Abstract
Purpose: :
To identify the differential diagnostic features of glaucomatous optic neuropathy (GON) and non-glaucomatous optic neuropathy (non-GON) in spectral domain optical coherence tomography(SD-OCT) optic nerve imaging.
Methods: :
Patients with a linear cup/disc ratio of 0.6 - 0.7 were enrolled and assigned to GON and non-GON group per diagnosis. GON subjects had documented high tension glaucoma without history of central nervous system(CNS) disorders. Non-GON subjects had documented optic neuropathy secondary to CNS pathology. Clinical IOP/CCT, optic nerve observations including the cup/disc ratio, pallor and rim thinning/notch were recorded. Linear cup/disk ratio was confirmed by Heidelberg Retinal Tomography (HRT) II (Heidelberg Engineering, Heidelberg, Germany). Humphrey Field (Carl Zesis Meditec AG, Jena, Germany) 24-2 was performed for the pattern visual defect evaluation and the mean deviation/pattern standard deviation recording. SD-OCT (Spectralis TM Heidelberg Engineering, Heidelberg, Germany) was employed for retinal ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer thickness (RFNL) measurement. Statistical analysis was done by R 2.12.1.
Results: :
22 eyes (12 GON, 10 non-GON) were studied. More patients in non-GON had optic nerve pallor (p<0.01). SD-OCT global RNFL thickness (μm) had no significant difference between GON and non-GON (75.58+/-14.32 and 81.71+/-18, p=0.4). Average RNFL thickness at inferior quadrant and inferotemporal quadrant were thinner in GON (92.83+/-27.75 and 92.83+/-26.86) than in non-GON(114.9+/-21.56 and 130.57+/-11.19), p=0.02 and 0.01. Average RNFL thickness at nasal quadrant was thinner in non-GON (56.57+/-19.7 ) than in GON (62.83+/-12.53),p=0.02.
Conclusions: :
GON and non-GON have different patterns of RNFL thinning per SD-OCT optic nerve imaging. GON tends to have thinner RNFL at inferior and inferior-temporal quadrants, while non-GON has thinner RNFL at nasal quadrant.
Keywords: imaging/image analysis: clinical