Bullous Keratopathy
What is bullous keratopathy?
Bullous keratopathy is a swelling of the cornea. The cornea is like a watch crystal over
the front of the eye, covering the iris and pupil. It is the main window into the eye. (link
to how eye works page) If the cornea is cloudy your vision will be cloudy.
Why does it happen?
In order to stay clear the cornea must constantly pump water out, into the aqueous (the
pool of fluid lying between the cornea and the iris and the pupil). A layer of cells lining
the inside (back) of the cornea, called endothelial cells, perform this pumping. All of us
are born with a fixed number of these cells and cannot produce new endothelial cells.
The total number of cells decreases gradually with age. Also, they can die off with
injury, intraocular surgery, like cataract surgery, glaucoma, and with inflammation or
infection inside the eye. If there are not enough cells to pump out water the cornea will
swell.
What are the symptoms?
Often vision is not affected until the swelling becomes severe. Only your doctor may be
able to detect this swelling. Eventually the swelling progresses to the point that the
cornea becomes hazy, like in the figures above. Bubbles or blisters can form within the
skin layer over the surface of the cornea. When this occurs people commonly
experience light sensitivity, glare and irritation as well as reduced vision. In some people
their vision and other symptoms are worst when they wake up and improve as the day
progresses.
Sometimes the blisters rupture, causing sharp pain, a feeling like there is a foreign
object in your eye, light sensitivity, tearing and decreased vision. Contact your doctor if
this occurs.
How is bullous keratopathy treated?
No treatment is necessary if you have no symptoms. There is no treatment that will
improve endothelial cell function or prevent your from losing more cells with time. If your
vision is starting to become cloudy there are two things that may improve it:

Hypertonic (salty) eye drops and ointment can decrease the swelling by drawing
water out of the cornea. Two percent and 5% sodium chloride drops are available,
and generally are taken 4-5 times daily. The hypertonic ointment is more effective
but the ointment itself often blurs your vision, so it is usually instilled at bedtime.
These drops are available in most pharmacies, and without a prescription.

A hair dryer can be used to dry the cornea. If your vision is blurry when you wake
up and clears over time, the hair dryer can speed up this process. Hold the dryer out
to the side or at arm’s length and blow the warm, dry air across your face. This can
be performed for about 5 minutes.
These treatments can also be used to decrease discomfort. In some cases a soft
contact lens can be worn to decrease discomfort. If vision is insufficient for daily
activities or significant discomfort persists in spite of these treatments, corneal
transplantation should be considered. (link to corneal transplant surgery)
For further information:
http://www.emedicine.com/oph/topic107.htm