The surface coat on human corneal endothelium

Area of Science:

• Ophthalmology
• Cell Biology
• Biochemistry

Background:

• The posterior surface of the corneal endothelium plays a critical role in maintaining corneal clarity and function.
• Understanding the composition of structures on the endothelial surface is essential for diagnosing and treating corneal diseases.

Purpose of the Study:

• To investigate the presence and nature of a substance coating the posterior endothelial surface of human cadaver corneas.
• To characterize the chemical and structural elements of this coating material.

Main Methods:

• Scanning electron microscopy (SEM) was employed to visualize the corneal endothelium.
• Ruthenium red-osmium tetroxide staining was used to selectively bind to and highlight the coating material.
• Enzymatic digestion with urokinase and trypsin was performed to analyze the coating's composition.

Main Results:

• SEM revealed a distinct coating material selectively bound by ruthenium red-osmium tetroxide on the posterior endothelial surface.
• The coating was absent on autolyzed cells and denuded areas of Descemet's membrane.
• Partial digestion by urokinase and trypsin indicated the presence of at least three distinct structural or chemical elements within the coating.

Conclusions:

• A previously unidentified substance coats the posterior corneal endothelium.
• This coating material possesses a complex composition, likely involving multiple molecular components.
• Further research is warranted to elucidate the precise nature and function of this endothelial coating.