title: Changes in lens stiffness due to capsular opacification in accommodative lens refilling.
abstract: Accommodation may be restored to presbyopic lenses by refilling the lens capsular bag with a soft polymer. After this accommodative lens refilling prevention of capsular opacification is a requirement, since capsular opacification leads to a decreased clarity of the refilled lens. It has been hypothesized that capsular fibrosis causing the capsular opacification results in increased stiffness of the lens capsular bag, therewith contributing to a decrease in accommodative amplitude of the lens. However, the change in viscoelastic properties of refilled lenses due to capsular fibrosis has never been measured directly. In this study we examined natural lenses from enucleated porcine eyes and refilled lenses directly after refilling and after three months of culturing, when capsular fibrosis had developed, and determined their viscoelastic properties with a low load compression tester. Control refilled lenses were included in which capsular opacification was prevented by treatment with actinomycin D. We related lens stiffening to the degree of capsular opacification, as derived from the microscopic images taken with a confocal laser scanning microscope. Overall, the refilled lenses directly after refilling were softer than refilled lenses after three months of culturing, and refilled lenses treated with actinomycin D were softer compared with untreated refilled lenses. The degree of capsular opacification as assessed by microscopy corresponds to an increase in lens stiffness. This indicates that the viscoelastic properties of the refilled lens are influenced by capsular fibrosis and modulated by treatment of the lens epithelium. In conclusion, this study shows that the development of capsular fibrosis negatively affects the viscoelastic properties of isolated, cultured refilled lenses.
authors.affiliation: University of Groningen, University Medical Center Groningen, Dept. of Ophthalmology, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Laboratory for Experimental Ophthalmology, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, W.J. Kolff Institute, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands. Electronic address: l.m.nibourg@umcg.nl.
authors.forename: Lisanne M
authors.initials: LM
authors.lastname: Nibourg
authors.affiliation: University of Groningen, University Medical Center Groningen, W.J. Kolff Institute, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Dept. of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Prashant K
authors.initials: PK
authors.lastname: Sharma
authors.affiliation: University of Groningen, University Medical Center Groningen, W.J. Kolff Institute, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, Dept. of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Theo G
authors.initials: TG
authors.lastname: van Kooten
authors.affiliation: University of Groningen, University Medical Center Groningen, Dept. of Ophthalmology, Hanzeplein 1, 9713 GZ Groningen, The Netherlands; University of Groningen, University Medical Center Groningen, W.J. Kolff Institute, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Koopmans
mesh_terms: D000065:Accommodation, Ocular; D000818:Animals; D058442:Capsule Opacification / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control; D019923:Capsulorhexis; D003609:Dactinomycin / Q000494:pharmacology; D004195:Disease Models, Animal; D004548:Elasticity / Q000502:physiology*; D054459:Elasticity Imaging Techniques; D005355:Fibrosis; D007908:Lens, Crystalline / Q000502:physiology*; D009924:Organ Culture Techniques; D057852:Posterior Capsule of the Lens / Q000187:drug effects* / Q000473:pathology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012826:Silicone Elastomers / Q000008:administration & dosage*; D034421:Sus scrofa
chemical_list: D011500:Protein Synthesis Inhibitors; D012826:Silicone Elastomers; D003609:Dactinomycin
keywords: Capsule opacification; Elasticity imaging techniques; Lens accommodation; Lens refilling; Sus scrofa domesticus