 suppl l:S653. Google Scholar20. Huang Y. Tuft SJ. Meek KM. A histochemical and x-ray diffraction study of keratoconus epikeratoplasty. Cornea 1996;15:320-328. Google Scholar21. Perez-Santonja JJ. Bellot J, Claramonte P, Ismail MM. Alio JL. Laser in situ keratomileusis to correct high myopia. J Cataract Refract Surg 1997;23:372-385. Google Scholar22. Amin AR. Speaker MG, Seedor JA, Kopiin RS. Donnenfeld ED. LASIK for correction of myopia and astigmatism following penetrating keratoplasty. Invest Ophthalmol Vis Sci 1998;39( suppl i:S746. Google Scholar23. Brodie SE. A finite-element model simulation of the differential geometry of radial keratotomy. Invest Ophthalmol Vis Sci 1998;39( suppl i:S348. Google Scholar24. Epstein D, Vinciguerra P, Azzolini M. Long-term results of PRK with topography-matched optical zone diameters for the correction of compound myopic astigmatism. Invest Ophthalmol Vis Sci 1998;39(supp>l):S920. Google Scholar25. Schwiegerling J, Snyder RVV, MacRae SM, Palmer ML. (1998) Visual performance predictions and customization of photorefractive keratectomy ? PRK) ablation patterns using a schematic eye. Invest Ophthalmol Vis Sci 1998; 39( suppl ):S921. Google Scholar26. Sborgia C, Alessio G. Boscia F. Corneal interactive programmed topographic ablation ? CIPTA): Preliminary results. Invest Ophthalmol Vis Sci 1998;39( suppl ):S921. Google Scholar27. Rowsey JJ, Fouraker BD. Corneal coupling principles. Intl Ophthalmol Clin 1996:36:29-38. Google Scholar28. Ta CN, Manche EE. Laser in-situ keratomileusis for the treatment of low, moderate, and high myopia. Invest Ophthalmol Vis Sci 1998;39( suppl ):S747. Google Scholar29. Purohit A. McCarey BE. Thompson KP. Sine wave ananlysis of corneal topography following refractive corneal surgery. Invest Ophthalmol Vis Sci 1998:39( suppl ):S1035. Google Scholar30. Melles GRJ. Binder PS. Anderson JA. Variation in healing throughout the depth of long-term, unsutured. corneal wounds in human autopsy specimens and monkeys. Arch Ophthalmol 1994:112:100-109. Google Scholar31. Simonsen AH. Andreassen TT. Bendix K. The healing strength of corneal wounds in the human eye. Exp Eye Res 1995:35:287-292. Google Scholar32. Melles GRJ. Binder PS. Beekhuis WH, Wijdh RHJ. Moore MN, Anderson JA. SundarRaj N. Scar tissue orientation in unsutured and sutured corneal wound healing. Br J Ophthalmol 1995;79:760-765. Google Scholar33. Anders N. Pham DT. Antoni HJ, Wollensak J. Postoperative astigmatism and relative strength of tunnel incisions: a prospective clinical trial. J Cataract Refract Surg 1997:23:332-336. Google Scholar Previous article Next article FiguresReferencesRelatedDetailsCited by Karimi A, Razaghi R, Girkin C and Downs J (2022) Ocular biomechanics during improvised explosive device blast: A computational study using eye-specific models, Injury, 10.1016/j.injury.2022.02.008, 53:4, (1401-1415), Online publication date: 1-Apr-2022. Karimi A, Razaghi R, Girkin C and Downs J (2021) Ocular biomechanics due to ground blast reinforcement, Computer Methods and Programs in Biomedicine, 10.1016/j.cmpb.2021.106425, 211, (106425), Online publication date: 1-Nov-2021. Joo J, Kim B and Chun H (2021) Application of computational modeling to improve cornea transplant surgery, Journal of the Korean Physical Society, 10.1007/s40042-021-00279-9, 79:9, (874-881), Online publication date: 1-Nov-2021. Wang S and Hatami-Marbini H (2020) Constitutive Modeling of Corneal Tissue: Influence of Three-Dimensional Collagen Fiber Microstructure, Journal of Biomechanical Engineering, 10.1115/1.4048401, 143:3, Online publication date: 