title: Can Variability of Pattern ERG Signal Help to Detect Retinal Ganglion Cells Dysfunction in Glaucomatous Eyes?
abstract: OBJECTIVE
  To evaluate variability of steady-state pattern electroretinogram (SS-PERG) signal in normal, suspected, and glaucomatous eyes.
  
  
  METHODS
  Twenty-one subjects with suspected glaucoma due to disc abnormalities (GS), 37 patients with early glaucoma (EG), and 24 normal control (NC) were tested with spectral-domain optical coherence tomography (SD-OCT), standard automated perimetry (SAP), and SS-PERG. Mean deviation (MD), pattern standard deviation (PSD), retinal nerve fiber layer (RNFL), and ganglionar complex cells (GCC) were evaluated. The SS-PERG was recorded five consecutive times and the amplitude and phase of second harmonic were measured. PERG amplitude and coefficient of variation of phase (CVphase) were recorded, and correlation with structural and functional parameters of disease, by means of one-way ANOVA and Pearson's correlation, was analysed.
  
  
  RESULTS
  PERG amplitude was reduced, as expression of retinal ganglion cells (RGCs) dysfunction, in EG patients and GS subjects compared to NC patients (P < 0.0001). CVphase was significantly increased in EG patients and GS subjects, compared to healthy (P < 0.0001), and it was also correlated with PSD (P = 0.0009), GCC (P = 0.028), and RNFL (P = 0.0078) only in EG patients.
  
  
  CONCLUSIONS
  Increased intrasession variability of phase in suspected glaucomatous eyes may be a sign of RGCs dysfunction.
authors.affiliation: Social Health District, Glaucoma Center, Azienda Sanitaria Locale, Via Fermi, 72015 Fasano, Brindisi, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Mavilio
authors.affiliation: Ophthalmology Unit, Glaucoma Service, Azienda Ospedaliera "Cardinale G. Panico", 73039 Tricase, Lecce, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Scrimieri
authors.affiliation: Ophthalmology Unit, Glaucoma Service, Azienda Ospedaliera "Cardinale G. Panico", 73039 Tricase, Lecce, Italy.
authors.forename: Donato
authors.initials: D
authors.lastname: Errico
mesh_terms: D000368:Aged; D015331:Cohort Studies; D004596:Electroretinography / Q000379:methods*; D005260:Female; D005901:Glaucoma / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D012165:Retinal Ganglion Cells / Q000502:physiology*