Ibopamine in glaucoma diagnostics: a new pharmacological provocative test

Purpose: Ibopamine is used when performing provocative tests, thanks to its pharmacological property of increasing ocular pressure in eyes with outflow system impairment. This study summarizes the latest results that we have achieved with reference to its clinical-diagnostic use. Methods: 175 (250 eyes) POAG patients, 101 (190 eyes) glaucoma suspects with mild ocular hypertension, 39 (64 eyes) NTG patients and 163 (326 eyes) healthy volunteers underwent an ibopamine provocative test. Among the POAG and the glaucoma suspects, 49 (92 eyes) and 20 (38 eyes) patients were selected who, starting from the performing of ibopamine test, had at least one year of perimetric follow-up. These patients have been assessed for the perimetric defect progression in relation to the (negative or positive) response to ibopamine. Results: the ibopamine test was positive for 92% of the glaucomatous patients, 61% of the glaucoma suspects, 52% of the NTG patients and 0% of the healthy volunteers. It was observed that 28% of the ibopamine-positive glaucoma suspects showed a perimetric deterioration during an average 2.5-year follow-up. No perimetric deterioration was found on ibopamine-negative glaucoma suspects (Fisher's exact test: p = 0.038). Among glaucomatous patients, 46% of the test-positive individuals showed a progressive trend of the perimetric defect, as against about 8% of glaucomatous test-negative patients (Fisher's exact test: p = 0.003). Conclusions: We believe that the ibopamine provocative test can be usefully applied especially to epidemiological screening studies to identify patients who might develop ocular hypertension or glaucoma and in the follow-up of glaucoma suspects, to identify individuals who have a greater risk of developing perimetric defects.     

The dexamethasone provocative test: a predictive tool for glaucoma?

A retrospective follow-up study of 134 patients (84 women and 50 men) tested for their responsiveness to topically administered corticosteroids was carried out. Of the 134 patients tested, 34 (25.4%) had a high response (IOP rise greater than or equal to 16 mmHg), 66 (49.3%) an intermediate (IOP rise 6-15 mmHg) and 34 (25.4%) a low response (IOP rise less than or equal to 5 mmHg) to topically administered 0.1% dexamethasone eye drops. Follow-up time varied from 5 to 15 years (mean 7.1 years). During the follow-up period 29 (21.6%) patients developed glaucoma. Of these, 9 (31.0%) were high responders and 7 (24.0%) had a low response to corticosteroids. Log-linear analysis showed no correlation between corticosteroid response and development of glaucoma in the study eye (SD = 0.232, DF = 2, P = 0.890), the control eye (SD = 1.234, DF = 2, P = 0.540) or both eyes (SD = 0.618, DF = 2, P = 0.734). At the final examination 75 patients (56%) had an IOP of greater than or equal to 22 mmHg. Of these ocular hypertensive patients 28 (37.3%) were high responders, and 15 (20%) had a low response to corticosteroids. Of the whole material of 134 patients 44 had a family history of glaucoma. Eleven (25.1%) of these were high responders and 14 (31.8%) low responders. Of the 29 patients who developed glaucoma 8 had a family history of glaucoma. Of these 3 were high responders and 3 low responders. The results indicate that the dexaprovocative test yielded relatively limited value in the screening of patients for glaucoma.     

Blood flow in the optic nerve head and factors that may influence it

In the recent past there has been great interest in the blood supply of the optic nerve head (ONH), how to evaluate ONH blood flow, and what factors influence it, in health and disease. This is because evidence has progressively accumulated that there is vascular insufficiency in the ONH in both anterior ischemic optic neuropathy (AION) and glaucomatous optic neuropathy (GON)-two major causes of blindness or of seriously impaired vision in man. For the management and prevention of visual loss in these two disorders, a proper understanding of the factors that influence the blood flow in the ONH is essential. The objective of this paper is, therefore, to review and discuss all these factors. The various factors that influence the vascular resistance, mean blood pressure and intraocular pressure are discussed, to create a better basic understanding of the ONH blood flow, which may help us toward a logical strategy for prevention and management of ischemic disorders of the ONH.     

