0
Research Papers

A Study of the Mechanical Forces on Aphakic Iris-Fixated Intraocular Lenses

[+] Author and Article Information
Peyman Davvalo Khongar

Department of Civil,
Chemical and Environmental Engineering,
University of Genoa,
Genoa 16145, Italy
e-mail: peyman.davvalo.khongar@edu.unige.it

Jan Oscar Pralits

Department of Civil,
Chemical and Environmental Engineering,
University of Genoa,
Genoa 16145, Italy
e-mail: jan.pralits@unige.it

Paolo Soleri

Ophtec BV,
Groningen 9728 NR, The Netherlands
e-mail: p.soleri@ophtec.com

Mario Romano

Department of Biomedical Sciences,
Humanitas University,
Rozzano,
Milano 20090, Italy
e-mail: mario.romano@hunimed.eu

Rodolfo Repetto

Department of Civil, Chemical and
Environmental Engineering,
University of Genoa,
Genoa 16145, Italy
e-mail: rodolfo.repetto@unige.it

Manuscript received February 21, 2018; final manuscript received June 7, 2018; published online August 20, 2018. Assoc. Editor: Anna Pandolfi.

J Biomech Eng 140(11), 111009 (Aug 20, 2018) (8 pages) Paper No: BIO-18-1097; doi: 10.1115/1.4040588 History: Received February 21, 2018; Revised June 07, 2018

Iris-fixated aphakic intraocular lenses (IFIOL) are used in cataract surgery when more common intraocular lenses (IOL) cannot be adopted because of the absence of capsular bag support. These lenses can be implanted on either the posterior or the anterior surface of the iris. In this work, we study whether one of these options is preferable over the other from the mechanical point of view. In particular, we focus on the forces that the IFIOL transmits to the iris, which are associated with the risk of lens dislocation. We study the problem numerically and consider aqueous flow induced by saccadic rotations in the cases of an IFIOL in the anterior and posterior sides of the iris. The considered IFIOL is the Artisan Aphakia +30.0 D lens (IFIOL) produced by Ophtec BV. We perform the simulations in openfoam. We find that the forces transmitted by the aphakic IFIOL to the iris are significantly higher in the case of posterior implantation. This suggests that lens implantation on the posterior surface of the iris might be associated with a higher risk of lens dislocation, when an inadequate amount of iris tissue is enclavated during implantation.

FIGURES IN THIS ARTICLE
<>
Copyright © 2018 by ASME
Topics: Lenses (Optics)
Your Session has timed out. Please sign back in to continue.

