Assessment of age-related changes in lens capsule biomechanics using atomic force microscopy

K.S. Avetisov

Krasnov Research Institute of Eye Diseases

ORCID: 0000-0001-9195-8908

N.A. Bakhchieva

Research Institute of Eye Diseases

S.E. Avetisov

Krasnov Research Institute of Eye Diseases;
Sechenov First Moscow State Medical University

ORCID: 0000-0001-7115-4275

I.A. Novikov

Krasnov Research Institute of Eye Diseases

ORCID: 0000-0003-4898-4662

A.V. Shitikova

Research Institute of Eye Diseases

A.A. Frolova

Institute for Regenerative Medicine of the Sechenov University

P.S. Timashev

Institute for Regenerative Medicine of the I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University)

Assessment of age-related changes in lens capsule biomechanics using atomic force microscopy

Authors:

K.S. Avetisov, N.A. Bakhchieva, S.E. Avetisov, I.A. Novikov, A.V. Shitikova, A.A. Frolova, P.S. Timashev

More about the authors

Journal: Vestnik Oftalmologii. 2021;137(1): 28‑34

DOI: 10.17116/oftalma202113701128

Downloaded: 19

To cite this article:

Avetisov KS, Bakhchieva NA, Avetisov SE, Novikov IA, Shitikova AV, Frolova AA, Timashev PS. Assessment of age-related changes in lens capsule biomechanics using atomic force microscopy. Vestnik Oftalmologii. 2021;137(1):28‑34. (In Russ., In Engl.)
https://doi.org/10.17116/oftalma202113701128

Close metadata

Studies devoted to the assessment of lens capsule biomechanics can be divided into fundamental and applied. The former are oriented towards analysis of various indicators characterizing elasticity of the capsule as a basal membrane that maintains and changes the shape of the lens, and the latter deal with widespread introduction of modern microinvasive methods of phaco surgery into clinical practice.

PURPOSE

To assess age-related changes in lens capsule biomechanics based on atomic force microscopy (AFM).

MATERIAL AND METHODS

The study included 50 central fragments of the anterior capsule of the human lens obtained intraoperatively during ultrasonic phacoemulsification by continuous circular capsulorhexis. The measurements were carried out in the Fast Force Volume (FFV) mode. The force curves were processed in the Nanoscope Analysis software (Bruker, USA) using the Hertz model that allows calculating the Young’s modulus of the capsule sample based on the dependence of the force on the puncture depth.

RESULTS

There was no statistically significant difference in the «stiffness» of the inner and outer surfaces before and after removal of the subcapsular epithelium (p=0.25). In all cases, the inner surface of the capsule turned out to be «harder» than the outer one. In this case, the ratio of Young’s modulus of the inner and outer surfaces has a significant dependence on age (p<0.001). With an increase in age from 50 to 90 years, this ratio decreased from ~7 to ~1.5. This was due to a simultaneous change in Young’s modulus of the opposite nature: an increase in the stiffness of the outer surface and its decrease in the inner one.

CONCLUSION

It is possible to assess lens capsule biomechanics using AFM if the subcapsular epithelium is present. In this case, the objects of study are the areas of the capsule free of epithelium, and the epithelial cells themselves can be used to identify the inner surface of the capsule. Regardless of age, the stiffness of the inner surface of the anterior lens capsule significantly exceeds that of the outer surface.

Keywords:

anterior lens capsule

atomic force microscopy

age-related changes

Authors:

K.S. Avetisov

Krasnov Research Institute of Eye Diseases

ORCID: 0000-0001-9195-8908

N.A. Bakhchieva

Research Institute of Eye Diseases

S.E. Avetisov

Krasnov Research Institute of Eye Diseases;
Sechenov First Moscow State Medical University

ORCID: 0000-0001-7115-4275

I.A. Novikov

Krasnov Research Institute of Eye Diseases

ORCID: 0000-0003-4898-4662

A.V. Shitikova

Research Institute of Eye Diseases

A.A. Frolova

Institute for Regenerative Medicine of the Sechenov University

P.S. Timashev

Institute for Regenerative Medicine of the I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University)

Received:

04.11.2020

Accepted:

23.11.2020

List of references:

