The Unified Visual Function Scale Assessments Show Inter- and Intraobserver Agreement and Correlate with Patient Quality of Life in Skull Base Parasellar Tumors

Introduction The authors have previously described the Unified Visual Function Scale (UVFS). Here, we assessed intra- and interobserver reliability of the scale, and investigated correlations with patient quality of life (QoL). Methods Eight healthcare practitioners independently applied the UVFS in 20 representative cases from our parasellar meningioma series. Scoring was compared with consensus grades assigned by lead authors. Inter- and intraobserver agreement was measured using intraclass correlation coefficient (ICC), Fleiss's κ, and Cohen's κ, respectively. Patient QoL was assessed Visual Function Questionnaire 25 (VFQ-25) or Activities of Daily Vision Scale (ADVS), and correlated with UVFS grades for each eye. Results The interobserver ICC was 0.734 (95% confidence interval [CI]: 0.652–0.811), with Fleiss's κ of 0.758, 0.691, and 0.899 for grades A, B, and C, respectively. The intraobserver ICC was 0.758 (95% CI: 0.638–0.872), and Fleiss's κ was 0.604, 0.268, and 0.910 for grades A, B, and C respectively. The Cohen's κ for agreement between UVFS category grades and consensus grades was 0.816 (95 CI: 0.698–0.934). Survey response rate was 51% (27/53). The UVFS demonstrated strong correlation with VFQ-25 subdivisions general vision (r = 0.7712), near activities (r = 0.7262), peripheral vision (r = 0.6722), and driving (r = 0.6608), and also demonstrated strong correlation with the overall ADVS score (r = 0.5902). Conclusion This study shows that the UVFS is valid within a small subset of observers, and accurately reflects patient QoL. It is robust and practical, which make it suitable for broad implementation.