Objectives 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.
- ocular surface
- optic nerve
- public health
- Stratus OCT
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Competing interests None.
Patient consent Obtained.
Ethics approval The study was approved by the institutional review board of Tor Vergata University Hospital, in adherence to the tenets of the Declaration of Helsinki.
Provenance and peer review Not commissioned; externally peer reviewed.