Corneal ectatic disorders or corneal ectasia are a group of uncommon, noninflammatory,
eye disorders
This is a partial list of human eye diseases and disorders.
The World Health Organization (WHO) publishes a classification of known diseases and injuries, the International Statistical Classification of Diseases and Related Health Problems, or ...
characterised by bilateral thinning of the central, paracentral, or peripheral
cornea
The cornea is the transparency (optics), transparent front part of the eyeball which covers the Iris (anatomy), iris, pupil, and Anterior chamber of eyeball, anterior chamber. Along with the anterior chamber and Lens (anatomy), lens, the cornea ...
.
Types
*
Keratoconus
Keratoconus is an eye disorder in which the cornea, the transparent front part of the eye, gradually thins and bulges outward into a cone shape. This causes distorted vision, including blurry vision, double vision, increased nearsightedness, ...
, 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
Pellucid marginal degeneration (PMD) is a degenerative corneal condition, often confused with keratoconus. It typically presents with painless vision loss affecting both eyes. Rarely, it may cause acute vision loss with severe pain due to perfor ...
, 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 astigmatism. LASIK surgery is p ...
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 layer anteriorly, and Descemet's membrane posteriorly.
At its centre, ...
.
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 lens (optics), lenses placed directly on the surface of the Human eye, eyes. Contact lenses are ocular prosthetic devices used by over 150 million people worldwide, and they can be worn to correct ...
and
intrastromal corneal ring segments for correcting
refractive errors
Refractive error is a problem with focus (optics), focusing light accurately on the retina due to the shape of the eye and/or cornea. The most common types of refractive error are myopia, near-sightedness, hyperopia, far-sightedness, astigmatis ...
caused by irregular corneal surface,
corneal collagen cross-linking to strengthen a weak and ectatic cornea,
or
corneal transplant
Corneal transplantation, also known as corneal grafting, is a surgical procedure where a damaged or diseased cornea is replaced by Corneal button, donated corneal tissue (the graft). When the entire cornea is replaced it is known as penetrating ...
for advanced cases.
References
External links
International Journal of Keratoconus and Ectatic Corneal Diseases
{{Eye pathology, globe
Disorders of sclera and cornea
Eye diseases