Physiological diurnal variability and characteristics of the ocular pulse amplitude (OPA) with the dynamic contour tonometer (DCT-Pascal<Superscript>®</Superscript>)

PURPOSE: The Pascal dynamic contour tonometer (DCT) allows measurement of intraocular pressure (IOP) independently of corneal properties. It records, simultaneously, haemodynamic IOP fluctuations and the difference between the systolic and the diastolic IOP corresponding to the ocular pulse amplitude (OPA). The OPA indirectly reflects choroidal perfusion and could be considered as an independent risk factor in glaucoma. We aimed to establish the physiological diurnal variability of the OPA and its correlations with other biophysical parameters because its characteristics remain partly unclear. METHOD: Prospective study including 52 eyes of 28 normal subjects with Goldmann applanation tonometry (GAT) IOPs < 22 mmHg. Subjects treated with systemic medications that could interfere with blood pressure or heart rate were excluded. IOP was measured at 9:00 am, 1:00 pm, and 4:00 pm by GAT and DCT. Two consecutive GAT followed by three consecutive DCT measurements were performed in each session by the same clinician (SP). Only DCT measurements with quality 1 and 2 were taken into account. Blood pressure, pulse rate, and central corneal thickness (CCT) were recorded after the last IOP measurements. Spearman correlation coefficient was used for assessment of correlations. RESULTS: Mean age was 40 +/- 14 years. Mean DCT values were significantly higher than GAT readings (mean = 16.8 +/- 2.0 vs. 15.2 +/- 2.8 mmHg, P < 0.02). The mean OPA was 2.2 +/- 0.7 mmHg (range: 1-3.4 mmHg). The mean amplitude of diurnal OPA fluctuations was 0.4 mmHg. There was no significant difference in the mean OPA values at each time of the diurnal curve. The intraclass correlation (ICC) of only one OPA measurement in relation to part of total variance due to inter-measurement variation was 78%. Averaging over three independent readings of OPA improved ICC to 91%. The OPA was correlated with GAT (r = 0.31, P < 0.0001) and DCT IOP measurements (r = 0.49, P < 0.0001). It was correlated neither with blood pressure nor with age. OPA values of both eyes of the same individual were highly correlated (r = 0.89, P < 0.0001). CONCLUSION: In normal healthy eyes, the ocular pulse amplitude remains stable during normal outpatient office hours and was not correlated with blood pressure or age of patients.     

动态轮廓眼压计在正常人群中的应用及其影响因素分析

目的评价动态轮廓眼压计（DCT）与Goldmann压平眼压计（GAT）测量值之间的关系,寻找DCT眼压测量值的影响因素;分析DCT所测眼压脉动振幅（OPA）与DCT眼压值、中央角膜厚度（CCT）、角膜屈光力（CCV）、眼轴长度（AL）、前房深度（ACD）、收缩压（SBP）、舒张压（DBP）和心率（HR）的关系。方法分别测量正常人60例60眼的DCT眼压、GAT眼压、CCT、CCV、AL、ACD以及HR、SBP、DBP等指标,比较GAT、DCT2种眼压计测量的相关性及DCT测量值的影响因素。结果 DCT与GAT所测眼压平均值分别为（16.04±2.57）mmHg和（14.20±2.93）mmHg。DCT眼压值较GAT眼压值高,差异有统计学意义（t=6.454,P〈0.01）。DCT眼压值与GAT眼压值呈正相关（r=0.684,P〈0.01）。DCT眼压值与CCT不相关（r=0.212,P=0.105）,GAT眼压值与CCT呈正相关（r=0.291,P=0.024）。60例正常人的OPA均值为（2.50±0.89）mmHg,OPA与年龄、DCT眼压值、CCT、SBP、DBP、HR均不相关（P〉0.05）,与CCV呈正相关（r=0.343,P=0.007）。结论在正常人群中DCT眼压值与GAT眼压值有较好的相关性,DCT的眼压测量值不受CCT、CCV等因素的影响。DCT眼压值、CCT、SBP、DBP、HR等对OPA无明显影响。     

Longitudinal analysis of age-related changes in intraocular pressure in South Korea

Purpose

To assess the changes in intraocular pressure (IOP) with age in South Korea

Methods

Subjects aged 20–79 who had been receiving health examinations at a university hospital were enrolled. They completed physical and ophthalmic examinations. Subjects with ocular disease that could possibly affect their IOP were excluded. The relationships between IOP and age, blood pressure, heart rate, body mass index, blood chemistry, and electrolyte were analyzed using a linear mixed model.

Results

Of the 33 712 subjects, 31 857 participants were enrolled. In a cross-sectional analysis, IOP also showed a negative correlation in all age groups (respectively, P<0.001). In particular, patients in their 60s~80s had a less steep decreasing slope of IOP with age than patients in their 20s~30s (correlation coefficient −0.260 and −0.168, respectively). In longitudinal analysis, negative trend was shown in the slope of tendency in total subjects. When analyzing the effect of gender on the relationship between age and IOP, females had a less steep decreasing slope of IOP with age than males by 0.05 mm Hg. With regard to systemic parameters, systolic blood pressure and heart rate were positively correlated with IOP (P<0.001).

Conclusion

IOP was significantly decreased with age, although the amount of change was small. In women and older age groups, IOP was less decreased than that of men and young age groups. In addition, IOP was positively associated with systolic blood pressure and heart rate.     

The distribution of intraocular pressures in the general population

A variety of studies are reviewed in which intraocular pressure (IOP) was determined in defined, general populations. The studies exhibit a remarkably consistent pattern for the frequency distribution of IOP. The distribution conforms well to a normal curve for pressures up to 21 mm Hg, after which a distinct skewness to the right begins to appear. When the data are grouped by age and sex, the degree of right skewness intensifies with age. Mean IOP increases with age. Some studies also show higher mean levels for women than men, but not all do. The arbitrary nature of specifying upper limits of normality is stressed. In addition, the literature is reviewed concerning the arguments for a mixture of two overlapping normal (or lognormal) curves vs a continuum for the distribution of IOP.     

海拔变化对高原列车行车人员眼压的影响

目的:动态监测不同海拔高度时京藏线列车行车人员的眼压变化,探讨海拔改变对该人群眼压的影响并分析原因。方法:随机整群抽样,选取长期往返于北京与拉萨之间的京藏线列车某一车组全体行车人员,选择去程不同海拔点T1(200m)、T2(2500m)和T3(4500m)及返程R1(4500m)、R2(2500m)作为监测点进行眼压监测,同时检测血压、血氧饱和度、心率。采用方差分析和Pearson相关进行统计学分析,P<0.05为差异有统计学意义。结果:眼压在海拔超过2500m以后,与低海拔(200m)所测值存在显著差异(P<0.05),海拔4500m与其他各点眼压差异有统计学意义(P<0.05)。各监测点的眼压水平与血氧饱和度、心率、收缩压和舒张压均无显著相关性(P>0.05)。结论:高原列车行车过程中随海拔升高行车人员眼压波动,高海拔可导致眼压升高,可能与气压降低、眼球生物学改变和高原缺氧的全身反应有关。     

Chronic topical administration of WIN-55-212-2 maintains a reduction in IOP in a rat glaucoma model without adverse effects

Glaucoma, one of the leading causes of blindness, is associated with high intraocular pressure (IOP) as a risk factor. The aim of this study was to examine both local and systemic effects of chronic topical administration of the synthetic CB1/CB2 agonist, WIN-55-212-2 and its potential to sustain ocular hypotension. WIN-55-212-2 (0.5%) or Tocrisolve, the vehicle, was administered topically three times daily to rats with surgically created glaucoma for 4 weeks, followed by a 1-week washout period. IOP, blood pressure and heart rate were measured weekly along with confocal microscopy and slit lamp biomicroscopy to detect ocular toxicity. IOP decreased rapidly by up to 47% in the WIN-55-212-2 treated group from 14.1+/-0.7 to 6.6+/-0.2 mmHg. The decrease was maintained during the treatment period. After the washout period, IOP (12.3+/-0.2 mmHg) was not different from baseline. In the contralateral eye, IOP showed a downward trend. Tocrisolve alone had no effect on IOP. No changes in blood pressure, heart rate or indicators of ocular toxicity were noted within either group. Topical application of WIN-55-212-2 significantly deceased IOP for duration of treatment. The decrease was sustained without the development of tolerance. Following cessation of therapy, IOP rapidly returned to baseline. No significant cardiovascular effects or ocular toxicity were noted during chronic topical therapy with either drug or vehicle.     

白内障超声乳化吸除术中高灌注压下眼内血流的变化

目的 探讨高灌注压下白内障超声乳化吸除术时搏动性眼血流的变化及相关影响因素。设计  前瞻性非比较性病例系列。研究对象 白内障超声乳化吸除术患者23例。方法 应用搏动性眼血流分析仪分别在手术前、手术中动态测量眼内搏动性眼血流参数,包括搏动性眼血流量（POBF）、脉搏周期内平均眼压等,心电监护仪记录心率及血压。术前基线观察点为手术开始置开睑器后,术中超声乳化阶段及皮质抽吸阶段各测量1次。分析年龄、眼压、心率和血压与POBF的相关性。主要指标 搏动性眼血流量,眼压。结果 患者术前基线、超声乳化阶段、皮质抽吸阶段测得的搏动性眼血流量分别为（16.43±6.52）、（12.36±9.60）、（8.24±6.55）μl/秒。与术前基线相比,术中超声乳化及皮质抽吸时的搏动性眼血流量均有不同程度下降。在皮质抽吸时搏动性眼血流量较超声乳化时进一步下降,与基线值相比差异均有统计学意义（P均<0.001）。患者术前基线、超声乳化阶段、皮质抽吸阶段的平均眼压分别为（21.10±4.10）、 （59.64±13.83）、 （39.72±10.04）mm Hg。与术前基线眼压相比,术中两个观察点的眼压明显升高,且均有统计学意义（P均<0.05）。患者年龄和眼压与POBF呈负相关（b=-0.068,P<0.001和b=-0.012,P<0.001）,心率和收缩压与POBF呈正相关（b=0.005,P=0.046;b=0.007,P<0.001）。结论 白内障超声乳化手术在高灌注压的持续作用下,眼压明显升高,搏动性眼血流持续下降,提示持续高灌注压下的白内障超声乳化手术可造成眼内的血供减少。（眼科, 2013, 22:82-85）     

24小时血压参数与原发性开角型青光眼视神经损害的相关性

目的：研究24 h血压参数与原发性开角型青光眼（POAG）视神经损害之间的相关性。方法：病例对照研究。选择2013年6月至2016年12月期间成都市第一人民医院确诊的60例POAG患者作为POAG组,55 例正常人群作为对照组。2 组均进行24 h眼压和血压的同步监测,比较2 组受检者24 h血压参数、眼灌注压及眼压的差异,并分析POAG组患者24 h血压参数、眼灌注压及眼压与相关视功能之间的关系。采用独立样本t检验和多重线性回归等进行统计学分析。结果：①POAG组的24 h平均眼压、眼压差、眼灌注压差及脉压差显著高于对照组,2 组差异均有统计学意义（t =3.22、6.57、2.29、2.39,P ＜0.05）。②POAG组平均收缩压显著高于对照组（t =3.02,P =0.003）,其收缩压最高值、收缩压波动值、夜间平均收缩压、夜间最高收缩压及其波动值均显著高于对照组（t =4.38、5.27、4.13、4.13、 4.14,P ＜0.001）。③POAG组24 h平均舒张压、舒张压最高值、夜间平均舒张压、夜间舒张压最高值也显著高于对照组（t =2.22、2.50、2.29、2.10,P ＜0.05）。④POAG组患者的24 h血压相关参数与视神经损害相关性：平均眼压是POAG视野的平均缺损值（MD）的影响因素,二者呈负相关（b =-0.44,P =0.004）;盘周平均视网膜神经纤维层（RNFL）厚度与平均眼压（b =-0.956,P =0.001）、眼压差（b =-1.125,P =0.003）呈负相关;夜间平均舒张压（b =0.395,P ＜0.001）和夜间平均动脉压（b =0.046,P =0.001）分别与AP100和AP50值呈正相关。结论：①24 h血压相关参数与POAG的视神经损害之间存在相关性;②夜间眼灌注压、夜间舒张压和夜间动脉压可能是POAG视神经损害的影响因素;③在POAG的治疗中,稳定的血压和靶眼压有利于保持有效的稳定的眼灌注压,提示在关注降眼压治疗POAG的同时应该关注血压的变化。     

