To assess which is the most sensitive and specific exam for detecting early glaucomatous damage in ocular hypertensive patients (OH) among hemifield test pattern electroretinogram (PERG HF), frequency doubling technology (FDT) and optical coherence tomography retinal nerve fiber layer (OCT RNFL).Methods
Fifty-two OH patients (mean age of 56±9.6 yrs) with an intraocular pressure (IOP)>21mmHg and 52 healthy controls (mean age of 54.8±10.4 yrs) with IOP<21mmHg were assessed. All the patients had normal visual acuity, normal optic disc appearance and normal standard achromatic perimetric (SAP) indices. All subjects underwent OCT, FDT and PERG examination. Data were analyzed with Mann-Whitney test and Receiver Operating Characteristic (ROC) curve analysis.Results
OH patients showed thinner OCT-RNFL than controls, especially in the superior and inferior quadrant (respectively, 130.16±10.02 vs 135.18±9.27μm; p<0.011 and 120.14±11.0 vs 132.68±8.03μm; p=0.001) and a significantly higher FDT pattern standard deviation (PSD) (3.46±1.48 vs 1.89±0.7dB; p=0.001). As regards PERG examination, the amplitude of the N95 wave of the lower and upper PERG HF showed significant differences (respectively, p=0.037 and p=0.023) between the two groups. ROC curve analysis revealed a sensitivity of 92% and specificity of 86% for FDT PSD (with an area under the ROC curve of 0.942), whereas by using OCTConclusion
Our study show that FDT and PERG HF are the most sensitive and specific exams for detecting early glaucomatous damages in eyes with OH and can be useful in identifying those patients who may develop glaucoma and who need hypotensive ocular medications.