Keratoconus is an eye condition affecting the clear, dome-shaped front surface of the eye, known as the cornea. It involves a gradual thinning and outward bulging of the cornea, causing it to take on a cone-like shape. This alteration significantly impacts vision. This article explores keratoconus, clarifies its curability, and details available treatment options.
What is Keratoconus
Keratoconus is a progressive eye disorder where the cornea gradually thins and bulges outward, forming an irregular cone shape. This abnormal curvature distorts how light enters the eye, leading to blurred and distorted vision, often with increased nearsightedness and irregular astigmatism. Common symptoms include sensitivity to bright light, glare, difficulty with night driving, and occasionally, double vision in one eye. Individuals may also experience frequent changes in their eyeglass prescriptions as the condition progresses.
The exact cause of keratoconus is not fully understood, but it is believed to involve a combination of genetic and environmental factors. A family history of the condition increases the risk. Environmental factors, such as chronic eye rubbing due to allergies or irritation, are also associated with the development and progression of keratoconus.
Can Keratoconus Be Cured
There is no “cure” for keratoconus that can completely reverse corneal changes or eliminate the condition. It is a chronic, progressive condition requiring ongoing management. Treatments primarily aim to halt its progression, improve visual acuity, and manage associated symptoms.
Interventions stabilize the cornea and enhance vision, preventing further deterioration. Early interventions are beneficial, as they can reduce the likelihood of needing more invasive procedures later. While underlying structural abnormalities cannot be completely reversed, modern treatments can significantly slow or stabilize the condition.
Available Treatment Options
Treatment for keratoconus involves a staged approach, addressing both vision correction and disease progression. Initial strategies focus on improving vision, while later interventions aim to strengthen the cornea or, in advanced cases, replace it. The choice of treatment depends on the stage and severity of the condition.
Vision Correction
In the early stages of keratoconus, vision problems may be corrected with eyeglasses, which can help with mild nearsightedness and astigmatism. However, as the corneal shape becomes more irregular, eyeglasses often become less effective. Contact lenses then become a primary method for vision correction.
Rigid gas permeable (RGP) contact lenses are frequently prescribed. Their rigid structure creates a smooth, uniform surface over the irregular cornea, providing clearer vision than eyeglasses. These lenses are custom-fitted to the individual’s unique corneal topography and require precise adjustment.
For those who find RGP lenses uncomfortable, hybrid lenses, which have an RGP center surrounded by a soft skirt, or “piggyback” systems (an RGP lens worn over a soft lens) may offer better comfort while maintaining optical clarity. Scleral lenses are a larger-diameter option that rest on the white part of the eye (sclera) and vault over the entire cornea, creating a tear-filled space that smooths out corneal irregularities. These lenses provide excellent vision and comfort, especially in more advanced cases of keratoconus.
Halting Progression
Corneal cross-linking (CXL) is a procedure designed to strengthen the cornea and prevent further bulging. This minimally invasive treatment involves applying riboflavin (vitamin B2) eye drops to the cornea. The cornea is then exposed to ultraviolet A (UVA) light, which activates the riboflavin to form new bonds between the collagen fibers within the cornea. This process increases the rigidity and stability of the cornea, aiming to stop or significantly slow the progression of the condition and reduce the likelihood of needing a corneal transplant.
Surgical Interventions
For advanced cases of keratoconus where vision cannot be adequately corrected with contact lenses or if there is significant corneal thinning or scarring, surgical options may be considered. Intracorneal ring segments, often referred to as Intacs, are small, clear plastic inserts placed within the cornea to help flatten and reshape it. This can improve vision and make contact lens wear more comfortable.
Corneal transplantation, also known as keratoplasty, is typically a last resort when other treatments are insufficient. This procedure involves replacing the damaged cornea with healthy donor tissue. Two main types include penetrating keratoplasty (PKP), a full-thickness transplant, and deep anterior lamellar keratoplasty (DALK), which replaces only the diseased outer and middle layers of the cornea while preserving the healthy inner layer. Corneal transplants generally have a high success rate, though they carry risks such as graft rejection and require ongoing medication.
Managing Keratoconus Over Time
Living with keratoconus involves consistent, long-term management to preserve vision and maintain eye health. Regular eye examinations are important to monitor the condition’s progression and adjust treatment plans as needed. Corneal topography, a mapping technique that measures the curvature of the cornea, is a key tool used to track changes in corneal shape.
Adherence to prescribed contact lens care routines is important for both vision and eye health. Avoiding eye rubbing, which can contribute to the progression of the condition, is a protective measure. Protecting the eyes from harmful UV light by wearing sunglasses can also be beneficial. Finding an ophthalmologist or optometrist with specialized experience in managing keratoconus can help ensure appropriate and effective care.