title: The role of amino acids in corneal stromal healing: a method for evaluating cellular density and extracellular matrix distribution.
abstract: OBJECTIVE
  To evaluate how amino acid supplementation influences the response of corneal stromal keratocytes and other components of the corneal stroma.
  
  
  METHODS
  We compared two groups of patients undergoing cataract surgery. Each group included 20 eyes of 20 patients. Patients in Group 1 were treated with amino acids for 15 days before surgery, and patients in Group 2 did not receive amino acids (control). To evaluate differences and change in corneal stroma, we analyzed all of the operated corneas with confocal microscopy. The confocal images were then analyzed with a new method for measurement of corneal structure based on fractal dimension calculation. This led to a numerical value, D index (fractal surface dimension), an objective measurement of corneal stromal characteristics. This index is related to three factors: keratocyte density, stromal distribution pattern, and intercellular matrix structure.
  
  
  RESULTS
  Patients in the preoperative amino acid group showed higher keratocyte density values than those in the control group. We observed differences in cell distribution patterns and intercellular matrix structures between groups. Amino acid-treated patients had a corneal stroma with a D index value 10% higher than control group patients.
  
  
  CONCLUSIONS
  We hypothesized that preoperative oral supplements with amino acids may change the corneal stroma structure by increasing keratocyte density and modifying the intercellular matrix. A new method for the measurement of these changes was applied, which provides quantification of the stromal structure complexity with a single numerical value.
authors.affiliation: Department of Ophthalmology, Istituto Clinico Humanitas, Milan, Italy. paolo.vinciguerra@humanitas.it
authors.forename: Ingrid
authors.initials: I
authors.lastname: Torres Munoz
authors.forename: Fabio
authors.initials: F
authors.lastname: Grizzi
authors.forename: Carlo
authors.initials: C
authors.lastname: Russo
authors.forename: Fabrizio I
authors.initials: FI
authors.lastname: Camesasca
authors.forename: Nicola
authors.initials: N
authors.lastname: Dioguardi
authors.forename: Paolo
authors.initials: P
authors.lastname: Vinciguerra
mesh_terms: D000596:Amino Acids / Q000008:administration & dosage*; D016022:Case-Control Studies; D002387:Cataract Extraction / Q000379:methods; D002452:Cell Count; D003319:Corneal Stroma / Q000166:cytology* / Q000601:surgery; D019587:Dietary Supplements; D005109:Extracellular Matrix / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D018613:Microscopy, Confocal; D011300:Preoperative Care / Q000379:methods; D011897:Random Allocation; D014945:Wound Healing
chemical_list: D000596:Amino Acids