Evaluation of Corneal Epithelial Mapping in Diagnosis of Early Keratoconus by Anterior Segment Optical Coherence Tomography

The cornea, as the outermost refractive structure of the eye, plays a critical role in maintaining clear vision. Its transparency and structural integrity are essential for optimal visual function. Among the layers of the cornea, the corneal epithelium is of particular interest due to its dynamic nature and its ability to remodel in response to various physiological and pathological conditions. Accurate and repeatable measurement of corneal epithelial thickness (CET) is therefore crucial for diagnosing and managing corneal diseases, such as keratoconus, and for planning refractive surgeries Keratoconus, a progressive corneal ectatic disorder, is characterized by thinning and protrusion of the cornea, leading to irregular astigmatism and visual impairment. Early detection and monitoring of keratoconus rely heavily on precise corneal imaging, including CET mapping. While AS-OCT has shown promise in evaluating CET in both healthy and keratoconic eyes, the repeatability of these measurements must be thoroughly evaluated to ensure their clinical utility Early diagnosis with subsequent corneal crosslinking (CXL) can slow-down or stop keratoconus progression.9 Identifying subclinical keratoconus is extremely important in refractive surgery screening to avoid iatrogenic ectasia. Anterior and posterior corneal topography combined with total cornea thickness measurements and localisation of the thinnest area are the parameters used commonly for diagnosing and staging of corneal ectasias. Recently, epithelial thickness is also added as an additional parameter and is shown to be useful for both early diagnosis and grading of keratoconus Corneal imaging is an essential tool in modern eye care. Initially, the curvature of the anterior corneal surface constituted the ground for the estimation of corneal optical properties and diagnosis of ectatic disorders like keratoconus. Gradually the importance of the posterior corneal curvature as well as its thickness gained significance. In