title: Applications of different types of gas-permeable contact lenses in keratoconus and their visual results.
abstract: OBJECTIVE
  To show applications of different types of gas-permeable contact lenses in patients with keratoconus and to compare visual acuity (VA) results.
  
  
  METHODS
  A total of 229 eyes of 133 patients who used different types of rigid gas-permeable contact lenses between April 2003 and April 2010 at the Cornea and Contact Lens Unit of Eye Clinic 2 of the Ministry of Health, Ulucanlar Eye Training and Research Hospital, were included. Visual acuity of patients was classified as uncorrected and corrected with eyeglasses and corrected with contact lenses. The patients were compared in terms of VA, daily contact lens wear time, and complications.
  
  
  RESULTS
  A total of 70 out of 133 (52.6%) patients in our study were male, and 63 (47.4%) were female. The mean age was 25.9 ± 7.03 years (12-45). As for the classification of the 229 eyes included in the study, 136 of 229 (59.4%) eyes had moderate keratoconus, 88 (38.4%) had advanced keratoconus, and 5 (2.2%) had severe keratoconus. Following the contact lens application, the VA in all patients increased when compared to uncorrected and corrected with eyeglasses groups and the difference was statistically significant (p<0.005). When a comparison of different types of contact lenses was made, a statistically significant difference was not found (p>0.5) in terms of increase in VA. When patients were evaluated in terms of contact lens wear times, it was observed that Boston Equalens II was preferred by patients wearing lenses 4-8 hours/day. For patients wearing lenses more than 8 hours a day, Rose K lens was used the most. No serious complication was observed in any of the patients that would lead them to stop wearing contact lenses during the follow-up period. There was also no need for keratoplasty in any patient during the follow-up period.
  
  
  CONCLUSIONS
  We detected an increase in VA in patients with rigid contact lenses. In addition, some contact lenses were better tolerated by patients and were used for a longer time during the day.
authors.affiliation: Department of Ophthalmology, S.B. Ankara Sincan Lokman Hekim Hospital, Ankara - Turkey.
authors.forename: Burcu
authors.initials: B
authors.lastname: Kazanci
authors.forename: Dilay
authors.initials: D
authors.lastname: Ozek
authors.forename: Alparslan
authors.initials: A
authors.lastname: Anayol
authors.forename: Ayşe
authors.initials: A
authors.lastname: Balikçi
authors.forename: Dilek
authors.initials: D
authors.lastname: Ileri
authors.forename: Pelin
authors.initials: P
authors.lastname: Yilmazbaş
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003261:Contact Lenses; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D017755:Prosthesis Fitting; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult