title: Effect of incision size and site on corneal endothelial changes in cataract surgery.
abstract: OBJECTIVE
  To compare endothelial damage induced by different cataract incision sites and sizes using specular microscopy.
  
  
  METHODS
  Department of Ophthalmology, Hospital of San Donà di Piave, Venice, Italy.
  
  
  METHODS
  Eighty-one eyes having phacoemulsification were randomly assigned to 1 of 3 groups of 27 eyes each: 3.5 mm clear corneal incision (CCI) with silicone foldable intraocular lens (IOL) implantation; 5.5 mm sutured CCI with poly(methyl methacrylate) (PMMA) IOL implantation; 5.5 mm scleral tunnel with PMMA IOL implantation. All incisions were centered at the 120-degree semimeridian; that is, they were superotemporal in right eyes and superonasal in left eyes. Noncontact specular microscopy was performed in the center and at the 12 o'clock position preoperatively as well as 1 week and 1, 3, and 12 months postoperatively. The endothelial cell density, mean cell area, cell size variation coefficient, percentage of hexagonality, and corneal thickness were considered.
  
  
  RESULTS
  Progressive endothelial cell loss and an increase in mean cell area occurred in all groups during the follow-up. The cell loss percentages relative to the endothelial center appeared similar among the groups and slightly although not significantly lower in the scleral tunnel group. The scleral tunnel group had a statistically significant lower cell loss percentage at the 12 o'clock position than the 2 CCI groups at all follow-ups.
  
  
  CONCLUSIONS
  The scleral tunnel group had less postoperative endothelial damage than the 2 CCI groups, with a statistically significant difference at the 12 o'clock position. This is probably because the scleral tunnel incision is placed more posteriorly and therefore induces less direct and indirect endothelial trauma.
authors.affiliation: Department of Ophthalmology, Hospital of San Donà di Piave, Via Nazario Sauro n. 23, 30027 San Donà di Piave, Venice, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Beltrame
authors.forename: Maria L
authors.initials: ML
authors.lastname: Salvetat
authors.forename: Giobatta
authors.initials: G
authors.lastname: Driussi
authors.forename: Marzio
authors.initials: M
authors.lastname: Chizzolini
mesh_terms: D000368:Aged; D002452:Cell Count; D048429:Cell Size; D003315:Cornea / Q000601:surgery*; D004728:Endothelium, Corneal / Q000473:pathology*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D008297:Male; D018918:Phacoemulsification; D019904:Polymethyl Methacrylate; D011446:Prospective Studies; D012590:Sclera / Q000601:surgery*; D012826:Silicone Elastomers; D013524:Surgical Flaps
chemical_list: D012826:Silicone Elastomers; D019904:Polymethyl Methacrylate