小梁切除术对视乳头血流的影响

目的 研究小梁切除术对慢性开角型青光眼（POAG）病人术眼视乳头的血流动力学影响。方法 用海德堡视网膜血流仪（HRF）分别检测出15例POAG病人小梁切除术前和术后1周眼视乳头筛板区微血管的血流动力学参数（血管容积、血流和血液流速）。进行术前、术后自身对照。结果 POAG病人小梁切除术后术眼眼压较术前显著降低（P＜0．01）。术后术眼视乳头筛板区平均血管溶积、血流量和流速较术前有显著升高（P＜0．01）。眼压下降与血管容积、血流量、流速增加之间呈正相关，但无显著性差异（P＞0．05）。结论 小梁切除术能有效降低眼压，同还能改善视乳头筛板区的血流情况，但眼压降低幅度与血管容积、血流量、流速增加幅度没有平行关系。     

高眼压下视乳头形态和血流改变的顺序研究

目的:探索机械压力导致的高眼压下视乳头形态学改变和视网膜血管密度改变的顺序。方法:前瞻性研究。纳入健康志愿者34例34眼。A组23例,其测试流程包括基线,两段高眼压期(15mmHg和30mmHg分别持续2min)和恢复期。B组11例,其高眼压期为眼压升高15mmHg持续10min。每阶段均采用OCT测量视乳头的布氏膜开口距离(BMO)、视乳头表面深度(ONHSD)和黄斑中心凹下脉络膜厚度(SFCT),并采用OCTA测量血管密度。结果:A组第一次眼压升高后,视乳头血管密度下降[浅层毛细血管丛,从(67.39±7.65)%降至(43.78±5.89)%,P<0.05],BMO距离、ONHSD和黄斑血管密度、SFCT均无改变。在第二次眼压升高后,视乳头及黄斑区的血管密度均下降,BMO距离、ONHSD增加(均P<0.05)。B组眼压升高后,视乳头及黄斑区的血管密度均下降,BMO距离增加,SFCT不变。视乳头的血管密度降低与BMO距离增加没有相关性(r=0.050,P>0.05)。结论:视乳头组织相对于形态学改变,更容易出现血流改变。在眼压升高过程中,视乳头和黄斑区的血流动力学改变特征不同。     

原发性开角型青光眼与正常人群搏动性眼血流量比较研究

目的　探讨原发性开角型青光眼 (POAG)的血流变化规律 ,及其作为诊断指标的敏感性和特异性。方法　选择POAG患者 10 0例 (10 0只眼 ) ,其中男、女各 5 0例 ,均取单眼测量。POAG诊断标准 :(1) 3次不同时间测量眼压值 >2 5mmHg(1mmHg =0 133kPa) ,眼压升高时房角开放 ;(2 ) 2 4h眼压差值 >8mmHg ;(3)典型青光眼性视乳头改变 ;(4)典型青光眼性视野缺损。正常对照者男、女各5 0例 (5 0只眼 ) ,选择条件 :(1)性别相同 ;(2 )年龄相差 <5岁 ;(3)屈光不正 ,屈光度数差异 <± 2 0 0DS。采用搏动性眼血流量 (POBF)测定仪 ,测量项目包括搏动性眼血流量、脉搏周期内眼压变化值(IOPPA)、脉率 (PR)、最大眼压值 (Max Iop)、最小眼压值 (Min IOP)、眼压均值 [(Max IOP Min IOP) /2次眼压均值 (Ave IOP) ]。青光眼组与正常对照组测定数值比较采用配对t检验 ,Ave IOP的变化值及视野检测均值和标准差与POBF的变化值做相关性分析 ;计算POBF值作为诊断指标的特异性和敏感性。结果　POAG组与正常对照组非研究因素有可比性 ,POAG组POBF值为 (9 72± 3 4 7) μl/s ,正常对照组POBF值为 (12 0 4± 4 6 8) μl/s;POAG患者的POBF、PV、PA、Ave IOP值均小于正常对照组 ,差异有显著意义 (P <0 0 5 )。视野检测均值和标准差与PO     

