title: Visual impairment and vision-related quality of life in the Early Manifest Glaucoma Trial after 20 years of follow-up.
abstract: OBJECTIVE
  To determine the association between vision-related quality of life (VRQOL) and levels of visual function loss in the Early Manifest Glaucoma Trial (EMGT).
  
  
  METHODS
  Two hundred and fifty-five patients were included in the EMGT between 1993 and 1997 and followed regularly by ophthalmic examinations. A Swedish translation of the National Eye Institute Visual Function Questionnaire 25 (NEI VFQ-25) was self-administered at several follow-up visits until 2014. We analysed the association between Rasch-calibrated NEI VFQ-25 scores and visual function in the best eye at the final follow-up visit.
  
  
  RESULTS
  Ninety-one per cent (233/255) of all participants completed the NEI VFQ-25 at least once. In univariate logistic regression analysis, NEI VFQ-25 scores were modestly associated with visual acuity (VA) (r(2)  = 0.330, p < 0.001), visual field index (VFI) (r(2)  = 0.200, p < 0.001) and perimetric mean deviation (MD) (r(2)  = 0.193, p < 0.001). In multivariate analysis, VA and VFI together accounted for approximately 40% (r(2)  = 0.380) of the NEI VFQ-25 scores. NEI VFQ-25 scores were significantly higher for patients with no visual impairment (mean 73 ± 22) than for visually impaired patients (mean 31 ± 15, p < 0.001). VFI worse than 50% or MD worse than -18 dB was significantly associated with low VRQOL scores (p < 0.001).
  
  
  CONCLUSIONS
  Our results support the widespread, albeit arbitrary, use of a better-eye visual field of <50% as an important threshold for a significant reduction in VRQOL.
authors.affiliation: Department of Ophthalmology, Skåne University Hospital, Lund University, Malmö, Sweden.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Peters
authors.affiliation: Department of Ophthalmology, Skåne University Hospital, Lund University, Malmö, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Heijl
authors.affiliation: Department of Ophthalmology, Helsingborg University Hospital, Helsingborg, Sweden.
authors.forename: Lena
authors.initials: L
authors.lastname: Brenner
authors.affiliation: Department of Ophthalmology, Skåne University Hospital, Lund University, Malmö, Sweden.
authors.forename: Boel
authors.initials: B
authors.lastname: Bengtsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017889:Exfoliation Syndrome / Q000503:physiopathology / Q000523:psychology; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000503:physiopathology / Q000523:psychology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life / Q000523:psychology*; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires; D014786:Vision Disorders / Q000503:physiopathology / Q000523:psychology*; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology; D019987:Persons with Visual Disabilities / Q000523:psychology*
keywords: blindness; low vision; open-angle glaucoma; vision-related quality of life; visual impairment