Keratoconus: Symptoms and Treatment

Keratoconus is a progressive eye disease that affects the cornea of the eye. The normally round cornea thins and weakens in the keratoconus, bulging into a cone-like shape. This irregular shape distorts how light enters the eye. In turn, it causes blurry vision and other visual disturbances. The exact cause of keratoconus is not fully understood; however, it is believed that a combination of genetic and environmental factors could be responsible for it. This condition usually begins in adolescence or early adulthood and gradually progresses.

Symptoms of Keratoconus

The symptoms of keratoconus can vary in severity depending on the condition’s progress. In the early stages, the signs may be subtle and can be mistaken for other vision problems like nearsightedness or astigmatism. With the progression of the condition, the symptoms become more noticeable, and they are as follows:

1. Blurry or Distorted Vision: One of the symptoms of keratoconus is blurred vision. This occurs because the cornea’s irregular shape prevents light from focusing properly on the retina. Objects may appear stretched, distorted, or even shadowed. Patients often describe it as seeing double or ghost images, particularly in low-light conditions.
2. Frequent Prescription Changes: People with keratoconus often must change their eyeglasses frequently. As the disease progresses, the cornea continues to change shape, leading to increasingly poor vision that requires stronger corrective lenses.
3. Increased Sensitivity to Light: Light sensitivity, or photophobia, is another vital symptom of keratoconus. Concerned people may experience discomfort or glare in bright light, especially when driving at night or in brightly lit environments.
4. Halos and Starbursts Around Lights: People with keratoconus may notice halos or starbursts around lights, especially at night, because the irregular curvature of the cornea leads to uneven light bending.
5. Eye Irritation or Strain: People with keratoconus often experience frequent eye irritation, including itching or a gritty sensation. Additionally, as the eye strains to focus with a misshapen cornea, patients might experience headaches and discomfort.
6. Sudden Vision Loss or Sharp Decline in Vision: In some cases, keratoconus can lead to a sudden and rapid worsening of vision, particularly if a corneal rupture occurs. This condition, called corneal hydrops, happens when fluid inside the eye enters the cornea, causing swelling and a severe decline in vision. While it is rare, this is considered a medical emergency and requires immediate attention.

Treatment Options for Keratoconus

The treatments for keratoconus are as follows:

1. Eyeglasses and Soft Contact Lenses: In the early stages, patients may experience improved vision with glasses or soft contact lenses. However, as the cornea becomes more irregular, these conventional treatments may become less effective.
2. Rigid Gas Permeable (RGP) Contact Lenses: RGP lenses are often prescribed for keratoconus patients because they provide a smoother refractive surface. Some patients may require specialised hybrid lenses, which combine a rigid centre with a soft outer ring for increased comfort.
3. Corneal Cross-Linking (CXL): Corneal cross-linking is a relatively new procedure that aims to strengthen the corneal tissue and slow the progression of keratoconus. In this treatment, riboflavin (vitamin B2) drops are applied to the cornea, which is then exposed to ultraviolet (UV) light. This interaction strengthens the collagen fibres in the cornea, preventing further thinning and bulging. This treatment is particularly effective when the disease is detected in its early stages.
4. Intacs: Intacs are small, crescent-shaped plastic inserts surgically implanted in the cornea. They help to flatten the cornea and improve vision by reshaping its curvature. Remember, intacs do not cure keratoconus but can help reduce its symptoms in moderate cases.
5. Scleral and Hybrid Lenses: Scleral lenses may be recommended for patients who do not tolerate RGP lenses. These large-diameter lenses rest on the sclera and vault over the cornea, providing a smoother optical surface.
6. Corneal Transplant: In severe cases where other treatments are ineffective, a corneal transplant (keratoplasty) may be necessary. This involves replacing the damaged cornea with healthy donor tissue. While a corneal transplant can restore vision, the recovery process is lengthy, and there is also a risk of rejection or complications.

Thus, keratoconus is a progressive and potentially debilitating condition, but with early diagnosis and appropriate treatment, many patients can maintain good vision and lead normal lives.