Relative change in diurnal mean ocular perfusion pressure: a risk factor for the diagnosis of primary open-angle glaucoma

PURPOSE: To investigate diurnal change and pattern of variation in intraocular pressure (IOP) and systolic (SBP) and diastolic (DSP) blood pressures in a group with untreated primary open-angle glaucoma (uPOAG) and compare it with an age-matched, normal group. METHODS: IOP, SBP, and DBP were measured in 14 patients with uPOAG and in 14 normal subjects, every hour between 7 AM and 10 PM and the mean ocular perfusion pressure (MOPP) was calculated. Mixed-effect linear models were used to analyze the repeated-measures data in which both fixed and random effects were included. The relative diurnal change was calculated as the percentage decrease from maximum. RESULTS: The uPOAG group had the higher IOP (P < 0.001) and lower MOPP (P = 0.025). There was a significant diurnal change in IOP, SBP, DBP, and MOPP in both groups (P < 0.001). The pattern of diurnal variation in IOP (P = 0.137), SBP (P = 0.569), and DBP (P = 0.937) was not significantly different between groups but was significantly different for MOPP (P = 0.040). MOPP and IOP were most similar at 7 AM and 1 PM. Postprandial hypotension was significant for SBP, DBP, and MOPP (P < 0.001), but not IOP (P = 0.388) in both groups. The relative change in MOPP was larger in the uPOAG group (38% vs. 26%, P < 0.001), but the change in IOP was similar (42% vs. 41%, P = 0.786). There was a significant effect of DBP on IOP over the course of the day in the uPOAG group (P = 0.011) but not in the normal group (P = 0.733). CONCLUSIONS: The relative diurnal change in IOP was similar in both uPOAG and normal subjects but MOPP showed a significant difference. MOPP significantly decreased after lunch, and was at its lowest in uPOAG at 7 AM, when IOP was at its highest. A significant association was found between diurnal DBP and IOP in uPOAG.     

Autoregulation of human optic nerve head blood flow in response to acute changes in ocular perfusion pressure

Background: Studies in animals have demonstrated that optic nerve head (ONH) blood flow (F_onh) is autoregulated, but there is a lack of evidence for such a process in humans. Therefore, we investigated the relationship between F_onh and mean ocular perfusion pressure (PP_m) in normal volunteers when PP_m is decreased through elevation of the intraocular pressure (IOP). Methods: Laser Doppler flowmetry (LDF) was used to measure relative mean velocity (Vel_ohn), volume (Vol_onh) and F_onh of blood at sites of the ONH away from visible vessels, while PP_m was decreased in two ways: (1) rapidly, by IOP increments of 15 s duration, and (2) slowly, by IOP increments of 2 min duration, both by scleral suction cup in one eye of each of nine subjects. Results: A rapid and large decrease of PP_m of more than 100% induced a decrease of more than 80% in F_onh. With the slower decrease in PP_m F_onh remained constant down to a PP_m of 22 mm Hg (IOP=40 mm Hg) and then decreased, predominatly due to a decrease in Vel_ohn. Immediately after removal of the suction cup, F_onh increased transiently by 44% above baseline. Conclusions: This study demonstrates efficient blood flow autoregulation in the OHN, which is probably brought about by an increase in vascular capacitance. The magnitude of the reactive hyperaemia agrees with the compensatory decrease in ONH vascular resistance during IOP elevation. The time scale of the autoregulatory process and the dependence of the hyperaemia upon duration of IOP elevation suggest a metabolic mechanism of autoregulation.     

Pulsatile ocular blood flow in primary open-angle glaucoma and ocular hypertension

PURPOSE: To compare pulsatile ocular blood flow measurements in untreated ocular hypertensive (OHT) subjects and primary open-angle glaucoma (POAG) patients. DESIGN: A prospective observational study in an institutional setting. METHODS: A total of 97 subjects were recruited to the study (50 ocular hypertensives, 24 glaucoma patients, and 23 normal subjects). "High-risk" OHT had intraocular pressure (IOP) > 25 mm Hg; "low-risk" OHT had IOP 相似文献   

Ocular blood flow and systemic blood pressure in patients with primary open-angle glaucoma and ocular hypertension