References

WHO, 2012, “Global Data on Visual Impairments 2010,” World Health Organization, Geneva, Switzerland.
Sparrow, J. , Taylor, H. , Qureshi, K. , Smith, R. , Birnie, K. , and Johnston, R. , 2012, “The Cataract National Dataset Electronic Multi-Centre Audit of 55 567 Operations: Risk Indicators for Monocular Visual Acuity Outcomes,” Eye, 26(6), p. 821. [CrossRef] [PubMed]
Hashemi, H. , Khabazkhoob, M. , Rezvan, F. , Etemad, K. , Gilasi, H. , Asgari, S. , Mahdavi, A. , Mohazzab-Torabi, S. , and Fotouhi, A. , 2016, “Complications of Cataract Surgery in Iran: Trend From 2006 to 2010,” Ophthalmic Epidemiol., 23(1), pp. 46–52. [CrossRef] [PubMed]
Ang, G. S. , and Whyte, I. F. , 2006, “Effect and Outcomes of Posterior Capsule Rupture in a District General Hospital Setting,” J. Cataract Refractive Surg., 32(4), pp. 623–627. [CrossRef]
Forlini, M. , Soliman, W. , Bratu, A. , Rossini, P. , Cavallini, G. M. , and Forlini, C. , 2015, “Long-Term Follow-Up of Retropupillary Iris-Claw Intraocular Lens Implantation: A Retrospective Analysis,” BMC Ophthalmol., 15(1), p. 143. [CrossRef] [PubMed]
Gonnermann, J. , Klamann, M. K. , Maier, A.-K. , Rjasanow, J. , Joussen, A. M. , Bertelmann, E. , Rieck, P. W. , and Torun, N. , 2012, “Visual Outcome and Complications After Posterior Iris-Claw Aphakic Intraocular Lens Implantation,” J. Cataract Refractive Surg., 38(12), pp. 2139–2143. [CrossRef]
Rüfer, F. , Saeger, M. , Nölle, B. , and Roider, J. , 2009, “Implantation of Retropupillar Iris Claw Lenses With and Without Combined Penetrating Keratoplasty,” Graefe's Arch. Clin. Exp. Ophthalmol., 247(4), p. 457. [CrossRef]
Gonnermann, J. , Torun, N. , Klamann, M. K. , Maier, A.-K. B. , Sonnleithner, C. V. , Joussen, A. M. , Rieck, P. W. , and Bertelmann, E. , 2013, “Visual Outcomes and Complications Following Posterior Iris-Claw Aphakic Intraocular Lens Implantation Combined With Penetrating Keratoplasty,” Graefe's Arch. Clin. Exp. Ophthalmol., 251(4), pp. 1151–1156. [CrossRef]
Hazar, L. , Kara, N. , Bozkurt, E. , Ozgurhan, E. B. , and Demirok, A. , 2013, “Intraocular Lens Implantation Procedures in Aphakic Eyes With Insufficient Capsular Support Associated With Previous Cataract Surgery,” J. Refractive Surg., 29(10), pp. 685–691. [CrossRef]
Schallenberg, M. , Dekowski, D. , Hahn, A. , Laube, T. , Steuhl, K.-P. , and Meller, D. , 2014, “Aphakia Correction With Retropupillary Fixated Iris-Claw Lens (Artisan)–Long-Term Results,” Clin. Ophthalmol., 8, pp. 137–141. [PubMed]
De Silva, S. R. , Arun, K. , Anandan, M. , Glover, N. , Patel, C. K. , and Rosen, P. , 2011, “Iris-Claw Intraocular Lenses to Correct Aphakia in the Absence of Capsule Support,” J. Cataract Refractive Surg., 37(9), pp. 1667–1672. [CrossRef]
Farrahi, F. , Feghhi, M. , Haghi, F. , Kasiri, A. , Afkari, A. , and Latifi, M. , 2012, “Iris Claw Versus Scleral Fixation Intraocular Lens Implantation During Pars Plana Vitrectomy,” J. Ophthalmic Vision Res., 7(2), p. 118. https://www.ncbi.nlm.nih.gov/m/pubmed/23275819/
Dyson, R. , Fitt, A. J. , Jensen, O. E. , Mottram, N. , Miroshnychenko, D. , Naire, S. , Ocone, R. , Siggers, J. H. , and Smithbecker, A. , 2004, “Post Re-Attachment Retinal Re-Detachment,” Fourth Medical Study Group, University of Strathclyde, Glasgow, Scotland, pp. 1–30.
Repetto, R. , Stocchino, A. , and Cafferata, C. , 2005, “Experimental Investigation of Vitreous Humour Motion Within a Human Eye Model,” Phys. Med. Biol., 50(19), pp. 4729–4743. [CrossRef] [PubMed]
Repetto, R. , Pralits, J. O. , Siggers, J. H. , and Soleri, P. , 2015, “Phakic Iris-Fixated Intraocular Lens Placement in the Anterior Chamber: Effects on Aqueous Flowphakic Iris-Fixated Intraocular Lens Placement,” Invest. Ophthalmol. Visual Sci., 56(5), pp. 3061–3068. [CrossRef]
Kapnisis, K. , Van Doormaal, M. , and Ethier, C. R. , 2009, “Modeling Aqueous Humor Collection From the Human Eye,” J. Biomech., 42(15), pp. 2454–2457. [CrossRef] [PubMed]
Hong, A. R. , Sheybani, A. , and Huang, A. J. , 2015, “Intraoperative Management of Posterior Capsular Rupture,” Curr. Opin. Ophthalmol., 26(1), pp. 16–21. [CrossRef] [PubMed]
Stocchino, A. , Repetto, R. , and Cafferata, C. , 2007, “Eye Rotation Induced Dynamics of a Newtonian Fluid Within the Vitreous Cavity: The Effect of the Chamber Shape,” Phys. Med. Biol., 52(7), pp. 2021–2034. [CrossRef] [PubMed]
Repetto, R. , Siggers, J. , and Stocchino, A. , 2010, “Mathematical Model of Flow in the Vitreous Humor Induced by Saccadic Eye Rotations: Effect of Geometry,” Biomech. Model. Mechanobiol., 9(1), pp. 65–76. [CrossRef] [PubMed]
Abouali, O. , Modareszadeh, A. , Ghaffariyeh, A. , and Tu, J. , 2012, “Numerical Simulation of the Fluid Dynamics in Vitreous Cavity Due to Saccadic Eye Movement,” Med. Eng. Phys., 34(6), pp. 681–692. [CrossRef] [PubMed]
Modarreszadeh, A. , and Abouali, O. , 2014, “Numerical Simulation for Unsteady Motions of the Human Vitreous Humor as a Viscoelastic Substance in Linear and Non-Linear Regimes,” J. Non-Newtonian Fluid Mech., 204, pp. 22–31. [CrossRef]
Worgul, B. V. , 1991, The Edward S Harkness Eye Institute Resident's Basic Science Study Guide, Columbia University Press, New York.
Woo, S. L. , Kobayashi, A. , Lawrence, C. , and Schlegel, W. , 1972, “Mathematical Model of the Corneo-Scleral Shell as Applied to Intraocular Pressure-Volume Relations and Applanation Tonometry,” Ann. Biomed. Eng., 1(1), pp. 87–98. [CrossRef] [PubMed]
Pavlin, C. J. , Harasiewicz, K. , and Foster, F. S. , 1992, “Ultrasound Biomicroscopy of Anterior Segment Structures in Normal and Glaucomatous Eyes,” Am. J. Ophthalmol., 113(4), pp. 381–389. [CrossRef] [PubMed]
Gesell, T. F. , Hopewell, J. W. , Lantz, M. W. , Osborne, J. W. , Scott, B. R. , Seltzer, S. M. , Shore, R. E. , and Worgul, B. V. , 1999, “Biological Effects and Exposure Limits For “Hot Particles”,” National Council on Radiation Protection and Measurements, Bethesda, MD, NCRP Report No. 130.
Beswick, J. A. , and McCulloch, C. , 1956, “Effect of Hyaluronidase on the Viscosity of the Aqueous Humour,” Br. J. Ophthalmol., 40(9), pp. 545–548. [CrossRef] [PubMed]
Becker, W. , 1989, “Metrics,” The Neurobiology of Saccadic Eye Movements, R. Wurtz and M. Goldberg , eds., Amsterdam, The Netherlands.
Abouali, O. , Modareszadeh, A. , Ghaffarieh, A. , and Tu, J. , 2012, “Investigation of Saccadic Eye Movement Effects on the Fluid Dynamic in the Anterior Chamber,” ASME J. Biomech. Eng., 134(2), p. 021002. [CrossRef]

