73 - Noninflammatory Ectatic Disorders

Abstract

Noninflammatory ectatic diseases of the cornea include keratoconus, post-keratorefractive corneal ectasia, pellucid marginal degeneration, keratoglobus, and posterior keratoconus. Corneal thinning is the common characteristic of these ectatic diseases. Thinning at the apex of corneal protrusion is the hallmark of keratoconus. In pellucid marginal degeneration, corneal protrusion is central to a peripheral band of corneal thinning. In keratoglobus, the cornea is diffusely steep and thin with maximum thinning in the periphery. Keratoconus, pellucid marginal degeneration, and keratoglobus share a basic treatment algorithm early in the course of disease. Visual correction begins with glasses followed by contact lens fitting. Patients with mild to moderate keratoconus may benefit from cornea crosslinking to help limit progression. Intrastromal ring insertion may improve contact lens tolerance and visual function. When the above treatments fail to achieve adequate visual function, deep anterior lamellar keratoplasty or penetrating keratoplasty has the potential to restore vision.