Abstract / Summary
Purpose: To investigate whether N-acetylcysteine (NAC) and Polygonum cuspidatum extract enhance riboflavin/ultraviolet-A crosslinking (CXL), exploring a potential adjunctive strategy for corneal and scleral tissue stabilization. Methods: In this pilot ex vivo study, 12 human corneal buttons and 12 scleral strips were assigned to six groups: untreated controls, CXL alone, adjunctive treatment alone, and adjunctive treatment before, after, or both before and after CXL. Accelerated CXL was performed at 9 mW/cm2 for 10 min (5.4 J/cm2). Resistance to collagenase-mediated degradation and corneal protein release were evaluated. Results: CXL increased corneal degradation time from 7 ± 2 to 14 ± 2 days and scleral degradation time from 10 ± 2 to 19 ± 3 days. Combined pre- and post-CXL adjunctive treatment further prolonged resistance to 21 ± 2 days in corneas (p < 0.001) and 27 ± 3 days in sclerae (p < 0.01), compared with CXL alone. Corneal protein release decreased by 84% and 52% at days 5 and 10, respectively (both p < 0.01). Conclusions: These preliminary findings suggest that biochemical adjuncts may enhance CXL-mediated extracellular matrix stabilization, opening new perspectives for ocular wall reinforcement. This approach could support future therapeutic strategies targeting corneal weakening in keratoconus and scleral remodeling in progressive myopia, with potential extensions to refractive surgery in thin corneas. Further experimental and clinical validation is warranted.