title: Functional Visual Acuity of Early Presbyopia.
abstract: OBJECTIVE
  To evaluate visual function in patients with early presbyopia using the functional visual acuity (FVA) test.
  
  
  METHODS
  This study included 27 eyes of 27 healthy older volunteers (mean age, 44.1 ± 2.6 years) and 14 eyes of 14 healthy young volunteers (mean age, 28.4±4.8 years). The distance-corrected visual acuity (DCVA), distance-corrected near VA (DCNVA), subjective amplitude of accommodation (AA), and distance and near pupillary diameters were measured. The distance FVA and distance-corrected near FVA (DCNFVA) were measured using the FVA Measurement System. The standard Schirmer test and standard tear break-up time measurement also were performed.
  
  
  RESULTS
  The logarithm of the minimum angle of resolution (logMAR) DCVA was better than 0 in all subjects. The percentages of subjects with logMAR DCNVA below 0 was significantly lower in the presbyopia group than in the young group. The DCNFVA in the presbyopia group was significantly (P < 0.001) poorer than the DCNVA in that group. Significant linear negative correlations were seen between the DCNVA and AA (r = -0.507, P < 0.001) and the DCNFVA and AA (r = -0.681, P < 0.001) in the older subjects. Stepwise regression analysis showed that only the AA was a significant factor predictive of the DCNFVA in the presbyopia group. Tear function parameters were not adopted in the regression model.
  
  
  CONCLUSIONS
  Measurement of the DCNFVA can detect decreased AA in early presbyopia better than measurement of the conventional near VA. The DCNFVA is a good index for early presbyopia.
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Katada
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Japan.
authors.forename: Kazuno
authors.initials: K
authors.lastname: Negishi
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shigeno
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Japan.
authors.forename: Megumi
authors.initials: M
authors.lastname: Saiki
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Japan.
authors.forename: Hidemasa
authors.initials: H
authors.lastname: Torii
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Japan.
authors.forename: Minako
authors.initials: M
authors.lastname: Kaido
authors.affiliation: Department of Ophthalmology, Keio University School of Medicine, Shinanomachi, Shinjuku-ku, Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tsubota
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology; D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000503:physiopathology*; D012029:Refraction, Ocular / Q000502:physiology; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult