Relation Between Structural Measurements by Spectral Domain Optical Coherence Tomography (RTVue-100) and Functional Parameters in Glaucoma Patients

Abstract

Purpose: : to evaluate relationship between structural measurements of Retinal Nerve Fiber Layer thickness (RNFL) and Retinal Ganglion Cells layer thickness (GCC) measured by spectral domain optical coherence tomography (RTVue-100) 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 and GCC assessment by RTVue-100 (Optovue Inc. Fremont CA), visual field testing by SAP, SWAP and FDT matrix 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).We included in the analysis the second repetition of visual field.All tests were reliable (false positive <15%; fixation losses and false-negative responses <25%).Linear regression analysis was used to analyse data

Results: : We found strong relationship between FDT matrix mean deviation (MD) and RNFL average (R²:0.77; p<0.0001) and good relation between FDT matrix pattern standard deviation (PSD) ( R²: 0.63; p= 0.0002), FDT matrix mean retinal sensitivity( MS)(R²=0.65;p=0.0002) and RNFL average. Similar results were found for sector analysis in FDT matrix MS and RNFL sectors.It was found weak relation between SAP MD(R²:0.32; p=0.008), SAP PSD (R²:0.41, p=0.0025 ), SAP MS (R²:0.25; p= 0.02), SWAP MD (R² :0.31; p=0.01) , SWAP PSD (R²:0.46; p=0.001) and RNFL average.SWAP PSD and GCC (R²:0.23; p=0.03) was weakly related. No relation between GCC and other functional parameters was found.

Conclusions: : Our study suggests that structural measurements of RNFL in RTVue-100 are related with FDT matrix functional parameters in glaucoma patients.

Keywords: nerve fiber layer • visual fields • ganglion cells