Corneal ectasia

Corneal Ectasia

Corneal ectasia is a progressive thinning and bulging of the cornea, the clear, dome-shaped surface that covers the front of the eye. This condition can lead to significant visual impairment and is often associated with refractive surgery complications, such as LASIK.

Pathophysiology

Corneal ectasia occurs when the structural integrity of the cornea is compromised, leading to a protrusion and thinning of the corneal tissue. This can result from genetic predispositions, such as in keratoconus, or as a complication of surgical procedures that weaken the corneal structure.

Keratoconus

Keratoconus is a non-inflammatory eye condition in which the normally round cornea thins and begins to bulge into a cone-like shape. This abnormal shape prevents the light entering the eye from being focused correctly on the retina and causes distortion of vision.

Post-LASIK Ectasia

Post-LASIK ectasia is a rare but serious complication of LASIK surgery. It occurs when the cornea becomes unstable after the procedure, leading to progressive thinning and bulging. Risk factors include pre-existing corneal abnormalities, excessive removal of corneal tissue, and inadequate residual stromal bed thickness.

Diagnosis

Diagnosis of corneal ectasia involves a comprehensive eye examination, including:

• Corneal topography: This imaging technique maps the surface curvature of the cornea and is crucial for detecting early signs of ectasia.
• Pachymetry: Measurement of corneal thickness to assess thinning.
• Visual acuity tests: To determine the extent of vision impairment.

Treatment

Treatment options for corneal ectasia aim to stabilize the cornea and improve vision. These include:

• Corneal collagen cross-linking (CXL): A procedure that strengthens corneal tissue to halt progression.
• Contact lenses: Specially designed lenses, such as rigid gas permeable or scleral lenses, can improve vision by providing a smooth refractive surface.
• Corneal transplant: In advanced cases, a corneal transplant may be necessary to restore vision.

Prognosis

The prognosis for corneal ectasia varies depending on the severity and the treatment applied. Early detection and intervention are crucial for preventing significant vision loss.

Prevention

Preventive measures focus on careful screening before refractive surgery to identify patients at risk of developing ectasia. This includes thorough corneal mapping and assessment of corneal thickness.

Also see

• Keratoconus
• LASIK
• Corneal topography
• Corneal transplant

External

• Age-Related Macular Degeneration

• Amblyopia (Lazy Eye)

• Anophthalmia and Microphthalmia

• Astigmatism

B

• Behçet's Disease* Bietti's Crystalline Dystrophy

• Blepharitis* Blepharospasm

C

• Cataracts

• Coloboma

• Color Blindness

• Corneal Conditions

D

• Diabetic Retinopathy

• Dry Eye

F

• Floaters

G

• Glaucoma

I

• Idiopathic Intracranial Hypertension

L

• Low Vision

M

• Macular Edema

• Macular Hole

• Macular Pucker

P

• Pink Eye

R

• Rare Diseases

• Refractive Errors

• Retinal Detachment

• Retinitis Pigmentosa

• Retinoblastoma

• Retinopathy of Prematurity

S

• Stargardt Disease

U

• Usher Syndrome

• Uveitis

V

• Vitreous Detachment