Barraquer RL, Michael R, Abreu R, et al. Human lens capsule thickness as a function of age and location along the sagittal lens perimeter. Invest Ophthalmol Vis Sci. 2006;407:2053-2060.
Fisher RF, Pettet BE. The postnatal growth of the capsule of the human crystalline lens. J Anat. 1972;112(Pt 2):207-214.
Krag S, Olsen T, Andreassen T. Biomechanical Characteristics of the Human Anterior Lens Capsule in Relation to Age. Invest Ophthalmol Vis Sci. 1997;38:357-363.
Cammarata P, Cantu-Crouch D, Oakford L, Morrill A. Macromolecular Organization of Bovine Lens Capsule. Tissue Cell. 1986;18:83-97.
Iomdina E, Bauer S, Kotliar K. Biomekhanika glaza: teoreticheskiye aspekti I klinicheskiye prilozheniya [Eye Biomechanics: theoretical aspects and clinical Applications]. M.: Real Time.; 2015. (In Russ.).
Wang K, Pierscionek BK. Biomechanics of the human lens and accommodative system: Functional relevance to physiological states. Prog Retin Eye Res. 2019;71:114-131.
Fisher RF. Elastic constants of the human lens capsule. J Phisiol. 1969;201:1-19.
Fisher RF, Wakely J. The elastic constants and ultrastructural organization of a basement membrane (Lens Capsule). Proc R Soc. 1976;193:335-358. https://doi.org/10.1098/rspb.1976.0051
Fisher RF, Hayes BP. Thickness and volume constants and ultrastructural organization of basement membrane (Lens Capsule). J Physiol. 1979;293:229-245. https://doi.org/10.1113/jphysiol.1979.sp012887
Danielson CC. Tensile mechanical and creep properties of Descemet’s membrane and lens capsule. Exp Eye Res. 2004;79:343-350. https://doi.org/10.1016/j.exer.2004.05.014
Pedrigi RM, David G, Dziezyc J, Humphrey JD. Regional mechanical properties and stress analysis of the human anterior lens capsule. Vis Res. 2007;47:1781-1789. https://doi.org/10.1016/j.visres.2007.03.014
Krag S, Andreassen T. Biomechanical Measurements of the Porcine Lens Capsule. Exp Eye Res. 1996;62:253-260. https://doi.org/10.1006/exer.1996.0030
Friedman NJ, Palanker DV, Schuele G, et al. Femtosecond laser capsulotomy. J Cataract Refract Surg. 2011;37:1189-1198.
Auffarth GU, Reddy KP, Ritter R, et al. Comparison of the maximum applicable stretch force after femtosecond laser-assisted and manual anterior capsulotomy. J Cataract Refract Surg. 2013;39:105-109. https://doi.org/10.1016/j.jcrs.2012.08.065
Andreo LK, Wilson ME, Apple DJ. Elastic properties and scanning electron microscopic appearance of manual continuous curvilinear capsulorhexis and vitrectorhexis in an animal model of pediatric cataract. J Cataract Refract Surg. 1999;25:534-539. https://doi.org/10.1016/s0886-3350(99)80051-0
Sandor GL, Kiss Z, Bocskai ZI, et al. Comparison of the Mechanical Properties of the Anterior Lens Capsule Following Manual Capsulorhexis and Femtosecond Laser Capsulotomy. J Cataract Refract Surg. 2014;30:660-664. https://doi.org/10.3928/1081597x-20140903-08
Sandor GL, Kiss Z, Bocskai ZI, et al. Evaluation of the Mechanical Properties of the Anterior Lens Capsule Following Femtosecond Laser Capsulotomy at Differrent Pulse Energy Settings. J Cataract Refract Surg. 2015;31:153-157. https://doi.org/10.3928/1081597x-20150220-02
Pedrigi RM, Dziezyc J, Humphrey JD. Altered mechanical behavior and properties of the human anterior lens capsule after cataract surgery. Exp Eye Res. 2009;89:575-580. https://doi.org/10.1016/j.exer.2009.06.001
Avetisov KS, Bakhchieva NA, Avetisov SE, Novikov IA, Belikov NV, Khaydukova IV. Biomechanical aspects of anterior capsulotomy in cataract surgery. Vestnik oftal’mologii. 2017;133(3):82-88. (In Russ.). https://doi.org/10.17116/oftalma2017133382-88
Avetisov KS, Bakhchieva NA, Avetisov SE, Novikov IA, Golovchenko AV, Shitikova AV. Atomic force microscopy in the study of the eye anterior segment structures. Vestnik oftal’mologii. 2020;136(1):103-110. (In Russ.). https://doi.org/10.17116/oftalma2020136011103
Halfter W, Monnier C, Muller D, et al. The bi-Functional organization of human basement membranes. PLoS One. 2013;8:e67660. https://doi.org/10.1371/journal.pone.0067660
Reyes Lua M, Oertle P, Camenzind L. Superior rim stability of the lens capsule following manual over femtosecond laser capsulotomy. Investig Ophthalmol Vis Sci. 2016;57:2839-2849.
Simsek C, Oto S, Yilmaz DD. Comparison of mechanical properties of the anterior lens capsule in senile cataract, senile cataract with trypan blue application and pseudoexfoliation syndrome. J Cataract Refract Surg. 2017;43:1054-1061.
Ziebarth NM, Arrieta E, Feurer WJ, et al. Primate lens capsule elasticity assessed atomic force microscopy. Exp Eye Res. 2011;92:490-494. https://doi.org/10.1016/j.exer.2011.03.008

Close metadata