Does the pilocarpine phenylephrine provocative test help in the management of acute and subacute angle closure glaucoma?

The pilocarpine phenylephrine provocative test (PPPT) has been described as a highly sensitive method to identify eyes suffering from or at risk of angle closure glaucoma (ACG). This paper reports on average 10 years follow-up of the outcome of cases of primary acute ACG and subacute ACG in which the management was determined by the result of the PPPT--a positive result indicating the need for a peripheral iridectomy, a negative result conservative treatment. In spite of a negative PPPT the fellow eyes of cases of acute ACG treated conservatively had a high rate (40%) of development of ACG. Similarly, in eyes with a history of subacute ACG with a negative PPPT, ACG developed at some stage during the follow-up in 60%. Peripheral iridectomy alone resulted in normal intraocular pressure in 63% of eyes that had suffered an attack of acute ACG. In hypertensive eyes that presented with subacute ACG, however, only one eye became normotensive following peripheral iridectomy alone. In the subacute ACG group a positive PPPT was closely related to the presence of glaucomatous optic disc damage. These results indicate that the PPPT lacks sensitivity in detecting eyes at risk of angle closure glaucoma, and a positive result is likely in eyes with damaged outflow that will not respond to peripheral iridectomy.     

An evaluation of the darkroom prone provocative test in family members of primary angle closure glaucoma patients

PURPOSE: To compare ocular biometric parameters with darkroom prone provocative test (DRPPT) in family members of primary angle closure glaucoma (PACG) patients. METHODS: One hundred and forty-nine family members of 46 PACG patients underwent ocular examination included slit lamp biomicroscopy, gonioscopy, fundus examination using +90 D lens, Goldmann applanation tonometry, darkroom prone provocative test, perimetry on Humphrey's field analyzer II and optic disc evaluation using HRT II. Ultrasonic ocular biometry and the DRPPT were then performed. IOP>or=8 mmHg rise from baseline with iridocorneal touch was considered as a positive test. RESULTS: Of the 149 family members examined, 55 (36.9%) were found to have PACG. Forty (72.7%) of these had subacute PACG and 15 (27.3%) were found to have chronic PACG. Thirty-nine (70.3%) of the affected members showed a positive DRPPT. Mean anterior chamber depth (ACD) was 2.03+/-0.3, 2.3+/-0.4, 2.7+/-0.3 mm (P=0.0001) and mean lens thickness was 4.41+/-0.39, 3.99+/-0.5, 3.93+/-0.4 mm (P=0.0001) in DRPPT positives, borderlines and negatives respectively. ROC curve (ACD) plotted showed cutoff value of 2.07 mm (sensitivity 88.57%) for screening. CONCLUSION: Anterior chamber is shallowest, lens is thickest and axial length is shortest in affected and DRPPT positive, family members of PACG patients.     

Evaluation of laser iridectomy in angle-closure glaucoma: provocative tests.

An argon laser iridectomy was performed on 18 eyes of 14 patients with closed-angle glaucoma. The intraocular pressure (IOP) was controlled in all but one eye within normal limits. Variable amounts of pigment were found on gonioscopy in all cases. The mydriasis test was positive in one eye (5.5%) after homatropine and in 5 eyes (28%) after tropicamide drops. 80% of the positive results occurred in lightly pigmented irides. The dark-prone position test was positive in 7 eyes (38%), 71% of the positive results occurring in heavily pigmented irides. Tomography was also performed; the possibility of trabecular damage is discussed.     

The efficacy of brimonidine in preventing intraocular pressure elevation in the provocative test for primary angle-closure glaucoma.