PURPOSE: There is evidence that altered optic nerve head (ONH) blood flow may play a role in the development and progression of glaucoma. In the present study, the baseline characteristics were examined in a study population participating in a clinical trial in which the ocular hemodynamic effects of timolol and dorzolamide were compared. METHODS: One hundred forty patients with primary open-angle glaucoma (POAG) or ocular hypertension (OHT) were included in this trial and their baseline parameters compared with those of a group of 102 age-matched control subjects. Scanning laser Doppler flowmetry was used to measure blood flow in the temporal neuroretinal rim and the cup of the ONH. Pulsatile choroidal blood flow was assessed by laser interferometric measurement of fundus pulsation amplitude. In addition, hemodynamic parameters and mean arterial pressure were calculated in both groups. RESULTS: All ocular hemodynamic parameters were significantly lower in the POAG/OHT group compared with the healthy control group (P < 0.001 each). In addition, a significant positive correlation between laser Doppler flowmetry readings and mean arterial pressure was observed in patients with glaucoma but not in healthy control subjects. Likewise, the correlation coefficient between fundus pulsation amplitude and mean arterial pressure was higher in patients with glaucoma than in healthy control subjects. CONCLUSIONS: The present study indicates reduced ONH and choroidal blood flow and an abnormal association between blood pressure and ocular perfusion in patients with primary open-angle glaucoma or ocular hypertension, independent of topical antiglaucoma medication. Hence, vascular dysregulation appears to be an early manifestation in glaucoma that is not caused by pharmacologic intervention.     

Episcleral venous pressure in untreated primary open-angle and normal-tension glaucoma

The aim of this prospective study was to investigate episcleral venous pressure (EVP) in different forms of glaucoma in comparison with age-matched controls. EVP was measured by means of a venomanometer in 32 eyes with untreated primary open-angle glaucoma (POAG), 36 eyes with untreated normal-tension glaucoma (NTG) as well as 56 control eyes without ophthalmological disease other than cataract. In addition to ophthalmological standard examination, cardiovascular parameters such as systolic and diastolic blood pressure and heart rate were recorded. In the POAG group, EVP was 12.1 +/-0.5 mm Hg and in the NTG group 11.6 +/- 0.4 mm Hg. This was significantly different from EVP of the controls (9.5 +/- 0.2 mm Hg). The EVP/intraocular pressure (IOP) ratio was significantly different in NTG patients (80.0% +/- 3.2) in comparison with both POAG patients (67.1% +/- 2.8) and controls (69.2% +/- 2.4). The difference between IOP and EVP (IOP - EVP) was 6.2 +/- 0.6 in the POAG, 3.1 +/- 0.45 in the NTG and 4.5 +/- 0.4 in the control group. All these values were significantly different from each other. Regression analysis revealed a significant linear correlation between EVP and IOP in both the NTG and the POAG group. In the control group, however, the correlation was weak. This study is the first to demonstrate differences in EVP between untreated NTG and POAG and an age-matched healthy control group.     

原发性开角型青光眼视盘及视网膜血流的研究

目的探讨原发性开角型青光眼患者和正常人视盘及其周边视网膜血液供应是否存在差异.方法本研究采用了一种新型共焦扫描激光多普勒血流仪--海德堡视网膜血流仪(heidelberg retina     

Condition of ocular blood supply in patients with primary open-angle glaucoma with normal pressure

The condition of discharge of intraocular fluid (IOF), the value of systemic arterial pressure (AP), the condition of mean dynamic arterial pressure in the ocular artery (Pm.ophth.) an the perfusion ocular pressure (Pperf.) were examined in patients with normal pressure glaucoma (NPG). A decrease in the IOF discharge from 0.16 +/- 0.02 cu mm per 1 mm Hg at the NPG initial stage to 0.11 +/- 0.01 cu mm per 1 mm Hg at the NPG deteriorated stage was established. The value of decrease of the systemic AP within an interval of 100 to 116 mm Hg is observed in patients with NPG by 6.9 times more often as compared to the controls (in 42.2% and 6.1% of cases, respectively). A reliable reduction of Pm.ophth. by 4.0 mm Hg and of Pperf.--by 4.9 mm Hg was found in patients with NPG as compared with Pm.ophth. and Pperf. in the controls with the same systemic AP values; the deficit of the ocular volumetric blood flow reached 10.9%. The treatment of NPG patients must be related with improving the IOF discharge, with reducing the genuine intraocular pressure (Po) to a tolerable level, and with increasing the systemic AP, Pm.ophth. and Pperf. to the mean statistically normal level.     

