title: Quality of life in glaucoma and its relationship with visual function.
abstract: OBJECTIVE
  The aims of this study were (a) to explore patients self-reported visual disability resulting from glaucoma by means of a questionnaire developed for this purpose; (b) identify activities strongly associated with a measure of visual field loss, (c) to quantify different psychophysical aspects of visual function; (d) to assess the relationship between objective measures of visual function and patients' perception of their vision-related quality of life.
  
  
  METHODS
  Three groups of glaucoma patients (n = 47) with mild (n = 18), moderate (n = 19), and severe visual field loss (n = 10) and a group of normal controls (n = 19) underwent a comprehensive clinical examination, completed a questionnaire and, on a separate visit, performed a number of psychophysical tests of visual function.
  
  
  METHODS
  Questionnaire responses (vision-related quality of life, general health and psychosocial variables), visual acuity, visual fields, Esterman binocular disability scores, contrast sensitivity, critical flicker frequency, color vision, dark adaptation, glare disability (brightness acuity), and stereoacuity scores were measured.
  
  
  RESULTS
  Fifteen of the 50 questions were noted to have a strong significant relationship with a measure of visual field loss and were included in a new questionnaire scale, the Glaucoma Quality of Life - 15 (GQL-15). The scale validity showed a significant correlation with perimetric mean deviation (MD) values (r = -0.6; P < 0.0001), the reliability of the scale was high (Cronbach alpha = 0.95), and test-retest reliability of the questionnaire was strong (r = 0.87). An overall statistically significant decrease in performance-related quality of life was noted between normal subjects and all groups of glaucoma patients. A significant relationship was found between the scale questionnaire summary performance measure and a number of psychophysical tests: Pelli-Robson contrast sensitivity (r = -0.45, P < 0.001), glare disability (r = -0.41, P < 0.001), Esterman binocular visual field test (r = -0.39, P < 0.001), dark adaptation (r = 0.34, P = 0.007), and stereopsis (r = 0.26, P = 0.04).
  
  
  CONCLUSIONS
  Perceived visual disability relating to certain tasks (particularly involving dark adaptation and disability glare, activities demanding functional peripheral vision such us tripping over and bumping into objects and outdoor mobility tasks) was significantly associated with the severity of binocular visual field loss. As a result, a new glaucoma-specific questionnaire scale with good performance characteristics is presented in this study. The difficulties encountered by patients in everyday life (as measured with the questionnaire) were also mirrored in their performance on a number of psychophysical tests, especially contrast sensitivity, glare disability, Esterman binocular visual field test, and dark adaptation.
authors.affiliation: Department of Ophthalmology, Princess Alexandra Eye Pavilion, Edinburgh, Scotland, United Kingdom. Patricia.Nelson@scotdb.com
authors.forename: Patricia
authors.initials: P
authors.lastname: Nelson
authors.forename: Peter
authors.initials: P
authors.lastname: Aspinall
authors.forename: Orestis
authors.initials: O
authors.lastname: Papasouliotis
authors.forename: Bruce
authors.initials: B
authors.lastname: Worton
authors.forename: Colm
authors.initials: C
authors.lastname: O'Brien
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003118:Color Perception / Q000502:physiology; D015350:Contrast Sensitivity / Q000502:physiology; D003623:Dark Adaptation / Q000502:physiology; D004185:Disability Evaluation; D005260:Female; D005425:Flicker Fusion / Q000502:physiology; D019466:Glare; D005901:Glaucoma / Q000503:physiopathology* / Q000523:psychology; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D011795:Surveys and Questionnaires; D014786:Vision Disorders / Q000503:physiopathology* / Q000523:psychology; D014792:Visual Acuity / Q000502:physiology; D014794:Visual Fields / Q000502:physiology