title: [Keratoconus and corneal transplant clinical study].
abstract: OBJECTIVE
  to determine the frequency and clinical characteristics of patients with keratoconus and a corneal transplant (CT) at an ophthalmology reference hospital.
  
  
  METHODS
  retrospective, cross-sectional, observational, descriptive study of 166 patients with diagnosis of keratoconus and CT.
  
  
  RESULTS
  average age of 37.59 years, 97 males (58.43%), 69 females (41.56%). The primarily affected eye was the left one (95 cases, 57 %). Coef C -0.01265. The age at the keratoconus diagnosis was between 20 and 29 years (77 cases, 46.40 %), with an average of 24.5 years. The most frequent signs and symptoms were blurred vision: 140 (84.33 %), itching: 100 (60.24 %), photophobia: 20 (12.04 %). Associated systemic diseases: Down Syndrome 2 cases, (1.20 %), asthma 6 cases (3.61 %), atopic dermatitis 14 cases (8.43 %), allergic rhinitis 10 cases (6.02 %). Related ocular diseases: allergic conjunctivitis 72 cases (43.47 %).
  
  
  CONCLUSIONS
  There is strong association between the corneal microtrauma secondary to itching resulting from allergic processes and keratoconus. A timely diagnosis is of great importance to diminish the progression to corneal scarring requiring a CT.
authors.affiliation: Instituto Mexicano del Seguro Social, Distrito Federal, México.
authors.forename: María Luisa
authors.initials: ML
authors.lastname: Ruiz-Morales
authors.forename: Karla
authors.initials: K
authors.lastname: Verdiguel-Sotelo
authors.forename: Adriana
authors.initials: A
authors.lastname: Hernández-López
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D016039:Corneal Transplantation; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000453:epidemiology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult