Corneal ectatic disorders

The "conical cornea" that is characteristic of keratoconus.

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.^[1]

• Keratoconus, a progressive, noninflammatory, bilateral, asymmetric disease, characterized by paraxial stromal thinning and weakening that leads to corneal surface distortion.^[2]
• Keratoglobus, a rare noninflammatory corneal thinning disorder, characterised by generalised thinning and globular protrusion of the cornea.^[3]
• Pellucid marginal degeneration, a bilateral, noninflammatory disorder, characterized by a peripheral band of thinning of the inferior cornea.^[4]
• 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 eye surgery.^[5]
• Terrien's marginal degeneration, a painless, noninflammatory, unilateral or asymmetrically bilateral, slowly progressive thinning of the peripheral corneal stroma.^[6]

Treatment

Treatment options include contact lenses and intrastromal corneal ring segments for correcting refractive errors caused by irregular corneal surface,^[7][8] corneal collagen cross-linking to strengthen a weak and ectatic cornea,^[9] or corneal transplant for advanced cases.

References

1. "Corneal ectatic disorders (keratoconus and pellucid marginal degeneration)". AAO ONE Network. American Academy of Ophthalmology.
2. Weissman, Barry A; Yeung, Karen K. "Keratoconus". Medscape.
3. Wallang, B S; Das, S (28 June 2013). "Keratoglobus". Eye 27 (9): 1004–1012. doi:10.1038/eye.2013.130. PMID 23807384.
4. Rasheed, Karim; Rabinowitz, Yaron. "Pellucid Marginal Degeneration". Medscape.
5. "Ectasia After LASIK". American Academy of Ophthalmology.
6. "Terrien marginal degeneration". American Academy of Ophthalmology.
7. Marsack, Jason D.; Parker, Katrina E.; Applegate, Raymond A. (December 2008). "Performance of Wavefront-Guided Soft Lenses in Three Keratoconus Subjects". Optometry and Vision Science 85 (12): E1172–E1178. doi:10.1097/OPX.0b013e31818e8eaa.
8. Marsack, JD; Parker, KE; Niu, Y; Pesudovs, K; Applegate, RA (November 2007). "On-eye performance of custom wavefront-guided soft contact lenses in a habitual soft lens-wearing keratoconic patient.". Journal of refractive surgery (Thorofare, N.J. : 1995) 23 (9): 960–4. PMID 18041254.
9. Avni-Zauberman, N; Rootman, DS (November 2014). "Cross-linking and intracorneal ring segments--review of the literature.". Eye & contact lens 40 (6): 365–70. doi:10.1097/icl.0000000000000091. PMID 25320956.

External links

• International Journal of Keratoconus and Ectatic Corneal Diseases