Assessment of vision-related quality of life in patients with homonymous visual field defects

Abstract

Background and purpose: Homonymous visual field defects (HVFDs) are among the most common disorders that occur in the elderly after vascular brain damage and can have a major impact on quality of life (QOL). Aims of this study were to describe the vision-targeted, health-related QOL in patients with HVFDs after cerebrovascular lesion, and to determine the relationship between patients' self-reported difficulties and the characteristics of HVFDs in the binocular visual field.

Methods: The German version of the 25-item National Eye Institute Visual Functioning Questionnaire (NEI-VFQ-25) was used. NEI-VFQ-25 scores for patients were compared to reference values of healthy German subjects from Franke (Z Med Psychol 7:178-184, 1999). Extent and location of absolute HVFDs were assessed by binocular semi-automated kinetic perimetry (SKP) within the 90 degrees visual field. Correlations of the NEI-VFQ-25 scores of patients with the area of sparing within the affected hemifield (A-SPAR) were estimated by Spearman's r (s).

Results: The mean NEI-VFQ-25 composite score for 33 patients (time span after brain injury at least 6 months) was 77.1, which was significantly lower (p < 0.0001) than the reference value for 360 healthy subjects (composite score = 90.6), and this was also the case for general vision, near activities, vision specific mental health, driving, colour, and peripheral vision. The score for general health was also significantly lower in patients than in reference subjects (p < 0.0001). A weak correlation of the composite score with A-SPAR (r (s) = 0.38) was observed.

Conclusions: Our findings indicate that detectable decrements in vision-targeted, health-related QOL are observed in patients with homonymous visual field loss. A relationship of the perceived visual functioning with objective parameters is by definition difficult; however, understanding what components of visual function affect certain visual tasks, would help in developing more efficient, clinical assessment strategies. The results reveal a tendency for increasing QOL with advancing size of the area of sparing within the affected hemifield (A-SPAR). The lack of a strong correlation between NEI-VFQ-25 subscales and A-SPAR suggests that an assessment of the visual field may not accurately reflect patients' perceived difficulty in visual tasks. Additional consideration of visual exploration via eye and head movements may improve the correlation between visual function and its perception.