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).
Fifty-two patients with OH (24 men and 28 women, mean age of 56 ± 9.6 years) with an intraocular pressure (IOP) > 21 mmHg and fifty-two control patients (25 men and 27 women, mean age of 54.8 ± 10.4 years) with IOP < 21 mmHg, 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.
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).