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Long‐term biomechanical properties after collagen crosslinking of sclera using glyceraldehyde
Author(s) -
Wollensak Gregor,
Iomdina Elena
Publication year - 2008
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2007.01156.x
Subject(s) - sclera , medicine , biomaterial , ophthalmology , surgery , biomedical engineering
. Purpose: Chemical crosslinking by glyceraldehyde has been shown to increase significantly the biomechanical rigidity of sclera. It might therefore become an option for a sclera‐based treatment of progressive myopia. The present pilot study was designed to test the long‐term biomechanical efficiency of the new crosslinking method. Methods: Six Chinchilla rabbits were treated with sequential sub‐Tenon’s injections of 0.15 ml 0.5 m glyceraldehyde, which were given in the supero‐nasal quadrant of the right eye (OD) five times over 14 days. The rabbits were killed 4 months and 8 months after crosslinking treatment, respectively. Biomechanical stress–strain measurements of scleral strips from the treatment area were performed and compared to non‐treated contralateral control sclera using a microcomputer‐controlled biomaterial testing device. In addition, the eyes were examined histologically by light microscopy to evaluate possible side‐effects. Results: Following the crosslinking treatment, the ultimate stress was 10.2 ± 2.3 MPa after 4 months and 8.5 ± 2.2 MPa after 8 months versus 2.4 ± 0.3 MPa in the controls (increases of 325% and 254.17%, respectively); Young’s modulus was 104.6 ± 13.7 MPa after 4 months and 53.2 ± 5.2 MPa after 8 months versus 9.6 ± 1.3 MPa in the controls (increases of 989.6% and 554.17%, respectively); and ultimate strain was 15.8 ± 1.5% after 4 months and 24.1 ± 0.7% after 8 months versus 38.4 ± 4.6% in the controls (decreases of 58.84% and 37.24%, respectively). Histologically, no side‐effects were found. Conclusion: Our new method of scleral collagen crosslinking proved very efficient in increasing scleral biomechanical strength over a period of up to 8 months. Glyceraldehyde can be applied easily by sequential parabulbar injections. Before clinical application in myopic patients, a study in an animal myopia model is recommended.