Purpose:
To examine the tensile strength of rabbit sclera after cross-linking with glyceraldehyde in various concentrations and temperature.
Methods:
Equatorial rabbit sclera was dissected into 5mmx4mm longitudinal strips and incubated in normal saline (control), 0.01%, 0.1% and 0.5% glyceraldehyde at 4°C for 1, 24 and 72hours. This was repeated for normal saline (control) and 0.5% glyceraldehyde at 37°C for 24, 48 and 72hours. Maximum load, tensile stress and strain at maximum load, load, tensile stress and strain at break were tested with the Instron 5542A tester at extension rate of 1 mm/min and stress strain curve computed.
Results:
0.01% glyceraldehyde treated sclera showed increased tensile strength versus other concentrations and close to control at 4°C (Figure 1) at all durations. At 37°C, treated sclera had up to 6-fold higher tensile strength compared to control (Figure 2). Fig 1: Stress strain curve of rabbit sclera at 4°C at 24hours (specimen 1: control, specimens 2, 3, 4 treated with 0.01%, 0.1% and 0.5% glyceraldehyde). Fig 2: Stress strain curve of rabbit sclera at 37% at 48hours (Specimens 1, 2: controls, specimens 3, 4 treated with 0.5% glyceraldehyde).
Conclusions:
Glyceraldehyde-treated rabbit sclera showed increased tensile strength at 37°C compared to 4°C. 0.01% glyceraldehyde may be an optimal concentration for future studies on potential in control of myopia progression.
Keywords: sclera • refractive error development • myopia