正常眼压性青光眼、原发性开角型青光眼患者及正常人DCT眼压及OPA的比较性研究

目的探讨在原发性开角型青光眼(PrimaryOpenAngleGlaucoma,POAG)及正常眼压性青光眼(NormalTensionGlaucoma,NTG)患者使用动态轮廓眼压计(DynamicContourTonometer,DCT)测量时的影响因素。方法POAG、NTG及正常对照组各31例,测量了Goldmann压平眼压(GoldmannApplanationTonometer,GAT)、DCT眼压、眼脉动幅度值(OcularPulseAmplitude,OPA)、以及心率(HeartRate,HR)、收缩压(SystolicBloodPressure,SBP)、舒张压(DiastolicBloodPressure,DBP)等指标,评估GAT、DCT两种眼压计测量的一致性,分析测量中的影响因素,并比较三组被检者OPA的差异;结果除HR以外(P=0.130),三组被检者的DCT眼压、OPA、GAT眼压、HR、SBP及DBP均存在显著性差异(P<0.05)。其中,正常对照组OPA为(2.85±1.15)mmHg,NTG组为(1.99±1.04)mmHg,POAG组为(3.00±1.07)mmHg,POAG组与正常对照组比较差异(P=0.568)无显著性意义,与NTG组比较差异有显著性意义(P<0.001),NTG组与正常对照组(P=0.003)比较有显著性意义;结论DCT眼压和GAT眼压表现出良好的一致性,DCT的测量结果可信;POAG、NTG患者和正常人的OPA存在差异。     

开角型青光眼与正常大陷凹眼中视乳头旁萎缩区的比较研究

目的研究原发性开角型青光眼(POAG)、正常眼压性青光眼(NTG)与正常大陷凹眼的视乳头旁脉络膜萎缩区(PPA)的差异及其与视野的关系。方法利用计算机图像分析系统对拍摄的视乳头立体图像进行测量,比较42例(42只眼)POAG、40例(40只眼)NTG与45例(45只眼)正常大陷凹眼之间PPA的发生率及大小差异,分析PPA的有关参数与视乳头结构指标、视野分级之间的相关性。所有入选患者的屈光度(等效球镜度数)均在+3.00~-3.00D之间。结果正常大陷凹组、POAG组及NTG组α区的出现率分别为85.4%、100.0%、95.0%,β区的出现率分别为19.1%、48.9%、37.5%,POAG组和NTG组的α区和β区的出现率均大于正常大陷凹组,差异均有统计学意义(P<0.05)。正常大陷凹组、POAG组及NTG组β区面积分别为(0.08±0.25)、(0.24±0.36)、(0.14±0.21)mm2,POAG组的β区面积大于正常大陷凹组,差异有统计学意义(P<0.05)。三组的α区面积差异无统计学意义(Chi-Square=4.534,P=0.104)。而POAG组与NTG组间上述各指标及α区和β区出现率的差异均无统计学意义(P>0.05)。青光眼患者视乳头结构指标与视野相关分析结果表明,杯/盘比值与视野受损分级之间有较强相关性(r=0.5624,P<0.01)。而α区面积、β区面积与视野受损分级之间均为低相关性(α区:r=0.246,P<0.01;β区:r=0.2302,P<0.01)。有无青光眼性视野缺损相关因素的Logistic回归分析结果显示,在包括年龄、性别、屈光度、杯/盘比值分级指标及α区面积和β区有无的多个因素中,仅年龄和杯/盘比值分级指标被证实为两个可能的影响因素。结论排除了-3.00D以上的中高度近视人群后,POAG和NTG患者的α区和β区出现率及β区面积虽与正常大陷凹者有所不同,但其与视野缺损程度的相关性较传统的视乳头结构指标低,在两组青光眼患者间也未见明显差异。由此认为PPA不能作为诊断POAG的独立指标,也不能作为POAG与NTG的鉴别诊断指标。     

