Abstract
Purpose: :
To investigate the relationship between Flicker perimetry, optic nerve head (ONH) stereometric parameters by Heidelberg Retina Tomograph 3 (HRT3) and Fourier domain optical coherence tomography (FD-OCT) parameters.
Methods: :
One randomly selected eye of 23 primary open-angle glaucoma (POAG) patients and 27 ocular hypertension (OHT) patients were included in this cross sectional study. POAG patients were classified when they had abnormal standard automated perimetry (SAP) visual fields (VFs) and/or ONHs. OHT patients were classified when they had normal SAP VFs and ONHs and intraocular pressure (IOP)>21mmHg. All the patients underwent SAP (G1 program) and Flicker perimetry (G1 program, Dynamic Strategy), with the Octopus 301. All patients underwent ONH imaging with HRT3 (version 3.1). Each patient also underwent both Nerve Head Map (NHM4) scanand Macular Map (MM7) scan by means of a FD-OCT (RTVue, Optovue, Fremont, CA, USA). Correlations between Flicker perimetry indices [foveal sensitivity, mean defect (MD), mean sensitivity (MS) and loss variance (LV)], global HRT3 parameters and FD-OCT parameters [retinal nerve fiber layer (RNFL) thickness and ganglion cells complex (GCC) thickness] were analyzed using Spearman correlation coefficient (r).
Results: :
Foveal sensitivity was associated (p<0.05) with the HRT3 parameters maximum contour depression and reference height as well as with the FD-OCT parameter RNFL thickness inferiorly. It was also significantly correlated (p<0.01) with CLM temporal, GCC average thickness, inferior GCC thickness, superior GCC thickness, average RNFL thickness, and superior RNFL thickness. MS was associated (p<0.05) with maximum cup depth, CLM temporal inferior and RB discriminant function value. A correlation (p<0.05) was found between MD and certain HRT3 parameters (reference height, RB). MD was also significantly correlated (p<0.01) with mean cup depth and CLM temporal inferior. LV was associated (p<0.05) with average GCC thickness, superior and inferior RNFL thickness. It was also highly associated (p<0.01) with the following HRT3 parameters: rim area, cup area, cup/disc area ratio, vertical and horizontal cup/disc ratio, CLM temporal inferior, FSM and RB discriminant function values.
Conclusions: :
A significant correlation was found between Flicker perimetry indices, HRT3 ONH measurements and FD-OCT parameters. This structure function relationship might be useful in early detection and follow up of glaucoma.
Keywords: perimetry • optic disc • imaging/image analysis: clinical