title: Pattern electroretinogram (PERG) in the early diagnosis of optic nerve dysfunction in the course of Graves' orbitopathy.
abstract: OBJECTIVE
  The present study was design to evaluate the pattern electroretinogram in the diagnosis of early changes in visual function of patients with Graves' orbitopathy without perimetrical signs of optic nerve neuropathy.
  
  
  METHODS
  19 eyes from ten patients, mean age 36 +/- 6.8 SD. comprising (7 F and 3 M) with GO, affected by (1-4) NOSPECS severity class were enrolled in the study. 22 eyes from eleven healthy volunteers served as a control. The pattern electroretinogram was recorded with TE-1000 headset electrode using PRIMUS 2,5 (Tomey). The temporal frequency of PERG was 2 Hz and the check size was 10. Student's t-test was used for the statistical analysis of mean and standard deviations. Statistical significance was assumed at p < 0.05 for all analyses. Cut-off points, sensitivity and specificity of the pattern elektroretinogram parameters assessed by receiver operating characteristic curves were performed by Medcalc
  
  
  RESULTS
  In patients with Graves' orbitopathy a significantly decreased P50 amplitude was found (2.04 +/- 0.99 vs. 2.69 +/- 0.88 in healthy controls). Receiver operating characteristic curves analysis revealed a high sensitivity of P50 amplitude and N95-P50 amplitude for discrimination between Graves' orbitopathy and healthy group (78.9% and 81.8%, respectively). The specificity of P50 amplitude was fairly high (63.6%) while N95-P50 amplitude was rather low (47.4%).
  
  
  CONCLUSIONS
  The reduction of the P50 amplitude could be a marker of an early ischemic optic nerve dysfunction in patients with Graves' orbitopathy. The evaluation of the pattern electroretinogram P50 and N95-P50 amplitude might be a fairly sensitive test for screening dysthyroid optic neuropathy.
authors.affiliation: Department of Pediatric Ophthalmology with Centre for Treatment of Strabismus, Medical University of Bialystok, Poland. przemyslaw.pawlowski@umb.edu.pl
authors.forename: Pawłowski
authors.initials: P
authors.lastname: Przemysław
authors.forename: Myśliwiec
authors.initials: M
authors.lastname: Janusz
authors.forename: Bakunowicz-Łazarczyk
authors.initials: BŁ
authors.lastname: Alina
authors.forename: Górska
authors.initials: G
authors.lastname: Maria
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D018450:Disease Progression; D042241:Early Diagnosis; D004596:Electroretinography / Q000379:methods*; D005260:Female; D049970:Graves Ophthalmopathy / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009900:Optic Nerve / Q000503:physiopathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis* / Q000209:etiology; D010364:Pattern Recognition, Visual; D011044:Poland; D012680:Sensitivity and Specificity; D014794:Visual Fields