原发性开角型青光眼患者和健康对照者眼内压中度改变对眼血流动力学的影响

Purpose: There is some indirect evidence for altered autoregulation in patients with glaucoma, but only a few studies have measured ocular blood flow directly during changes in ocular perfusion pressure. The present study was designed to compare pulsatile choroidal blood flow and optic nerve head (ONH) blood flow during moderate increases in intraocular pressure (IOP) in patients with primary open-angle glaucoma (POAG) and normal controls. Design: Two nonrandomized studies comparing blood flow responses in glaucoma patients and controls in an open design. Participants and Controls: Sixteen patients with POAG glaucoma and 16 healthy gender-matched and age-matched controls were included in the choroidal blood flow experiments. The ONH blood flow experiment was performed in 14 POAG patients and 14 healthy gender-matched and age-matched controls. Methods:In the first study, pulsatile choroidal blood flowwas assessed by laser interferometric measurement of fundus pulsation amplitude (FPA). In the second study, ONH blood flow was measured using laser Doppler flowmetry. In both cohorts, the IOP was increased stepwise by 10 and 20 mmHg using a suction cup. Main Outcome Measures: Fundus pulsation amplitude and ONH blood flow. Results: The baseline values of FPA and ONH blood flow were lower in glaucoma patients as compared with age-matched and gender-matched healthy controls. In patients with POAG, FPA decreased by -4.5± 5.8% and -11.3± 4.9% during elevation of IOP of 10 and 20 mmHg, respectively. These results were not different from the results in healthy controls, where FPA decreased by -5.1± 3.4% and -12.2± 4.9% at the 2 pressure levels (P=0.23 between groups). Optic nerve head blood flow showed no changes during the increase of IOP of 10 and 20 mmHg in either of the 2 groups (glaucoma patients, + 2.1± 14.7% and-0.8± 15.2% ; healthy controls, + 4.3± 12.0% and + 0.2± 14.2% ; P=0.83 between groups). Conclusions: The present study does not provide evidence for altered autoregulation in patients with POAG during a moderate increase in IOP. However, these results do not necessarily contradict the concept of vascular dysregulation in glaucoma.

小梁切除术对眼血流量的影响

Background/aim: Current evidence suggests that vascular insufficiencies in the optic nerve head play an important part in the pathogenesis of glaucomatous optic neuropathy. Trabeculectomy is the most common operative procedure for the treatment of medically uncontrolled glaucoma. This study was conducted to investigate whether trabeculectomy may improve ocular haemodynamics. Methods:30 patients with primary open angle glaucoma about to undergo trabeculectomy were included in the study. Patients were evaluated before surgery and at 2 and 10 weeks after trabeculectomy. Optic nerve head blood flow (OnhBF) was assessed with scanning laser Doppler flowmetry. Fundus pulsation amplitude (FPA) measurements were obtained with laser interferometry. Results: Because of the decrease in intraocular pressure there was a significant increase in ocular perfusion pressure (OPP) following trabeculectomy (18.5% (SD 12.0% ) and 19.0% (17.1% ) at 2 and 10 weeks postoperatively; P < 0.001). A significant increase in OnhBF was observed after trabeculectomy (11.6% (16.4% ) and 16.2% (20.2% ) for each postoperative visit, respectively; P< 0.001)-. FPA was also significantly higher compared with baseline values (17.2% (17.3% ) and 17.4% (16.3% ), respectively; P< 0.001). A significant association between the increase in OPP and the increase in OnhBF and FPA was observed 10 weeks after surgery (r=0.47; P=0.009, and r=0.50; P=0.005, respectively). Conclusion: The results of this study suggest that trabeculectomy improves ocular blood flow in patientswith chronic open angle glaucoma.

视网膜侧支静脉和黄斑静脉闭塞后激光光凝治疗对视网膜血管直径的影响

Objective: To investigate the response of retinal vessel diameters to photocoa gulation treatment and their role for the success of laser treatment in patients with retinal vein occlusion. Methods: The study included 14 patients with branc h vein occlusion or macular vein occlusion. The ophthalmologic examination inclu ded best-corrected visual acuity, biomicroscopy, fundus photography, and fluore scein angiography. Retinal vessel diameters were quantified before and after las er photocoagulation using a retinal vessel analyzer. Main Outcome Measure: Retin al vessel diameters. Results: In cases manifesting macular vein occlusions, no s ignificant change of the vessel diameter in any vessel was observed during the f ollow-up period. In the group with branch vein occlusion, all vessels tended to constrict after the laser photocoagulation. The effect of laser treatment on re tinal vessel diameters was significant for superotemporal (P=0.045, analysis of variance ANOVA) and inferotemporal branch veins (P=0.03, ANOVA). Vasoconstrict ion was more pronounced in the occluded branch veins (P=.009, ANOVA) compared wi th the nonaffected veins (P=.12; ANOVA). The change of visual acuity after 3 mon ths was correlated with the change of vessel diameter 3 months after laser treat ment for occluded venular branches (r=0.78, P=.02, linear regression). There was no correlation between the number of laser burns and the change of vessel diame ters in the affected veins in this period (r=0.12, P=.75, linear regression). Co nclusions: Our results show that retinal photocoagulation in patients with branc h vein occlusion has a vasoconstrictive effect on occluded veins. The correlatio n between the change in visual acuity and the change in vessel diameter indicate s that branch vein constriction after photocoagulation may be an early indicator of the success of laser treatment.