Structural Characteristics of Advanced-Stage Keratoconus on Anterior Segment-Optical Coherence Tomography
Reshma S. Suresh, Janarthanam Jothi Balaji, Anupriya Kohli, Natarajan RadhikaAbstract
Aim:
This study aimed to profile advanced-stage keratoconus (KC) using anterior segment-optical coherence tomography (AS-OCT) by evaluating corneal morphological changes and quantitative parameters.
Materials and Methods:
A retrospective study was conducted on records of advanced and mild-to-moderate KC from January 1, 2022, to December 31, 2023. AS-OCT (MS-39, CSO, Italy) was used to analyze qualitative and quantitative parameters in advanced KC. Comparisons were made with corneal tomography (Pentacam HR Oculus, Wetzlar, Germany) for both groups.
Statistical Analysis Used:
Central corneal cross-sectional area and stromal scarring were quantified using ImageJ software. Pearson correlation and regression analyses evaluated the relationship between parameters. A literature review was conducted to support these findings.
Results:
This study included 43 eyes with advanced KC (mean age: 27.87 ± 13.93 years) and 44 eyes with mild-to-moderate KC (mean age: 30.74 ± 13.92). The best corrected visual acuity (LogMAR) was 0.70 (0.50–1.00) in advanced KC and 0.20 (0.00–0.30) in mild-to-moderate KC. Central corneal thickness was significantly lower in advanced KC (284.06 ± 75.68 µm) than in mild-to-moderate KC (428.95 ± 49.56 µm). Significant differences were observed in keratometry, epithelial/stromal thickness, curvature profiles, and Bowman’s and Descemet’s membrane changes. Scar intensity, epithelial alterations, and Descemet’s detachment did not differ between groups.
Conclusions:
AS-OCT enables detailed assessment of corneal microstructure in KC, revealing layer-specific changes not captured by conventional tomography. As an adjunct to Belin’s ABCD classification and Pentacam, it may aid in improved evaluation of disease severity and structural alterations, particularly in advanced KC.