Anatomical Considerations
Potentially Adverse Effects

Microcystic Edema (Punctate Staining)
Progressive corneal hypoxia can lead to the rupture of certain epithelial cell membranes which in turn can result in the formation of microcysts. Microcysts are the result of fluid which has accumulated in the spaces caused by the rupture of these cells. Microcystic edema is best seen utilizing a slit lamp with retro-illumination. Flourescein can also be used to outline intact microcysts and stain the punctate areas where microcysts have ruptured.

 

The illustration above depicts the gradation of contact-lens-induced corneal epithelial microcystic edema. Typically this edema is centrally located. The mycrocysts are frequently interspersed with punctate epithelial defects which result from microcyst rupture.