Anterior optic nerve blood flow in experimental optic atrophy

This study attempts to establish whether neurogenic optic atrophy induces changes in anterior optic nerve circulation and to determine how noninvasive techniques of measuring blood flow in vivo compare to microsphere distribution. Five cats underwent unilateral optic nerve transection in the orbital apex and a sham procedure in the contralateral eye. Two to three months later, no abnormalities were detected by fluorescein angiography. Laser Doppler measurements demonstrated a 53% decrease in red blood cell speed through the capillaries of the atrophic optic nerve heads in vivo. Optic disk reflectance measurements of anterior optic nerve blood volume in vivo demonstrated a 51% decrease in the estimated blood volume of the capillaries in atrophic optic nerve heads. Flow was calculated on the basis of these noninvasive measurements and demonstrated an average decrease of 74% in optic atrophy. Histologic studies of microsphere distribution demonstrated an average decrease of 80% in flow to the anterior optic nerve in optic atrophy. These results suggest that anterior optic nerve blood flow is significantly reduced in primary neurogenic optic atrophy. This study also demonstrates that the noninvasive measurements of blood flow are substantiated by histologic evaluation of microsphere distribution.     

原发性开角型青光眼患者不同体位眼灌注压昼夜波动趋势分析

Objective To characterize the circadian fluctuation of ocular perfusion pressure (OPP) in different position  in patients with newly diagnosed, untreatedprimary open-angle glaucoma（POAG）. Design Cohort study. Participants Nineteen patients with POAG (19 eyes) and eighteen healthy controls (18 eyes) were included in the Peking University Shenzhen Hospital. Methods POAG patients and healthy controls were included and underwent 24-hour monitoring of IOP and blood pressure. On 10:00, 14:00, 18:00 and 22:00 o’clock in the daytime, all the subjects were monitored in sitting position, then POAG patients were monitored again after lying down for 5 minutes. On 2:00, 5:00 and 7:00 o’clock at night all the subjects were monitored in supine position, then POAG patients were monitored again after sitting for 5 minutes. Calculating the mean ocular perfusion pressure (MOPP), the systolic ocular perfusion pressure (SOPP) and diastolic perfusion pressure (DOPP) by the formula and analyzing the data. Main Outcome Measures  MOPP, SOPP, DOPP. Results In both groups of habitual position (sitting position in day and supine position in night), the nocturnal MOPP, SOPP and DOPP were lower than diurnal. In both groups, the nocturnal MOPP was lower than diurnal in habitual position (POAG group t=4.092, P=0.000; healthy group t=4.513, P=0.000). However, there was no obvious difference between those two groups (t=-0.973, P=0.350). POAG group had higher 24-hour fluctuation of MOPP (t=2.204, P=0.039), higher nocturnal fluctuation of SOPP (t=3.097, P=0.018), higher nocturnal and 24-hour fluctuation of DOPP than healthy group, all the differences had statistical significance (all P<0.05).  In POAG group , there was no statistical difference between the nocturnal MOPP and the diurnal MOPP in sitting position or in supine position of 24 h (all P>0.05). POAG group had higher 24-hour mean MOPP in sitting position than in supine position, the difference had statistical significance (t=4.306, P=0.001).  Comparing the MOPP of  POAG group  in habitual position with in sitting position of 24 h, there was no statistical difference(t=-2.101, P=0.080). However, POAG group had higher 24-hour mean MOPP in habitual position than in supine position of 24 h, the difference had statistical significance (t=2.707, P=0.035). Conclusions There circadian fluctuation of  OPP in different position in POAG pations can not be treated as the same. The nocturnal MOPP  was lower than diurnal in habitual position, but there was no obvious difference in the 24h-sitting position and 24h-supine position.  (Ophthalmol CHN, 2017, 26: 20-25）     

Changes in optic nerve head blood flow after therapeutic intraocular pressure reduction in glaucoma patients and ocular hypertensives