1-Mar-2021. Pandolfi A (2020) Cornea modelling, Eye and Vision, 10.1186/s40662-019-0166-x, 7:1, Online publication date: 1-Dec-2020. Efraim Y, Chen F, Stashko C, Cheong K, Gaylord E, McNamara N and Knox S (2020) Alterations in corneal biomechanics underlie early stages of autoimmune-mediated dry eye disease, Journal of Autoimmunity, 10.1016/j.jaut.2020.102500, 114, (102500), Online publication date: 1-Nov-2020. Angelillo M, Montanino A and Pandolfi A (2020) On the Connection Between Geometry and Statically Determined Membrane Stresses in the Human Cornea, Journal of Biomechanical Engineering, 10.1115/1.4044742, 142:5, Online publication date: 1-May-2020. Datta P, Vyas V, Dhara S, Chowdhury A and Barui A (2019) Anisotropy Properties of Tissues: A Basis for Fabrication of Biomimetic Anisotropic Scaffolds for Tissue Engineering, Journal of Bionic Engineering, 10.1007/s42235-019-0101-9, 16:5, (842-868), Online publication date: 1-Sep-2019. Bubnova I (2019) Biomechanics of Eye Globe and Methods of Its Study Biomechanics, 10.5772/intechopen.80327 Voronin G and Bubnova I (2019) Changes in biomechanical properties of the cornea after keratorefractive surgery, Vestnik oftal'mologii, 10.17116/oftalma2019135041108, 135:4, (108), . Xue C, Xiang Y, Shen M, Wu D and Wang Y (2018) Preliminary Investigation of the Mechanical Anisotropy of the Normal Human Corneal Stroma, Journal of Ophthalmology, 10.1155/2018/5392041, 2018, (1-7), Online publication date: 17-Oct-2018. Xiang Y, Shen M, Xue C, Wu D and Wang Y (2018) Tensile biomechanical properties and constitutive parameters of human corneal stroma extracted by SMILE procedure, Journal of the Mechanical Behavior of Biomedical Materials, 10.1016/j.jmbbm.2018.05.042, 85, (102-108), Online publication date: 1-Sep-2018. Consejo A and Rozema J (2018) Scleral Shape and Its Correlations With Corneal Astigmatism, Cornea, 10.1097/ICO.0000000000001565, 37:8, (1047-1052), Online publication date: 1-Aug-2018. Jin K, Shin Y and Hyon J (2017) Effects of chalazia on corneal astigmatism, BMC Ophthalmology, 10.1186/s12886-017-0426-2, 17:1, Online publication date: 1-Dec-2017. Kim T, Noh S and Jin K (2017) The Effects of Distance Between the Corneal Apex and the Inner and Outer Corneal Wound Edges on Corneal Astigmatism After Cataract Surgery, Journal of Refractive Surgery, 33:7, (460-468), Online publication date: 1-Jul-2017. Bekesi N, Dorronsoro C, de la Hoz A, Marcos S and Karamichos D (2016) Material Properties from Air Puff Corneal Deformation by Numerical Simulations on Model Corneas, PLOS ONE, 10.1371/journal.pone.0165669, 11:10, (e0165669) Lanchares E, Buey M, Cristóbal J, Calvo B, Ascaso F and Malvè M (2016) Computational Simulation of Scleral Buckling Surgery for Rhegmatogenous Retinal Detachment: On the Effect of the Band Size on the Myopization, Journal of Ophthalmology, 10.1155/2016/3578617, 2016, (1-10), . Hashemi H, Khabazkhoob M, Soroush S, Shariati R, Miraftab M and Yekta A (2016) The location of incision in cataract surgery and its impact on induced astigmatism, Current Opinion in Ophthalmology, 10.1097/ICU.0000000000000223, 27:1, (58-64), Online publication date: 1-Jan-2016. Skalicky S (2016) The Cornea and Sclera Ocular and Visual Physiology, 10.1007/978-981-287-846-5_3, (29-46), . Quantock A, Winkler M, Parfitt G, Young R, Brown D, Boote C and Jester J (2015) From nano to macro: Studying the hierarchical structure of the corneal extracellular matrix, Experimental Eye Research, 10.1016/j.exer.2014.07.018, 133, (81-99), Online publication date: 1-Apr-2015. Girard M, Dupps W, Baskaran M, Scarcelli G, Yun