What is Keratoconus?
Keratoconus is an eye condition characterized by the thinning and bulging of the cornea, causing it to assume a cone shape. This results in blurry and distorted vision, increased sensitivity to light, and difficulty with night driving. The condition usually begins in the late teens to early 20s and can progress over a period of 10 to 20 years. It often affects both eyes and can lead to very different vision between the two eyes. While the exact cause is unknown, genetic and environmental factors are thought to be involved. Treatment options range from glasses and contact lenses to procedures such as corneal collagen cross-linking and cornea transplant, depending on the stage of the disease. Keratoconus cannot be prevented, but avoiding eye rubbing and seeking early treatment can help manage the condition effectively
What are the risk factors for developing keratoconus?
The risk factors for developing keratoconus include:
- Genetics: Patients with a family history of keratoconus or certain systemic disorders, such as Down syndrome, are at a higher risk
- Eye Rubbing: Chronic eye rubbing is associated with the development and progression of keratoconus
- Allergies and Atopy: Allergic eye conditions, asthma, and eczema have been identified as potential risk factors for keratoconus
- Parental Consanguinity: Studies have shown that parental consanguinity is a significant risk factor for the development of keratoconus
- Exposure to Sunlight and Smoking: Some research suggests that exposure to sunlight and smoking may also be associated with an increased risk of keratoconus
These factors highlight the multifactorial nature of the disease, involving a combination of genetic and environmental influences. Understanding these risk factors can help in identifying individuals who may be at a higher risk for developing keratoconus.
What are the systemic disorders that increase the risk of keratoconus?
Systemic disorders that increase the risk of developing keratoconus include:
- Retinitis pigmentosa: A condition affecting the retina
- Down syndrome: A genetic disorder
- Ehlers-Danlos syndrome: A group of connective tissue disorders
- Marfan syndrome: A genetic disorder that affects the body’s connective tissue
- Hay fever and asthma: Allergic conditions
These systemic disorders are believed to be associated with an increased risk of developing keratoconus. Understanding these risk factors is important for identifying individuals who may be at a higher risk for the condition
What are the symptoms of keratoconus
The symptoms of keratoconus include:
- Blurred or Distorted Vision: This is often one of the earliest symptoms and may lead to frequent changes in eyeglass or contact lens prescriptions
- Increased Sensitivity to Light: Many individuals with keratoconus experience heightened sensitivity to bright light, which can cause discomfort and difficulty with daily activities
- Glare and Halos Around Lights: Patients may notice halos around lights, especially at night, which can further impact their vision and quality of life
- Difficulty Seeing at Night: This can be due to the glare, halos, and overall visual disturbances caused by the condition
- Eye Irritation or Headaches Associated with Eye Pain: Some individuals may experience eye irritation, frequent headaches, or eye pain, particularly as the condition progresses
It’s important to note that symptoms can vary between individuals and may change as the disease progresses. If you experience any of these symptoms, it’s essential to contact us for a comprehensive evaluation and appropriate management
How is keratoconus diagnosed?
Keratoconus is diagnosed through a combination of methods, including a comprehensive eye exam and specialized tests. The condition is not easily diagnosed in its early stages, as routine eye examination equipment may not detect the subtle changes in corneal thickness. The following tests are commonly used for diagnosis:
- Corneal Topography: This sophisticated, noninvasive imaging technique provides a “map” of the curvature of the cornea, allowing for the detection of irregularities characteristic of keratoconus
- Keratoscopy: This test measures corneal thickness and can also be used to diagnose the disorder
- Slit-Lamp Examination: A vertical beam of light is directed on the surface of the eye, and a low-powered microscope is used to view the cornea, evaluating its shape and looking for other potential problems in the eye
- Eye Refraction: This test measures your eyes using special equipment to determine the sharpest vision, and it may involve looking through a device that contains wheels of different lenses or using a hand-held instrument called a retinoscope
- Keratometry: This exam involves focusing a circle of light on the cornea and measures the reflection to determine the basic shape of the cornea
- Computerized Corneal Mapping: Special photographic tests, such as corneal tomography and corneal topography, record images to create a detailed shape map of the cornea. Corneal tomography can also measure the thickness of the cornea, often detecting early signs of keratoconus before it is visible by slit-lamp examination
These tests, along with a review of medical and family history, help in diagnosing keratoconus. Dr Yang will generally suspect keratoconus if the patient has a high astigmatism correction on their glasses and but is still not able to see clearly or if the patient has a constantly changing prescription within a few months or a year. It is important to perform a thorough evaluation in order to diagnose keratoconus.
Treatments for keratoconus
The treatment for keratoconus depends on the stage of the disease. In the early stages, vision can be corrected with glasses or soft contact lenses. As the condition progresses, special types of hard contact lenses, such as Rigid Gas Permeable (RGP) or scleral lenses, may be needed. Other treatment options include:
- Corneal Collagen Cross-Linking: This procedure involves the application of riboflavin (vitamin B2) eye drops followed by exposure to ultraviolet (UV) light to strengthen the cornea and prevent further progression of the disease
- Implantable Ring Segments (INTACS): These are small plastic crescent-shaped inserts that are surgically placed in the cornea to help flatten the cone and improve vision
- Cornea Transplant (Penetrating Keratoplasty): In advanced cases, a cornea transplant may be recommended, where the diseased cornea is replaced with corneal tissue from a human donor. This is usually considered when other treatments are not effective
- Specialized Contact Lenses: Options such as scleral lenses and hybrid contact lenses are available for patients with keratoconus, providing improved vision and comfort
- Glasses or Contact Lenses: These are used to correct vision impairment during the early stages of keratoconus, with frequent prescription adjustments possibly needed as the disease progresses
- Monitoring and Regular Eye Care: Patients with keratoconus require regular monitoring by an eye care professional to assess the progression of the disease and adjust treatments as necessary
It’s important to see our optometrist to determine the most suitable treatment based on the individual’s condition and stage of keratoconus. Early intervention and regular follow-up care are key to managing the disease effectively