Merck Manual

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Introduction to Corneal Disorders


Melvin I. Roat

, MD, FACS, Sidney Kimmel Medical College at Thomas Jefferson University

Last full review/revision Aug 2022| Content last modified Sep 2022
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Symptoms that suggest corneal involvement (eg, rather than simple conjunctivitis) include unilateral involvement, pain (foreign body sensation and ache—not just a gritty sensation), particularly with exposure to light (photophobia), and decreased visual acuity.

Corneal disorders include the following:

Evaluation of the cornea requires fluorescein staining and, when available, slit lamp examination Slit-lamp examination The eye can be examined with routine equipment, including a standard ophthalmoscope; thorough examination requires special equipment and evaluation by an ophthalmologist. History includes location... read more , and sometimes microbial studies. Patients with symptoms or evidence of keratitis should be referred to an ophthalmologist.

Pearls & Pitfalls

  • Do a slit-lamp examination and fluorescein staining if patients have a red eye with pain, foreign body sensation, and/or decreased visual acuity.

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