Abstract
Purpose :
Accurate characterisation of the physical properties of the retina is essential for understanding the effects of age, disease mechanisms and developing effective surgical interventions. Ex vivo measurements have been used to do this, however the effect of storage conditions on the results of these biomechanical tests are unclear. This study aimed to investigate the impact of commonly used laboratory storage media on the mechanical performance of retinal samples.
Methods :
Freshly enucleated porcine eyes were dissected to obtain 3x9mm superior vertical strips. Strips underwent incubation in one of the following storage media: porcine vitreous (control), phosphate-buffered saline (PBS), balanced salt solution (BSS) or Ringer’s solution, for 60 minutes at 4°C. The thickness of each strip was determined before and after incubation using light microscopy. Strips, four per group, were then subjected to uniaxial load-to-failure testing at ambient temperature in the same media in which they were incubated. Statistical analysis using a repeated measures T-test (thickness) or Kruskal–Wallis and Games-Howell tests (Maximum stress) was performed.
Results :
The mean maximum stress for the control (vitreous) was 5.1 kPa. It was higher for samples stored in BSS (7.4kPa, p=<0.05) but lower in Ringer’s solution (1.6kPa, p<0.001), and then PBS (0.4kPa, p<0.001). The mean thickness for samples incubated in PBS & Ringer’s increased by 49% (p= 0.0001) but did not increase for vitreous and BSS (p=0.9)
Conclusions :
The study revealed the biomechanical properties of porcine retina vary depending on storage media. BSS-incubated samples exhibited strength closest to the control samples. Therefore, it is critical to exercise caution when interpreting biomechanical changes in the retina and other soft tissues.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.