MR Imaging of the Anterior Visual Pathway in Primary Open-Angle Glaucoma: Correlation with Octopus 101 Perimetry and Spectralis Optical Coherence Tomography Findings.

PURPOSE: To investigate structural changes in the visual pathway measured by magnetic resonance imaging (MRI) and its relationship with the clinical severity of glaucoma in primary open-angle glaucoma (POAG) patients. MATERIALS AND METHODS: The study included 28 patients with POAG and 26 age- and sex-matched healthy volunteers. All the subjects underwent spectral domain optical coherence tomography (OCT) of the peripapillary retina nerve fiber layer (RNFL). The optic nerve diameter (OND), chiasma height (Ch), and lateral geniculate nucleus height (LGNh) were measured bilaterally using a 1.5-Tesla MRI system. RESULTS: The mean values of the OND and LGNh were significantly lower in the POAG group (OND: right p = 0.043 and left p = 0.048; LGNh: right p = 0.008 and left p = 0.025). The OND was not correlated with the clinical stage of glaucoma, but it was correlated with the ipsilateral RNFL thickness. The Ch was correlated with the ipsilateral clinical stage (right r = -0.536, p = 0.004; left r = -0.537, p = 0.004) and average RNFL thickness (RNFLav) (right r = 0.655, p < 0.001; left r = 0.626, p < 0.001). The sum of bilateral clinical stages and left clinical stages showed significant correlations with the right and left LGNh and the sum of both the right and left LGNh. The left RNFLav and the sum of the right-left RNFLav were significantly correlated with all LGNh measurements. CONCLUSIONS: 1.5-Tesla MRI can detect structural changes in the visual pathway early in the course of glaucoma. Thin optic nerve can be a risk factor for glaucoma. The Ch and LGNh seem to be correlated with the clinical stage of glaucoma and RNFL thickness. In particular, LGN can be a target of glaucomatous damage.

The factors influencing peripapillary choroidal thickness in primary open-angle glaucoma.

PURPOSE: To investigate whether there is a difference between primary open-angle glaucoma (POAG) patients and control group with regard to choroidal thickness (CT) and the factors influencing CT. METHODS: Ninety eyes of 90 patients who were being followed up with POAG and 72 eyes of 72 healthy subjects matched for age and gender were included. Peripapillary retinal nerve fiber layer thickness (RNFLT), peripapillary CT, lamina cribrosa thickness (LCT), and prelaminar tissue thickness (PTT) were measured with spectral-domain optical coherence tomography (SD-OCT) enhanced depth imaging (EDI) in all patients. RESULTS: According to multi-variable linear regression analysis results, the factors influencing CT were found as axial length (AL) (B = -22.78, p = 0.002), intraocular pressure (IOP) (B = -7.95, p = 0.001), age (B  = -1.77, p = 0.009), and radial pulse rate (B  = 1.42, p = 0.015). A statistically significant relationship was not detected between CT and central corneal thickness, mean deviation value of visual field, cup/disk ratio, RNFLT, LCT, PTT. CT was found significantly thinner in glaucoma group (147.5 ± 61.2 µm) compared to control group (167.1 ± 37.3 µm). However, IOP was found significantly higher (p < 0.001) and pulse rate was found significantly lower (p = 0.021) in POAG group. IOP and pulse rate were considered to have affected CT difference between the groups. In advanced and worser stage patients, there were significant positive correlations between CT and RNFLT in inferior and superior quadrants. CONCLUSIONS: In addition to previous studies, IOP and pulse rate were detected to be effective on CT. Further studies are required for determining the whole factors effective on CT and better understanding CT and glaucoma relationship.