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 Keratoglobus (from Greek language, Greek: ''kerato-'' horn, cornea; and Latin: ''globus'' round) is a degenerative non-inflammation, inflammatory disorder of the human eye, eye in which structural changes within the cornea cause it to become extrem ...

, 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 Post-LASIK ectasia is a condition similar to keratoconus where the cornea starts to bulge forwards at a variable time after LASIK, PRK, or SMILE corneal laser eye surgery. However, the physiological processes of post-LASIK ectasia seem to be diffe ...

, 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 Terrien marginal degeneration is a noninflammatory, unilateral or asymmetrically bilateral, slowly progressive thinning of the peripheral corneal stroma. Cause The cause of Terrien marginal degeneration is unknown, its prevalence is roughly equal ...

, 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 An intrastromal corneal ring segment (ICRS) (also known as intrastromal corneal ring, corneal implant or corneal insert) is a small device surgically implanted in the cornea of the eye to correct vision. Two crescent or semi-circular shaped ring ...

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 Corneal cross-linking (CXL) with riboflavin (vitamin B2) and UV-A light is a surgical treatment for corneal ectasia such as keratoconus, PMD, and post-LASIK ectasia. It is used in an attempt to make the cornea stronger. According to a 2015 Coc ...

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