New Trends in Quantitative Assessment of the Corneal Barrier Function

The cornea is a very particular tissue due to its transparency and its barrier function as it has to resist against the daily insults of the external environment. In addition, maintenance of this barrier function is of crucial importance to ensure a correct corneal homeostasis. Here, the corneal epithelial permeability has been assessed in vivo by means of non-invasive tetrapolar impedance measurements, taking advantage of the huge impact of the ion fluxes in the passive electrical properties of living tissues. This has been possible by using a flexible sensor based in SU-8 photoresist. In this work, a further analysis focused on the validation of the presented sensor is performed by monitoring the healing process of corneas that were previously wounded. The obtained impedance measurements have been compared with the damaged area observed in corneal fluorescein staining images. The successful results confirm the feasibility of this novel method, as it represents a more sensitive in vivo and non-invasive test to assess low alterations of the epithelial permeability. Then, it could be used as an excellent complement to the fluorescein staining image evaluation.

[1]  R. Villa,et al.  Flexible probe for in vivo quantification of corneal epithelium permeability through non-invasive tetrapolar impedance measurements , 2013, Biomedical Microdevices.

[2]  G. Gabriel,et al.  A non-invasive method for an in vivo assessment of corneal epithelium permeability through tetrapolar impedance measurements. , 2012, Biosensors & bioelectronics.

[3]  Kousaku Okubo,et al.  Characteristics of the Human Ocular Surface Epithelium , 2001, Progress in Retinal and Eye Research.

[4]  Yansui Li,et al.  Intracellular [Na+], Na+ pathways, and fluid transport in cultured bovine corneal endothelial cells. , 2004, Experimental eye research.

[5]  A Guimerà,et al.  Method and device for bio-impedance measurement with hard-tissue applications , 2008, Physiological measurement.

[6]  R. Villa,et al.  Non-invasive intraocular pressure monitoring with a contact lens engineered with a nanostructured polymeric sensing film , 2011 .

[7]  E. Calderón,et al.  Portable Device for Microelectrode Array Bio-impedance Measurements , 2009 .

[8]  Hitoshi Sasaki,et al.  Acute Corneal Epithelial Change after Instillation of Benzalkonium Chloride Evaluated Using a Newly Developed in vivo Corneal Transepithelial Electric Resistance Measurement Method , 2007, Ophthalmic Research.

[9]  Enrico Boldrini,et al.  Arabinogalactan as Active Compound in the Management of Corneal Wounds: In Vitro Toxicity and In Vivo Investigations on Rabbits , 2010, Current eye research.

[10]  Nuo Dong,et al.  Localization and Expression of Zonula Occludins-1 in the Rabbit Corneal Epithelium following Exposure to Benzalkonium Chloride , 2012, PloS one.

[11]  Rosa Villa,et al.  Portable 4 Wire Bioimpedance Meter with Bluetooth Link , 2009 .

[12]  S. P. Srinivas,et al.  Measurement of corneal epithelial permeability to fluorescein. A repeatability study. , 1997, Investigative ophthalmology & visual science.

[13]  G. Gabriel,et al.  Non-invasive assessment of corneal endothelial permeability by means of electrical impedance measurements. , 2010, Medical engineering & physics.

[14]  A Irimajiri,et al.  [Dielectric measurements on the rabbit cornea using a surface electrode]. , 1993, Nippon Ganka Gakkai zasshi.

[15]  H. Schwan,et al.  THE DIELECTRIC PROPERTIES OF THE BOVINE EYE LENS. , 1964, IEEE transactions on bio-medical engineering.

[16]  M Reim,et al.  [Measuring electrical impedance in normal and pathologic corneas]. , 1991, Fortschritte der Ophthalmologie : Zeitschrift der Deutschen Ophthalmologischen Gesellschaft.

[17]  H Ren,et al.  Corneal epithelial fluorescein staining. , 1995, Journal of the American Optometric Association.

[18]  Rosa Villa,et al.  Manufacturing and full characterization of silicon carbide-based multi-sensor micro-probes for biomedical applications , 2007, Microelectron. J..

[19]  Randall W. Smith,et al.  Modulation of tight junction properties relevant to fluid transport across rabbit corneal endothelium. , 2007, Experimental eye research.

[20]  André Mermoud,et al.  Wireless contact lens sensor for intraocular pressure monitoring: assessment on enucleated pig eyes , 2009, Acta ophthalmologica.

[21]  J Rosell,et al.  Electrical impedance tomography of the eye: in vitro measurements of the cornea and the lens. , 1996, Physiological measurement.

[22]  Hiroshi Sasaki,et al.  Quantitative evaluation of corneal epithelial injury caused by n-heptanol using a corneal resistance measuring device in vivo , 2012, Clinical ophthalmology.

[23]  J. McLaren,et al.  Clinical responses of the corneal endothelium. , 2004, Experimental eye research.