PURPOSE: To detect and quantify changes in optic nerve head (ONH) and peripapillary retinal blood flow by scanning laser Doppler flowmetry (SLDF) in open-angle glaucoma (OAG) and ocular hypertension (OHT) after therapeutic intraocular pressure (IOP) reduction. DESIGN: Prospective, nonrandomized, self-controlled trial. PARTICIPANTS: Twenty patients with OAG and 20 patients with OHT with clinical indications for therapeutic IOP reduction were prospectively enrolled. INTERVENTION: IOP reduction was achieved by medical, laser, or surgical therapy. All patients had IOP reductions more than 20% and a minimum of 4 weeks follow-up. MAIN OUTCOME MEASURES: Blood flow measurements were performed by SLDF analysis software (version 3.3) using Heidelberg Retina Flowmeter images. Statistical evaluations were performed on both groups using a two-tailed distribution paired t test. RESULTS: Twenty patients with OAG had a mean IOP reduction of 37% after treatment. In these patients, mean (+/- standard deviation) rim blood flow increased by 67% (from 158 +/- 79 arbitrary units to 264 +/- 127 arbitrary units, P = 0.001), whereas mean temporal peripapillary retinal flow decreased by 7.4% (P = 0.24), and mean nasal peripapillary retinal flow increased by 0.3% (P = 0.96). Twenty OHT patients had a mean IOP reduction of 33% after treatment. In contrast to the OAG group, neither the mean rim blood flow (7.5% increase from 277 +/- 158 arbitrary units to 298 +/- 140 arbitrary units, P = 0.41) nor the mean temporal (P = 0.35) or nasal (P = 0.88) peripapillary retinal flow changed significantly. CONCLUSIONS: For a similar percentage of IOP reduction, OAG patients had a statistically significant improvement of blood flow in the neuroretinal rim of the ONH, whereas OHT patients did not demonstrate such a change. Peripapillary retinal blood flow, expected to be affected less in glaucoma, remained stable in both groups. In addition to indicating a response to therapy in OAG patients, the reported changes in rim perfusion suggest that ONH autoregulation may be defective in OAG while intact in OHT.     

Diurnal variation of intraocular pressure in primary open-angle glaucoma.

Intraocular pressure was measured with a Goldmann applanation tonometer in 12 normal individuals (24 eyes), 14 ocular hypertensives (28 eyes), and 14 patients (27 eyes) with primary open-angle glaucoma every hour for 24 hours. In most subjects, pressure was highest sometime during the day and pressure elevation before rising was not demonstrated. The lowest intraocular pressure was most frequently observed early in the morning, whether the patient was normotensive or hypertensive. Fourteen of 27 glaucomatous eyes had intraocular pressure below 20 mm Hg early in the morning.     

Optic nerve blood flow is diminished in eyes of primary open-angle glaucoma suspects.

PURPOSE: The purpose of this study was to evaluate optic nerve blood flow in primary open-angle glaucoma suspect eyes with normal automated visual fields, in an attempt to elucidate how early in the glaucomatous disease process changes in optic nerve blood flow become apparent. METHODS: Twenty-one eyes (21 patients) suspected of having primary open-angle glaucoma were studied prospectively and compared with a previously reported cohort of 22 eyes (22 patients) with primary open-angle glaucoma and 15 eyes (15 subjects) of age-matched controls. Primary open-angle glaucoma suspect eyes had untreated intraocular pressure greater than 21 mm Hg and normal visual fields using Humphrey program 24-2 or 30-2 with a full threshold strategy. Laser Doppler flowmetry was used to measure optic nerve head blood velocity, volume, and flow at four quadrants in the optic nerve, in the cup, and in the foveola of one eye of each patient. The mean flow from the superotemporal rim, inferotemporal rim, and cup was calculated (Flow(3)) and identified as the main outcome measure. Measurements from primary open-angle glaucoma suspect eyes were compared with corresponding measurements from controls and eyes with primary open-angle glaucoma; a Student t test was employed with a Bonferroni corrected P value of.025 to account for comparisons of primary open-angle glaucoma suspects both to controls and to eyes with primary open-angle glaucoma. RESULTS: Compared with controls, Flow(3) was 24% lower in primary open-angle glaucoma suspect eyes (P <.0003). In primary open-angle glaucoma suspect eyes, flow was 16% lower in the superotemporal rim (P <.007), 35% lower in the cup (P <.007), and 22% lower in the inferotemporal neuroretinal rim (P <.029) compared with controls. No significant difference between primary open-angle glaucoma suspect and control eyes was seen in the inferonasal rim, superonasal rim, or foveola. No significant difference was detected at any location between primary open-angle glaucoma suspect eyes and eyes with primary open-angle glaucoma. CONCLUSIONS: Laser Doppler flowmetry detected circulatory abnormalities in primary open-angle glaucoma suspects who did not have any manifest visual field defect. Decreases in flow in glaucoma suspects were similar in magnitude to those of subjects with primary open-angle glaucoma. These data suggest that impaired optic nerve blood flow develops early in the glaucomatous process and does not develop solely as a result of glaucoma damage.     

