title: Effect of aging on optical quality and intraocular scattering using the double-pass instrument.
abstract: OBJECTIVE
  To assess the effect of aging on optical quality in a normal population.
  
  
  METHODS
  We prospectively examined 100 normal eyes of 100 healthy volunteers (50 men, 50 women; ages, 20-69 years; mean age ± standard deviation, 44.6 ± 15.5 years). We quantitatively assessed the values of MTF cutoff frequency, Strehl ratio, and objective scattering index (OSI), using an Optical Quality Analysis System™ (Visiometrics, Terrassa, Spain). We took these measurements three times each, and the mean value obtained was used for statistical analysis. We investigated the relationships between subject age and these optical quality parameters.
  
  
  RESULTS
  The mean MTF cutoff frequency, Strehl ratio, and OSI, were 27.76 ± 8.41, 0.17 ± 0.05, and 1.29 ± 0.76 cycles/degree, respectively. We found a significant negative correlation between subject age and MTF cutoff frequency (Pearson's correlation coefficient r = -0.606, p < 0.001), and between age and Strehl ratio (r = -0.649, p < 0.001). We also found a significant positive correlation between subject age and OSI (r = 0.691, p < 0.001).
  
  
  CONCLUSIONS
  The MTF cutoff frequency and the Strehl ratio are significantly decreased, and the OSI is significantly increased, by aging, indicating that the optical quality of the eye is degraded in older subjects.
authors.affiliation: Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan. kamiyak-tky@umin.ac.jp
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Kamiya
authors.forename: Kyoko
authors.initials: K
authors.lastname: Umeda
authors.forename: Hidenaga
authors.initials: H
authors.lastname: Kobashi
authors.forename: Kimiya
authors.initials: K
authors.lastname: Shimizu
authors.forename: Takushi
authors.initials: T
authors.lastname: Kawamorita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uozato
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007908:Lens, Crystalline / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012015:Reference Standards; D012016:Reference Values; D012542:Scattering, Radiation; D014787:Vision Tests / Q000379:methods / Q000592:standards*; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult