June 2017
Volume 58, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2017
Mechanisms of corneal intraepithelial nerve damage after exposure to hyperosmolar solutions in rat.
Author Affiliations & Notes
  • Kamila Mizerska
    Department of Ophthalmology, Weill Cornell Medicine, New York, New York, United States
  • Valentina Dallacasagrande
    Department of Ophthalmology, Weill Cornell Medicine, New York, New York, United States
  • Harumitsu Hirata
    Department of Ophthalmology, Weill Cornell Medicine, New York, New York, United States
  • Carl F. Marfurt
    Indiana University School of Medicine, Gary, Indiana, United States
  • Mark Rosenblatt
    Department of Ophthalmology and Visual Sciences, University of Illinois , Chicago, Illinois, United States
  • Footnotes
    Commercial Relationships   Kamila Mizerska, None; Valentina Dallacasagrande, None; Harumitsu Hirata, None; Carl Marfurt, None; Mark Rosenblatt, None
  • Footnotes
    Support  NIH Grants EY023555 (HH), EY018594 (MIR), and the Research to Prevent Blindness Grants to Department of Ophthalmology, Weill Cornell Medical College
Investigative Ophthalmology & Visual Science June 2017, Vol.58, 799. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to Subscribers Only
      Sign In or Create an Account ×
    • Get Citation

      Kamila Mizerska, Valentina Dallacasagrande, Harumitsu Hirata, Carl F. Marfurt, Mark Rosenblatt; Mechanisms of corneal intraepithelial nerve damage after exposure to hyperosmolar solutions in rat.. Invest. Ophthalmol. Vis. Sci. 2017;58(8):799.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Our recent work has shown that exposure of the rat cornea to hyperosmolar solutions induces morphological alterations in corneal intraepithelial nerves. The mechanisms for these changes remain unknown. The purpose of this study was to investigate, using a novel nerve fragmentation quantification technique, possible neural and epithelial mechanisms underlying these changes.

Methods : Immunohistochemistry: The eyes of each rat were exposed to hyperosmolar solutions (HOS; 600 and 1000 mOsm NaCl) or artificial tears (ATs), respectively, for 30 min to 3 hours. Another group of animals was treated with 200 µM Nifedipine or 2% Lidocaine in 1000 mOsm NaCl. The morphology of the corneal epithelial innervation was evaluated by staining corneal whole mounts with an antibody against beta-III tubulin. Damage (fragmentation) of corneal intraepithelial nerves acquired from z-stack images of central corneal areas was assessed quantitatively and expressed as nerve fragments/sq mm. Corneal cross sections were stained for ZO-1 as a marker for epithelial tight junctions. Electrophysiology: Single corneal neurons were recorded extracellularly from rat trigeminal ganglia. The neuronal responses to corneal drying (an important stimulus for tearing) were noted before, and after, applying 200 µM Nifedipine or 2% Lidocaine in 1000 mOsm NaCl or ATs.

Results : Immunohistochemistry: The morphometric analyses indicated that corneal nerve damage appeared even after short (30 min) exposure to 600 mOsm NaCl (p<0.0001). Corneal nerve morphology was not changed after adding a Ca++ channel blocker to the 1000 mOsm NaCl solution. Corneal cross sections stained for ZO-1 appeared to reveal diminished immunostaining intensity in 1000 mOsm NaCl-treated animals compared to controls. Electrophysiology: The responses of corneal neurons to hyperosmolar solutions (1000 mOsm) were abolished by 200 µM Nifedipine or 2% Lidocaine.

Conclusions : The novel morphometric approach used in this study enables automated and accessible evaluation of corneal nerve damage caused by short term exposure to hyperosmolar solutions. These results demonstrate for the first time that corneal nerve damage due to hyperosmotic tears might be a result of a combination of different mechanisms (neurotoxicity and decreased tight junction protein expression). These findings may contribute to a better understanding of signs and symptoms observed in dry eye patients.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×