Abstract
Purpose: :
to test relation between Retinal Nerve Fiber Layer thickness (RNFL) measuremements with scanning laser polarimeter (GDxVCC) and functional parameters measured by standard automated perimetry (SAP), Short wavelength automated perimetry (SWAP) and frequency-doubling technology (FDT) in glaucoma patients.
Methods: :
Thirty glaucomatous patients underwent a complete ophthalmological examination, RNFL assessment by GDxVCC (Carl Zeiss Meditec Inc.) visual field testing by SWAP, FDT Matrix and SAP, in randomized order and repeated two times.SWAP and SAP were performed using the SITA program of Humphrey Field Analyzer (Carl Zeiss Meditec, Dublin, CA) over the central 24 degrees of the retina.FDT Matrix was performed using the 24-2 full-threshold program of Humphrey FDT (Carl Zeiss Meditec, Dublin, CA).All tests were reliable (false positive <15%; fixation losses and false-negative responses <25%) and the last repetition was included in the analysis.Linear regression analysis was used to analyse data.
Results: :
GDxVCC TSNIT Average (TSNIT) was moderate related with FDT matrix mean deviation (MD) and pattern standard deviation (PSD) (R2: 0.5, p<0.004; R2 0.58, p=0.001), while it was weakly related with mean retinal sensitivity (MS) ( R2: 0.35, p=0.02). It was found moderate relation between TSNIT and SAP PSD (R2: 0.56, p=0,0004) and weak relation with SAP MD and SAP MS (R2: 0.39, p=0.005; R2: 0.31, p=0.01). TSNIT was also weakly related with SWAP PSD (R2: 0.4, p=0.004). Similar results were found for sector analysis in FDT matrix MS, SAP MS and RNFL sectors. GDxVCC Nerve Fiber Indicator (NFI) strongly related to FDT Matrix MD (R2: 0.70, p=0.0002), while it was weakly and moderate related to PSD and MS respectively ( R2: 0.48, p=0.006; R2: 0.59, p=0.001). NFI weakly related to all SAP parameters (MD R2: 0.35, p= 0.01; PSD R2: 0.46, p=0.001; MS R2: 0.27, p=0.02), while it was moderate related to SWAP PSD and weakly to SWAP MD ( R2: 0.57, p=0.0003; R2: 0.29, p=0.002).
Conclusions: :
Our study suggests that structural measurements with GDxVCC are related to FDT Matrix functional parameters in glaucoma patients.
Keywords: nerve fiber layer • visual fields • ganglion cells