PURPOSE: To quantify decreases in health-related quality of life (HRQoL) for given deterioration in clinical measures of vision; to describe the shape of these relationships; and to test whether the gradients of these relationships change with duration of visual loss. DESIGN: A prospective, longitudinal study of patients treated with verteporfin photodynamic therapy in the United Kingdom National Health Service. PARTICIPANTS: Patients with neovascular age-related macular degeneration (AMD) treated in 18 ophthalmology departments in the United Kingdom with expertise in management of neovascular AMD. METHODS: Responses to HRQoL questionnaires (Short Form 36 [SF-36] and National Eye Institute Visual Functioning Questionnaire [NEIVFQ]) and clinical measures of vision were recorded at baseline and at follow-up visits. Mixed regression models were used to characterize the relationships of interest. MAIN OUTCOME MEASURES: Measures of vision were best-corrected visual acuity (BCVA) and contrast sensitivity (CS). The SF-36 physical and mental component scores (PCS and MCS), SF-6D utility, and distance, near, and composite NEIVFQ scores were derived to characterize HRQoL. RESULTS: The SF-6D, PCS, and MCS were linearly associated with BCVA; predicted decreases for a 5-letter drop in BCVA in the better-seeing eye were 0.0058, 0.245, and 0.546, respectively (all P<0.0001). Gradients were not influenced by duration of follow-up. Models predicting distance, near, and composite NEIVFQ scores from BCVA were quadratic; predicted decreases for a 5-letter drop in BCVA in the better-seeing eye were 5.08, 5.48, and 3.90, respectively (all P<0.0001). The BCVA predicted HRQoL scores more strongly than CS. CONCLUSIONS: Clinically significant deterioration in clinical measures of vision is associated with small decreases in generic and vision-specific HRQoL. Our findings are important for further research modeling the cost effectiveness of current and future interventions for neovascular AMD.