title: 30 years of contact lens prescribing for keratoconic patients in Turkey.
abstract: OBJECTIVE
  To assess retrospectively the course, the rate of bilateralness, prognosis, visual acuity with contact lenses, and corneal changes of a cohort with keratoconus.
  
  
  METHODS
  Patients applying to Istanbul Faculty of Medicine, Department of Ophthalmology, Contact Lens Division during the period 1975-2005 with the diagnosis of keratoconus were recruited. The follow-up time ranged from 1.5 years to 25 years. This cohort consisted of 273 male, 245 female patients. The patients' ages ranged from 12 years to 54 years (mean age 34.8+/-10.1 years). 518 cases' 1004 eyes were divided into four groups according to their mean keratometry values. The changes in visual acuity, keratometry values and the measurements of the used contact lenses were compared with each other, and statistical significance was sought.
  
  
  RESULTS
  By self-report, the mean starting age of keratoconus was found to be 22.5+/-7.6 years (range 7-35 years). 59 (11.4%) of 518 patients had unilateral keratoconus occurrence. The acute hydrops rate was found to be 0.3% (5 patients). In patients with advanced keratoconus, new contact lenses were applied with steeper radius of curvature. Penetrating keratoplasty was applied to 15 eyes (1.5%). Visual acuity examination on the patients' last visit, when compared to previous examinations, was found to have decreased by 2-3 Snellen lines due to advancing keratoconus.
  
  
  CONCLUSIONS
  Keratoconus has shown to be a self-limited disease and in our study, with the use of contact lenses, successful outcomes which delayed the need for surgery were achieved in 98.9% of eyes (989/1004 eyes).
authors.affiliation: Department of Ophthalmology, Istanbul Faculty of Medicine, University of Istanbul, 34390 Istanbul, Turkey. lbilgin@istanbul.edu.tr
authors.forename: Lale K
authors.initials: LK
authors.lastname: Bilgin
authors.forename: Senay
authors.initials: S
authors.lastname: Yilmaz
authors.forename: Bilge
authors.initials: B
authors.lastname: Araz
authors.forename: Serdar B
authors.initials: SB
authors.lastname: Yüksel
authors.forename: Turan
authors.initials: T
authors.lastname: Sezen
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003261:Contact Lenses / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007640:Keratoconus / Q000453:epidemiology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D055656:Prescriptions / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014421:Turkey / Q000453:epidemiology; D055815:Young Adult