Viscoelastic protection from endothelial damage by air bubbles

Area of Science:

• Ophthalmology
• Surgical Innovation
• Biomaterials Science

Background:

• The corneal endothelium is vulnerable to damage from air bubbles during ophthalmic surgery.
• Viscoelastic materials are commonly used to protect ocular tissues during procedures like phacoemulsification.
• Understanding the protective mechanisms of different viscoelastic agents is crucial for preventing intraocular complications.

Purpose of the Study:

• To evaluate the efficacy of various viscoelastic materials in protecting the corneal endothelium from air bubble-induced damage.
• To compare the protective effects of Healon, Healon GV, and Viscoat during phacoemulsification and irrigation/aspiration procedures.

Main Methods:

• Standardized phacoemulsification and irrigation/aspiration (I/A) procedures were performed on human eye-bank and rabbit eyes.
• Viscoelastic materials (Healon, Healon GV, Viscoat) were used with or without air bubble exposure.
• Endothelial integrity was assessed using F-actin staining, scanning electron microscopy (SEM), and transmission electron microscopy (TEM).

Main Results:

• Phacoemulsification without viscoelastic material, or with Healon/Healon GV, resulted in significant endothelial cell loss consistent with air bubble damage.
• Viscoat demonstrated effective protection, with intact endothelial cells observed after phacoemulsification.
• TEM analysis revealed a thinner mucinous layer on Viscoat-exposed endothelium after I/A, suggesting a potential interaction mechanism.

Conclusions:

• Viscoat provides superior protection to the corneal endothelium against air bubble damage compared to Healon and Healon GV.
• The protective effect of Viscoat is attributed to its function as a physical barrier.
• Viscoat's adherence and protective properties may be linked to its interaction with the endothelial mucinous layer.