The purpose of this study was to evaluate the efficacy of 0.2% brimonidine tartrate in preventing intraocular pressure (IOP) elevation in the dark-prone provocative test for primary angle-closure glaucoma (PACG). Twenty-two eyes from 22 patients with angle-closure glaucoma were enrolled in this study. Each of the selected eyes had previously tested positive in a recent dark-prone test. One drop of 0.2% brimonidine tartrate was then instilled in each eye 2 hours prior to a second dark-prone test. An IOP elevation of greater than 8 mmHg was regarded as a positive result. The IOP elevation in the first dark-prone test was 11.91 +/- 5.17 (range: 5.7 - 27.3) mmHg, while the IOP only increased 5.70 - 2.96 (range: 2.9 - 12.2) mmHg in the second dark-prone test that was pre-treated with 0.2% brimonidine tartrate (p < 0.001). A significant difference was also noted in the pre-test IOP (15.59 +/- 3.86 mmHg vs. 13.33 +/- 3.65 mmHg, p = 0.008) as well as in the post-test IOP (27.62 +/- 7.27 mmHg vs. 19.03 +/- 3.50 mmHg, p < 0.001) in the two sequential dark-prone tests. All but three of the initially positive dark-prone tests (86.46%) converted to negative tests after pre-treatment with brimonidine. There was a significant effect of 0.2% brimonidine tartrate in the prevention of IOP elevation in PACG patients previously found to test positive in the dark-prone provocative test.     

Analysis of risk factors that may be associated with progression from ocular hypertension to primary open angle glaucoma

Background: As a multifactorial disease, glaucoma may be associated with pressure‐dependent and pressure‐independent factors. Ocular hypertension (OHT) may develop into primary open angle glaucoma (POAG) for many patients. Groups with OHT and POAG were compared for pressure‐dependent and independent risk factors. A high prevalence of any factor(s) could indicate a contribution to progression from OHT to POAG. Methods: A sample of patients with POAG (n = 438) and with OHT (n = 301) were selected from those attending a tertiary referral private glaucoma practice, and data were collected regarding age and intraocular pressure at the time of diagnosis, sex, family history of glaucoma, systemic hypertension, diabetes, Raynaud's phenomenon, migraine and myopia. Results: After multivariate analysis, older age at time of diagnosis (χ²₅ = 73.89, P < 0.001), myopia (odds ratio [OR] = 1.5, 95% confidence interval [CI] 1.0?2.2; P < 0.05), a family history of glaucoma (OR = 1.6, 95% CI 1.1?2.3; P < 0.01) and a high intraocular pressure (χ²₄ = 16.96; P = 0.002) were found to be more prevalent among those with POAG. No other significant differences could be found between the two groups. Conclusion: Patients who have OHT may be at higher risk of developing POAG if they also have myopia, a family history of glaucoma or are of older age.     

The full-field temporal contrast sensitivity test for glaucoma: influence of cataract

Purpose: To determine the influence of lens opacities on temporal contrast sensitivity, measured by the full-field flicker test (”Erlangen flicker test”). Methods: Thirty-six consecutive patients (mean age 71.1±11.6 years, 12 male, 24 female, refractive error –1.5±3.8 dpt) with cataract (visual acuity 0.21±0.16, retinal acuity 0.56±0.32, no glaucoma) were studied. Temporal contrast sensitivity (full-field flicker test, 37.1 Hz) and lens opacity (back scatter Lens Opacity Meter, Interzeag) were measured preoperatively and on the 3rd postoperative day. Statistics: nonparametric tests (Wilcoxon-test, Spearman correlation coefficient, Mann-Whitney U-test). Results: No significant difference was seen in temporal contrast sensitivity pre- and postoperatively, but there was a significant difference in lens opacity measurements pre- and postoperatively. No significant correlation was found between temporal contrast sensitivity and lens opacity values preoperatively and postoperatively. Conclusion: The temporal contrast sensitivity, measured by the full-field flicker test, seems to be independent of lens opacity due to the range of cataract included in this study. The data indicate that the full-field flicker test is useful for early glaucoma detection even in patients with cataract formations. Received: 4 October 1999 Revised: 14 December 1999 Accepted: 10 January 2000     

