Abstract
Purpose: :
To evaluate the predictive value of retinal ganglion cells damage in patients with ocular hypertension (OH) and open angle glaucoma (OAG) with RTVue-100 Fourier-domain optical coherence tomography (FD-OCT) compared to frequency-doubling technique perimetry (FDT).
Methods: :
112 eyes (36 healthy, 57 OH, 19 OAG) of 56 patients (mean age 57,4 ± 7,4), underwent a complete ophthalmic examination, retinal nerve fibre layer (RNFL) and ganglion cell complex (GCC) thicknesses with FD-OCT and FDT-perimetry (N30-5 algorithm, Carl Zeiss Meditec Inc, Dublin, CA) using mean deviation (FDT- MD) and pattern standard deviation (FDT-PSD). Pearson correlation analysis was performed among all the measurements to assess their correlation and receiver-operating-characteristic (ROC) curves area was calculated and considered reliable when the lower bound of 95% confidence interval was at least 0,6 finding the most predictive variables. The cut-off of these variables was found, with a focus on the values obtained by separating the pathological quartile from the healthy quartiles. To select the best model predicting pathologic pattern using cut-off values, a logistic multivariated regression was performed. A ROC curve was finally performed on the best model.
Results: :
Average GCC (cut-off 95 µm), FDT PSD (cut-off 3.6), FDT MD (cut-off -1.7) are the most predictive variables. Logistic multivariated regression provided an Average GCC Odds Ratio (OR) 21,8 (95% CI 4,6-103,9) P<0,0005; FDT PSD OR 4.9 (95% CI 1,6-14,9) P=0,005 and FDT MD OR 3,4 (95% CI 1,1-11,0) P=0,04. ROC curve analysis over the predicted probability of the multivariated model was 0,883 (95% CI 0,822-0,945) P<0,0005. Average GCC (cut-off 95µm) sensibility is 100% and specificity is 94%, with an error of misattribution of 3,6%.
Conclusions: :
Average GCC is the most predictive variable of early glaucomatous damage among analyzed variables, implying that GCC loss is detectable earlier than both RNFL harm and FDT-perimetry deficit. However the combination of function and morphology by using FDT-perimetry and FD-OCT performs better than each single method used separately.
Keywords: ganglion cells • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • intraocular pressure