Temporal Analysis of Tear Fluid Proteome Reveals Critical Corneal Repair Events After Photorefractive Surgery

To map time-resolved tear proteome changes during corneal epithelial wound healing after photorefractive keratectomy (PRK) and nominate tear-based biomarker panels with translational potential.

Tears from 10 healthy adults were collected before PRK (Pre), ∼30-60 minutes after PRK (D0), and day 3 (D3) using Schirmer strips. Proteins were extracted (SP3), trypsin-digested, and analyzed by DIA on an Evosep One-timsTOF HT platform. DIA-NN (1% FDR) provided identification/quantification. Paired contrasts (Pre vs. D0; Pre vs. D3) defined differentially abundant proteins (adjusted P < 0.05; |fold change|≥2) for pathway enrichment. A stringent screen (adjusted P < 0.001; FC>2.5) and UniProt-based annotation distinguished secreted versus intracellular candidates.

Across 2025 identified proteins, 909 (∼45%) were significantly modulated. D0 tears showed an "injury/ECM" program (e.g., TGFBI, lumican, keratocan, fibrinogen chains, complement C8B, APOA1), whereas D3 shifted toward remodeling and epithelial polarity with regulated proteolysis (e.g., SERPINA3, MMP7, THBS1, MUC5B, CXCL17). A subset persisted across time points (e.g., A2M, haptoglobin, OLFML3). Intracellular signatures paralleled phase transitions: D0 was enriched for chromatin/DNA-repair and RNA-binding proteins (histones, XRCC5/Ku80, HNRNPs), whereas D3 highlighted transport/cytoskeletal factors linked to apical remodeling and fluid/ion handling (AQP5, NHERF1/EBP50, ANO1/TMEM16A, ACTN1, RDX). H6PD was elevated at both D0 and D3.

Time-stamped, tear-accessible biomarker panels emerge from this analysis: early-injury (TGFBI, lumican/keratocan, fibrinogen/complement), sustained (A2M, haptoglobin, OLFML3), and late-remodeling/epithelial (SERPINA3, MMP7, THBS1, MUC5B, CXCL17), with complementary intracellular markers (AQP5/NHERF1/ANO1). These candidates may support perioperative monitoring, risk stratification (delayed closure, stromal haze), and phase-adapted therapy after PRK, warranting prospective clinical validation.