Evaluating and Improving Functional Driving Vision of Patients With Astigmatism
Condition: Astigmatism
MeSH terms: Astigmatism
Study type: Interventional

Summary: 
      Small amounts of astigmatism are often uncorrected in contact lens wearers. The effect with
      respect to driving is unknown, but it could threaten safe operation of a motor vehicle,
      especially under conditions such as nighttime driving when visual abilities are highly
      challenged. This study measures driving-specific visual abilities and simulated driving
      performance in participants with astigmatism who either have or do not have their astigmatism
      corrected. The primary hypothesis is that at a tactical level, contact lenses correcting for
      astigmatism will result in safer driving performance overall. The secondary hypothesis is
      that at an operational level, contact lenses correcting for astigmatism will result in better
      driving-specific visual performance.
    

Detailed description: 
      Safe driving relies heavily on "good vision." Good vision while driving relates to multiple
      abilities, such as dynamic visual acuity, contrast sensitivity, management of glare and
      peripheral vision, etc. While spherical contact lenses address issues of correction of visual
      acuity as determined by forward static vision tests, if they do not provide visual acuity
      both immediately and smoothly with eye movement then vision can be compromised. Glare can be
      a problem as well when contact lenses are off center. Fluctuating vision as a result of lens
      movement on the eye could be especially problematic and frustrating for patients who have
      astigmatism. Furthermore, experiencing moments of blurred vision no matter how brief can be
      potentially hazardous while driving. The 1*DAY ACUVUE® MOIST for ASTIGMATISM contact lenses
      have a unique blink-activated stabilization system to prevent rotation of the lens on the
      eye, and may have significant visual advantages for drivers with astigmatism. These lenses
      provide continuous corrected acuity compared to non-ballasted contact lenses, and thus are
      potentially safer for driving. Contact comparison will consist of 1*DAY ACUVUE® MOIST
      (spherical control) versus 1*DAY ACUVUE® MOIST for ASTIGMATISM (the daily disposable
      astigmatism alternative).

      The study will investigate the potential advantages of contact lenses specifically designed
      to correct for astigmatism, compared to similar correction with spherical contacts, for adult
      licensed drivers with astigmatism, employing a double-blind (subjects and research assistant
      blind to hypotheses), randomized, cross-over design (spherical, vs. astigmatism contacts).
      This will be a multi-stage study comprised of the following:

      Preliminary study to determine the likelihood of detecting a significant difference between
      the standard spherical and astigmatism contacts in a full Randomize Clinical Trial (n=12;
      data and power analysis)
    

Intervention name(s): 1-DAY ACUVUE® MOIST contact lenses; 1-DAY ACUVUE® MOIST for ASTIGMATISM contact lenses; No contact lenses
Intervention type(s): Device; Device; Other
Intervention description(s): spherical contact lenses worn during simulated driving tests; toric contact lenses worn during simulated driving tests; simulated driving tests
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: astigmatism, contact lens, driving