What is keratoconus?
Keratoconus is a progressive eye condition in which the normally round, dome-shaped cornea thins and bulges into a cone-like shape. This abnormal shape deflects light as it enters the eye, resulting in distorted vision. The exact cause of keratoconus is unknown, but it is thought to be a mix of genetic, environmental, and possibly hormonal factors. The condition usually begins in adolescence or early adulthood and can last for 10-20 years before stabilizing.
Keratoconus symptoms include blurred vision, increased sensitivity to light and glare, frequent eyeglass prescription changes, and, in severe cases, corneal scarring. As the condition worsens, everyday tasks like reading, driving, and recognizing faces can become difficult. The diagnosis is usually confirmed using corneal topography, which maps the shape of the cornea, and pachymetry, which measures corneal thickness.
Understanding keratoconus is critical for early detection and management, as prompt treatment can slow progression and improve visual outcomes. The severity of the condition determines the treatment options, which range from glasses and contact lenses to advanced surgical options.
Classic Methods for Treating Keratoconus
The traditional treatment and management of keratoconus focuses on improving vision and slowing its progression. These approaches include the use of eyeglasses, contact lenses, and various surgical procedures.
Contact lenses and eyeglasses: In the early stages of keratoconus, glasses or soft contact lenses can correct minor refractive errors caused by the irregular shape of the cornea. However, as the condition progresses and the cornea becomes more conical, these solutions may no longer be adequate for vision correction.
- Rigid gas permeable (RGP) lenses: RGP lenses are a popular treatment for keratoconus. These lenses have a smooth, regular surface that refocuses light entering the eye, thereby correcting vision distortion caused by the irregular corneal shape. RGP lenses, while effective, can be uncomfortable for some patients and take some time to adjust to.
- Hybrid Lenses: Hybrid lenses combine a rigid central zone with a soft peripheral skirt, providing the clarity of RGP lenses while increasing comfort. These lenses are especially useful for patients who are unable to tolerate RGP lenses.
- Scleral Lens: Scleral lenses are larger than traditional contact lenses and rest on the sclera (the white part of the eye), not the cornea. They vault over the irregular corneal surface, resulting in a smooth optical surface that offers excellent vision correction and comfort.
Corneal Cross Linking (CXL): Corneal crosslinking is a minimally invasive procedure that strengthens the cornea and slows the progression of keratoconus. The procedure consists of applying riboflavin (vitamin B2) eye drops to the cornea, followed by exposure to ultraviolet (UV) light. This procedure promotes the cross-linking of collagen fibers in the cornea, increasing its rigidity and stability. CXL can be used alone or in conjunction with other treatments and has been shown to effectively prevent further corneal deformation.
Intacs: Intacs are small crescent-shaped implants that are placed in the cornea to flatten its conical shape and improve vision. The procedure is relatively quick and can be done with local anesthesia. Intacs are typically recommended for patients with mild to moderate keratoconus who cannot see clearly with contact lenses. However, they may not be appropriate for all patients, especially those with advanced keratoconus or significant corneal scarring.
Corneal Transplants: In advanced cases of keratoconus where other treatments fail to adequately correct vision, corneal transplantation (keratoplasty) may be required. There are two primary types of corneal transplantation for keratoconus:
- Penetrating Keratoplasty (PK): PK involves removing the entire thickness of the diseased cornea and replacing it with a donor cornea. While PK is effective, it is not without risks, including graft rejection, infection, and astigmatism.
- Deep Anterior Lamellar Keratoplasty (DALK): DALK preserves the patient’s healthy endothelium (the cornea’s innermost layer) while replacing only diseased layers. This procedure lowers the likelihood of graft rejection and other complications associated with PK.
Traditional keratoconus treatments have helped many patients manage the condition and improve their vision. However, they have limitations. Discomfort with contact lenses, the invasive nature of surgical procedures, and the possibility of complications highlight the need for ongoing innovation in keratoconus treatment.
Innovative Keratoconus Treatment Methods
Recent advances in medical research and technology have resulted in significant improvements in the treatment and management of keratoconus. These cutting-edge approaches provide patients with more effective, less invasive, and potentially safer treatment options.
Custom Contact Lenses
Contact lens technology advancements have resulted in the creation of personalized lenses that provide better vision correction and comfort for keratoconus patients.
- Wavefront Guided Lenses: Advanced imaging techniques map the patient’s eye’s unique optical imperfections to create wavefront-guided contact lenses. These lenses offer highly customized vision correction, addressing both lower-order (myopia, hyperopia) and higher-order (coma, trefoil) aberrations found in keratoconus.
- 3D Printed Lenses: The use of 3D printing technology enables the creation of bespoke contact lenses that are exactly the shape and contour of the patient’s cornea. This personalized approach improves the fit, comfort, and optical performance of the lenses.
Advances in Corneal Crosslinking
Corneal cross-linking has advanced with new techniques and adjunctive therapies to improve its efficacy and safety.
