title: Correlation between contrast sensitivity and visual acuity in retinitis pigmentosa patients.
abstract: OBJECTIVE
  High-contrast figures such as Landolt rings are insufficient to evaluate the function of the foveal cones of retinitis pigmentosa (RP) patients. We investigated the correlation between visual function as determined with Landolt rings and with the Vistech Contrast Sensitivity Function Test (VCTS) at various spatial frequencies, in addition to the Cambridge Low Contrast Grating (CLCG).
  
  
  METHODS
  The study included 30 retinitis pigmentosa patients (53 eyes). All patients were assessed with Landolt rings, the Vistech method, and the CLCG. We estimated the relative contribution of contrast sensitivity to visual acuity by VCTS at each spatial frequency and by CLCG by simple linear regression analysis.
  
  
  RESULTS
  The results of the regression analysis of VCTS at 1.5, 3.0, and 6.0 cycles/degree showed a significant correlation between Landolt rings and VCTS and between CLCG and VCTS that was strongest at 6.0 cycles/degree. There was no significant correlation between Landolt rings and VCTS or between CLCG and VCTS at 12.0 and 18.0 cycles/degree. Patients with a visual acuity of 20/25 and CLCG greater than 100 were divided into two groups according to their contrast sensitivity at 18.0 cycles/degree on VCTS.
  
  
  CONCLUSIONS
  The VCTS at the highest frequency was useful for evaluating the foveal visual function in RP patients having good visual acuity with the Landolt rings. Thus, contrast sensitivity should be useful in detecting minute impairment or improvement of visual function in RP.
authors.affiliation: Department of Ophthalmology, Takasaki National Hospital, Gunma, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Akeo
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Hiida
authors.forename: Masamichi
authors.initials: M
authors.lastname: Saga
authors.forename: Rikako
authors.initials: R
authors.lastname: Inoue
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Oguchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012174:Retinitis Pigmentosa / Q000150:complications / Q000503:physiopathology*; D014792:Visual Acuity / Q000502:physiology*