Imaging pathology in archived cornea with Fuchs' endothelial corneal dystrophy including tissue reprocessing for...

Area of Science:

• Ophthalmology
• Corneal Science
• Microscopy

Background:

• Fuchs' endothelial corneal dystrophy (FECD) involves pathological changes in the posterior cornea, specifically guttae in Descemet's membrane.
• Archived corneal tissue is valuable for studying FECD, especially with emerging cell-based therapies that minimize tissue excision.
• Conventional processing of archived tissue yields low backscatter electron yield, making it unsuitable for advanced 3D imaging techniques like SBF SEM.

Purpose of the Study:

• To adapt archived human corneal tissue for high-resolution 3D imaging using serial block face scanning electron microscopy (SBF SEM).
• To overcome limitations of conventional processing that hinder imaging of aged specimens.

Main Methods:

• Utilized archived, conventionally processed full-thickness human corneal tissue from FECD patients.
• Applied de-plastination and additional contrasting agents (uranyl acetate, lead acetate) to epoxy resin-embedded specimens.
• Examined selected regions using SBF SEM with backscatter electron detection for 3D imaging.

Main Results:

• Developed a protocol to enhance contrast in conventionally processed archived corneal specimens for SBF SEM.
• Successfully achieved 3D reconstruction of corneal endothelium and guttae in Descemet's membrane.
• Demonstrated the utility of enhanced SBF SEM for visualizing pathological changes in large tissue volumes.

Conclusions:

• Modified SBF SEM imaging is effective for studying archived corneal tissue, overcoming previous limitations.
• This technique provides valuable 3D insights into the structural changes associated with FECD.
• The methodology can be applied to other aged or conventionally processed biological samples for advanced imaging.