Evaluation of pulsatile ocular blood flow in primary open-angle glaucoma: Trabeculectomy vs medical therapy

This study compared the effect of trabeculectomy vs medical therapy on pulsatile ocular blood flow (POBF) in eyes with primary openangle glaucoma. Thirty-eight patients with primary open-angle glaucoma, in whom one eye had glaucoma surgery and the other eye received topical antiglaucoma, therapy, underwent bilateral POBF testing before treatment and at 3-month follow-up The POBF in trabeculectomy-treated eyes was significantly higher at 3 months than in contralateral eyes treated medically. The authors have stated that they do not have a significant financial interest or other relationship with any product manufacturer or provider of services discussed in this article.     

Assessment of optic disk blood flow in patients with open-angle glaucoma

PURPOSE: To characterize optic disk blood flow in patients with open-angle glaucoma compared with age-matched healthy control subjects. METHODS: In this prospective cross-sectional study, 90 eyes of 90 patients with open-angle glaucoma and 61 eyes of 61 age-matched healthy control subjects were evaluated. Flow in the optic disk cup and the neuroretinal rim were assessed with scanning laser Doppler flowmetry. Fundus pulsation amplitude in the cup and the macula were assessed with laser interferometry. Visual field mean deviation was measured with the Humphrey 30 to 2 program. RESULTS: Flow in the neuroretinal rim (-18%, P =.002), and in the cup (-46%, P <.001) and fundus pulsation amplitude in the cup (-33%, P <.001) and in the macula (-24%, P <.001) were significantly lower in patients with open-angle glaucoma compared with healthy control subjects. A significant association between blood flow measurements in the cup and fundus pulsation amplitudes in the cup was observed in both study cohorts. A significant association was also observed between the mean defect from visual field testing and ocular hemodynamic parameters. CONCLUSIONS: Reduced optic disk perfusion in patients with open-angle glaucoma is evidenced from two independent methods in the present study. Moreover, our data indicate that reduced ocular blood flow in these patients is linked to visual field changes. It remains to be established whether compromised optic disk and choroidal blood flow contributes to optic disk damage in glaucomatous eyes or is a secondary functional phenomenon.     

原发性开角型及慢性闭角型青光眼患者视盘毛细血管密度和视野缺损的关联性研究

目的 本研究旨在通过分析原发性开角型青光眼(POAG)患者和慢性原发性闭角型青光眼(PACG)患者的视盘毛细血管密度与视野缺损的相关性,探讨视盘毛细血管密度在青光眼诊断和病情评估中的价值。方法 纳入2017年9月2018年9月我院收治的POAG患者90例(90眼)作为POAG组,慢性PACG患者75例(75眼)作为PACG组,2组的年龄、性别和视野平均缺损(MD)值进行了匹配。此外,纳入同期性别、年龄匹配的60位健康体检者60眼作为对照组。检测所有参与者的视盘毛细血管密度、视网膜神经纤维层(RNFL)厚度及视野缺损情况。结果 POAG和PACG患者的平均RNFL厚度和平均毛细血管密度均显著低于正常人(P<0.05),而POAG患者和PACG患者的平均RNFL厚度和平均毛细血管密度差异没有统计学意义(P>0.05)。对于POAG患者,其视盘上方、下方、颞侧和全区的RNFL厚度与视野MD值呈负相关(r=-0.525,-0.462,-0.246,-0.453,P均<0.05),但是鼻侧的RNFL厚度与视野MD值无相关性(r=-0.198,P>0.05)。4个区域和全区的毛细血管密度与视野MD值均呈显著负相关(r=-0.341,-0.426,-0.285,-0.298,-0.557,P均<0.05)。对于PACG患者,仅上方、下方和全区的RNFL厚度与视野MD值相关(r=-0.543,-0.604,-0.448,P均<0.05),但是4个区域及全区的毛细血管密度均与视野MD值显著相关(r=-0.613,-0.494,-0.179,-0.413,-0.589,P均<0.05)。结论 视盘毛细血管密度与POAG和PACG患者的视野缺损相关,视盘毛细血管密度的变化对于青光眼的诊断和病情评估有重要的参考价值。