Validation of the Italian Version of the Visual Function and Corneal Health Status (V-FUCHS) Questionnaire: A Patient-Reported Visual Disability Instrument for Fuchs’ Endothelial Corneal Dystrophy

: Background/Objectives: The Visual Function and Corneal Health Status (V-FUCHS) questionnaire assesses vision-related quality of life in patients affected by Fuchs endothelial corneal dystrophy (FECD) through 15 items, which are divided into the "visual acuity (VA) Factor" and "glare Factor" domains. The purpose of this study was to translate and validate the Italian version of the V-FUCHS instrument. Methods: The original V-FUCHS questionnaire was translated into Italian using certified forward and backward translation methods and administered to patients with FECD undergoing a unilateral or bilateral Descemet membrane endothelial keratoplasty (DMEK) for FECD and healthy controls. Its test-retest reliability was assessed by administering the questionnaire twice, four weeks apart. Modified Krachmer grade, best-corrected visual acuity (BCVA) and central corneal thickness (CCT) were also measured. Results: A total of 74 participants, aged 45 to 83 years, were prospectively enrolled and divided into five subgroups: mild-to-moderate FECD (n = 18), advanced FECD (n = 15), unilateral DMEK (n = 9), bilateral DMEK (n = 12), and healthy controls (n = 20). Retest reliability confirmed the consistency and agreement of their responses (intraclass correlation coefficient > 0.90 for both factors). The Italian V-FUCHS effectively discriminated between different stages of FECD severity, with significant differences in VA and glare factor scores across all subgroups (p < 0.001). While both BCVA and CCT showed correlations with V-FUCHS scores, only the association between the VA factor and BCVA was statistically significant (p < 0.05), indicating that the VA factor meaningfully reflects patients' measured VA. Conclusions: The proposed Italian version of the V-FUCHS questionnaire is a valid and reliable tool for assessing visual disability in patients with FECD before and after DMEK. This instrument may aid in optimizing endothelial keratoplasty timings and evaluating postoperative symptomatic improvements in FECD patients.