title: Clinical Evaluation of Large Diameter Rigid-Gas Permeable Versus Soft Toric Contact Lenses for the Correction of Refractive Astigmatism. A MultiCenter Study.
abstract: OBJECTIVE
  This study aims to address the clinical performance of a large diameter rigid gas permeable lens (LRGP) in a group of subjects with low-to-moderate (0.75-2.75 D) refractive astigmatism. An additional goal was to determine whether soft toric or LRGP contact lenses performed better objectively in the correction of astigmatism and to determine which modality is preferred by subjects.
  
  
  METHODS
  This was a multisite prospective cross-over clinical study. Ten asymptomatic contact lens wearers per site (four university clinics) were recruited and randomly assigned to group A or group B. Group A was assigned to start wearing Comfilcon A soft toric lens first, for two weeks, and then crossed over to LRGP lenses (Boston XO, 14.3 mm diameter miniscleral lens). Group B initially wore LRGP lenses and then crossed over to soft toric lenses. For each type of lens worn, low-contrast and high-contrast visual acuity (VA) were evaluated at distance. At the conclusion of the study, after two months, all subjects completed a questionnaire in which they were asked to indicate their preference for one type of lens (soft toric or LRGP) and to rate the quality of vision in day-to-day activities.
  
  
  RESULTS
  Thirty-six of 38 (94.7%) subjects completed the study with 75% preferring the vision of the LRGP lens as compared to the soft toric lenses worn in the study. 52.7% expressed a preference to continue with this modality despite only 38.8% reporting that these LRGP lenses are easy or very easy to handle. Wear time, subjective comfort, and subjective vision ratings exhibited no significant difference between the two groups.
  
  
  CONCLUSIONS
  In a population of asymptomatic contact lens wearers, LRGP lenses can be considered as a good alternative to soft toric lenses for the correction of refractive astigmatism.
authors.affiliation: École d'optométrie de l'Université de Montréal (L.M.), Montreal, Quebec, Canada; University of Missouri-St. Louis College of Optometry (E.S.B.), St. Louis, MO; Lake Havasu (S.L.W.), AZ; Illinois College of Optometry (R.R., J.S.H.), Chicago, IL; and Michigan College of Optometry (B.W.M., A.D.), Big Rapids, Michigan.
authors.forename: Langis
authors.initials: L
authors.lastname: Michaud
authors.forename: Edward S
authors.initials: ES
authors.lastname: Bennett
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Woo
authors.forename: Renee
authors.initials: R
authors.lastname: Reeder
authors.forename: Bruce W
authors.initials: BW
authors.lastname: Morgan
authors.forename: Amy
authors.initials: A
authors.lastname: Dinardo
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Harthan
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000534:rehabilitation*; D003263:Contact Lenses, Hydrophilic; D018592:Cross-Over Studies; D005260:Female; D006801:Humans; D008297:Male; D017060:Patient Satisfaction; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult