[Amebic liver abscess and late recurrence with no travel in an endemic area]. / Abcès amibien hépatique avec récidive tardive en l'absence de séjour récent en zone d'endémie.

Amebic liver abscess is the main complication of amebic dysentery. Recurrences after treatment and apparent healing are very uncommon. The purpose of this report is to describe the case of a patient with a very late relapse of an amebic liver abscess, 10 years after the first episode. This recurrence seems due to an incomplete initial treatment. This case illustrates the reason for and importance of complying with the current therapeutic strategy: nitroimidazole followed by a luminal agent to eradicate intestinal amebic colonization.

Central and peripheral arteriovenous passage times of the retina in glaucoma.

The purpose of this paper was to estimate arteriovenous passage (AVP) times, taking into account the non-uniform distribution of arrival times over the vessel diameter, and assessment of respective differences between 15 normal controls (N), 30 primary open-angle glaucoma (POAG) and 30 normal-pressure glaucoma (NPG) patients. Arrival times in retinal vessels were assessed from digitized scanning laser fluorescein angiograms. The arrival times were assessed as a function of position (juxtamural versus axial) in the vessel. This differentiation, based on the measurement position in the vessel, enabled the estimation of AVP times of the posterior pole and of the peripheral retina. The overall, juxtamural and axial AVP times were prolonged in POAG as compared to both N and NPG (P<0.03). The difference in axial AVP times between POAG and normal subjects was considerably larger than the juxtamural values. The distribution of AVP times was considerably larger in POAG patients than in N subjects and NPG patients. Retinal AVP times are prolonged in POAG patients as compared to N and NPG. The wider distribution of AVP times in POAG patients may point to a generalized microvascular alteration. Since the axial AVP times seem to provide the largest differences between NPG and POAG patients, this measurement may be preferred over more general AVP times. The axial AVP times may possibly reflect peripheral vascular changes, e.g. increased vascular resistance. The underlying mechanisms causing these differences are at present unknown.

Lens extraction for uncontrolled angle-closure glaucoma: long-term follow-up.

PURPOSE: To evaluate the long-term effects of extraction of incipient cataracts or clear lenses on glaucoma control in patients with subacute or chronic angle-closure glaucoma. SETTING: Department of Ophthalmology, University of Amsterdam, The Netherlands. METHODS: This retrospective analysis comprised 22 extracapsular lens extractions with implantation of a posterior chamber intraocular lens in 18 patients with chronic or subacute angle-closure glaucoma (Group 1). The effect of glaucoma control was evaluated using visual field examination, diurnal intraocular pressure (IOP) curves, gonioscopic appearance, and number of antiglaucoma medications. The results were compared with those in 25 eyes of 19 patients with chronic angle-closure glaucoma in whom a filtering procedure was performed (Group 2). RESULTS: Glaucoma control was achieved in 15 eyes (68%) in Group 1 and in 17 eyes (68%) in Group 2. Mean preoperative IOP was 27.9 mm Hg +/- 8.1 (SD) and 29.0 +/- 7.7 mm Hg, respectively. Mean postoperative IOP was 17.1 +/- 2.9 mm Hg (Group 1) and 14.8 +/- 6.6 mm Hg (Group 2) after a mean follow-up of 52.6 and 58.9 months, respectively. Mean number of ocular hypotensive medications preoperatively was 2.3 +/- 0.8 in Group 1 and 2.2 +/- 0.8 in Group 2 and at last follow-up, 1.3 +/- 0.7 and 0.52 +/- 0.8, respectively. Twenty eyes (91%) in Group 1 had the same or better final visual acuity than before surgery. In Group 2, the final visual acuity was unchanged or better in 13 eyes (52%) and worse in 12 eyes (48%); subsequent cataract surgery was performed in 9 (75%) of these 12 eyes. Additional incisional surgery was done or recommended in 6 eyes (27%) in Group 1 and 20 eyes in Group 2 (80%). CONCLUSION: Drainage surgery in patients with angle-closure glaucoma proved to be associated with multiple surgical interventions and deterioration in visual function. The choice of first a cataract procedure with the option of a future trabeculectomy may be a more attractive approach in patients with subacute or chronic angle-closure glaucoma than trabeculectomy followed by an optional cataract procedure.

Additive ocular hypotensive effect of latanoprost and acetazolamide. A short-term study in patients with elevated intraocular pressure.

OBJECTIVE: To investigate the additive ocular hypotensive effect of latanoprost on the intraocular pressure (IOP) reduction induced by a suboptimal dose of acetazolamide, a carbonic anhydrase inhibitor. DESIGN: A short-term, randomized, placebo-controlled, double-masked study. PARTICIPANTS: Twenty-four patients with glaucoma with elevated IOPs. INTERVENTION: Acetazolamide 250 mg twice daily from day 1 to day 18. Topical 50 micrograms/ml latanoprost or placebo eye drops bilaterally instilled once daily from day 4 to day 18. MEAN OUTCOME MEASURES: IOP, conjunctival hyperemia. RESULTS: The mean IOP of 19.5 mmHg during acetazolamide treatment was further reduced to 16.8 mmHg after topical administration of latanoprost, i.e., a decrease of 2.9 +/- 2.8 mmHg (15%, P < 0.001). Administration of placebo to patients on acetazolamide resulted in an upward drift of 1.3 mmHg (6%, P = 0.03). A modest but statistically significant increase in conjunctival hyperemia was found in the latanoprost-treated group, but did not affect the masking. CONCLUSIONS: This short-term study indicates that the combination of topically applied latanoprost and a suboptimal dose of systemic carbonic anhydrase inhibitor is useful in the management of glaucoma.

A comparison of retinal and choroidal hemodynamics in patients with primary open-angle glaucoma and normal-pressure glaucoma.

PURPOSE: To quantify, compare, and assess differences between retinal and choroidal hemodynamics in normal control subjects and patients with ocular hypertension, primary open-angle glaucoma, and normal-pressure glaucoma. METHODS: Video fluorescein angiograms were made in 20 normal subjects, 11 patients with ocular hypertension, 45 patients with primary open-angle glaucoma, and 43 patients with normal-pressure glaucoma. Choroidal dye build-up curves were analyzed using an exponential model. The model time constant tau reflected the local blood refreshment time, the time needed to replace the blood volume in a tissue volume. Retinal arteriovenous passage time was estimated from the time lapse between retinal arterial and venous dye curves. RESULTS: The retinal arteriovenous passage time was longer in patients with primary open-angle glaucoma compared with normal subjects and patients with normal-pressure glaucoma; the average arteriovenous passage times (+/-SEM) in normal subjects and in patients with ocular hypertension, primary open-angle glaucoma, and normal-pressure glaucoma were, respectively, 2.44 +/- 0.19, 2.90 +/- 0.37, 3.02 +/- 0.17, and 2.55 +/- 0.15 seconds. Choroidal tau was longest in the normal-pressure glaucoma group but not as long in the primary open-angle glaucoma group; tau values in normal subjects and patients with ocular hypertension, primary open-angle glaucoma, and normal-pressure glaucoma were, respectively, 4.6 +/- 0.29, 5.6 +/- 0.69, 6.2 +/- 0.39, and 7.1 +/- 0.33 seconds. CONCLUSIONS: Whereas choroidal circulation is especially slower in patients with normal-pressure glaucoma, retinal circulation is delayed in patients with primary open-angle glaucoma. The choroidal and retinal vascular systems behave differently in primary open-angle and normal-pressure glaucoma, which may be important in the management of glaucoma.

Analysis of variance of microspheres blood flow measurements in rabbits.

