Cornea & External Disease


Keratoconus is a common disorder in which the central part of the cornea becomes thinner (see Fig 1). This causes a bulging in the cornea and gives it a cone or nipple shape.

Figure 1

Figure 2


Most patients have keratoconus in both eyes, but, some eyes may show only a lot of astigmatism, resulting in blurriness which is the reason for a first visit to the doctor.

This condition usually begins in the later teens or early 20’s and is progressive, usually to the age of 40. A spontaneous perforation is rare. Severe rubbing of the cornea can cause a break in the deepest layer of the cornea which causes swelling (edema) with a white spot in the cornea giving poor vision (Fig 2). This usually lasts for 6 to 16 weeks.


The cause is unknown and less than 10% of patients have a family history of this disorder.

Treatment Options

Some cases of keratoconus are mild and patients only require glasses. The majority of patients, however, need to wear rigid contact lenses. A new treatment called corneal cross-linking can help strengthen the cornea to prevent further weakening of the cornea.  If all the above fail, then a partial (DALK) or a full thickness (PKP) corneal transplant is done to rehabilitate vision.

Additional Information

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