title: Randomized Crossover Trial of Silicone Hydrogel Presbyopic Contact Lenses.
abstract: OBJECTIVE
  To assess the performance of four commercially available silicone hydrogel multifocal monthly contact lens designs against monovision.
  
  
  METHODS
  A double-masked randomized crossover trial of Air Optix Aqua multifocal, PureVision 2 for Presbyopia, Acuvue OASYS for Presbyopia, Biofinity multifocal, and monovision with Biofinity contact lenses was conducted on 35 presbyopes (54.3 ± 6.2 years). After 4 weeks of wear, visual performance was quantified by high- and low-contrast visual acuity under photopic and mesopic conditions, reading speed, defocus curves, stereopsis, halometry, aberrometry, Near Activity Visual Questionnaire rating, and subjective quality of vision scoring. Bulbar, limbal, and palpebral hyperemia and corneal staining were graded to monitor the impact of each contact lens on ocular physiology.
  
  
  RESULTS
  High-contrast photopic visual acuity (p = 0.102), reading speed (F = 1.082, p = 0.368), and aberrometry (F = 0.855, p = 0.493) were not significantly different between presbyopic lens options. Defocus curve profiles (p < 0.001), stereopsis (p < 0.001), halometry (F = 4.101, p = 0.004), Near Activity Visual Questionnaire (F = 3.730, p = 0.007), quality of vision (p = 0.002), bulbar hyperemia (p = 0.020), and palpebral hyperemia (p = 0.012) differed significantly between lens types, with the Biofinity multifocal lens design principal (center-distance lens was fitted to the dominant eye and a center-near lens to the nondominant eye) typically outperforming the other lenses.
  
  
  CONCLUSIONS
  Although ocular aberration variation between individuals largely masks the differences in optics between current multifocal contact lens designs, certain design strategies can outperform monovision, even in early presbyopes.
authors.affiliation: *DOptom †PhD Ophthalmic Research Group, School of Life and Health Sciences, Aston University, Birmingham, United Kingdom (AS, DL, JSW); and Specsavers, Kingston, London, United Kingdom (AS).
authors.forename: Ahmed
authors.initials: A
authors.lastname: Sivardeen
authors.forename: Deborah
authors.initials: D
authors.lastname: Laughton
authors.forename: James S
authors.initials: JS
authors.lastname: Wolffsohn
mesh_terms: D057128:Aberrometry; D000328:Adult; D000368:Aged; D055253:Color Vision / Q000502:physiology; D003263:Contact Lenses, Hydrophilic; D018592:Cross-Over Studies; D003867:Depth Perception / Q000502:physiology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D008297:Male; D008875:Middle Aged; D055095:Optics and Photonics; D011305:Presbyopia / Q000503:physiopathology / Q000628:therapy*; D012826:Silicone Elastomers; D011795:Surveys and Questionnaires; D014792:Visual Acuity / Q000502:physiology
chemical_list: D012826:Silicone Elastomers; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate