title: Population prevalence of tilted and torted optic discs among an adult Chinese population in Singapore: the Tanjong Pagar Study.
abstract: OBJECTIVE
  To determine the prevalence of tilted and torted optic discs and associated risk factors among Chinese adults in Singapore.
  
  
  METHODS
  As part of a population-based survey, optic disc stereophotographs of both eyes were obtained, and left eyes were analyzed using imaging software. A tilted optic disc was defined as an index of tilt (ratio of minimum to maximum optic disc diameter) less than 0.75. The angle of tilt was defined as the angle between the maximum and vertical optic disc diameter, and optic discs were graded as torted if the angle of tilt exceeded 15 degrees .
  
  
  RESULTS
  Twenty-six of 739 subjects (3.5%) had tilted optic discs, and 478 (64.7%) had torted optic discs. Myopia was present in 23 of 26 eyes (88.5% [95% confidence interval, 69.9%-97.6%]) with tilted optic discs and in 211 of 661 eyes (31.9% [28.4%-35.6%]) without tilted optic discs (P < .001). On multivariate analysis, myopia (spherical equivalent) was a significant risk factor for tilted optic discs (P < .001). Index of tilt was not associated with corneal astigmatism or with cylindrical refractive error. Seventeen eyes (65.4%) with tilted optic discs had an optic disc morphologic abnormality, but none were glaucomatous.
  
  
  CONCLUSIONS
  The prevalence of tilted optic discs among this Chinese population was 3.5%. Tilted optic discs were associated with myopia but not with glaucoma.
authors: Glaucoma Department, Singapore National Eye Centre and Singapore Eye Research Institute, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
authors: Alicia C S
authors: AC
authors: How
authors: Gavin S W
authors: GS
authors: Tan
authors: Yiong-Huak
authors: YH
authors: Chan
authors: Tina T L
authors: TT
authors: Wong
authors: Steve K
authors: SK
authors: Seah
authors: Paul J
authors: PJ
authors: Foster
authors: Tin
authors: T
authors: Aung
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D044466:Asian People / Q000208:ethnology*; D003430:Cross-Sectional Studies; D005124:Eye Abnormalities / Q000175:diagnosis / Q000208:ethnology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000208:ethnology; D009898:Optic Disk / Q000002:abnormalities* / Q000473:pathology; D010781:Photography; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D012846:Singapore / Q000453:epidemiology