Our guide to the condition and its treatment
Our eyes are amazing, but like the rest of the body, they are not immune to conditions that can affect their structure and function. One such condition is keratoconus, a progressive eye disorder that causes the cornea (the clear, dome-shaped front part of the eye) to thin and bulge into a cone-like shape. This change in shape distorts vision, making everyday activities like reading, driving, or recognising faces increasingly difficult.
In this blog, we’ll explore what keratoconus is, its causes, symptoms, and treatment options, as well as the impact it can have on your daily life and how to manage it.
Keratoconus
Keratoconus is a condition in which the normally round cornea thins out and begins to bulge outward into a cone shape. The cornea is responsible for focusing light onto the retina, helping us to see clearly. When it changes shape, light entering the eye gets scattered, resulting in blurred or distorted vision. This irregular shape causes astigmatism and can also induce shortsightedness (myopia), making it harder to see things clearly both near and far.
Keratoconus usually affects both eyes, though one eye may be more affected than the other. The condition typically begins in adolescence or early adulthood and can progress over several years.
What causes keratoconus?
The exact cause of keratoconus is still unknown, but researchers believe it results from a combination of genetic, environmental, and biochemical factors. Some of the possible contributing factors include:
Genetics Approximately 10% of individuals with keratoconus have a family member who also has the condition, indicating a hereditary component.
Eye rubbing Vigorous or chronic eye rubbing has been associated with the development and progression of keratoconus. People with allergies such as eczema, which can cause itchy eyes, may be at higher risk due to frequent rubbing.
Underlying conditions Some medical conditions, such as Down syndrome, Ehlers-Danlos syndrome, or connective tissue disorders, have been linked to a higher prevalence of keratoconus.
Oxidative stress Studies suggest that keratoconus may be related to an imbalance in enzymes that normally help protect the cornea from damage caused by oxidative stress, leading to weakening of the corneal tissue.
Symptoms of keratoconus
Keratoconus symptoms typically start with mild vision changes and can progress over time. The early symptoms may be mistaken for common vision problems like shortsightedness or astigmatism, but over time, the changes become more noticeable. Some of the common signs and symptoms include:
Blurred or distorted vision Vision becomes wavy or blurred, making objects appear warped.
Increased sensitivity to light and glare Bright lights may cause discomfort, especially at night.
Frequent changes in spectacle prescription As the cornea changes shape, your prescription may need to be adjusted more often.
Double vision in one eye (monocular diplopia) People with keratoconus might see ghost images or halos around lights.
Difficulty with night vision Seeing clearly in low light conditions becomes more challenging.
As keratoconus progresses, traditional glasses or soft contact lenses may no longer provide clear vision. The shape of the cornea may become more irregular, further distorting vision.
Diagnosis of keratoconus
To diagnose keratoconus, an ophthalmologist will conduct a comprehensive eye exam which includes:
Corneal topography This is the most common diagnostic tool used to map the surface curvature of the cornea. It creates a detailed "map" of the cornea, highlighting any irregularities.
Pachymetry This test measures the thickness of the cornea to detect any thinning.
Slit-lamp examination A slit-lamp exam allows the eye specialist to examine the cornea for other clinical changes associated with keratoconus.
Early diagnosis is essential in managing keratoconus because treatments are more effective when started in the earlier stages of the condition.
Treatment options for keratoconus
There is no cure for keratoconus, but there are several treatment options to help improve vision and slow the progression of the condition.
1. Spectacles and soft contact lenses (early stages)
In the early stages of keratoconus, glasses or soft contact lenses may correct vision. However, as the condition progresses and the cornea becomes more irregular, these solutions may no longer provide clear vision.
2. Rigid gas permeable (RGP) contact lenses
When soft lenses no longer provide adequate correction, rigid gas permeable lenses are often prescribed. These lenses maintain their shape on the eye’s surface, providing better vision by creating a smoother refractive surface.
3. Scleral lenses
Scleral lenses are larger than standard contact lenses and rest on the white part of the eye (the sclera) instead of the cornea. They vault over the irregular cornea, providing a smooth optical surface and improving vision. These lenses are particularly helpful in advanced keratoconus cases.
4. Corneal cross-linking
Corneal cross-linking is a minimally invasive procedure designed to halt the progression of keratoconus. During the procedure, riboflavin (vitamin B2) eye drops are applied to the cornea, which is then activated by ultraviolet (UV) light. This strengthens the collagen fibres in the cornea, preventing further thinning. While cross-linking does not reverse keratoconus, it can stop the condition from worsening.
5. Intacs
Intacs are small, crescent-shaped inserts placed in the cornea to help flatten its shape and improve vision. This is often considered in cases where contact lenses are no longer effective but corneal transplantation is not yet necessary.
6. Corneal transplant (keratoplasty)
In advanced cases where vision cannot be corrected with contact lenses or other treatments, a corneal transplant may be required. This procedure involves replacing the damaged cornea with healthy donor tissue. Though highly successful, recovery can take several months, and the patient may still need glasses or contact lenses afterwards.
Living with keratoconus
Keratoconus can have a significant impact on your daily life, especially if your vision becomes severely compromised. Here are a few tips for managing the condition:
Avoid eye rubbing This is especially important as eye rubbing can worsen keratoconus by contributing to corneal thinning.
Wear protective eyewear If you engage in sports or other activities that could cause eye injury, always wear protective goggles.
Regular eye check-ups Frequent visits to your eye doctor are crucial for monitoring the progression of the condition and adjusting treatment as needed.
Emotional support Since keratoconus can affect your quality of life, particularly if it progresses to the point where a corneal transplant is needed, finding support groups can help you cope with the emotional impact.
Managing keratoconus
Keratoconus may sound like a daunting diagnosis, but with early detection and proper management, many people with the condition lead normal, productive lives. Advances in treatments such as corneal cross-linking have greatly improved outcomes, helping to slow the progression of keratoconus and maintain vision for many years.
If you or a loved one is experiencing any symptoms of keratoconus, early intervention is key. Consulting an eye care professional is recommended to explore your options and develop a treatment plan tailored to your needs. Please do contact us for more information.