Interlamellar adhesive strength in human eyebank corneas

Area of Science:

• Ophthalmology
• Biomechanical Engineering
• Materials Science

Background:

• Interlamellar biomechanical properties of corneal stroma are largely uncharacterized.
• These properties are potentially significant for corneal wound healing and refractive surgery outcomes.
• Understanding stromal collagen lamellar adhesion is crucial for advancing ophthalmic procedures.

Purpose of the Study:

• To quantify the interlamellar adhesive strength of human corneal stroma.
• To investigate the relationship between corneal location (central vs. peripheral) and stromal adhesion.
• To elucidate the biomechanical factors contributing to corneal lamellar cohesion.

Main Methods:

• Measuring interlamellar adhesive strength using a tearing force test on human eyebank corneas.
• Analyzing lamellar separation patterns via histology at central and peripheral corneal sites.
• Correlating biomechanical measurements with observed collagen lamellar organization.

Main Results:

• Mean central corneal interlamellar adhesive strength was 14.2 g-wt/mm, suggesting proteoglycan bond dominance.
• Adhesive strength increased towards the corneal periphery, reaching approximately 28-32 g-wt/mm.
• Histology revealed smooth lamellar separation centrally and torn lamellae peripherally, indicating increased tensile contribution.

Conclusions:

• Corneal stromal interlamellar adhesion varies significantly from center to periphery.
• The peripheral cornea exhibits greater adhesive strength due to a more robust, obliquely oriented collagen network.
• Findings provide critical biomechanical data for understanding corneal integrity, wound healing, and surgical interventions.