3-T Diffusion tensor imaging of the optic nerve in subjects with glaucoma: correlation with GDx-VCC, HRT-III and Stratus optical coherence tomography findings.
OBJECTIVE
To correlate diffusion-tensor imaging (DTI) of the optic nerve with morphological indices obtained by scanning laser polarimetry (GDx-VCC); confocal scanning laser ophthalmoscopy (Heidelberg III retinal tomograph; HRT-III) and optical coherence tomography (Stratus OCT).


METHODS
Thirty-six subjects (12 with no eye disease and 24 with perimetrically diagnosed glaucoma) were examined. One eye for each participant was studied with 3-Tesla DTI (with automatic generation of mean diffusivity (MD) and fractional anisotropy (FA) values); GDx-VCC, HRT-III and OCT. Single and multiple regression analyses of all variables studied were performed.


RESULTS
MD displayed the strongest correlation with linear cup/disc ratio (LCDR) from HTR-III (r=0.662), retinal nerve fibre layer (RNFL) thickness (avThickn) from OCT (r=-0.644), and nerve fibre index (NFI) from GDx (r=0.642); FA was strongly correlated with the LCDR (r=-0.499). In multiple regression analyses, MD correlated with LCDR (p=0.02) when all variables were considered; with avThickn (p<0.01) (analysis of all RNFL parameters); with NFI (p<0.01) (analysis of all GDx parameters); with avThickn (p<0.01) (analysis of OCT parameters); with LCDR (p=0.01) (analysis of HRT-III morphometric parameters) and with linear discriminant function (RB) (p=0.02) (analysis of HRT-III indices). As for FA, it correlated with avThickn (p=0.02) when we analysed the OCT parameters and with RB (p=0.01) (analysis of HRT-III indices).


CONCLUSIONS
DTI parameters of the axonal architecture of the optic nerve show good correlation with morphological features of the optic nerve head and RNFL documented with GDx-VCC, HRT-III and OCT.
Department of Experimental Medicine and Surgery, Ophthalmology Unit, University of Rome Tor Vergata, Via Montpellier 1, Rome 00133, Italy. nucci@med.uniroma2.it
Carlo
C
Nucci
Raffaele
R
Mancino
Alessio
A
Martucci
Francesca
F
Bolacchi
Guglielmo
G
Manenti
Claudio
C
Cedrone
Franco
F
Culasso
Roberto
R
Floris
Luciano
L
Cerulli
Francesco Giuseppe
FG
Garaci
D000368:Aged; D001369:Axons / Q000473:pathology; D056324:Diffusion Tensor Imaging / Q000379:methods*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D007834:Lasers; D008297:Male; D008875:Middle Aged; D009887:Ophthalmoscopy / Q000379:methods*; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology; D057109:Scanning Laser Polarimetry / Q000379:methods*; D041623:Tomography, Optical Coherence / Q000379:methods*