Eyal Walter1, Ran Matlov Kormas2, Arie L Marcovich3,4, Yotam Lior5, Xiaomeng Sui6, Daniel Wagner6, Boris Knyazer1. 1. Department of Ophthalmology, Faculty of Health Sciences, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel. 2. Department of Ophthalmology, Faculty of Health Sciences, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel. ran_kormas@yahoo.com. 3. Department of Ophthalmology, Kaplan Medical Center, Rehovot, Israel. 4. Department of Plant and Environmental Sciences, The Weizmann Institute of Science, Rehovot, Israel. 5. Soroka Clinical Research Center, Soroka University Medical Center, Ben-Gurion University of the Negev, Beer-Sheva, Israel. 6. Department of Materials and Interfaces, The Weizmann Institute of Science, Rehovot, Israel.
Abstract
PURPOSE: To determine the effect of the hormones estrogen and progesterone on the biomechanical properties of porcine corneas. METHODS: Thirty fresh porcine corneas were acquired from an abattoir. The corneas were equally divided into three groups. Groups were incubated for 1 week in Eusol-C solution containing supra-physiologic concentrations of estrogen, progesterone, or control (no added hormone). After incubation, the central corneal thickness (CCT) of each cornea was measured using an electronic caliper, and then the corneas were cut into strips. The strips were then clamped in the pneumatic jaws of a computer-controlled biomaterial tester (Instron 4502, USA) and stretched at a constant rate of 1 mm/min until tissue rupture while constantly recording the stress and strain of the tissue. Stress-strain curves were plotted and Young's modulus was calculated for each corneal strip. RESULTS: Average corneal thickness was 873.5 ± 143.1 μm for the control group, 928.0 ± 97.7 μm for the estrogen group, and 922.0 ± 116.7 μm for the progesterone group (data presented as mean ± SD). There was no statistically significant difference between the groups regarding the CCT (p = 0.89). The average Young's modulus was 17.00 ± 3.46 MPa for the control group, 16.95 ± 6.83 MPa for the progesterone group, and 12.33 ± 3.24 MPa for the estrogen group. The difference between the control and estrogen groups was statistically significant (p = 0.018) while the difference between the control and progesterone groups was not (p = 0.72). CONCLUSION: Estrogen has a relaxing effect on the porcine cornea, resulting in reduced stiffness of the tissue. Progesterone has no significant effect on the biomechanical properties of porcine corneas. Estrogen and progesterone do not significantly affect CCT.
PURPOSE: To determine the effect of the hormones estrogen and progesterone on the biomechanical properties of porcine corneas. METHODS: Thirty fresh porcine corneas were acquired from an abattoir. The corneas were equally divided into three groups. Groups were incubated for 1 week in Eusol-C solution containing supra-physiologic concentrations of estrogen, progesterone, or control (no added hormone). After incubation, the central corneal thickness (CCT) of each cornea was measured using an electronic caliper, and then the corneas were cut into strips. The strips were then clamped in the pneumatic jaws of a computer-controlled biomaterial tester (Instron 4502, USA) and stretched at a constant rate of 1 mm/min until tissue rupture while constantly recording the stress and strain of the tissue. Stress-strain curves were plotted and Young's modulus was calculated for each corneal strip. RESULTS: Average corneal thickness was 873.5 ± 143.1 μm for the control group, 928.0 ± 97.7 μm for the estrogen group, and 922.0 ± 116.7 μm for the progesterone group (data presented as mean ± SD). There was no statistically significant difference between the groups regarding the CCT (p = 0.89). The average Young's modulus was 17.00 ± 3.46 MPa for the control group, 16.95 ± 6.83 MPa for the progesterone group, and 12.33 ± 3.24 MPa for the estrogen group. The difference between the control and estrogen groups was statistically significant (p = 0.018) while the difference between the control and progesterone groups was not (p = 0.72). CONCLUSION:Estrogen has a relaxing effect on the porcine cornea, resulting in reduced stiffness of the tissue. Progesterone has no significant effect on the biomechanical properties of porcine corneas. Estrogen and progesterone do not significantly affect CCT.
Authors: Arthur Hammer; Olivier Richoz; Samuel Arba Mosquera; David Tabibian; Florence Hoogewoud; Farhad Hafezi Journal: Invest Ophthalmol Vis Sci Date: 2014-05-02 Impact factor: 4.799
Authors: Paulina Escandon; Sarah E Nicholas; Rebecca L Cunningham; David A Murphy; Kamran M Riaz; Dimitrios Karamichos Journal: Int J Mol Sci Date: 2022-01-14 Impact factor: 5.923