title: Use of subjective and objective criteria to categorise visual disability.
abstract: BACKGROUND
  Visual disability is categorised using objective criteria. Subjective measures are not considered.
  
  
  OBJECTIVE
  To use subjective criteria along with objective ones to categorise visual disability.
  
  
  METHODS
  Ophthalmology out-patient department; teaching hospital; observational study.
  
  
  METHODS
  Consecutive persons aged >25 years, with vision <20/20 (in one or both eyes) due to chronic conditions, like cataract and refractive errors, were categorized into 11 groups of increasing disability; group-zero: normal range of vision, to group-X: no perception of light, bilaterally. Snellen's vision; binocular contrast sensitivity (Pelli-Robson chart); automated binocular visual field (Humphrey; Esterman test); and vision-related quality of life (Indian Visual Function Questionnaire-33; IND-VFQ33) were recorded.
  
  
  METHODS
  SPSS version-17; Kruskal-wallis test was used to compare contrast sensitivity and visual fields across groups, and Mann-Whitney U test for pair-wise comparison (Bonferroni adjustment; P < 0.01). One-way ANOVA compared quality of life data across groups; for pairwise significance, Dunnett T3 test was applied.
  
  
  RESULTS
  In 226 patients, contrast sensitivity and visual fields were comparable for differing disability grades except when disability was severe (P < 0.001), or moderately severe (P < 0.01). Individual scales of IND-VFQ33 were also mostly comparable; however, global scores showed a distinct pattern, being different for some disability grades but comparable for groups III (78.51 ± 6.86) and IV (82.64 ± 5.80), and groups IV and V (77.23 ± 3.22); these were merged to generate group 345; similarly, global scores were comparable for adjacent groups V and VI (72.53 ± 6.77), VI and VII (74.46 ± 4.32), and VII and VIII (69.12 ± 5.97); these were merged to generate group 5678; thereafter, contrast sensitivity and global and individual IND-VFQ33 scores could differentiate between different grades of disability in the five new groups.
  
  
  CONCLUSIONS
  Subjective criteria made it possible to objectively reclassify visual disability. Visual disability grades could be redefined to accommodate all from zero-100%.
authors.forename: Garima
authors.initials: G
authors.lastname: Kajla
authors.forename: Jolly
authors.initials: J
authors.lastname: Rohatgi
authors.affiliation: Department of Ophthalmology, University College of Medical Sciences and GTB Hospital, University of Delhi, Delhi, India.
authors.forename: Upreet
authors.initials: U
authors.lastname: Dhaliwal
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001766:Blindness / Q000534:rehabilitation*; D015350:Contrast Sensitivity; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011788:Quality of Life; D011795:Surveys and Questionnaires; D014792:Visual Acuity; D014794:Visual Fields