S, Quigley H, Sigal I and Strouthidis N (2014) Translating Ocular Biomechanics into Clinical Practice: Current State and Future Prospects, Current Eye Research, 10.3109/02713683.2014.914543, 40:1, (1-18), Online publication date: 2-Jan-2015. Vasta M, Gizzi A and Pandolfi A (2014) On three- and two-dimensional fiber distributed models of biological tissues, Probabilistic Engineering Mechanics, 10.1016/j.probengmech.2014.05.003, 37, (170-179), Online publication date: 1-Jul-2014. Jeong H, Jung B, Hwang H and Kim H (2014) Comparison of Higher Order Aberrations and Astigmatism after On-Axis Small Incision Cataract Surgery, Journal of the Korean Ophthalmological Society, 10.3341/jkos.2014.55.2.182, 55:2, (182), . Calzada B, Sancho E and del Buey Sayas M (2014) Modelo biomecánico del globo ocular Biomecánica y arquitectura corneal, 10.1016/B978-84-9022-649-0.50034-X, (359-366), . Boote C, Dooley E, Gardner S, Kamma-Lorger C, Hayes S, Nielsen K, Hjortdal J, Sorensen T, Terrill N, Meek K and Boulton M (2013) Quantification of Collagen Ultrastructure after Penetrating Keratoplasty – Implications for Corneal Biomechanics, PLoS ONE, 10.1371/journal.pone.0068166, 8:7, (e68166) FOSTER C, GONGAL D, BEGAJ T and LUO M (2013) EMBEDDED COLLAGEN DEFORMATION MODELS FOR COMPUTATIONAL MODELING OF HEALTHY, KERATOCONIC, AND CROSSLINKED CORNEAS, Journal of Mechanics in Medicine and Biology, 10.1142/S0219519413500243, 13:03, (1350024), Online publication date: 1-Jun-2013. Abad J (2012) Paradoxical central corneal steepening after collagen crosslinking in a case with intrastromal corneal ring segments, Journal of Cataract and Refractive Surgery, 10.1016/j.jcrs.2012.07.013, 38:10, (1879-1880), Online publication date: 1-Oct-2012. Dupps W and Hallahan K (2012) Biomechanics in refractive surgery Ophthalmic Surgery: Principles and Practice, 10.1016/B978-1-4377-2250-5.00028-X, (172-178), . Lanchares E, Malvè M and Calvo B (2012) Patient-Specific Biomechanical Framework for Aiding Clinical Decisions in Eye Surgery Patient-Specific Computational Modeling, 10.1007/978-94-007-4552-0_7, (161-193), . Zhou Y, Wu Z, Ge J, Wan P, Li N, Xiang P, Gao Q and Wang Z (2011) Development and Characterization of Acellular Porcine Corneal Matrix Using Sodium Dodecylsulfate, Cornea, 10.1097/ICO.0b013e3181dc8184, 30:1, (73-82), Online publication date: 1-Jan-2011. Dawson D, Ubels J and Edelhauser H (2011) Cornea and Sclera Adler's Physiology of the Eye, 10.1016/B978-0-323-05714-1.00004-2, (71-130), . Elsheikh A (2009) Finite Element Modeling of Corneal Biomechanical Behavior, Journal of Refractive Surgery, 26:4, (289-300), Online publication date: 1-Apr-2010. Pandolfi A (2010) Computational Biomechanics of the Human Cornea Computational Modeling in Biomechanics, 10.1007/978-90-481-3575-2_15, (435-466), . Meek K and Boote C (2009) The use of X-ray scattering techniques to quantify the orientation and distribution of collagen in the corneal stroma, Progress in Retinal and Eye Research, 10.1016/j.preteyeres.2009.06.005, 28:5, (369-392), Online publication date: 1-Sep-2009. McMonnies C (2009) Mechanisms of Rubbing-Related Corneal Trauma in Keratoconus, Cornea, 10.1097/ICO.0b013e318198384f, 28:6, (607-615), Online publication date: 1-Jul-2009. Elsheikh A and Alhasso D (2009) Mechanical anisotropy of porcine cornea and correlation with stromal microstructure, Experimental Eye Research, 10.1016/j.exer.2009.01.010, 88:6, (1084-1091), Online publication date: 1-Jun-2009. Lombardo M, Lombardo G, Friend D, Serrao S and Terry M (2009) Long-term Anterior and Posterior Topographic Analysis of the Cornea After Deep