Keratoconus

/Keratoconus
Keratoconus 2018-06-28T07:02:59+00:00

What Is Keratoconus?

At Gerry & Johnson Optometrists, our contact lens specialist optometrists are recognzied by their peers as having expertise in contact lens fitting and management of conditions like keratoconus. We have three corneal topopgrahers in our practice, and a vast range of other latest technology equiptment to measure the thickness of the cornea, digitally image the retina, macula and optice nerve (inside of the eye) and also scan through the layers of the retina to monitor conditions like glaucoma and macular degeneration.

Normal cornea

Normal cornea

Keratoconic cornea

Keratoconic cornea

Keratoconus is an eye condition in which the normally round cornea (the clear dome over the coloured part of the eye) thins and begins to bulge into a cone-like shape. This cone shape deflects light as it enters the eye on its way to the light-sensitive retina, causing distorted vision. Keratoconus can occur in one or both eyes and often begins during a person’s teens or early 20s. It is a disorder rather than a disease; and doesn’t typically causes any pain or discomfort of the eyes, although difficulties with allergies and contact lens fitting need to be managed.

Keratoconus can cause substantial distortion of vision, with multiple images, streaking and sensitivity to light noticed by a person. It is typically diagnosed in your teen years and may or may not progress up until around age 30, at which point it often stabilizes.

 

What Causes Keratoconus?

Keratoconus likely arises from a number of different factors: including genetic, environmental or cellular, any of which may form the trigger for the onset of the condition. New research suggests the weakening of the corneal tissue that leads to keratoconus may be due to an imbalance of enzymes within the cornea.

kerato3

Risk factors for weakening of the cornea include a genetic predisposition, explaining why keratoconus can affect more than one member of the same family. Keratoconus is also associated with allergic conditions like asthma, excema and hayfever; excessive eye rubbing, a history of poorly fitted contact lenses and chronic eye irritation.

 

Keratoconus Treatments

In the mildest form of keratoconus, eyeglasses or soft contact lenses may help. But if the disease progresses and the cornea thins and becomes increasingly more irregular in shape, glasses and soft contacts no longer provide adequate vision correction.

Optical treatments for moderate and advanced keratoconus include gas permeable (RGP or rigid) contact lenses and scleral and semi-scleral lenses. These lenses correct the keratoconic distortion and vault over the cornea, replacing its irregular shape with a smooth, uniform refracting surface to improve vision. Your tears fill in the space between the eye surface and the back of the contact lens to provide optimum vision.

Surgical treatments include collagen cross-linking, which is a new treatment designed to halt the progression of keratoconus. Other surgical options, such as corneal transplant, are only used if specially designed contact lenses do not provide satisfactory vision.

 

Corneal Topography (Mapping)

Corneal mapping allows for accurate measurement of keratoconus, and monitoring for any progression. This uses a specialized instrument called a Corneal Topographer, which is an expert device forming part of our suite of cutting edge diagnostic technology.  In this image below you will see a very mild keratoconus shaped cornea on the right, and a moderately keratoconic cornea on the left which shows the cone in red. Looking at the profiles at the bottom of the image, you will be able to see the pointed cone shape of keratoconus which corresponds to the red area on the colour map.

Moderate keratoconus

Moderate keratoconus

Mild keratoconus

Mild keratoconus