Tear proteomic analysis from offspring of Keratoconus patients: new insights into corneal biomechanical weakness and disease risk stages

Abstract

Purpose: To analyze the tear proteome of keratoconus offspring (O-KC) and assess the molecular drivers underlying corneal biomechanical weakening at KC-risk stages. Methods: This cross-sectional study included 80 O-KC young participants and 42 controls without a KC family history. Based on the corneal biomechanical behavior, O-KC eyes were classified as low, moderate, and high-risk of KC development (O-KC-LR, O-KC-MR, O-KC-HR). Tear fluid was extracted using Schirmer strips, and the proteomic profile was mapped using LC-MS/MS. Bioinformatic tools were used to determine the dysregulated protein's biological implications. The sensitivity-specificity of each biomarker for differentiating between controls and O-KC groups was determined. Logistic regression analysis (LRA) identified the optimal subset of predictors for modeling each biomechanical condition's probability. Results: Twenty-nine percent of O-KC eyes showed moderate/high alterations in corneal biomechanical behavior. Fifteen proteins were dysregulated in the tear samples of O-KC groups compared to controls (P < 0.05). Dysregulated proteins were associated with oxidative stress, cell adhesion, cytoskeleton organization, and mechanotransduction paths such as RhoA, mTOR, or E-cadherin/N-cadherin signaling. LRA determined three protein panels with high sensitivity-specificity for discriminating between the control and O-KC groups with different biomechanical risks. Conclusions: This study revealed promising new biomarkers for early detection of KC risk. Oxidative stress and cellular structural alterations seem to begin long before clinical signs and even before the biomechanical alterations can be detected with current clinical tools. Understanding how an initial imbalance of oxidative stress affects cellular mechanobiology is critical to developing new therapeutic strategies for the early treatment of KC.