Lamellar Endothelial Keratoplasty, Cornea, 10.1097/ICO.0b013e31818d33c7, 28:4, (408-415), Online publication date: 1-May-2009. Tu K and Aslanides I (2009) Orbscan II Anterior Elevation Changes Following Corneal Collagen Cross-Linking Treatment for Keratoconus, Journal of Refractive Surgery, 25:8, (715-722), Online publication date: 1-Jan-2009. Elsheikh A, Ross S, Alhasso D and Rama P (2009) Numerical Study of the Effect of Corneal Layered Structure on Ocular Biomechanics, Current Eye Research, 10.1080/02713680802535263, 34:1, (26-35), Online publication date: 1-Jan-2009. Dupps W (2009) Principles of biomechanics in refractive surgery Corneal Surgery, 10.1016/B978-0-323-04835-4.50087-2, (711-719), . Pandolfi A and Holzapfel G (2008) Three-Dimensional Modeling and Computational Analysis of the Human Cornea Considering Distributed Collagen Fibril Orientations, Journal of Biomechanical Engineering, 10.1115/1.2982251, 130:6, Online publication date: 1-Dec-2008. Naeser K (2008) Assessment and Statistics of Surgically Induced Astigmatism, Acta Ophthalmologica, 10.1111/j.1755-3768.2008.01234.x, 86:thesis1, (1-28) Shuker S (2014) Mechanism and emergency management of blast eye/orbital injuries, Expert Review of Ophthalmology, 10.1586/17469899.3.2.229, 3:2, (229-246), Online publication date: 1-Apr-2008. Elsheikh A, Alhasso D and Rama P (2008) Assessment of the epithelium's contribution to corneal biomechanics, Experimental Eye Research, 10.1016/j.exer.2007.12.002, 86:2, (445-451), Online publication date: 1-Feb-2008. (2008) Experimental Assessment of Corneal Anisotropy, Journal of Refractive Surgery, 24:2, (178-187), Online publication date: 1-Jan-2008. Dupps W and Wilson S (2008) Biomechanics and Wound Healing in Refractive Surgery Albert &Jakobiec's Principles &Practice of Ophthalmology, 10.1016/B978-1-4160-0016-7.50075-8, (971-980), . McMonnies C and Boneham G (2007) Corneal Curvature Stability With Increased Intraocular Pressure, Eye & Contact Lens: Science & Clinical Practice, 10.1097/01.icl.0000246910.02437.62, 33:3, (130-137), Online publication date: 1-May-2007. Li L and Tighe B (2007) Nonlinear analysis of static axisymmetric deformation of the human cornea, Computational Materials Science, 10.1016/j.commatsci.2006.04.004, 38:4, (618-624), Online publication date: 1-Feb-2007. Dupps W, Netto M, Herekar S and Here R (2007) Surface Wave Elastometry of the Cornea in Porcine and Human Donor Eyes, Journal of Refractive Surgery, 23:1, (66-75), Online publication date: 1-Jan-2007. Read S, Collins M and Carney L (2021) A review of astigmatism and its possible genesis, Clinical and Experimental Optometry, 10.1111/j.1444-0938.2007.00112.x, 90:1, (5-19), Online publication date: 1-Jan-2007. Borasio E, Mehta J and Maurino V (2006) Torque and flattening effects of clear corneal temporal and on-axis incisions for phacoemulsification, Journal of Cataract and Refractive Surgery, 10.1016/j.jcrs.2006.09.010, 32:12, (2030-2038), Online publication date: 1-Dec-2006. Pandolfi A and Manganiello F (2006) A model for the human cornea: constitutive formulation and numerical analysis, Biomechanics and Modeling in Mechanobiology, 10.1007/s10237-005-0014-x, 5:4, (237-246), Online publication date: 24-Oct-2006. Rajan M, O'Brart D, Jaycock P and Marshall J (2006) Effects of Ablation Diameter on Long-term Refractive Stability and Corneal Transparency after Photorefractive Keratectomy, Ophthalmology, 10.1016/j.ophtha.2006.06.030, 113:10, (1798-1806), Online publication date: 1-Oct-2006. Dupps W and Wilson S (2006) Biomechanics and wound healing in the cornea, Experimental