Keratoconus

• Medical and family history review, and 
• Conduction of an eye exam. 

• Eye refraction: For this keratoconus test, special equipment is used to measure the eyes to check for vision problems. The patient will be asked to look through a device that contains wheels of different lenses, to help ascertain which combination gives you the sharpest vision. This may also be done through the use of a hand-held instrument to evaluate your eyes.
• Slit-lamp examination: For this keratoconus test, a vertical beam of light is directed on the surface of the eye and a low-powered microscope is used to view the eye. This helps to evaluate the shape of your cornea and also looks for other potential eye problems.
• Keratometry: For this keratoconus test, a circle of light is focused on your cornea to measure the reflection, to ascertain the basic shape of your cornea. A value ≥ 47.2 Diopters is suggestive of keratoconus.
• Computerized corneal mapping: For this keratoconus test, special photographic tests, such as corneal tomography and corneal topography, are carried out to record images and create a detailed shape-map of the cornea. While corneal tomography measures the thickness of your cornea, corneal tomography detects early signs of keratoconus before it becomes visible by slit-lamp examination.
• Ultrasonic Pachymetry: This keratoconus test is used to confirm and measure thinning in the cornea.

• Slowing the progression of the disease,
• Improving your vision, and
• Corneal transplant.

1. Slowing the progression of the disease

Symptoms

There are a couple of keratoconus symptoms. However, they are susceptible to changes as the disease progresses. Keratoconus symptoms include

• Blurry or distorted vision.
• Sensitivity to bright lights and glare occurs. This can make night driving difficult..
• Frequent changes of eyeglass prescriptions.
• Unexpected worsening or clouding of vision
• Progressive near-sightedness and irregular astigmatism may develop as the cornea becomes more irregular in shape. 
• Difficulty in seeing at night.
• Eye irritation and headaches associated with eye pain.
• Double vision when looking with just one eye, and triple ghost images

Causes

The exact cause of keratoconus is unknown. Although genetic and environmental factors are thought to play a role, as around 1 in 10 people with a keratoconus have at least a parent with the condition. Researchers also think, from researches, that some people are more likely to get it from birth.

Researches also suggest that the weakening of the corneal tissue that leads to keratoconus may be as a result of an imbalance of the collagen enzymes within the cornea. This imbalance makes the cornea more prone to oxidative damage by free radicals, thereby causing it to weaken and bulge forward.

This oxidative damage and weakening of the cornea may be due to a genetic predisposition, explaining why keratoconus often affects more than one member of the same family.

It has also been established that keratoconus is associated with excessive eye rubbing, overexposure to ultraviolet rays from the sun, a history of poorly fitted contact lenses and chronic eye irritation.

FAQ

• What is keratoconus?

Keratoconus is a condition that occurs when the cornea thins out and protrudes like a cone. The change in the shape of the cornea takes light rays out of focus. Thus causing vision to be blurry and distorted, and making daily tasks such as reading or driving difficult.

• When should I see a doctor?

You should see an eye doctor (an ophthalmologist or an optometrist) when your eyesight begins to rapidly worsen. Although, this might be caused by an irregular curvature of the eye (known as astigmatism). The doctor may also check for signs of keratoconus during routine eye exams.

• What are the risk factors for keratoconus?

The following mentioned factors have been found to predispose people to keratoconus

1. A family history of keratoconus.
2. An atopic disorder.
3. Vigorous rubbing the eye.
4. Lax eyelids
5. Some connective tissue disorders (such as, Ehlers-Danlos syndrome, Marfan syndrome, osteogenesis imperfecta)
6. History of Down syndrome, hay fever, asthma and retinitis pigmentosa
7. Certain congenital disorders with poor vision (such as, Leber congenital optic neuropathy, and retinopathy of prematurity).
8. Obstructive sleep apnea.
9. Race: A study carried out on keratoconus discovered that Blacks or Latinos are approximately 50% more likely to suffer keratoconus than whites. 

• Are there any complications with keratoconus?

A couple of complications may arise

1. Cornea swelling leads to a sudden reduction in the quality of vision and scarring of the cornea.
2. In advanced stages of keratoconus, the cornea may become scarred, particularly when the cone is prominent. A scarred cornea worsens vision problems and may require cornea transplant surgery.

• Will I need surgery for keratoconus?

Most times keratoconus treatment does not require a cornea transplant. The use of a contact lens or glasses is enough to treat and correct visions. 

However, in circumstances where vision can no longer be corrected with the use of glasses or contact lenses, surgery may be recommended. 

• What are the stages of keratoconus?

There are two stages of keratoconus – latent stage (recognisable by a placido disc only) and early stage. 

The early stages were subdivided into two categories as:

1. Keratoconus fruste, which entails 1 to 4 degree deviation of the horizontal axis of the placido disc.
2. Early or mild keratoconus, which entails 5 to 8 degree deviation of the horizontal axis.

• How can I prevent keratoconus?

Quite unfortunate, keratoconus cannot be prevented, or should I say there’s no known way to prevent its occurrence. It is, however, advised one should avoid rubbing the eyes.