Lamellar changes in the keratoconic cornea

Area of Science:

• Ophthalmology
• Histology
• Biomedical Engineering

Background:

• Keratoconus is a progressive thinning disorder of the cornea.
• Understanding its ultrastructural basis is crucial for developing effective treatments.

Purpose of the Study:

• To identify ultrastructural changes in keratoconus.
• To correlate lamellar count with corneal thinning in keratoconus.

Main Methods:

• Transmission electron microscopy was used on human corneal buttons.
• Lamellar counts were performed in anterior-posterior orientation.
• Digital montages were created for detailed analysis.

Main Results:

• Keratoconic corneas exhibited lamellar splitting and loss of anterior lamellae.
• Stromal thickness was reduced in keratoconus (372 ± 62 μm) vs. normal corneas (446 ± 89 μm).
• Lamellar density differed significantly between anterior and posterior stroma in keratoconus.

Conclusions:

• Lamellar splitting and anterior lamellar loss are key ultrastructural changes in keratoconus.
• These changes, along with pressure gradients, may explain central corneal thinning.
• Morphometric analysis provides a basis for understanding keratoconus progression.