- Accelerated cross-linking: Accelerated CXL employs higher-intensity UV light for a shorter duration, reducing overall treatment time while maintaining the same therapeutic effect. This approach reduces patient discomfort and the risk of complications from prolonged UV exposure.
- Custom Cross-Linking: Customized CXL tailors UV light exposure and riboflavin application to the patient’s unique corneal characteristics. This personalized treatment approach seeks to maximize therapeutic benefits while minimizing potential side effects.
Topography-Based Treatments
Topography-guided treatments use detailed corneal mapping to guide surgical and non-surgical interventions, increasing the precision and effectiveness of keratoconus management.
- Topography-Guided Photorefractive Keratectomy (TG-PRK): TG-PRK is a laser eye surgery that reshapes the cornea using topographical data. This procedure can correct irregular astigmatism and improve visual acuity in patients with keratoconus. TG-PRK is frequently combined with corneal cross-linking to stabilize the cornea after surgery.
- Topography-Guided Intacs Corneal topography can be used to guide the placement of Intacs, allowing for better visual outcomes. This tailored approach ensures that the implants deliver the greatest therapeutic benefit.
Gene and Molecular Therapies
Advances in genetic and molecular biology are paving the way for new treatments that address the underlying causes of keratoconus.
- Genetic Therapy: Gene therapies to correct genetic mutations associated with keratoconus are currently under development. Gene therapy has the potential to slow or even reverse the progression of keratoconus by addressing the underlying cause.
- Collagen Enhancing Therapies: Potential treatments for keratoconus include molecular therapies that enhance collagen cross-linking and synthesis. These therapies may strengthen the corneal structure and prevent further deformation.
Advanced Imaging and Diagnostic Tools
Innovative imaging technologies are improving keratoconus diagnosis and monitoring, allowing for more precise and detailed assessments.
- Coronal Tomography: Corneal tomography produces three-dimensional images of the cornea, revealing detailed information about its shape, thickness, and biomechanical properties. This advanced diagnostic tool aids in the early detection of keratoconus and informs treatment planning.
- Ocular Response Analyzer (ORA): The ORA assesses the cornea’s biomechanical properties, including its elasticity and resistance to deformation. This information is useful in diagnosing keratoconus and determining the risk of disease progression.
Minimal Invasive Surgical Techniques
New surgical techniques are being developed to provide less invasive keratoconus treatments with shorter recovery times and fewer complications.
- SMILE (Small Incision Lenticule Extraction): SMILE is a minimally invasive laser eye surgery that removes a small lenticule of corneal tissue via a tiny incision. This procedure reshapes the cornea, improving vision while causing minimal disruption to the corneal structure. While SMILE is primarily used for refractive errors, it is being studied for its potential use in keratoconus.
- Femtosecond Laser-Assisted Keratoplasty: The use of femtosecond lasers in corneal transplantation improves the precision and safety of the procedure. Femtosecond laser-assisted deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) provide better results and a lower risk of complications.
Artificial corneas
Artificial corneas, or keratoprostheses, are being developed to provide a treatment option for patients with severe keratoconus who are not eligible for traditional corneal transplantation.
- Boston Keratoprosthesis (KPro): The Boston KPro is a popular artificial cornea that can improve vision in patients suffering from severe corneal disease. The device consists of a clear plastic optical element and a donor cornea. The Boston KPro has demonstrated promising results in restoring vision and improving quality of life in patients with advanced keratoconus and other corneal pathologies.
- AlphaCor: AlphaCor is a biocompatible hydrogel-based artificial cornea. Its purpose is to integrate with the surrounding tissue, promoting stability and lowering the risk of rejection. AlphaCor may be an effective option for patients who have failed traditional grafts or are not candidates for conventional transplantation.
Personalized Medicine
The future of keratoconus treatment is personalized medicine, which tailors therapies to each individual patient based on genetic, molecular, and clinical factors.
- Genetic Profile: Advanced genetic profiling techniques can detect specific mutations and biomarkers associated with keratoconus. This information can help guide the choice of targeted therapies and improve treatment outcomes.
- Customised Treatment Plans: Advances in imaging, genetic profiling, and diagnostic tools enable the creation of personalized treatment plans based on each patient’s unique characteristics. Personalized treatment plans can enhance the precision and efficacy of medical and surgical procedures.
Telemedicine & Remote Monitoring
Telemedicine is helping to manage keratoconus, especially for patients in remote or underserved areas.
- Remote Consultations: Telemedicine platforms allow for remote consultations with ophthalmology specialists, providing timely access to expert care. This approach can help with early diagnosis, treatment planning, and follow-up care.
- Digital Health Monitoring: Wearable devices and mobile apps can track ocular health indicators and send continuous data to healthcare providers. This information can be used to modify treatment plans and ensure that keratoconus is managed effectively.
