Correlation of Macular Sensitivity Measures and Visual Acuity to Vision-related Quality of Life in Patients with Age-related Macular Degeneration

Abstract

Background: Visual acuity is commonly used as a functional outcome measure in patients with age-related macular degeneration (AMD), despite having a weak correlation with self-perceived visual quality of life. Microperimetry is a useful method of detecting loss of macular function. We wanted to investigate the relationship between these two objective visual outcome measures and subjective vision-related quality of life, finding out which objective measure is more patient-relevant. Methods: Fifty-six consecutive patients with AMD were recruited to the study. Participants were required to complete the Visual Function Questionnaire 39, the Early Treatment Diabetic Retinopathy Study visual acuity examination and a microperimetry assessment using the Micro Perimeter 3. One patient withdrew consent and seven patients dropped out due to cooperation difficulties under microperimetry. Forty-eight patients with AMD were included in the study: thirty-three patients with late AMD (exudative AMD and/or geographic atrophy) and fifteen patients with early (non-exudative) AMD. The right eye was included as standard, as was the eye with the best-corrected visual acuity. Results: There was a higher correlation between vision-related quality of life and macular sensitivity (rho=0.371; p=0.034) than between vision-related quality of life and visual acuity (rho=0.334; p=0.058) in patients with late AMD. These correlations were not statistically significant in patients with early AMD. Composite score (rho=0.405; p=0.019) and near-distance activities score (rho=0.469; p=0.006) correlated highest with the nasal inner macular sub-region in patients with late AMD. Correlations between composite score and macular sub-regions in patients with early AMD were not significant, but near-distance activities score correlated highest with the nasal outer macular sub-region in these patients (rho=0.735; p=0.002). Conclusions: Macular sensitivity as measured using microperimetry correlates significantly better with vision-related quality of life than visual acuity, showing it to be a more patient-relevant outcome measure in patients with late AMD. Furthermore, the nasal sub-regions of the macula appear to be preferred retinal loci in patients with AMD. Trial registration: This study, registration number SJ-618, was registered with the Region Zealand Ethics Committee on 3 rd July 2017.