title: A Pilot Study to Propose a "Harm Scale", a New Method to Predict Risk of Harm to the Corneal Endothelium Caused by Longitudinal Phacoemulsification, and the Subsequent Effect of Endothelial Damage on Post Operative Visual Acuity.
abstract: OBJECTIVE
  To study the effect of longitudinal phacoemulsification energy on corneal endothelium and to evaluate the relationship between changes of endothelial cells and postoperative visual acuity.
  
  
  METHODS
  This prospective clinical observational cohort study included 50 patients with cataract who underwent longitudinal phacoemulsification. Sequential quantitative and qualitative morphometric endothelial cell analyses of the cornea were performed 4 weeks preoperatively and 6 weeks postoperatively using noncontact specular microscopy.
  
  
  RESULTS
  There was a relationship between ECL percentage (ECL%) and the 5-score harm scale, well-described by a linear model (one-way ANOVA, R2 = 73.3%). Analyzing the distribution of ECL% Mean with Tukey post-hoc pairwise comparison test (P < 0.001), the value of ECL = 20% has been regarded as cut-off to discriminate patients who obtained an excellent postoperative best-corrected visual acuity (BCVA > 85 letters) from those who just had a good visual outcome (BCVA ≤ 85 letters). There was a significant correlation among the 5-score harm scale, phaco energy intraoperatively delivered, and average cell area postoperatively.
  
  
  CONCLUSIONS
  The 5-score harm scale, a new method that enables to pigeonhole cataracts taking into account nucleus hardness and phaco times, allows to predict the harm on corneal endothelium after longitudinal phacoemulsification. Assessment of ECL% permits to discriminate between patients with excellent BCVA and with just good BCVA, postoperatively.
authors.affiliation: Department of Surgical Sciences, Unit of Ophthalmology, Ospedale Maggiore, Bologna, Italy.
authors.forename: Francesco Saverio
authors.initials: FS
authors.lastname: Sorrentino
authors.affiliation: Department of Biomedical and Surgical Sciences, Section of Human Physiology, University of Ferrara, Ferrara, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Bonifazzi
authors.affiliation: Department of Biomedical and Surgical Sciences, Division of Ophthalmology, University of Ferrara, Ferrara, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Parmeggiani
authors.affiliation: Department of Biomedical and Surgical Sciences, Division of Ophthalmology, University of Ferrara, Ferrara, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Perri
mesh_terms: D000704:Analysis of Variance; D042783:Endothelial Cells / Q000473:pathology; D004728:Endothelium, Corneal / Q000473:pathology* / Q000601:surgery*; D006801:Humans; D018918:Phacoemulsification; D010865:Pilot Projects; D011184:Postoperative Period; D014792:Visual Acuity