Biomechanical Effects of Two Forms of PGF2α on Ex-vivo Rabbit Cornea

ABSTRACT

Purpose

To investigate the biomechanical effects of two synthetic prostaglandin F2α analogues (PGF2α), namely Travoprost and Tafluprost, on the ex-vivo rabbit cornea.

Materials and Methods

Ninety-six eyes of 48 Japanese white rabbits were divided into 3 equal groups randomly; the Travoprost treated group (Tra), the Tafluprost treated group (Taf) and the control group (Co). Eyes in Tra and Taf groups were preserved in storage medium for 10 days with 1:10 Travoprost and Tafluprost diluents, respectively; while the Co eyes were preserved in a similar but PGF2α-free medium. Twenty-four corneas of each group were tested under inflation conditions with up to 30 mmHg posterior pressure. The pressure-deformation data obtained experimentally were used in an inverse analysis process to derive the stress-strain behavior of the tissue, using which the tangent modulus, a direct measure of the tissue’s material stiffness, was calculated. The remaining eight specimens of each group were analyzed using electron microscopy for fibril diameter and interfibrillar spacing.

Results

Although the central corneal thickness increased significantly in the three groups after storage (p < .01), it was similar in all groups both before (p = .598) and after storage (p = .181). After treatment with Travoprost and Tafluprost, the corneas exhibited lower tangent modulus (by 29.2% and 29.8%, respectively, at 6 kPa stress) and larger stromal interfibril spacing (by 21.9% and 23.6%) compared with the control group. There was no significant change in fibril diameter with either Travoprost or Tafluprost treatment (p = .769).

Conclusions

The results demonstrated significant reductions in tangent modulus and increases in interfibrillar spacing, which were of similar magnitudes, with the application of two different forms of PGF2α.

KEYWORDS:

• Prostaglandin
• cornea
• biomechanics
• stromal fibril
• inverse analysis

Disclosure statement

The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.

Contributors

All authors have read and agree to the published version of the manuscript. Conceptualization, J.W. (Junjie Wang) and F.B.; methodology, R.Z., and A.Y.; software, X.Z. and A.E.; validation, R.Z. and Y.Z.; formal analysis, R.Z. and F.B.; investigation, Y.W.; data curation, X.Z., L.G. and J.W. (Jie Wu); writing – original draft, R.Z. and F.B.; writing – review & editing, J.W. (JunJie Wang), F.B. and A.E.; supervision, J.W. (JunJie Wang), F.B. and A.E.; funding acquisition, X.Z., J.W. (JunJie Wang) and F.B.

Additional information

Funding

This study was supported by the Zhejiang Provincial Natural Science Foundation of China under Grant (LY20H120001, LQ20A020008), the National Natural Science Foundation of China (31771020), the Projects of Medical and Health Technology Development Program in Zhejiang Province (2019RC056, 2018KY541, 2016ZHB012), the Science and Technology Plan Project of Wenzhou Science and Technology Bureau (Y20180172, Y20170198, Y20170792) and the General Projects of Department of Education of Zhejiang Province (Y201839651).