title: Frequency doubling technology, optical coherence technology and pattern electroretinogram in ocular hypertension.
abstract: BACKGROUND
  To assess which of three methods, namely, optical coherence tomography (OCT), pattern electroretinogram (PERG) or frequency-doubling technology (FDT), is the most sensitive and specific for detecting early glaucomatous damage in ocular hypertension (OH).
  
  
  METHODS
  Fifty-two patients with OH (24 men and 28 women, mean age of 56 ± 9.6 years) with an intraocular pressure (IOP) > 21 mm Hg and fifty-two control patients (25 men and 27 women, mean age of 54.8 ± 10.4 years) with IOP < 21 mm Hg, were assessed. All the patients had normal visual acuity, normal optic disk and normal perimetric indices.All subjects underwent OCT, FDT and PERG. Data were analyzed with unpaired t-tests, Chi-square test and Receiver Operating Characteristic (ROC) curve analyses.
  
  
  RESULTS
  In patients with OH, OCT showed retinal nerve fiber layer (RNFL) thinner than in control group in the superior quadrant (130.16 ± 10.02 vs 135.18 ± 9.27 μm, respectively; p < 0.011) and inferior quadrant (120.14 ± 11.0 vs 132.68 ± 8.03 μm; p < 0.001). FDT showed a significantly higher pattern standard deviation (PSD) (3.46  ± 1.48 vs 1.89 ± 0.7 dB; p < 0.001). With respect to PERG, only the amplitude showed significant differences (p < 0.044) between the two groups. ROC curve analysis revealed a sensitivity and specificity of 92% and 86%, respectively, for FDT-PSD (with an area under the ROC curve of 0.940), whereas with OCT, a sensitivity of 82% and a specificity of 74% was recorded in the inferior RNFL quadrant (with an area under the ROC curve of 0.806) finally with PERG amplitude we found a sensitivity of 52% and specificity of 77% (with an area under the ROC curve of 0.595).
  
  
  CONCLUSIONS
  FDT is the most sensitive and specific method for detecting early glaucomatous damage in eyes with OH, and together with OCT, can be useful in identifying those patients who may develop glaucoma.
  
  
  BACKGROUND
  ISRCT number: ISRCTN70295497.
authors.affiliation: Department of Specialistic Surgery and Anesthesiology Science, Ophthalmology Service, University of Bologna, Via Palagi 9, Bologna, Italy. mauro.cellini@unibo.it
authors.forename: Mauro
authors.initials: M
authors.lastname: Cellini
authors.forename: Pier Giorgio
authors.initials: PG
authors.lastname: Toschi
authors.forename: Ernesto
authors.initials: E
authors.lastname: Strobbe
authors.forename: Nicole
authors.initials: N
authors.lastname: Balducci
authors.forename: Emilio C
authors.initials: EC
authors.lastname: Campos
mesh_terms: D000368:Aged; D004596:Electroretinography / Q000379:methods*; D005260:Female; D005901:Glaucoma / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000150:complications* / Q000503:physiopathology; D012372:ROC Curve; D012165:Retinal Ganglion Cells / Q000473:pathology; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods*; D058609:Visual Field Tests / Q000379:methods*