title: Weighing of risk factors for penetrating keratoplasty graft failure: application of Risk Score System.
abstract: OBJECTIVE
  To analyze the relationship between the score obtained in the Risk Score System (RSS) proposed by Hickset alwith penetrating keratoplasty (PKP) graft failure at 1y postoperatively and among each factor in the RSS with the risk of PKP graft failure using univariate and multivariate analysis.
  
  
  METHODS
  The retrospective cohort study had 152 PKPs from 152 patients. Eighteen cases were excluded from our study due to primary failure (10 cases), incomplete medical notes (5 cases) and follow-up less than 1y (3 cases). We included 134 PKPs from 134 patients stratified by preoperative risk score. Spearman coefficient was calculated for the relationship between the score obtained and risk of failure at 1y. Univariate and multivariate analysis were calculated for the impact of every single risk factor included in the RSS over graft failure at 1y.
  
  
  RESULTS
  Spearman coefficient showed statistically significant correlation between the score in the RSS and graft failure (P<0.05). Multivariate logistic regression analysis showed no statistically significant relationship (P>0.05) between diagnosis and lens status with graft failure. The relationship between the other risk factors studied and graft failure was significant (P<0.05), although the results for previous grafts and graft failure was unreliable. None of our patients had previous blood transfusion, thus, it had no impact.
  
  
  CONCLUSIONS
  After the application of multivariate analysis techniques, some risk factors do not show the expected impact over graft failure at 1y.
authors.affiliation: Asociación Para Evitar la Ceguera en México, Hospital Luis Sánchez Bulnes, Mexico City 04030, México; Hospital Fundación Jiménez Díaz, Madrid 28040, Spain.
authors.forename: Abdo Karim
authors.initials: AK
authors.lastname: Tourkmani
authors.affiliation: Asociación Para Evitar la Ceguera en México, Hospital Luis Sánchez Bulnes, Mexico City 04030, México.
authors.forename: Valeria
authors.initials: V
authors.lastname: Sánchez-Huerta
authors.affiliation: Asociación Para Evitar la Ceguera en México, Hospital Luis Sánchez Bulnes, Mexico City 04030, México.
authors.forename: Guillermo
authors.initials: G
authors.lastname: De Wit
authors.affiliation: Asociación Para Evitar la Ceguera en México, Hospital Luis Sánchez Bulnes, Mexico City 04030, México.
authors.forename: Jaime D
authors.initials: JD
authors.lastname: Martínez
authors.affiliation: Hospital Fundación Jiménez Díaz, Madrid 28040, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Mingo
authors.affiliation: Hospital Fundación Jiménez Díaz, Madrid 28040, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Mahillo-Fernández
authors.affiliation: Hospital Fundación Jiménez Díaz, Madrid 28040, Spain.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Jiménez-Alfaro
keywords: graft failure; penetrating keratoplasty; score