中央角膜厚度对压平眼压计测量值的影响

目的采用非接触式角膜内皮镜测量高眼压症与临床常见类型青光眼患者的中央角膜厚度central corneal thickness(CCT),并与正常人CCT平均值比较,探讨CCT对青光眼诊断、分类与治疗的指导意义.方法采用KONAN非接触式角膜内皮镜测量中央角膜厚度,Goldmann压平眼压计测量眼内压(IOP).将39例52眼原发性开角型青光眼(POAG),32例45眼慢性闭角型青光眼(CACG),18例29眼高眼压症眼(OHT),15例24眼正常眼压性青光眼(NTG),34例66眼可疑开角型青光眼(GS)的CCT和IOP值与173例322眼正常眼进行比较研究.所有资料输入计算机后在Windows操作环境下使用SPSS10.0统计软件进行统计分析.结果平均CCT值比较高眼压症(OHT)眼(600.21±24.20μm)＞POAG眼(574.37±31.92μm)＞正常对照眼(554.78±32.61μm)＞NTG眼(528.43±36.40μm).OHT、NTG、POAG眼与正常眼的CCT值有差异(F=9.629,P=0.000),CACG眼与POAG及正常眼CCT值均无差异(P=0.119).GS眼CCT值(564.72±31.96μm)较正常眼厚.CCT与IOP成直线正相关,眼压测量值的校正公式为眼压校正值(mmHg)=-(测得的角膜厚度μm-555μm)×(1/24).IOP经CCT校正后,OHT眼平均高估1.89mHg,NTG眼平均低估1.1mmHg,POAG眼平均高估0.80mmHg.根据经CCT校正后的IOP值,13.5%POAG眼重新诊断为NTG眼,34.5%OHT眼重新诊断为正常眼,16.7%NTG眼重新诊断为POAG眼.结论非接触式角膜内皮镜能准确地测量中央角膜厚度.OHT眼CCT较厚,而NTG眼CCT较薄.CCT测量对青光眼的分类与治疗有重要的指导意义,应作为OHT、NTG及GS的常规检查项目.     

动态轮廓眼压计在正常眼压性青光眼及原发性开角型青光眼的应用研究

目的:应用动态轮廓眼压计(dynamic contour tonometer,DCT)测量正常眼压性青光眼(normal tension glaucoma,NTG)及原发性开角型青光眼(primary open angle glaucoma,POAG)患者的眼压(intraocular pressure,IOP)及眼脉动幅度值(ocular pulse amplitude,OPA),并探讨影响OPA测量值的相关因素。方法:选取NTG患者20例,POAG患者21例及正常对照组各20例,应用Goldmann压平眼压(Goldmann applanation tonometer,GAT)及DCT测量IOP,同时测量了中央角膜厚度(central corneal thickness,CCT)、眼轴(axial length,AL)、心率(heart rate,HR)、收缩压(systolic blood pressure,SBP)、舒张压(diastolic blood pressure,DBP)等指标,并探讨GAT,DCT两种眼压计测量的相关性,进而分析OPA测量值的影响因素。结果:三组被检者的IOP,OPA,SBP及DBP差异均有统计学意义(P<0.05),而CCT,AL及HR差异无统计学意义(P>0.05)。其中OPA值NTG组为(1.7±0.9)mmHg,POAG组为(2.8±0.7)mmHg,正常对照组为(2.4±0.6)mmHg;NTG组与POAG组比较(P=0.001),与正常对照组比较(P=0.005)差异均有统计学意义,POAG组与正常对照组比较(P=0.502)差异无统计学意义;OPA值与IOP,HR及CCT无相关性(P>0.05),与AL,SBP及DBP具有一定的相关性(P<0.05)。结论:NTG患者与POAG患者及正常人的OPA值存在差异,同时OPA值受AL及SBP及DBP影响。     

眼压已控制的青光眼患者的随访研究

目的：观察24例28眼接受抗青光眼手术后眼压控制在18mmHg（1mmHg=0.133kPa）以内的患者视盘地形图、视乳头血流和视野的变化,探讨三者的关系.方法：采用Heidelberg Retina Topography（HRT）和Heidelberg Retina Flowmetry（HRF）进行视网膜断层扫描、视乳头血流检查,用Octopus101电脑视野计常规阈值程序进行检查,每隔2mo复查,随访6mo,对所得数据进行分析.结果：早期青光眼患者随访6mo,视力、视野、视盘地形图参数无明显变化,3/10眼（33%）视乳头血流参数下降超过10%;18/18眼中晚期患者中央视力无明显变化,但平均视网膜敏感度（mean sensitivity,MS）有下降的趋势,视网膜神经纤维层厚度逐渐变薄,视乳头血流参数下降.结论：早期青光眼患者术后短期随访部分患者视乳头微循环功能有下降;中晚期患者短期随访视野指数MS、视乳头微循环和平均神经纤维层厚度有下降的趋势,且MS下降与后两个变量相关.     

正常眼压性青光眼与视盘血流灌注的关系

正常眼压性青光眼（normal tension glaucoma, NTG）是青光眼中的特殊类型,发病隐匿,机制未明,可能与视神经乳头血流灌注异常有关,如系统性低血压、全身或局部血管狭窄、眼部血流量下降、视神经乳头血流调控异常等,并最终导致视乳头和巩膜筛板血流灌注降低,发生NTG。（国际眼科纵览,2019, 43： 411-415）     

准分子激光原位角膜磨镶术患者视网膜微循环血流的研究

目的 本研究主要观察LASIK中负压吸引对视网膜微循环血流的影响。方法 采用海德堡视网膜血流仪分别对实施LASIK手术的低度，中度和高度的近视患者共38例62眼进行检测，测量视盘大血管，视盘颞侧盘沿，视盘鼻侧盘沿，颞侧视盘旁视网膜，鼻侧视盘旁视网膜和巩膜筛板的血流，并对其手术前后的血流量，血流速和红细胞移植速率进行统计分析。结果 LASIK手术前后，视盘大血管，视盘颞侧盘沿，视盘鼻侧盘沿，颞侧视盘旁视网膜，鼻侧视盘旁视网膜和筛板的血流量，血流速和红细胞移动速率均无显著性差异。结论 LASIK中负压吸引对视网膜微循环血流无临床病理性影响。     

Cup-to-disc ratio, intraocular pressure, and primary open-angle glaucoma in retinal venous occlusion

PURPOSE: To investigate the association of cup-to-disc ratio (CDR), intraocular pressure (IOP), and primary open-angle glaucoma (POAG) with the site of retinal venous occlusion (RVO) and optic nerve head swelling (ONHS). DESIGN: Prospective observational case series. PARTICIPANTS: Four hundred fifty consecutive cases from a single tertiary referral center. METHODS: Fundus photography of the retinopathy, 30 degrees stereo photography of the optic disc, and Goldmann applanation tonometry were the main parameters studied. The diagnosis of POAG was obtained from the referring ophthalmologist. MAIN OUTCOME MEASURES: The main outcome measures were the CDR, measured vertically through the center of the optic disc, and the site of RVO, identified as an arteriovenous (AV) crossing, optic cup, or optic nerve. Retinal venous occlusions occurring within the optic nerve were subdivided on the basis of the presence or absence of ONHS. RESULTS: There were poor correlations between CDR and IOP (r = 0.18; P = 0.000209) and CDR and age (r = 0.21; P = 0.000012). There were 197 AV crossing-sited RVOs (AV-RVOs) (43.8%) and 46 optic cup (OC)-sited RVOs (10.2%). The remainder occurred within the optic nerve; the ONHS group had 80 cases (17.8%) and the nonoptic nerve head swelling group (NONHS) had 127 cases (28.2%). The OC-RVO group tended to be the oldest of the four groups, whereas the ONHS group was the youngest (P < 0.000001). The mean CDR was significantly higher in the OC-RVO (0.65) compared with the rest of the groups (0.45-0.48). The proportion of cases with CDR > or = 0.7 was significantly higher in the OC-RVO group (39.1%) compared with the rest of the groups (0-6.3%). There was a trend (P = 0.000012) for IOP in the OC-RVO group (19.0 mmHg) and NONHS group (17.6 mmHg); the proportion of cases with IOP more than 21 mmHg was also higher in these cases (P = 0.00033). The prevalence of POAG was highest (P < 0.000001) in the OC-RVO group (39.1%) followed by the NONHS group (18.1%), ONHS group (8.8%), and AV-RVO (4.1%) group, respectively. CONCLUSIONS: Optic cup and optic nerve-sited RVO without ONHS are associated with raised IOP and may share a common management strategy aimed at controlling ocular pressure. Glaucomatous optic disc cupping, in contrast, seems to be important in the OC-sited RVO group only. Intraocular pressure, POAG, and glaucomatous optic disc cupping do not significantly seem to contribute to the development of RVO at an AV crossing or when the occlusion occurs within the optic nerve in association with ONHS.     

高眼压性和正常眼压性原发性开角型青光眼视神经损害特征的比较

目的探讨高眼压性原发性开角型青光眼(POAG)和正常眼压性青光眼(NTG)患者视神经损害的不同特点。方法应用德国Heidelberg公司生产的视网膜断层扫描仪对高眼压性POAG39例(47只眼)和NTG32例(38只眼)进行定量视盘参数和神经纤维层检查,并行眼底立体照相观察视网膜神经纤维层(RNFL)缺损类型,检测静态定量视野,并对检查结果进行比较。结果(1)NTG组视盘总体参数和分区(除颞侧外)盘沿面积、沿/盘面积小于高眼压性POAG组,而C/D大于高眼压性POAG组;平均RNFL厚度和RNFL面积在颞下和颞上小于高眼压性POAG组;总体盘沿容积小于高眼压性POAG组,总体平均视杯深度和颞下视杯面积大于高眼压性POAG组,两组差异均有统计学意义(P<005)。两组颞侧视盘各参数比较,差异无统计学意义(P>005)。(2)RNFL缺损类型高眼压性POAG组RNFL弥漫性缺损占5319%,局限性缺损占426%;NTG组弥漫性缺损占2105%,局限性缺损占5526%。两组RNFL缺损类型构成比比较,差异有统计学意义(P<001)。结论NTG较高眼压性POAG具有较大的C/D值、C/D面积比和窄盘沿面积,RNFL丢失严重。高眼压性POAG患者的RNFL以弥漫性缺损为主,NTG患者的RNFL以局限性缺损为主。两者视神经损害具有不同特点,其损害机制可能不同。(中华眼科杂志,2005,41136140)     

Effect of topical glaucoma medications on optic disc topography in normal tension glaucoma

PURPOSE: To investigate the effects of topical glaucoma medications on optic disc topography in patients with normal tension glaucoma (NTG) using confocal scanning laser ophthalmoscopy. SUBJECTS AND METHODS: We enrolled 39 NTG patients (39 eyes) who had not been treated for glaucoma. A combined medication of 0.005% latanoprost and 0.5% timolol gel was administered. Optic disc parameters were measured before and after the treatment using the Heidelberg Retina Tomograph (HRT). The treatment period was 20.2 +/- 6.4 days (mean +/- SD). RESULTS: Administration of these two drugs significantly decreased the intraocular pressure (IOP) from 16.7 +/- 1.9 mmHg to 12.3 +/- 1.9 mmHg (26.7 +/- 8.7% decrease). Cup area, cup/disk area ratio and cup volume decreased significantly, while the rim area increased significantly. Linear progression analysis showed a significant correlation between the percent decrease in the IOP and the topographic changes in the cup area, cup/disk area ratio, rim area, cup volume, rim volume, and height variation contour. When the subjects were divided into two groups: patients with high baseline IOP of more than 16 mmHg (HNTG group) and those with low baseline IOP below 15 mmHg (LNTG group), significant changes in several parameters were observed only in the HNTG group. CONCLUSIONS: These results suggest that the topographic changes in the optic disc were induced by the short-term topical glaucoma medications prescribed for the NTG patients, and the changes in several HRT parameters correlated with the percent decrease in the IOP.     

Optic neuropathies of different etiology and normal tension glaucoma: the point of differential diagnosis

62 patients (109 eyes) with glaucoma-like optic nerve head cupping and normal IOP indices (Po not more than 21 mm Hg) were examined to find the etiology of optic nerve changes. Regarding corneal biomechanics new-onset primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG) were diagnosed in 27% and 3% of examined patients respectively. In 59% of patients optic neuropathy (ON) of different etiology was found to be the cause of glaucoma-like optic nerve changes including compression ON due to lesion of intracranial portion of optic nerve and chiasma in 6% of cases. In 11% physiologic large optic nerve head cupping with normal visual functions and absence of nerve fiber structural changes was found.     

