title: Measurements of elastic modulus for human anterior lens capsule with atomic force microscopy: the effect of loading force.
abstract: The purpose of the study was to appraise the effect of loading force magnitude on the determination of the elastic modulus of the anterior lens capsule through atomic force microscopy. Four human anterior lens capsules taken during phacoemulsification cataract surgery were studied, free of epithelial cells, with atomic force microscopy. For the experiment, five different indentation loading forces were applied to near areas of the specimen. Experimental data was exported and analyzed according to the Hertz model to obtain the Young's modulus with regards to the elastic behavior of the material. Force-distance curves were acquired by applying a load of 2, 5, 10, 20 and 30 nN. When examining the results it was evident that determination of Young's modulus of the anterior lens capsule is dependent on the loading force concerning the examined range. Loading forces of 10 and 20 nN led to results without significant difference (p > 0.05) and more reproducible (coefficients of variation 12.4 and 11.7 %, respectively).
authors.affiliation: 2nd Department of Ophthalmology, Medical School, Aristotle University of Thessaloniki, "Papageorgiou" General Hospital, 56429, Thessaloníki, Greece, konstantinos.tsaousis@gmail.com.
authors.forename: Konstantinos T
authors.initials: KT
authors.lastname: Tsaousis
authors.forename: Panagiotis G
authors.initials: PG
authors.lastname: Karagiannidis
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Kopsachilis
authors.forename: Chrysanthos
authors.initials: C
authors.lastname: Symeonidis
authors.forename: Ioannis T
authors.initials: IT
authors.lastname: Tsinopoulos
authors.forename: Varvara
authors.initials: V
authors.lastname: Karagkiozaki
authors.forename: Lampros P
authors.initials: LP
authors.lastname: Lamprogiannis
authors.forename: Stergios
authors.initials: S
authors.lastname: Logothetidis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002386:Cataract / Q000503:physiopathology*; D055119:Elastic Modulus; D004547:Elastic Tissue; D004548:Elasticity / Q000502:physiology*; D006801:Humans; D007903:Lens Capsule, Crystalline / Q000502:physiology*; D018625:Microscopy, Atomic Force; D015203:Reproducibility of Results; D013314:Stress, Mechanical
references.citation: Jpn J Ophthalmol. 2000 May;44(3):318
references.pmid: 10913659
references.citation: Optom Vis Sci. 2010 Jul;87(7):E475-81
references.pmid: 20473237
references.citation: J Cataract Refract Surg. 2000 Apr;26(4):571-5
references.pmid: 10771232
references.citation: Scanning. 2012 Jul-Aug;34(4):247-56
references.pmid: 22331648
references.citation: Proc Natl Acad Sci U S A. 2011 Feb 1;108(5):1777-82
references.pmid: 21245358
references.citation: Phys Rev Lett. 1986 Mar 3;56(9):930-933
references.pmid: 10033323
references.citation: J Mol Recognit. 2011 May-Jun;24(3):483-9
references.pmid: 21504027
references.citation: J Biomech Eng. 2007 Jun;129(3):430-40
references.pmid: 17536911
references.citation: J Cataract Refract Surg. 2010 Sep;36(9):1573-8
references.pmid: 20692572
references.citation: Biochemistry. 2010 Aug 24;49(33):7023-32
references.pmid: 20677810
references.citation: Science. 2005 Nov 18;310(5751):1139-43
references.pmid: 16293750
references.citation: J Physiol. 1969 Mar;201(1):1-19
references.pmid: 5773553
references.citation: Cell Tissue Bank. 2013 Sep;14(3):407-12
references.pmid: 22836959
references.citation: Science. 1989 Mar 24;243(4898):1586-9
references.pmid: 2928794
references.citation: J Appl Physiol (1985). 2005 Apr;98(4):1547-53
references.pmid: 15772065
references.citation: Neuroimage. 1993 Sep;1(2):145-50
references.pmid: 9343565
references.citation: Biomaterials. 2010 Jul;31(21):5510-9
references.pmid: 20417965
references.citation: Invest Ophthalmol Vis Sci. 2000 Mar;41(3):680-6
references.pmid: 10711681
references.citation: Cell Tissue Res. 1997 Apr;288(1):111-8
references.pmid: 9042778
references.citation: Exp Eye Res. 2011 Jun;92(6):490-4
references.pmid: 21420953
references.citation: Nature. 2003 Nov 6;426(6962):30-1; discussion 31
references.pmid: 14603306
references.citation: Biophys J. 2004 Jan;86(1 Pt 1):617-28
references.pmid: 14695306