title: Changes in corneal parameters at confocal microscopy in treated glaucoma patients.
abstract: BACKGROUND
  The purpose of this study was to evaluate corneal parameters in treated glaucoma patients, nontreated glaucoma patients, and normal subjects using confocal microscopy.
  
  
  METHODS
  Forty patients with primary open-angle glaucoma and 22 untreated controls underwent confocal microscopy of the cornea using the Heidelberg retinal tomograph cornea module. The glaucoma group was divided into two subgroups, ie, patients on medical treatment for at least two years before inclusion (with beta-blockers or prostaglandin analogs) and nontreated glaucoma patients. The following corneal parameters were evaluated: endothelial cell density and number, reflectivity, and tortuosity of sub-basal nerves. For reflectivity and tortuosity, a dedicated grading scale ranging from 0 to 4 was used. Differences between treatments were also evaluated in the treated glaucoma group.
  
  
  RESULTS
  Number of fibers and reflectivity of the sub-basal plexus were significantly lower in glaucoma patients as compared with controls (2.5 ± 0.7 versus 2.9 ± 0.9, P = 0.006, and 2.3 ± 0.8 versus 2.7 ± 0.9, P = 0.04, respectively), whereas tortuosity was significantly higher (2.6 ± 1 versus 2.0 ± 0.8, P = 0.007). Endothelial cell density (measured as cells per mm(2)) was lower in the glaucoma group comparing treated patients with nontreated patients (2826 ± 285 versus 3124 ± 272, P = 0.0003). Comparing treated patients with nontreated patients, relevant differences were found in number (2.3 ± 0.7 versus 2.8 ± 0.8, P = 0.004), tortuosity (2.8 ± 1 versus 2.2 ± 0.8, P = 0.004), and reflectivity (2.2 ± 0.8 versus 2.6 ± 0.8, P = 0.04). No differences in corneal parameters were found between beta-blockers and prostaglandin analogs.
  
  
  CONCLUSIONS
  This study shows that differences in corneal parameters between glaucoma patients and controls may be due to the medical treatments used for glaucoma. These data should be taken into consideration in long-standing medical glaucoma treatment and in potential candidates for surgery.
authors.affiliation: Eye Clinic, San Giuseppe Hospital, University of Milan, Milan, Italy;
authors.forename: Stefano
authors.initials: S
authors.lastname: Ranno
authors.forename: Paolo
authors.initials: P
authors.lastname: Fogagnolo
authors.forename: Luca
authors.initials: L
authors.lastname: Rossetti
authors.forename: Nicola
authors.initials: N
authors.lastname: Orzalesi
authors.forename: Paolo
authors.initials: P
authors.lastname: Nucci