Effect of HEPES buffer on corneal storage in MK medium

Area of Science:

• Ophthalmology
• Corneal Preservation
• Tissue Engineering

Background:

• Corneal storage media are crucial for maintaining tissue viability before transplantation.
• Understanding the impact of additives like HEPES buffer on corneal physiology is essential.

Purpose of the Study:

• To evaluate the effect of HEPES buffer in modified MK medium on rabbit corneal storage and endothelial function.
• To assess corneal swelling and endothelial permeability after storage and perfusion.

Main Methods:

• Rabbit corneas were stored for 7 days in MK medium with or without HEPES buffer and phenol red.
• Corneal thickness, endothelial permeability (inulin, dextran), and cell morphology were analyzed.
• In vitro perfusion studies using specular microscopy assessed corneal swelling rates with different buffer solutions.

Main Results:

• Corneas stored in modified MK medium with HEPES buffer showed increased thickness.
• Endothelial permeability and cell integrity remained similar between storage solutions.
• Perfusion with HEPES buffer significantly increased corneal swelling compared to controls.

Conclusions:

• HEPES buffer impairs corneal endothelial pumping function, leading to swelling during storage and perfusion.
• The adverse effects of HEPES buffer may be transient, but long-term consequences require further investigation.
• The use of HEPES buffer in corneal storage solutions warrants caution and continued research for penetrating keratoplasty.