Characterization of age-related variation in corneal biomechanical properties.
An experimental study has been conducted to determine the stress-strain behaviour of human corneal tissue and how the behaviour varies with age. Fifty-seven well-preserved ex vivo donor corneas aged between 30 and 99 years were subjected to cycles of posterior pressure up to 60 mm Hg while monitoring their behaviour. The corneas were mechanically clamped along their ring of scleral tissue and kept in physiological conditions of temperature and hydration. The tissue demonstrated hyper-elastic pressure-deformation and stress-strain behaviour that closely matched an exponential trend. Clear stiffening (increased resistance to deformation) with age was observed in all loading cycles, and the rate of stiffness growth was nonlinear with bias towards older specimens. With a strong statistical association between stiffness and age (p < 0.05), it was possible to develop generic stress-strain equations that were suitable for all ages between 30 and 99 years. These equations, which closely matched the experimental results, depicted corneal stiffening with age in a form suitable for implementation in numerical simulations of ocular biomechanical behaviour.
Elsheikh
Ahmed
A
Division of Civil Engineering, University of Dundee, Dundee DD1 4HN, UK. a.i.h.elsheikh@dundee.ac.uk
Geraghty
Brendan
B
Rama
Paolo
P
Campanelli
Marino
M
Meek
Keith M
KM
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D003315:Cornea / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008875:Middle Aged; D013314:Stress, Mechanical
Br J Ophthalmol. 2005 Dec;89(12):1572-5
16299132
Surv Ophthalmol. 1994 May;38 Suppl:S191-7
7940143
J Biomech Eng. 2008 Apr;130(2):021011
18412498
Invest Ophthalmol Vis Sci. 2008 Oct;49(10):4232-6
18539943
Br J Ophthalmol. 1999 Oct;83(10):1106-11
10502567
Biochim Biophys Acta. 1992 Mar 20;1138(3):222-8
1547284
Cont Lens Anterior Eye. 2001;24(1):41-6
16303452
Nature. 1979 Nov 8;282(5735):213-5
492338
Clin Exp Optom. 2006 May;89(3):124-43
16637967
Exp Eye Res. 2004 Mar;78(3):503-12
15106929
Invest Ophthalmol Vis Sci. 1998 Mar;39(3):644-8
9501878
Invest Ophthalmol Vis Sci. 1992 Jun;33(7):2224-8
1607232
Curr Eye Res. 2007 Jan;32(1):11-9
17364730
Atherosclerosis. 1996 Dec 20;127(2):155-65
9125305
Metab Pediatr Syst Ophthalmol. 1983;7(4):183-8
6678372
Ophthalmic Physiol Opt. 1997 Jan;17(1):68-74
9135815
Bull Math Biol. 1999 May;61(3):551-72
17883231
Eye Contact Lens. 2007 Nov;33(6 Pt 1):265-71
17993819
Ophthalmology. 2004 Dec;111(12):2211-9
15582076
Biophys J. 1993 Jan;64(1):273-80
8431547
Exp Eye Res. 2008 May;86(5):783-90
18396276
Arch Ophthalmol. 1997 Aug;115(8):1051-7
9258228
J Struct Biol. 2005 Jan;149(1):1-6
15629652
J R Soc Interface. 2004 Nov 22;1(1):3-15
16849148
Vision Res. 2006 Mar;46(6-7):993-1001
16266736
Invest Ophthalmol Vis Sci. 1991 Jul;32(8):2244-58
2071337
Atherosclerosis. 1998 Sep;140(1):135-45
9733224
J Glaucoma. 2008 Jun-Jul;17(4):318-28
18552618
J Struct Biol. 2009 May;166(2):195-204
19258040
Br J Ophthalmol. 2005 Jul;89(7):851-4
15965165
Cornea. 1998 Sep;17(5):537-43
9756449
J Cataract Refract Surg. 2005 Jan;31(1):146-55
15721707
Exp Eye Res. 2004 Sep;79(3):343-50
15336496
J Biomech. 2001 Apr;34(4):533-7
11266678
Invest Ophthalmol Vis Sci. 2009 Nov;50(11):5226-37
19494203
Br J Ophthalmol. 2010 Apr;94(4):519-22
19833614
J Biomech Eng. 2006 Feb;128(1):150-60
16532629
Biochem J. 1998 Feb 15;330 ( Pt 1):345-51
9461529
Ann Biomed Eng. 2000 Sep;28(9):1093-100
11132193
Invest Ophthalmol Vis Sci. 1997 Feb;38(2):357-63
9040468
Curr Eye Res. 2008 Mar;33(3):205-13
18350431
Cont Lens Anterior Eye. 2008 Apr;31(2):95-102
18356094
Ann Biomed Eng. 2006 Jan;34(1):169-83
16474919
Br J Ophthalmol. 2000 Mar;84(3):318-23
10684845
Biochem Biophys Res Commun. 1996 Feb 15;219(2):311-5
8604983
Exp Eye Res. 2004 Mar;78(3):493-501
15106928
Exp Eye Res. 2008 Feb;86(2):445-51
18221938
Ann Ophthalmol. 1973 Mar;5(3):285-7 passim
4694913
J Refract Surg. 2007 Oct;23(8):808-18
17985801
Clin Exp Ophthalmol. 2002 Jun;30(3):173-5
12010208
Biomaterials. 2008 Oct;29(28):3896-904
18603294
J Biomech Eng. 1996 Nov;118(4):473-81
8950650