选择性激光小梁成形术治疗青光眼的临床观察

目的评价选择性激光小梁成形术(SLT)治疗原发性开角型青光眼(POAG)、正常眼压性青光眼(NTG)的疗效和安全性。方法选择局部用药眼压不能控制的原发性开角型青光眼20例(37眼),正常眼压性青光眼6例(10眼)。观察应用选择性激光小梁成形术后6个月眼压的变化。结果术后眼压平均降低幅度为4.86±2.14mmHg(24.04±10.21%),两组患眼的眼压在激光治疗后均有显著下降:开角型青光眼组术后6个月的眼压较术前平均下降5.44±2.32mmHg(24.90±11.09%);正常眼压性青光眼组平均下降2.71±1.12mmHg(19.06±7.19%)。术后暂时的眼压升高、前房炎症反应为常见的并发症。结论选择性激光小梁成形术具有降眼压效果明显、安全、实用、损伤小、可重复等特点,是治疗青光眼的一种较安全有效的方法。     

正常眼压性青光眼与原发性开角型青光眼24小时眼压曲线的比较

目的 通过24 h眼压的测量来深入分析比较正常眼压性青光眼(NTG)与原发性开角型青光眼(POAG)的眼压曲线特征.方法 前瞻性病例对照研究.收集2006年4月至2009年4月在上海市闸北区北站医院和复旦大学附属眼耳鼻喉科医院门诊就诊的NTG患者131例及POAG患者102例,测量24 h眼压,用非接触性眼压计从8 am起每隔2 h测一次眼压,0 am至6 am之间测得的为唤醒后即刻坐位眼压.主要观察指标为眼压波动曲线、平均眼压、峰值时间及眼压、谷值时间及眼压和眼压波动值.采用独立样本t检验和卡方检验比较各指标在两组之间的差异.结果 NTG组双眼平均眼压为(14.2±2.1)mmHg,低于POAG组[(19.9±3.5)mmHg];NTG组双眼峰值眼压为(17.0±2.4)mmHg,低于POAG组[(24.7±4.3)mmHg];NTG组双眼谷值眼压为(11.8±2.2)mmHg,低于POAG组[(16.5±3.1)mmHg];NTG组双眼眼压波动值为(5.2±1.8)mmHg低于POAG组(8.2±3.1)mmHg];两组的平均眼压、峰值、谷值及眼压波动值的差异均有统计学意义(t=-14.52、-16.44、-13.16、-8.90,P均＜0.01).NTG组63.3%患者、POAG组73.5%患者的峰值眼压位于门诊工作时间以外;尤其是NTG组有51.5%患者、POAG组有64.7%患者的峰值位于0 am至6 am时间段,两组差异有统计学意义(X2=8.150,P=0.017).结论 NTG及POAG患者24 h眼压曲线的变化规律具有相似性,是诊断和个体化治疗方案制订的依据,并可用作治疗随访中评价疗效和调整方案的重要参考指标.     

Absolute filling defects of the optic disc in fluorescein angiograms in glaucoma--a retrospective clinical study

