Keratoconus, a progressive eye disease characterized by corneal thinning and distortion, affects vision and can significantly impact quality of life. Early detection and careful monitoring are crucial for managing the condition and slowing its progression. Recent advancements in diagnostic techniques and a deeper understanding of contributing factors are refining how clinicians approach keratoconus care.
Understanding Keratoconus Progression
Keratoconus causes the normally round cornea to gradually bulge outward, creating an irregular astigmatism and blurred vision. While the exact cause remains unknown, a combination of genetic predisposition and environmental factors is believed to play a role. One significant environmental factor identified is vigorous eye rubbing, particularly in individuals with allergies. Research suggests that frequent eye rubbing can exacerbate the condition and accelerate its progression.
Diagnosing keratoconus involves a comprehensive eye exam, including topography and tomography. Corneal topography maps the curvature of the anterior corneal surface, while tomography provides detailed information about corneal thickness and internal structure. These tests help identify subtle changes that may indicate early-stage keratoconus, even before symptoms become noticeable.
The Role of Difference Mapping
Tracking progression is a key component of keratoconus management. William B. Trattler, MD, emphasizes the utility of “difference mapping” as a valuable tool. , at the Hawaiian Eye meeting, Dr. Trattler explained that difference mapping involves comparing a patient’s current corneal scan to their initial scan, highlighting areas of change. “What I love about topography is using a difference map,” he stated. “That’s where we take the original scan, the first time we saw the patient, and compare it to the most recent scan and look at the differences.”
According to Dr. Trattler, worsening keratoconus on a difference map typically manifests as steepening in already steep corneal areas and flattening in flatter regions. This visual representation allows clinicians to objectively assess the rate and pattern of progression, informing treatment decisions.
The Impact of Dry Eye Disease
It’s important to note that other conditions can mimic or confound keratoconus progression. Dr. Trattler highlights the significant impact of dry eye disease on topography analysis. “Dry eye can impact the topography analysis and make things look worse than they really are,” he cautioned. Clinicians should carefully evaluate patients for dry eye and address it appropriately before interpreting corneal scans. Addressing dry eye can provide a clearer picture of the true state of the cornea and prevent misinterpretation of progression.
Stages of Keratoconus and Clinical Signs
Keratoconus is often categorized into stages based on the severity of corneal distortion and visual impairment. Early stages may present with mild blurring and slight distortions, while more advanced stages can lead to significant visual impairment and require interventions like corneal cross-linking, Intacs, or even corneal transplantation.
Clinicians look for a range of signs and symptoms when assessing keratoconus progression. These include progressive myopia and irregular astigmatism that is difficult to correct with glasses, frequent changes in eyeglass prescriptions, visual blurring, ghosting or halos around lights, and specific corneal findings such as Fleischer’s ring, Vogt’s striae, Munson’s sign, and Rizzutti’s sign. The presence and severity of these signs help determine the stage of the disease and guide treatment planning.
Monitoring and Management
Effective management of keratoconus requires a personalized approach tailored to the individual patient’s needs and the rate of disease progression. Regular monitoring with corneal topography and tomography is essential to track changes and adjust treatment accordingly. While there is currently no cure for keratoconus, various treatments can help slow progression and improve vision. These include corneal cross-linking, which strengthens the cornea; Intacs, small plastic rings implanted in the cornea to reshape it; and specialized contact lenses designed to correct irregular astigmatism. In severe cases, corneal transplantation may be necessary.
Ongoing research continues to refine our understanding of keratoconus and develop new and improved treatment options. By staying informed about the latest advancements and employing a proactive approach to monitoring and management, clinicians can help patients with keratoconus maintain optimal vision and quality of life.
