Abstract
Corneal ectasia comprises keratoconus, keratoglobus, pellucid marginal degeneration,
and iatrogenic keratectasia. In all forms of corneal ectasia, there is a thinning
of the cornea, usually accompanied by steepening of the cornea, leading to irregular
astigmatism. Here, we provide an overview of histopathologic alterations of the various
corneal ectasias. Furthermore, histologic changes after surgical procedures that are
performed in severe cases of corneal ectasia, such as corneal cross-linking and penetrating
keratoplasty (pKPL), as well as refractive surgical procedures that may lead to postsurgical
ectasia are presented. In addition to a literature review, histopathologic archival
material was reviewed and examined to illustrate the specific histologic changes.
Key words
keratoconus - cross-linking - keratoplasty - post-LASIK ectasia - PMD
