Toshie Furuya

Role of Retinal Glial Cell Glutamate Transporters in Retinal Ganglion Cell Survival Following Stimulation of NMDA Receptor

Purpose: To investigate the role of glutamate transporters (GLTs)in retinal glial cells that were treated with N-methyl-D-aspartate (NMDA), in retinal ganglion cell (RGC) survival. Methods: Primary cultures of retinal glial cells or RGCs from 3-day-old Sprague-Dawley rats were employed in the present study. Retinal glial cells were treated with NMDA and changes in GLT mRNA and protein expression were analyzed. The effects of pretreating retinal glial cells with the GLAST-specific inhibitor, rottlerin (ROT), and the GLT-1-specific inhibitor, dihydrokainic acid (DHK), on RGC survival were investigated under exposure to NMDA. The amount of glutamate in the culture medium of retinal glial cells was measured by high-performance liquid chromatography. Results: NMDA treatment increased GLAST and GLT-1 expression. GLAST and GLT-1 mRNA expression increased by 2.94-fold and 3.36-fold at 12 h after treatment with the highest concentration of NMDA (33 mM), and by 1.41-fold and 1.39-fold at 24 h, respectively. GLT-1 and GLAST protein expression also increased. MK801, an NMDA-receptor antagonist, inhibited the NMDA-induced upregulation of GLT mRNA expression. Co-culture with retinal glial cells increased the survival rate of RGCs. ROT decreased the survival rate of RGCs, whereas DHK significantly increased the survival rate of RGCs treated with 33 mM NMDA. NMDA treatment reduced the total amount of glutamate in the culture medium, particularly when 33 mM NMDA was added to the medium. ROT pretreatment increased the amount of glutamate in the culture medium, whereas DHK pretreatment decreased it. Conclusion: GLAST and GLT-1 may have different roles in the survival of RGCs mediated by retinal glial cells. These results suggest that the NMDA-associated induction of GLTs plays an important role in RGC survival.

Comparison of the anterior ocular segment measurements using swept-source optical coherent tomography and a scanning peripheral anterior chamber depth analyzer

PurposeTo compare the anterior ocular segment measurements of two non-contact devices, i.e., anterior segment swept-source optical coherence tomography (SS-OCT) and the scanning peripheral anterior chamber depth analyzer (SPAC), in patients with glaucoma.Patients and methodsThis was a cross-sectional study of glaucoma patients visiting the Yamanashi University Hospital. The consistency and correlation of various parameters were studied between the SS-OCT and SPAC measurements, including the central corneal thickness (CCT), the central anterior chamber depth (ACD), the trabecular–iris angle (TIA), the angle opening distance (AOD), the area of the recessed angle (ARA), and the trabecular–iris space area (TISA) from the SS-OCT measurements, and the CCT, central ACD, SPAC grade, and SPAC-evaluated anterior chamber angle (ACA) from the SPAC measurements.ResultsSeventy right eyes of 70 patients (27 men, 43 women) with glaucoma were enrolled in the study. The mean patient age was 65.9 ± 14.5 years. The CCT measurements by SS-OCT and the SPAC were 528.3 ± 32.0 and 516.1 ± 28.5 μm, respectively (P < 0.001). The central ACD measurements by SS-OCT and the SPAC were 2.39 ± 0.44 and 2.73 ± 0.50 mm, respectively (P < 0.001). The two devices showed a significant correlation in terms of the CCT measurements (R2 = 0.667, P < 0.0001) and the central ACD measurements (R2 = 0.86, P < 0.0001), but SS-OCT give a significantly shallower central ACD measurement and a thinner CCT measurement compared with the SPAC. AOD, TIA, TISA, and the ARA were all significantly correlated with the SPAC grade and the ACA. Consistency between the two devices was reduced among eyes with primary angle closure.ConclusionsBased on our results, the SS-OCT and SPAC measurements of the anterior segment were significantly correlated, but the values cannot be considered to be directly interchangeable.

Longitudinal changes in anterior chamber configuration in eyes with open-angle glaucoma and associated factors.

PurposeTo investigate longitudinal changes in anterior chamber depth (ACD) and anterior chamber angle (ACA) and the associated factors in patients with primary open-angle glaucoma using the scanning peripheral ACD analyzer. MethodsThe scanning peripheral ACD analyzer evaluated ACD by numeric grade (ACDG 1 to 12) and ACA twice in 2003 and 2008. The exclusion criteria were as follows: history of laser or incisional surgery, other ocular diseases that may affect visual field, visual acuity less than 20/30, and treatment with pilocarpine ophthalmic solution. Patients with pseudophakic eye were used as control. ResultsOne hundred fifty-seven patients with glaucoma and 26 patients with pseudophakic eye were subjected to the analysis. ACDG and ACA of patients with glaucoma were significantly decreased from 7.2±2.3 to 6.5±2.1 (P<0.001) and from 34.2±12.6 to 28.1±10.3 degrees (P<0.0001), respectively, whereas patients with cataract surgery showed no significant changes in ACDG and ACA. The change in ACD was greater at the peripheral region than at the central region. The decrease in ACDG was significantly associated with deep initial ACDG and wide ACA. Patients having shallow ACDG and narrow ACA showed more rapid deterioration of visual field than those having deep ACDG and wide ACA. ConclusionsACDG and ACA decreased with age, and initial ACDG and ACA were related to the progression of open-angle glaucoma.

Changes in Peripheral Anterior Chamber Depth of a Case of Relapsing Polychondritis with Recurrent Secondary Angle Closure Glaucoma

A case of relapsing polychondritis showed IOP elevations three times during the follow-up due to the angle-closure mechanism. The peripheral anterior chamber depth (ACD) showed a good correlation with IOP elevation, but central ACD did not. The peripheral ACD could be more related to IOP elevation than central ACD.