Vision-Related Quality of Life in Glaucoma: Structural, Functional, and Clinical Correlates Using the Glau-QoL36

Abstract: Purpose: To evaluate the association between glaucoma severity, structural and functional clinical measures, and patient-reported quality of life (QoL) using the Glau-QoL36 questionnaire, and to identify the strongest predictors of QoL impairment among individuals with glaucoma. Methods: A cross-sectional analytical study was conducted among 50 clinically diagnosed glaucoma patients. Disease severity was classified using the Hodapp–Parrish–Anderson criteria based on visual field mean deviation (VF-MD). Clinical evaluation included intraocular pressure measurement, optical coherence tomography-derived retinal nerve fiber layer (RNFL) thickness, visual acuity, and vertical cup–disc ratio. QoL was assessed using the Glau-QoL36 instrument, comprising seven functional and psychosocial domains. Internal consistency, floor and ceiling effects, correlation analyses, multivariable regression modeling, and receiver operating characteristic (ROC) analysis were performed. Results: The mean age of participants was 63.5 ± 13.0 years, with moderate structural and functional impairment reflected in VF-MD (–7.9 ± 4.8 dB) and RNFL thickness (68.4 ± 12.2 µm). Glaucoma severity was significantly associated with QoL decline across all domains (p < 0.01), with the steepest reductions observed in Driving and Daily Life domains. Internal consistency of the questionnaire was strong across domains (Cronbach’s α = 0.71–0.86). Significant correlations were observed between functional impairment and emotional distress, particularly between Driving and Psychological domains (ρ = –0.48) and Daily Life and Anxiety (ρ = –0.44). RNFL strongly correlated with VF-MD (ρ = 0.72, p < 0.001), confirming expected structure–function relationships. In multivariable analysis, VF-MD emerged as the strongest independent predictor of total QoL (β = 0.46, p < 0.001). ROC analysis demonstrated high discrimination accuracy for QoL impairment (AUC = 0.82), with −10.5 dB identified as the optimal VF-MD threshold. Conclusion: Glaucoma severity demonstrates a progressive negative impact on both functional ability and psychological well-being. Visual field loss is the strongest determinant of reduced QoL, underscoring the importance of functional preservation in glaucoma management and patient-centered care strategies.