title: Glaucomatous retinal nerve fiber layer thickness loss is associated with slower reaction times under a divided attention task.
abstract: OBJECTIVE
  To examine the relationship between glaucomatous structural damage and ability to divide attention during simulated driving.
  
  
  METHODS
  Cross-sectional observational study.
  
  
  METHODS
  
  
  
  METHODS
  Hamilton Glaucoma Center, University of California San Diego.
  
  
  METHODS
  Total of 158 subjects from the Diagnostic Innovations in Glaucoma Study, including 82 with glaucoma and 76 similarly aged controls.
  
  
  METHODS
  Ability to divide attention was investigated by measuring reaction times to peripheral stimuli (at low, medium, or high contrast) while concomitantly performing a central driving task (car following or curve negotiation). All subjects had standard automated perimetry (SAP) and optical coherence tomography was used to measure retinal nerve fiber layer (RNFL) thickness. Cognitive ability was assessed using the Montreal Cognitive Assessment and subjects completed a driving history questionnaire.
  
  
  METHODS
  Reaction times to the driving simulator divided attention task.
  
  
  RESULTS
  The mean reaction times to the low-contrast stimulus were 1.05 s and 0.64 s in glaucoma and controls, respectively, during curve negotiation (P < .001), and 1.19 s and 0.77 s (P = .025), respectively, during car following. There was a nonlinear relationship between reaction times and RNFL thickness in the better eye. RNFL thickness remained significantly associated with reaction times even after adjusting for age, SAP mean deviation in the better eye, cognitive ability, and central driving task performance.
  
  
  CONCLUSIONS
  Although worse SAP sensitivity was associated with worse ability to divide attention, RNFL thickness measurements provided additional information. Information from structural tests may improve our ability to determine which patients are likely to have problems performing daily activities, such as driving.
authors: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors: Andrew J
authors: AJ
authors: Tatham
authors: Entropy Control, Inc, La Jolla, California; Department of Mechanical Engineering, Delft University of Technology, Delft, Netherlands.
authors: Erwin R
authors: ER
authors: Boer
authors: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors: Peter N
authors: PN
authors: Rosen
authors: Entropy Control, Inc, La Jolla, California.
authors: Mauro
authors: M
authors: Della Penna
authors: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors: Daniel
authors: D
authors: Meira-Freitas
authors: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors: Robert N
authors: RN
authors: Weinreb
authors: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California.
authors: Linda M
authors: LM
authors: Zangwill
authors: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California. Electronic address: fmedeiros@glaucoma.ucsd.edu.
authors: Felipe A
authors: FA
authors: Medeiros
mesh_terms: D001288:Attention / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D010775:Photic Stimulation; D011379:Prognosis; D011930:Reaction Time / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods; D058609:Visual Field Tests; D014794:Visual Fields