title: Ghost-image analysis in phakic intraocular lenses with central hole as a potential cause of dysphotopsia.
abstract: OBJECTIVE
  To analyse the optical effect of an artificial hole in the optic centre of posterior chamber phakic intraocular lenses.
  
  
  METHODS
  Institute of Experimental Ophthalmology, Saarland University, Homburg/Saar, Germany.
  
  
  METHODS
  Experimental simulation study.
  
  
  METHODS
  Four eye models with an ametropia of -4 D, -8 D, +4 D, and +8 D were created in the ray tracing software ASAP. Refractive correction of these models was implemented with a model of an Implantable Collamer Lens (ICL). Each eye was set up twice with 1 eye receiving a conventional ICL without a central hole and the second an ICL with a central hole. Ray bundles were traced for lateral visual field angles from 0 to 60 degrees in steps of 1 degree. Ray propagation and retinal illumination were then compared between the 2 ICL models.
  
  
  RESULTS
  All eye models showed ghost images originating from the anterior surface of the ICL. Eye models with the ICL with central hole showed additional light spots in the peripheral areas of the retina originating from reflections at the cylindrical wall of the central hole in the ICL. The average intensity of ghost images in the temporal retinal hemisphere was between 30 and 40 dB less than the maximum intensity of the primary image.
  
  
  CONCLUSIONS
  A central hole within a posterior chamber phakic intraocular lens may cause stray light and ghost images (positive dysphotopsia) although the on-axis visual quality of the eye with the ICL is mostly unaffected.
  
  
  BACKGROUND
  The authors have no financial interest in any of the material presented in this paper.
authors.affiliation: From the Institute of Experimental Ophthalmology (Eppig, Langenbucher), Saarland University, Homburg/Saar, Germany; Department of Ophthalmology (Spira, Tsintarakis, El-Husseiny, Müller, Seitz), Saarland University Medical Center, Homburg/Saar, Germany; Department of Physical Sciences (Cayless), Open University, Milton Keynes, Buckinghamshire, United Kingdom. Electronic address: timo.eppig@uks.eu.
authors.forename: Timo
authors.initials: T
authors.lastname: Eppig
authors.affiliation: From the Institute of Experimental Ophthalmology (Eppig, Langenbucher), Saarland University, Homburg/Saar, Germany; Department of Ophthalmology (Spira, Tsintarakis, El-Husseiny, Müller, Seitz), Saarland University Medical Center, Homburg/Saar, Germany; Department of Physical Sciences (Cayless), Open University, Milton Keynes, Buckinghamshire, United Kingdom.
authors.forename: Corinna
authors.initials: C
authors.lastname: Spira
authors.affiliation: From the Institute of Experimental Ophthalmology (Eppig, Langenbucher), Saarland University, Homburg/Saar, Germany; Department of Ophthalmology (Spira, Tsintarakis, El-Husseiny, Müller, Seitz), Saarland University Medical Center, Homburg/Saar, Germany; Department of Physical Sciences (Cayless), Open University, Milton Keynes, Buckinghamshire, United Kingdom.
authors.forename: Themistoklis
authors.initials: T
authors.lastname: Tsintarakis
authors.affiliation: From the Institute of Experimental Ophthalmology (Eppig, Langenbucher), Saarland University, Homburg/Saar, Germany; Department of Ophthalmology (Spira, Tsintarakis, El-Husseiny, Müller, Seitz), Saarland University Medical Center, Homburg/Saar, Germany; Department of Physical Sciences (Cayless), Open University, Milton Keynes, Buckinghamshire, United Kingdom.
authors.forename: Moatasem
authors.initials: M
authors.lastname: El-Husseiny
authors.affiliation: From the Institute of Experimental Ophthalmology (Eppig, Langenbucher), Saarland University, Homburg/Saar, Germany; Department of Ophthalmology (Spira, Tsintarakis, El-Husseiny, Müller, Seitz), Saarland University Medical Center, Homburg/Saar, Germany; Department of Physical Sciences (Cayless), Open University, Milton Keynes, Buckinghamshire, United Kingdom.
authors.forename: Alan
authors.initials: A
authors.lastname: Cayless
authors.affiliation: From the Institute of Experimental Ophthalmology (Eppig, Langenbucher), Saarland University, Homburg/Saar, Germany; Department of Ophthalmology (Spira, Tsintarakis, El-Husseiny, Müller, Seitz), Saarland University Medical Center, Homburg/Saar, Germany; Department of Physical Sciences (Cayless), Open University, Milton Keynes, Buckinghamshire, United Kingdom.
authors.forename: Marc
authors.initials: M
authors.lastname: Müller
authors.affiliation: From the Institute of Experimental Ophthalmology (Eppig, Langenbucher), Saarland University, Homburg/Saar, Germany; Department of Ophthalmology (Spira, Tsintarakis, El-Husseiny, Müller, Seitz), Saarland University Medical Center, Homburg/Saar, Germany; Department of Physical Sciences (Cayless), Open University, Milton Keynes, Buckinghamshire, United Kingdom.
authors.forename: Berthold
authors.initials: B
authors.lastname: Seitz
authors.affiliation: From the Institute of Experimental Ophthalmology (Eppig, Langenbucher), Saarland University, Homburg/Saar, Germany; Department of Ophthalmology (Spira, Tsintarakis, El-Husseiny, Müller, Seitz), Saarland University Medical Center, Homburg/Saar, Germany; Department of Physical Sciences (Cayless), Open University, Milton Keynes, Buckinghamshire, United Kingdom.
authors.forename: Achim
authors.initials: A
authors.lastname: Langenbucher
mesh_terms: D016477:Artifacts; D006801:Humans; D006956:Hyperopia / Q000601:surgery*; D019654:Lens Implantation, Intraocular; D008027:Light; D008962:Models, Theoretical; D009216:Myopia / Q000601:surgery*; D054120:Phakic Intraocular Lenses / Q000009:adverse effects*; D012029:Refraction, Ocular; D012542:Scattering, Radiation; D014786:Vision Disorders / Q000209:etiology*; D014792:Visual Acuity