Use of 2% hydroxypropyl methylcellulose to prevent the corneal swelling during the in vitro mechanical characterization

Abstract

The aim of this study was to assess the use of 2% HPMC during in vitro uniaxial tensile tests, with corneal strips immediately obtained or after storing the eyes for 24 h in 0.9% NaCl solution at 4 ℃. The purpose was to establish a standardized procedure to prevent phenomena which can modify the mechanical properties of the tissue. Rabbit eyes were divided into four groups. Group A had seven eyes that were preserved in NaCl solution for 24 h before testing. Group B had seven eyes that were immediately tested. In both groups, to prevent both swelling and dehydration, 2% hydroxypropyl methylcellulose (2% HPMC) was applied. Group C had seven eyes that were preserved in NaCl solution for 24 h before testing. Group D had seven eyes that were immediately tested. In both groups, HPMC was not applied. Regarding the mechanical response, groups with HPMC showed similar Cauchy stress–stretch curves and there were no statistically significant differences at 5%, 10% and 15% strain between them, which mean that both showed similar mechanical behavior. The same result was obtained between groups without HPMC. However, for coupled groups with and without HPMC, statistically significant differences at 10% and 15% strain were observed. On the other hand, when grouped by storage time, statistically significant differences were found between groups that had eyes preserved for 24 h with and without HPMC, respectively, as well as between groups immediately tested with and without HPMC, respectively, at 15% strain. Nevertheless, if coupled groups were considered, between groups that were preserved for 24 h in NaCl before testing and groups that were immediately tested, no statistically significant differences were obtained. In addition, the Cauchy stress–stretch curves of groups without HPMC showed a decreasing slope of the linear part (strain > 8%) of the graph during the experiment. In summary, the use of HPMC during the handling of the tissue from excision to testing seems to prevent both swelling and dehydration.

Keywords

Rabbit cornea hydroxypropyl methylcellulose biomechanical properties storage

Get full access to this article

View all access options for this article.

References

Hatami-Marbini

. Hydration dependent viscoelastic tensile behaviour of cornea. Ann Biomed Eng 2014; 42: 1740–1748.

Kling

Marcos

. Effect of hydration state and storage media on corneal biomechanical response from in vitro inflation tests. J Refract Surg 2013; 29: 490–497.

Lanchares

Del Buey

Cristóbal

et al.

Biomechanical property analysis after corneal collagen cross-linking in relation to ultraviolet A irradiation time. Graefes Arch Clin Exp Ophthalmol 2011; 249: 1223–1227.

Wollensak

Spoerl

Seiler

. Stress-strain measurements of human and porcine corneas after riboflavin-ultraviolet-A-induced cross-linking. J Cataract Refract Surg 2003; 29: 1780–1785.

Hatami-Marbini

Rahimi

. Effects of bathing solution on tensile properties of the cornea. Exp Eye Res 2014; 120: 103–108.

Szaflik

Liberek

Brix

. Corneal storage methods. Transplant Proc 2000; 32: 1424–1425.

Komuro

Hodge

Gores

et al.

Cell death during corneal storage at 4 ℃. Invest Ophthalmol Vis Sci 1999; 40: 2827–2832.

Armitage

. Preservation of human cornea. Transfus Med Hemother 2011; 38: 143–147.

Hatami-Marbini

Etebu

. Hydration dependent biomechanical properties of the corneal stroma. Exp Eye Res 2013; 116: 47–54.

10.

Vetter

Brueckner

Tubic-Grozdanis

et al.

Modulation of central corneal thickness by various riboflavin eyedrop compositions in porcine corneas. J Cataract Refract Surg 2012; 38: 525–532.

11.

Elsheikh

Anderson

. Comparative study of corneal strip extensometry and inflation tests. J R Soc Interface 2005; 2: 177–185.

12.

Lari

Schultz

Wang

et al.

Scleral mechanics: comparing whole globe inflation and uniaxial testing. Exp Eye Res 2012; 94: 128–135.

13.

Versura

Maltarello

Stecher

et al.

Dry eye before and after therapy with hydroxypropyl methylcellulose. Ultrastructural and cytochemical study in 20 patients. Ophthalmologica 1987; 198: 152–162.

14.

Toda

Shinozali

Tsubota

. Hydroxypropyl methylcellulose for the treatment of severe dry eye associated with Sjögren’s syndrome. Cornea 1996; 15: 120–128.

15.

Bøggild-Madsen

Bundgarrd-Nielsen

Hammer

et al.

Comparison of eye protection with methylcellulose an paraffin ointments during general anaesthesia. Can Anaesth Soc J 1981; 28: 575–578.

16.

Storr-Paulsen

. Analysis of the short-term effect of two viscoelastic agents on the intraocular pressure after extracapsular cataract extraction. Sodium hyaluronate 1% vs hydroxypropyl methylcellulose 2%. Acta Ophthalmol (Copenh) 1993; 71: 173–176.

17.

Pedersen

. Comparison of the protective effects of methylcellulose and sodium hyaluronate on corneal swelling following phacoemulsification of senile cataracts. J Cataract Refract Surg 1990; 16: 594–596.

18.

Smith

Lindstrom

. 2% hydroxypropyl methylcellulose as a viscous surgical adjunct. A multicenter prospective randomized trial. J Cataract Refract Surg 1991; 17: 839–842.