title: Videokeratographic anomalies in familial keratoconus.
abstract: OBJECTIVE
  To analyze videokeratography of relatives of established familial keratoconus (FK) patients to detect low-expressivity keratoconus and improve the diagnosis criteria of forme fruste keratoconus.
  
  
  METHODS
  Multicenter case-control study.
  
  
  METHODS
  Twenty-three families with 55 clinical keratoconus patients, 89 first-degree relatives, 43 other relatives, and a control group of 130 subjects.
  
  
  METHODS
  Videokeratography was performed on both eyes of patients after clinical examination, and corneal maps were analyzed. Statistical comparisons were conducted between first-degree and other relatives and a control population.
  
  
  METHODS
  Qualitative (using a 0.5-diopter [D] increment scale) and quantitative analyses of videokeratographs.
  
  
  RESULTS
  Two corneal patterns were overrepresented in the relatives of FK patients: the J and inverted-J form patterns. Results of the quantitative analysis of these suspect patterns showed that the inferior - superior values (reflecting the inferior - superior dioptric asymmetry) were close to 0.8 D and the Srax (relative skewing of the steepest radial axes) was superior to 21 degrees.
  
  
  CONCLUSIONS
  Our study using topography in clearly established genetic keratoconus families allowed us to detect suspect topographical patterns and brings new data to the difficult task of diagnosing forme fruste keratoconus.
authors.affiliation: Service Ophtalmologie, Hôpital Purpan, Toulouse, France.
authors.forename: David
authors.initials: D
authors.lastname: Levy
authors.forename: Helen
authors.initials: H
authors.lastname: Hutchings
authors.forename: Jean F
authors.initials: JF
authors.lastname: Rouland
authors.forename: José
authors.initials: J
authors.lastname: Guell
authors.forename: Carole
authors.initials: C
authors.lastname: Burillon
authors.forename: Jean L
authors.initials: JL
authors.lastname: Arné
authors.forename: Joseph
authors.initials: J
authors.lastname: Colin
authors.forename: Laurent
authors.initials: L
authors.lastname: Laroche
authors.forename: Michel
authors.initials: M
authors.lastname: Montard
authors.forename: Bernard
authors.initials: B
authors.lastname: Delbosc
authors.forename: Isabelle
authors.initials: I
authors.lastname: Aptel
authors.forename: Hervé
authors.initials: H
authors.lastname: Ginisty
authors.forename: Hélène
authors.initials: H
authors.lastname: Grandjean
authors.forename: Francois
authors.initials: F
authors.lastname: Malecaze
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D005192:Family Health; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007640:Keratoconus / Q000175:diagnosis* / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies