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Keratoconus

Author
Laura L Wayman, MD
Section Editor
Jonathan Trobe, MD
Deputy Editor
Janet L Wilterdink, MD

INTRODUCTION

Keratoconus is a noninflammatory disorder of the cornea of unknown etiology. It is characterized by progressive thinning and cone-shaped protrusion of the cornea leading to visual impairment (picture 1). Patients may present with blurry vision or a sudden decrease in visual acuity. Corrective lenses may be difficult to fit and require frequent changes due to progressive myopia and irregular astigmatism. Visual impairment is initially managed with corrective lenses but may require surgical correction as the disease progresses.

EPIDEMIOLOGY

Patients present at puberty or early adulthood. There are a wide range of prevalences reported in the general population, ranging from 50 to 230 per 100,000 [1-3]. There is no difference in incidence and prevalence between genders [1-5]. Some evidence suggests a higher incidence in Asians from the Indian subcontinent [6,7]. Another study did not support the association between Asians and keratoconus. However, the study did find that blacks and Latinos have approximately 50 percent higher odds of having keratoconus when compared with whites [8].

RISK FACTORS

Systemic disorders – Several studies have linked keratoconus to systemic disorders including Down syndrome, Ehlers-Danlos syndrome, and osteogenesis imperfecta [8,9]. None have been able to prove a direct cause-and-effect relationship.

Environment – Atopic disease, asthma, and hay fever have been associated with keratoconus; however, not all studies have found an association [3,9].

Eye-rubbing – Reports based on clinical observation have implicated eye rubbing as a risk factor for keratoconus [9].

           

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Literature review current through: Nov 2016. | This topic last updated: Fri May 13 00:00:00 GMT+00:00 2016.
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