An In Vitro Intact Globe Expansion Method for Evaluation of Cross-linking Treatments
Abstract
Purpose. To measure the tissue mechanical response to elevated intraocular pressure (IOP) using intact globe expansion of rabbit eyes. This method examined rabbit kit (2–3 weeks old) eyes as a model for weakened tissue and evaluated riboflavin/ UVA and glyceraldehyde cross-linking treatments. Methods. The ocular shape of enucleated eyes was photographed during a 24-hour period while a controlled IOP was imposed (either low IOP 22 mm Hg or high IOP 85 mm Hg). Untreated controls consisted of kit eyes tested at both low- and high IOP and adult eyes tested at high IOP. Treated kit eyes (dextran controls, riboflavin/UVA treatment of the cornea, and glyceraldehyde treatment of the entire globe) were tested at high IOP. Results. Low IOP elicited negligible creep of the sclera and very gradual creep of the cornea. In contrast, high IOP induced up to an 8% strain in the sclera and a 15% strain in the cornea of rabbit kit eyes. The expansion of adult eyes was less than one third that of kit eyes at the same, high IOP. Riboflavin/UVA treatment of corneas reduced expansion compared with that in both dextran-treated and untreated control corneas. Glyceraldehyde treatment prevented expansion of the cornea and sclera. Conclusions. The intact globe expansion method (GEM) imposes a loading geometry comparable to in vivo conditions and can quantify changes in mechanical stability as a function of testing conditions (e.g., IOP, tissue maturation, and therapeutic cross-linking) with small sample sizes and small variability. Rabbit kit eyes provide a model of weak tissue suitable for screening treatments that strengthen the cornea and sclera.
Additional Information
© 2010 Association for Research in Vision and Ophthalmology. Submitted for publication May 18, 2009; revised October 6, 2009; accepted December 15, 2009. Supported by That Man May See; National Institutes of Health Grant EY017484-01; the Jacobs Institute for Molecular Engineering for Medicine; and Caltech SURF (Summer Undergraduate Research Fellowship)Attached Files
Published - Mattson2010p10206Invest_Ophth_Vis_Sci.pdf
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Additional details
- PMCID
- PMC2891471
- Eprint ID
- 18616
- Resolver ID
- CaltechAUTHORS:20100609-094136042
- NIH
- EY017484-01
- Jacobs Institute for Molecular Engineering for Medicine
- Caltech Summer Undergraduate Research Fellowship (SURF)
- That Man May See Foundation
- Created
-
2010-07-01Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Jacobs Institute for Molecular Engineering for Medicine