title: Bevel toric multicurve rigid gas-permeable lens for keratoconus.
abstract: OBJECTIVE
  To evaluate the efficacy and safety of Twinbel bevel toric, a newly designed rigid gas-permeable (RGP) lens with a toric bevel curvature, for keratoconus.
  
  
  METHODS
  A retrospective analysis of nine eyes of patients with keratoconus who had been wearing RGP contact lenses and were switched to Twinbel bevel toric at Yamaguchi University Hospital. Visual acuity and contrast sensitivity were measured under photopic conditions. Complaint symptoms were recorded as primary outcome measures at follow-up visits. Efficacy and safety were evaluated at 12 weeks after the switch to Twinbel bevel toric or later.
  
  
  RESULTS
  Five eyes (55.6 %) showed an improvement in visual acuity with Twinbel bevel toric compared with the previous lens, whereas four eyes (44.4 %) maintained the same visual acuity as before. The mean best corrected visual acuity ± SD with Twinbel bevel toric was 0.01 ± 0.40 logMAR, significantly better (P = 0.044, paired Student's t test) than that (0.23 ± 0.51 logMAR) with the previous lens. Contrast sensitivity and subjective complaint scores did not differ significantly between Twinbel bevel toric and the previous lens. No serious complications of Twinbel bevel toric wear were observed.
  
  
  CONCLUSIONS
  Fitting of Twinbel bevel toric improved visual acuity in eyes affected by keratoconus, thus providing a viable alternative for management of such eyes.
authors.affiliation: Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, Japan. yanai@yamaguchi-u.ac.jp
authors.forename: Ryoji
authors.initials: R
authors.lastname: Yanai
authors.forename: Kiichi
authors.initials: K
authors.lastname: Ueda
authors.forename: Koh-Hei
authors.initials: KH
authors.lastname: Sonoda
mesh_terms: D000328:Adult; D003261:Contact Lenses; D019781:Corneal Topography; D005260:Female; D015590:Fluorophotometry; D006801:Humans; D007640:Keratoconus / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D017755:Prosthesis Fitting; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology