title: [Residual myopia after penetrating keratoplasty for keratoconus].
abstract: OBJECTIVE
  To study the results of penetrating keratoplasty for keratoconus analyzing the differences in ultimate spherical equivalent according to graft size and the trephine used in the recipient.
  
  
  METHODS
  Retrospective study of 38 patients that were divided into three groups. Group A is composed of patients with a 0.50 mm donor-recipient difference, 0.25 mm in group B and same-sized in group C. In each group visual acuity, spheric equivalent, keratometry and other parameters were assessed. Statistical analysis was performed by comparing the means of the parameters evaluated.
  
  
  RESULTS
  We found a better final visual acuity in group C when compared with group A, and a lower spherical equivalent when we compared groups A with C and A with B. The results were better in those groups where the donor-recipient difference was smaller.
  
  
  CONCLUSIONS
  We believe that it is convenient to minimize the size difference between donor and recipient or to use same-sized trephines to diminish the final spheric equivalent.
authors.affiliation: Hospital General Universitario Gregorio Marañón, Departamento de Oftalmología, Madrid, Spain. domingoblanca@hotmail.com
authors.forename: B
authors.initials: B
authors.lastname: Domingo Gordo
authors.forename: J
authors.initials: J
authors.lastname: Conejero Arroyo
authors.forename: P
authors.initials: P
authors.lastname: Balado Vázquez
mesh_terms: D005260:Female; D006801:Humans; D007640:Keratoconus / Q000601:surgery*; D015948:Keratoplasty, Penetrating / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000209:etiology*; D011183:Postoperative Complications; D012029:Refraction, Ocular; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity