Keratoconus is a progressive, bilateral corneal disease characterized by corneal thinning, protrusion, and vision impairment. Early diagnosis is essential to effectively manage the disease, and recent advancements in optical coherence tomography (OCT) are refining the methods of keratoconus classification.
The STEP system’s use of machine-derived OCT data allows for its application across various OCT platforms. Ongoing studies are assessing its effectiveness in both pre- and post-CXL treatment, which could enhance its utility in clinical practice.
Scheimpflug tomography and the Belin ABCD Staging System have been widely used for diagnosing and staging keratoconus. However, these methods may not fully capture the biomechanical properties and detailed epithelial-stromal interactions of the cornea. In response to this, researchers at the ELZA Institute have developed the STEP system, an OCT-based classification method that integrates both epithelial and stromal layers into a unified staging approach.
The STEP system utilizes two parameters: the minimum overall stromal thickness (ST) and the standard deviation of epithelial thickness (EP). This approach provides a more detailed understanding of keratoconus progression, offering insights that may assist in clinical decisions, especially concerning corneal cross-linking (CXL) protocols.
This new classification method is discussed in detail in the latest issue of Optha magazine. The article, authored by the ELZA Institute’s Dr. Emilio Torres-Netto MD, PhD, FARVO, outlines the development, validation, and potential clinical applications of the STEP system. The publication underscores the relevance of the STEP system in advancing our understanding and management of keratoconus.
By incorporating both epithelial and stromal data, the OCT-based STEP classification offers a methodical approach to keratoconus diagnosis. This system may support clinicians in making more informed decisions regarding the management and treatment of keratoconus.