Corneal ectatic disorders or corneal ectasia are a group of uncommon, noninflammatory,
eye disorders characterised by bilateral thinning of the central, paracentral, or peripheral
cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical ...
.
Types
*
Keratoconus, a progressive, noninflammatory, bilateral, asymmetric disease, characterized by paraxial stromal thinning and weakening that leads to corneal surface distortion.
*
Keratoglobus, a rare noninflammatory corneal thinning disorder, characterised by generalised thinning and globular protrusion of the cornea.
*
Pellucid marginal degeneration, a bilateral, noninflammatory disorder, characterized by a peripheral band of thinning of the inferior cornea.
*Posterior keratoconus, a rare condition, usually congenital, which causes a nonprogressive thinning of the inner surface of the cornea, while the curvature of the anterior surface remains normal. Usually only a single eye is affected.
*
Post-LASIK ectasia, a complication of
LASIK
LASIK or Lasik (''laser-assisted in situ keratomileusis''), commonly referred to as laser eye surgery or laser vision correction, is a type of refractive surgery for the correction of myopia, hyperopia, and an actual cure for astigmatism, sinc ...
eye surgery.
*
Terrien's marginal degeneration, a painless, noninflammatory, unilateral or asymmetrically bilateral, slowly progressive thinning of the peripheral
corneal stroma
The stroma of the cornea (or substantia propria) is a fibrous, tough, unyielding, perfectly transparent and the thickest layer of the cornea of the eye. It is between Bowman's membrane anteriorly, and Descemet's membrane posteriorly.
At its cent ...
.
Diagnosis
Usually diagnosed clinically by several clinical tests. Although some investigations might needed for confirming the diagnosis and to differentiate different types of corneal ectatic diseases.
*Corneal topography
*Corneal tomography
Treatment
Treatment options include
contact lenses
Contact lenses, or simply contacts, are thin lenses placed directly on the surface of the eyes. Contact lenses are ocular prosthetic devices used by over 150 million people worldwide, and they can be worn to correct vision or for cosmeti ...
and
intrastromal corneal ring segments for correcting
refractive errors
Refractive error, also known as refraction error, is a problem with focusing light accurately on the retina due to the shape of the eye and or cornea. The most common types of refractive error are near-sightedness, far-sightedness, astigmatism, ...
caused by irregular corneal surface,
corneal collagen cross-linking to strengthen a weak and ectatic cornea,
or
corneal transplant for advanced cases.
References
External links
International Journal of Keratoconus and Ectatic Corneal Diseases
{{Eye pathology, globe
Disorders of sclera and cornea
Eye diseases