Investigating the Tolerance of Corneal Endothelial Cells to Surgical Fluid Pressure Using Intact Porcine Eyes

It remains unclear if fluid pressures used during cataract surgeries contribute to iatrogenic corneal endothelial cell (CEC) loss.

A custom experimental platform was used to pressurize the anterior chamber of explanted porcine eyes to surgical fluid pressures of 60 mm Hg or 400 mm Hg for 5 minutes or 60 mm Hg for 45 minutes (n = 8 or 9 per group). The corneal endothelia were stained with a unique combination of nucleic acid viability dyes and were imaged using fluorescence microscopy without removing the cornea from the globe. The images were analyzed using custom code to quantify acute CEC loss as a percentage of CEC injury/death (PCI). The PCI values from the surgical pressure groups were compared to sham controls perfused to physiological pressures for each surgical duration. As a positive control, a group of eyes (n = 8) was perfused with deionized water to intentionally induce CEC injury/death.

No significant differences were observed in mean PCI values between any of the surgical fluid pressure groups and sham control groups, at either duration. The mean PCI of the positive control group was significantly different from all other groups, indicating that the method is able to detect CEC injury/death.

Our results suggest that the magnitudes of fluid pressure used over the duration of a cataract surgery do not significantly contribute to acute iatrogenic CEC loss.

Not only do the findings of this study answer a longstanding clinical question related to cataract surgery, but the platform introduced will facilitate testing how new cataract surgery devices and techniques affect CEC viability.