Modal Decomposition Analysis of Corneal Dynamic Waveform During Air Puff Disturbance

Keratoconus, a prevalent corneal disease, involves corneal thinning due to altered collagen orientation, leading to visual impairments like irregular astigmatism and conical protrusion, often manifesting during adolescence. Diagnosing early keratoconus (forme fruste keratoconus) alongside astigmatism poses a challenge for clinicians, particularly without comprehensive consideration of other aspects such as biomechanics. However, current biomechanical diagnostic methods heavily rely on statistical features obtained from tonometer readings, neglecting true corneal dynamics during air puff testing. This often results in the development of numerous features that may not effectively address the core issue. Our study introduces a biomechanical method that utilizes dynamic theory and modal analysis method to distinguish types of keratoconus dynamic waveform during the air-puff test using images from the advanced high-speed Scheimpflug camera. The results, derived from distinct corneal profile waveforms, achieve high sensitivity in distinguishing keratoconus patterns, and identified forme fruste keratoconus.