Factors that influence the prevalence of positive catch trials in glaucoma patients

We evaluated factors that influence the catchtrial response in automated perimetry by consecutively examining 408 glaucoma patients (703 eyes) with either the program 30-2 or a 76-point screen with a quantified defect on the Humphrey Field Analyzer. The prevalence of positive catch trials using both programs was: 15.9% fixation losses, 5.5% false-positives, and 17.0% false-negatives. The only significant difference between the two programs was a lower prevalence of false-negatives on the program 30-2 (P < 0.01). False-positive responses showed a significant positive correlation to fixation losses, and the catch trial response in general was correlated significantly to defect depth, test time, age, and visual acuity (P < 0.05). This study suggests that the prevalence of positive catch trials is not an independent variable when testing glaucoma patients with automated perimetry and is not reduced by using a screening strategy over a full-threshold exam.     

对比敏感度的影响因素分析

目的探讨亮度、眩光、空间频率、年龄和屈光不正度对对比敏感度的影响。方法用OPTEC6500对比敏感度仪模拟四种状态（85 cd／m^2无眩光、85 cd／m^2有眩光、3 cd／m^2无眩光和3 cd／m^2有眩光）,对402例患者进行对比敏感度检查．使用SPSS11．5统计软件对数据进行整理。结果①在85 cd／m^2和3 cd／m^2环境下,分辨低、中空间频率（1．5 c／d,3．0 c／d,6．0 c／d）物体时,有无眩光其对比敏感度的差异有统计学意义（P〈0．05）。②在分辨中、高空间频率（6．0 c／d,12．0 c／d,18．0 c／d）的物体时。不同亮度（85 cd／m^2和3 cd／m^2）对比敏感度的差异有统计学意义（P〈0．05）。③对于低度、中度及高度的近视患者来说．在85 cd／m^2无眩光、85 cd／m^2有眩光、3 cd／m^2无眩光、3 cd／m^2有眩光四种环境下,各种空间频率造成的对比敏感度的差异均有统计学意义（P〈0．05）。④对于各种屈光不正度的近视患者来说．在以下情况时屈光不正度造成的对比敏感度的差异有统计学意义：在85 cd／m^2无眩光状态下,空间频率为12．0 c／d的视标：在3 cd／m^2无眩光状态下,空间频率为6．0 c／d的视标：在3 cd／m^2有眩光状态下．空间频率为12．0 c／d和18．0 c／d的视标。（固在85 cd／m^2无眩光状态下,不同年龄（11-20岁,21～30岁,31～40岁,41～50岁）的患者．分辨不同空间频率的视标时,差异均有统计学意义（P〈0．05）。结论年龄、亮度、眩光、空间频率和屈光不正度五个因素均会在某些情况下对对比敏感度有不同程度的影响。     

青光眼心理状况分析及通过青光眼俱乐部对患者进行心理治疗的效果分析

目的:研究和分析青光眼患者的心理特点及青光眼俱乐部宣教和心理治疗在改善原发性青光眼患者的心理状况中起到的作用。方法:选择眼科门诊初诊原发性青光眼患者100例为研究对象,随机分为实验组（50例）和对照组（50例）。利用国际标准的SDS自评量表、SAS自评量表、SCL90自评量表进行心理测试。实验组在常规青光眼治疗外,进行半年青光眼俱乐部宣教及心理治疗,对照组仅进行常规青光眼治疗。半年后再次进行心理测试,利用软件进行分析。结果:实验组经过青光眼心理治疗后的患者的心理状况及较初诊时有明显改善（P<0.05）;实验组患者较之对照组心理状况改善明显（P<0.05）。青光眼心理具备八种心理特点,其中抑郁为主要心理症状。结论:以青光眼俱乐部为平台的青光眼宣教和心理治疗在原发性青光眼患者的治疗和日常保健中起到了重要的作用,应当积极推广。