BACKGROUND: Analysis of clinical importance of the size of filling defects in fluorescein angiograms in primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), ocular hypertension and subjects with physiological excavations in comparison to visual field loss, optic nerve head morphology and hemodynamics. PATIENTS AND METHODS: 75 patients (POAG, NTG, ocular hypertension) and 10 healthy subjects with physiological excavations were included in this study. In digitized video fluorescein angiograms (Scanning Laser Ophthalmoscope) the size of absolute filling defects of the optic disc was quantified in the early venous phase and expressed by percentage of the optic disc. Visual fields were obtained by conventional static perimetry (Humphrey 24-2) and graded in stages of glaucoma visual field defects (Aulhorn I-V). Optic disc excavations were evaluated as cup-to-disc-area-ratios. RESULTS: The filling defects correlated with the visual-field loss stages of Aulhorn and the visual field indices MD (mean deviation), PSD (pattern standard deviation) and CPSD (corrected pattern standard deviation). There was no correlation with the index SF (short-term fluctuation) and with systemic hemodynamics (blood pressure, perfusion pressure) or the IOP. Absolute filling defects correlated with the cup-to-disc-area-ratio in NTG. The absolute filling defects were larger in patients with glaucoma (POAG, NTG) in comparison to patients without glaucomatous visual field loss (ocular hypertension, glaucoma-like discs). No difference of filling defects was found in the glaucoma group (POAG, NTG). Patients with NTG had larger excavations and lower systolic blood pressures than patients with POAG. CONCLUSION: The size of fluorescein filling defects may be useful as a parameter for the evaluation of an ischemic lesion of the optic nerve head. Absolute filling defects may differentiate POAG from ocular hypertension and NTG from glaucoma-like discs without field defects. The results support the hypothesis that in POAG and NTG disturbances of the circulation result in similar filling defects of the optic disc and visual field loss.     

Effect of dorzolamide and timolol on ocular blood flow in patients with primary open angle glaucoma and ocular hypertension

BACKGROUND: There is evidence that perfusion abnormalities of the optic nerve head are involved in the pathogenesis of glaucoma. There is therefore considerable interest in the effects of topical antiglaucoma drugs on ocular blood flow. A study was undertaken to compare the ocular haemodynamic effects of dorzolamide and timolol in patients with primary open angle glaucoma (POAG) or ocular hypertension (OHT). METHODS: One hundred and forty patients with POAG or OHT were included in a controlled, randomised, double blind study in two parallel groups; 70 were randomised to receive timolol and 70 to receive dorzolamide for a period of 6 months. Subjects whose intraocular pressure (IOP) did not respond to either of the two drugs were switched to the alternative treatment after 2 weeks. Scanning laser Doppler flowmetry was used to measure blood flow in the temporal neuroretinal rim and the cup of the optic nerve head. Pulsatile choroidal blood flow was assessed using laser interferometric measurement of fundus pulsation amplitude. RESULTS: Five patients did not respond to timolol and were changed to the dorzolamide group, and 18 patients changed from dorzolamide treatment to timolol. The effects of both drugs on IOP and ocular perfusion pressure were comparable. Dorzolamide, but not timolol, increased blood flow in the temporal neuroretinal rim (8.5 (1.6)%, p<0.001 versus timolol) and the cup of the optic nerve head (13.5 (2.5)%, p<0.001 versus timolol), and fundus pulsation amplitude (8.9 (1.3)%, p<0.001 versus timolol). CONCLUSIONS: This study indicates augmented blood flow in the optic nerve head and choroid after 6 months of treatment with dorzolamide, but not with timolol. It remains to be established whether this effect can help to reduce visual field loss in patients with glaucoma.     

Normal-tension glaucoma: is it different from primary open-angle glaucoma?

PURPOSE OF REVIEW: Normal-tension glaucoma (NTG) is a common form of open-angle glaucoma throughout the world, and yet there are many unanswered questions regarding both the mechanisms of the optic neuropathy and the treatment of these patients. The present review considers how recent literature advances our understanding of both the mechanisms of glaucomatous damage and the treatment of patients with NTG. RECENT FINDINGS: The main theme in the current literature continues to be that NTG and primary open-angle glaucoma (POAG) represent a continuum of open-angle glaucomas, in which a certain level of intraocular pressure (IOP) is the predominant causative risk factor in POAG, while additional IOP-independent factors take increasing importance in NTG. There is considerable overlap between the two conditions, however, and within the population of NTG patients there are subsets in which IOP, blood flow and other factors assume relative importance. SUMMARY: In clinical practice, control of IOP remains the mainstay of managing NTG patients, but consideration must also be given to other factors, especially those that may influence perfusion of the optic nerve head. Treatment paradigms will likely change as researchers continue to investigate the mechanisms of glaucomatous optic neuropathy and search for IOP-independent neuroprotective agents.