Eye Research, 10.1016/j.exer.2006.03.015, 83:4, (709-720), Online publication date: 1-Oct-2006. Li L and Tighe B (2006) The anisotropic material constitutive models for the human cornea, Journal of Structural Biology, 10.1016/j.jsb.2005.10.014, 153:3, (223-230), Online publication date: 1-Mar-2006. Alastrué V, Calvo B, Peña E and Doblaré M (2005) Biomechanical Modeling of Refractive Corneal Surgery, Journal of Biomechanical Engineering, 10.1115/1.2132368, 128:1, (150-160), Online publication date: 1-Feb-2006. McMonnies C and Schief W (2006) Biomechanically Coupled Curvature Transfer in Normal and Keratoconus Corneal Collagen, Eye & Contact Lens: Science & Clinical Practice, 10.1097/01.icl.0000183177.22734.f3, 32:1, (51-62), Online publication date: 1-Jan-2006. Boote C, Dennis S, Huang Y, Quantock A and Meek K (2005) Lamellar orientation in human cornea in relation to mechanical properties, Journal of Structural Biology, 10.1016/j.jsb.2004.08.009, 149:1, (1-6), Online publication date: 1-Jan-2005. Pinsky P, van der Heide D and Chernyak D (2005) Computational modeling of mechanical anisotropy in the cornea and sclera, Journal of Cataract and Refractive Surgery, 10.1016/j.jcrs.2004.10.048, 31:1, (136-145), Online publication date: 1-Jan-2005. Grzybowski D, Roberts C, Mahmoud A and Chang J (2005) Model for nonectatic increase in posterior corneal elevation after ablative procedures, Journal of Cataract and Refractive Surgery, 10.1016/j.jcrs.2004.10.045, 31:1, (72-81), Online publication date: 1-Jan-2005. Boote C, Dennis S and Meek K (2004) Spatial mapping of collagen fibril organisation in primate cornea—an X-ray diffraction investigation, Journal of Structural Biology, 10.1016/j.jsb.2003.12.009, 146:3, (359-367), Online publication date: 1-Jun-2004. Doughty M and Bergmanson J (2021) Collagen fibril characteristics at the corneo‐scleral boundary and rabbit corneal stromal swelling, Clinical and Experimental Optometry, 10.1111/j.1444-0938.2004.tb03153.x, 87:2, (81-92), Online publication date: 1-Mar-2004. Aghamohammadzadeh H, Newton R and Meek K (2004) X-Ray Scattering Used to Map the Preferred Collagen Orientation in the Human Cornea and Limbus, Structure, 10.1016/j.str.2004.01.002, 12:2, (249-256), Online publication date: 1-Feb-2004. Stitzel J, Duma S, Cormier J and Herring I (2002) A Nonlinear Finite Element Model of the Eye With Experimental Validation for the Prediction of Globe Rupture 46th Stapp Car Crash Conference (2002), 10.4271/2002-22-0005, Oliveira-Soto L and Charman W (2002) Some possible longer-term ocular changes following excimer laser refractive surgery, Ophthalmic and Physiological Optics, 10.1046/j.1475-1313.2002.00022.x, 22:4, (274-288), Online publication date: 1-Jul-2002. Marcos S, Diaz-Santana L, Llorente L and Dainty C (2002) Ocular aberrations with ray tracing and Shack–Hartmann wave-front sensors: Does polarization play a role?, Journal of the Optical Society of America A, 10.1364/JOSAA.19.001063, 19:6, (1063), Online publication date: 1-Jun-2002. Kohnen S, Neuber R and Kohnen T (2002) Effect of temporal and nasal unsutured limbal tunnel incisions on induced astigmatism after phacoemulsification, Journal of Cataract and Refractive Surgery, 10.1016/S0886-3350(01)01215-9, 28:5, (821-825), Online publication date: 1-May-2002. Meek K and Quantock A (2001) The Use of X-ray Scattering Techniques to Determine Corneal Ultrastructure, Progress in Retinal and Eye Research, 10.1016/S1350-9462(00)00016-1, 20:1, (95-137), Online publication date: 1-Jan-2001. Request Permissions InformationCopyright 2013, SLACK IncorporatedPDF download