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Engineering a Light-Attenuating Artificial Iris. Invest Ophthalmol Vis Sci 2016 Apr 01;57(4):2195-202

Date

04/27/2016

Pubmed ID

27116547

Pubmed Central ID

PMC4849870

DOI

10.1167/iovs.15-17310

Scopus ID

2-s2.0-84964770541   3 Citations

Abstract

PURPOSE: Discomfort from light exposure leads to photophobia, glare, and poor vision in patients with congenital or trauma-induced iris damage. Commercial artificial iris lenses are static in nature to provide aesthetics without restoring the natural iris's dynamic response to light. A new photo-responsive artificial iris was therefore developed using a photochromic material with self-adaptive light transmission properties and encased in a transparent biocompatible polymer matrix.

METHODS: The implantable artificial iris was designed and engineered using Photopia, a class of photo-responsive materials (termed naphthopyrans) embedded in polyethylene. Photopia was reshaped into annular disks that were spin-coated with polydimethylsiloxane (PDMS) to form our artificial iris lens of controlled thickness.

RESULTS: Activated by UV and blue light in approximately 5 seconds with complete reversal in less than 1 minute, the artificial iris demonstrates graded attenuation of up to 40% of visible and 60% of UV light. There optical characteristics are suitable to reversibly regulate the incident light intensity. In vitro cell culture experiments showed up to 60% cell death within 10 days of exposure to Photopia, but no significant cell death observed when cultured with the artificial iris with protective encapsulation. Nuclear magnetic resonance spectroscopy confirmed these results as there was no apparent leakage of potentially toxic photochromic material from the ophthalmic device.

CONCLUSIONS: Our artificial iris lens mimics the functionality of the natural iris by attenuating light intensity entering the eye with its rapid reversible change in opacity and thus potentially providing an improved treatment option for patients with iris damage.

Author List

Shareef FJ, Sun S, Kotecha M, Kassem I, Azar D, Cho M

Author

Iris S. Kassem MD, PhD Associate Professor in the Ophthalmology and Visual Sciences department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Artificial Organs
Biomedical Engineering
Cells, Cultured
Cornea
Humans
Iris
Light
Magnetic Resonance Spectroscopy
Optics and Photonics
Ultraviolet Rays