title: Visual Performance of a Multifocal Contact Lens versus Monovision in Established Presbyopes.
abstract: OBJECTIVE
  To compare subjective and objective visual performance of the Air Optix Aqua Multifocal lens to monovision in a group of subjects requiring a medium level of reading-addition power.
  
  
  METHODS
  Fifty participants with reading additions between 1.25 and 2.00 diopters (inclusive) were randomized into a prospective, crossover clinical trial. They wore monovision and multifocals for 2 weeks in a randomized order. High- and low-contrast logMAR (logarithm of the minimum angle of resolution) acuity and stereopsis were measured at the beginning and end of each period. During each phase, participants performed specific tasks followed by subjective rating surveys and also completed satisfaction rating surveys on days 3, 7, and 12; all were transferred in real time using BlackBerry smartphones. A general rating survey was completed at the dispensing and 2-week visits.
  
  
  RESULTS
  Forty-nine participants completed the study (mean age, 52 years). Distance and near high- and low-contrast acuities were significantly better (p < 0.05) with monovision at all visits. High-contrast intermediate acuity was only better (p < 0.05) with multifocals after 2 weeks. Stereopsis was equivalent after 2 weeks, but better (p < 0.05) with multifocals at dispensing. Subjective ratings were generally equivalent between modalities although there was a trend for multifocals to be rated higher for focus changing and driving, whereas monovision tended to be rated higher for near tasks. For both corrections, the satisfaction survey showed no significant change between days 3, 7, and 12, and the general survey showed that comfort was maintained but subjective vision ratings decreased significantly over the 2 weeks. Twenty-five participants (51%) preferred multifocals, 18 (37%) preferred monovision, and the remaining 6 (12%) declared both unacceptable.
  
  
  CONCLUSIONS
  In this cohort, distance and near acuities were better with monovision, whereas the subjective ratings tended to favor the Air Optix Aqua Multifocal, with the exception of near performance. Preference was statistically similar between both corrections, with a trend toward preferring the multifocal.
authors.affiliation: *BSc(Hons), MCOptom, FAAO †PhD, MCOptom, FAAO ‡MOptom, FAAO Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada (JW, DF); and School of Medicine (Optometry), Deakin University, Waurn Ponds, Victoria, Australia (CW).
authors.forename: Jill
authors.initials: J
authors.lastname: Woods
authors.forename: Craig
authors.initials: C
authors.lastname: Woods
authors.forename: Desmond
authors.initials: D
authors.lastname: Fonn
mesh_terms: D000328:Adult; D000368:Aged; D003263:Contact Lenses, Hydrophilic; D018592:Cross-Over Studies; D003867:Depth Perception / Q000502:physiology*; D004867:Equipment Design; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000628:therapy*; D017060:Patient Satisfaction; D011305:Presbyopia / Q000503:physiopathology / Q000628:therapy*; D011446:Prospective Studies; D011795:Surveys and Questionnaires; D015348:Vision, Binocular / Q000502:physiology*; D014792:Visual Acuity / Q000502:physiology*