Figures

Grahic Jump Location
Fig. 1

(a) Different views of the Artisan Aphakia lens. (b) Cross section of the AC with the IFIOL implanted on the anterior surface of the iris. (c) Cross section of the VC with the IFIOL implanted on the posterior surface of the iris. Note that, for graphical reasons, the anterior and vitreous chambers have been moved apart.

Grahic Jump Location
Fig. 2

Cross section of the VC. The values of all parameters are given in Table 1.

Grahic Jump Location
Fig. 3

Angular velocity ω(t) (solid lines, left vertical axis) and angular acceleration α(t) (dashed-dotted lines, right vertical axis) of saccadic rotations of 10 deg, 20 deg, and 30 deg versus time [14]

Grahic Jump Location
Fig. 4

Validation of the numerical model. Motion of a viscous fluid within a rigid sphere performing a saccadic rotation. Radial profile of the normalized maximum azimuthal velocity uϕ,max. The radial coordinate r is normalized with the sphere radius R. The present numerical findings are compared with the experimental and analytical results of Repetto et al. [14] and with the numerical results of Abouali et al. [28]. We reproduced the conditions of experiment sac-11 in Ref. [14], R = 0.012 m, A = 40 deg, and ν = 1.4 × 10−4 m2/s.

Grahic Jump Location
Fig. 5

Maps of the pressure (left) and velocity magnitude (right) in the AC at different times. Saccade with an amplitude of 10 deg. Pressure in Pa and velocity in m/s.

Grahic Jump Location
Fig. 6

Various components of the force of the IFIOL on the iris versus time. Left columns: x-component and right column: y-component of the force. Each line corresponds to a Saccade with different amplitudes. The IFIOL is placed on the anterior surface of the iris. Vertical lines mark the time at which saccades end.

Grahic Jump Location
Fig. 7

Maps of the pressure (left) and velocity magnitude (right) in the VC at different times. Saccade with an amplitude of 10 deg. Pressure in Pa and velocity in m/s.

Grahic Jump Location
Fig. 8

Map of the velocity magnitude and streamlines in the anterior part of the VC. t = 0.05 s, saccade amplitude equal to 10 deg.

Grahic Jump Location
Fig. 9

Various components of the force of the IFIOL on the iris versus time. Left column: x-component and right column: y-component of the force. Each line corresponds to a Saccade with different amplitudes. The IFIOL is placed on the posterior surface of the iris. Vertical lines mark the time at which saccades end.

Grahic Jump Location
Fig. 10

Total force of the IFIOL on the iris, for the cases of anterior and posterior positioning, versus time. Left column: x-component and right column: y-component of the force. From the top to the bottom, 10 deg, 20 deg, and 30 deg, respectively.

Grahic Jump Location
Fig. 11

Maximum force in the x (left) and y (right) directions as a function of the saccade amplitude. For the x-component of the force, we consider the maximum of the absolute value of Ftotalx; for the y direction, we consider the maximum positive value for the dashed-dotted line and the maximum negative value for the solid line.

Tables

Errata

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In