Purpose To investigate control mechanisms for ocular blood flow changes after dynamic exercise using two different methods. Methods Changes over time in the tissue blood flow in the retina and choroid-retina of healthy volunteers were determined after dynamic exercise (Master's double two-step test), using scanning laser Doppler flowmetry (SLDF) and laser speckle flowgraphy (LSFG). Changes in intraocular pressure (IOP), blood pressure, plasma CO 2 gas concentration (pCO 2 ), and levels of nitric oxide (NO) metabolites were examined.Results Retinal blood flow measured by SLDF increased significantly only at 15 min after exercise. In contrast, normalized blur (NB) values in the choroid-retina, obtained by LSFG, increased significantly up to 60 min after exercise. Ocular perfusion pressure (OPP), calculated from IOP and blood pressure, increased significantly immediately and 15 min after exercise. The plasma NO metabolite levels increased significantly, although pCO 2 levels were unchanged. Conclusions Dynamic exercise changes OPP and produces increased tissue blood flow in the retina in the immediate postexercise period, while blood flow increases more persistently in the choroid-retina. Difference in control of blood flow in these two regions may be related to stronger autoregulatory mechanism of blood flow in the retina. Nitric oxide may play a role in the regulation of blood flow.
The 360-degree SLT was shown to be more effective than180-degree SLT for intermediateterm reduction in IOP of Japanese patients with open-angle glaucoma as an adjunctive treatment protocol.
Purpose:This paper compares the outcomes of the Ex-PRESS® Glaucoma Filtration Device (Alcon, Fort Worth, TX) implant observed in Japanese patients for 1 year with those of patients undergoing trabeculectomy.Patients and methods:The subjects comprised ten eyes of ten cases with open-angle glaucoma for which filtration surgery using Ex-PRESS (P-50) was performed by one operator from February 2008 and observed for at least 1 year (Ex-PRESS Group), and eleven eyes of eleven cases for which trabeculectomy was performed by the same operator (TE Group). For both groups, mitomycin C was used and a scleral flap was created after a fornix-based incision of the conjunctiva.Results:Hypotony and choroidal detachment were observed as early postoperative complications during a 1-week period in one-third of the cases in the TE Group, and failing vision in about 45%, while these were seen in fewer cases in the Ex-PRESS Group. No significant difference in intraocular pressure (IOP) was observed during the period, but IOP variations on the day following the surgery were obviously narrower in the Ex-PRESS Group than in the TE Group. Visual acuity was significantly poorer from 1 week to 3 months in the TE Group while it was stable in the Ex-PRESS Group. The Ex-PRESS Group had fewer cases of laser suture lysis and fewer administrations of glaucoma eyedrop, and no cases of progression in the stage of visual field defect.Conclusion:Filtration surgery using the Ex-PRESS is unlikely to cause early complications in Japanese patients. Similarly to the trabeculectomy, the intermediate-term control of IOP showed favorable results.
Purpose Diurnal variations in microcirculation of the ocular fundus in normal-tension glaucoma (NTG) were examined to compare with the normal control eyes. The correlation between progression of visual field impairment and diurnal variations in ocular circulation was also studied. Methods The subjects were 12 patients with NTG and 12 normal controls. Blood pressure (BP), intraocular pressure (IOP), ocular perfusion pressure (OPP), and square blur rate (SBR), an index of microcirculation acquired by the laser speckle method, were measured at 9 a.m. (morning), 3 p.m. (afternoon), and 9 p.m. (night). Diurnal variations in SBR were tested using the Friedman test and Wilcoxon signed ranks test. On the other hand, diurnal variations in BP, IOP, and OPP were tested by the analysis of variance. The visual field was evaluated at the same time as determining diurnal variation and again about 9 months later to calculate the change. The correlation between variation ratio in SBR and the change in visual field was examined by simple regression. Results A significant decrease (P ¼ 0.04) was found in SBR at night, as compared with the morning value, in the optic nerve head (ONH) of NTG, although no significant diurnal variations were found in SBR either in the choroid-retina or in normal control eyes. Other parameters showed no significant diurnal variations. The larger diurnal variation was in SBR of the ONH, and the more exacerbated visual field impairment was (r ¼ 0.59, P ¼ 0.04). Conclusion These findings suggest that diurnal variations in the microcirculation of the ONH may play a role in the progression of NTG.
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