Long-Term Changes in Corneal Power in Young Patients With Progressive and Nonprogressive Keratoconus

Area of Science:

• Ophthalmology
• Corneal Imaging
• Biomedical Optics

Background:

• Keratoconus (KC) is a progressive corneal ectasia affecting young individuals.
• Long-term corneal power changes in KC require accurate prediction for timely intervention.
• Anterior segment optical coherence tomography (OCT) offers detailed corneal surface analysis.

Purpose of the Study:

• To analyze long-term corneal power changes in young KC patients.
• To compare corneal power dynamics between progressive and non-progressive KC eyes.
• To identify predictive factors for KC progression using Fourier analysis of OCT data.

Main Methods:

• Retrospective review of OCT data from KC patients (<25 years) with ≥2 years follow-up.
• Classification of eyes into progressive (P) and non-progressive (NP) groups using the ABCD grading system.
• Fourier component analysis (spherical, astigmatism, asymmetry, higher-order irregularity) of anterior and posterior corneal surfaces.

Main Results:

• Significant differences in anterior spherical/higher-order (HO) irregularity and posterior spherical components between P and NP groups.
• Baseline posterior corneal HO irregularity, regular astigmatism, and asymmetry were significant predictors of KC progression.
• High predictive accuracy (AUC 0.796-0.740) for posterior corneal parameters in identifying progression.

Conclusions:

• Posterior corneal surface indices, including regular and irregular astigmatism, show promise as prognostic indicators for KC progression.
• Fourier analysis of OCT data can reveal subtle corneal changes predictive of KC development in young patients.
• Early identification of progressive KC is crucial for managing visual impairment.