The ultrastructure of contact lens induced changes

Area of Science:

• Ophthalmology
• Corneal Science
• Contact Lens Research

Background:

• The corneal endothelium is crucial for maintaining corneal clarity and hydration.
• Soft contact lenses (SCLs) are widely used, necessitating an understanding of their ocular effects.
• Previous research has indicated potential impacts of SCL wear on the corneal endothelium.

Purpose of the Study:

• To investigate the morphological changes in the human corneal endothelium following wear of a thick, low water content soft contact lens.
• To correlate findings from specular microscopy and electron microscopy to understand SCL-induced endothelial alterations.

Main Methods:

• Human corneas (n=15) were examined using specular and electron microscopy after SCL wear.
• Five control corneas without lens wear were analyzed using identical methods.
• Morphological changes in endothelial cells and posterior surface were documented.

Main Results:

• SCL wear induced significant endothelial changes in 12 out of 15 corneas.
• Specular microscopy revealed increased cell separation and areas of reduced reflectivity (blebs).
• Electron microscopy showed endothelial cell edema, posterior surface bulging, and intracellular/intercellular vacuoles in severe cases.

Conclusions:

• Soft contact lens wear can cause transient, reversible changes in corneal endothelial morphology.
• Edema and alterations in the posterior endothelial surface contour are key findings.
• These changes are attributed to disturbances in the endothelial environment caused by SCL wear.