噻吗洛尔和布林佐胺联合曲伏前列素治疗原发性开角型青光眼与高眼压患者的临床研究

目的比较噻吗洛尔和布林佐胺辅助曲伏前列素治疗原发性开角型青光眼(primary open-angle glaucoma,POAG)或高眼压(ocular hypertension,OHT)患者的效果。方法将使用曲伏前列素单剂药物治疗6周后眼压>18mmHg(1kPa=7.5mm-Hg)的POAG及OHT患者随机分为治疗组和对照组。治疗组40例(40眼)加入10g·L-1布林佐胺滴眼液(每日2次),对照组40例(40眼)加入5g·L-1噻吗洛尔滴眼液(每日2次)。随访2周、8周、14周、20周、26周的眼压、血压、心率,观察眼部症状和体征,26周检测与基线对应的相关参量,包括视野、视觉电生理、视网膜神经纤维层厚度、视盘盘沿面积、泪液功能等。计算26周时眼压≤18mmHg患者百分比。结果两组眼压与基线比较均有明显下降,差异均有显著统计学意义(均为P<0.01)。治疗组降眼压持续平稳,对照组眼压于20周后出现上升趋势。24h眼压描记显示治疗组降眼压稳定,昼夜眼压平稳,对照组夜间眼压控制欠佳。2组对患者血压无影响,治疗组对患者心率无影响,对照组在联合用药20周始出现心率抑制。联合用药后对照组视野光敏感度下降,泪膜稳定性下降,治疗组无明显异常。治疗组常见的副作用是眼部刺激症状、味觉异常、口干等,对照组副作用是眼异物感、干涩等。结论曲伏前列素单剂治疗不足时,添加布林佐胺和噻吗洛尔均能进一步降低眼压,布林佐胺长期及短期眼压波动幅度均比噻吗洛尔小,局部及全身副作用小。     

The effects of dopamine,haloperidol and bromocriptine on intraocular pressure

In a double-blind randomised, prospective single dose study, we measured intraocular pressure (IOP), pupil diameter, systemic blood pressure and heart rate in 43 ocular normotensive subjects before (baseline) and 2, 4, and 6 hours after topical instillation of the following drugs: dopamine 2% (n=11), a dopamine receptor blocking drug, haloperidol 0.5% (n=11), a dopamine receptor stimulating drug, bromocriptine 0.05% (n=11) and 0.1% (n=10).In the groups receiving dopamine or haloperidol, there were no significant differences in IOP compared with baseline values (p>0.01). But, a significant decrease in IOP compared with the baseline values was found in both bromocriptine groups (p<0.001). With the 0.05% and 0.1% concentrations, maximum reductions in intraocular pressure were 22.0%±5.8% and 28.4%±9.8%, respectively.No significant differences in mean pupil diameter, systemic blood pressure and heart rate were detected in all of these groups.In addition, in the group receiving bromocriptine 0.1%, there was no change in serum prolactin levels.These results suggest that topically administered bromocriptine has satisfactory intraocular pressure lowering capacity without serious ocular or systemic side effects. Consequently we conclude that, an ophthalmic formulation of bromocriptine may have substantial clinical potential for the treatment of glaucoma.