As part of a larger study on the interpretation of angiographically derived hemodynamic parameters, blood flow in several ocular tissues was measured using the radioactively labelled microspheres technique. As an unexpected secondary results, it was found that the microspheres data gave quantitative information on hyperaemic effects in the eye. This is the subject of the present paper. The measurements were made in 13 anaesthetized pigmented rabbits. In each animal, three blood flow measurements were performed at three different ocular perfusion pressures (60-15 mmHg). The perfusion pressures of the experimental eye were varied by changing the intra-ocular pressure. The contra-lateral eye served as a control. Labelled microspheres were used as a non-recirculating blood flow indicator, enabling the estimation of regional blood flows, in this case for the iris, ciliary body, peripheral choroid and peripapillary choroid separately. Using analysis of variance with perfusion pressure as covariate and taking into account the blood flow of the control eye, hyperaemia could be quantified in the experimental eye. Apart from a difference amongst animals, hyperaemia depended on tissue type. The amount of hyperaemia proved to be more pronounced in the anterior part of the eye, iris and ciliary body, and to decrease towards the posterior pole. With regard to the causes of this hyperaemia one could speculate about the invasive handling (anterior eye needles) topical administration of tropicamide, in combination with the general anaesthesia.

Fluorescein angiographic evaluation of the effect of latanoprost treatment on blood-retinal barrier integrity: a review of studies conducted on pseudophakic glaucoma patients and on phakic and aphakic monkeys.

Endogenous prostaglandins (PGs) have been claimed to play a role in the development of cystoid macular edema (CME). Two fluorescein angiographic studies evaluating the effect of latanoprost, a new ocular hypotensive PG analogue, on blood-retinal barrier integrity are, therefore, reviewed here. In the first study, six of eight unilaterally aphakic cynomolgus monkeys were treated bilaterally once daily for six months with 0.035% latanoprost (seven times the clinically used oculohypotensive concentration). Two of the animals served as controls. Fluorescein angiography of the fundus after one, three and six months of treatment revealed no leakage of fluorescein in any of the 16 eyes. In another study, pseudophakic eyes of 16 glaucoma patients who received twice-daily treatment with 0.006% latanoprost for four weeks were compared to eight patients treated with placebo. Biomicroscopic examination did not reveal any signs of CME and only one placebo-treated eye revealed a slight perifoveal leakage of fluorescein. These studies suggest that topically-applied latanoprost does not have a fluorescein angiographically detectable direct effect on the integrity of the blood-retinal barrier system in phakic or aphakic monkey eyes or in pseudophakic human eyes. This does not rule out the occurrence of CME in eyes more susceptible to CME, due to vitreous loss, posterior capsulotomy, or other postoperative situations. Especially in those eyes a study with latanoprost is proposed. Since, fluorescein angiography is a rather crude method of detecting abnormalities of the blood-retinal barriers, vitreous fluorometry in addition is suggested.

Reduced intraocular pressure and increased ocular perfusion pressure in normal tension glaucoma: a review of short-term studies with three dose regimens of latanoprost treatment.

Currently used ocular hypotensive agents do not effectively lower intraocular pressure (IOP) in some normal-tension glaucoma (NTG) patients. The prostaglandin F2 alpha analogue, latanoprost, has been shown to reduce IOP in normal subjects and ocular hypertensive glaucoma patients by increasing uveoscleral outflow. This mechanism is expected to be particularly effective in the lower IOP range that is typical of NTG. To date, three dose regimens of latanoprost have been shown to reduce IOP significantly in NTG. The IOP reductions of 14.2% and 15% obtained with twice-daily application of 0.0015% and 0.006% latanoprost, respectively, were comparable to the modest IOP reduction that has been reported for other glaucoma drugs in NTG. In contrast, once-daily application of 0.005% latanoprost resulted in a 21.4% IOP reduction. In another study that included 24-hour monitoring of systemic blood pressure and heart rate in NTG patients, the ocular perfusion pressure was found to improve more on once-daily 0.005% latanoprost than on twice-daily treatment with 0.5% timolol. Thus, once-daily 0.005% latanoprost appears to be a more effective and more convenient ocular hypotensive agent for treating NTG than currently used glaucoma drugs. However, long-term studies will ultimately be needed to establish the efficacy of this new drug to delay or prevent the progression of visual field loss in normal tension glaucoma.

The additive intraocular pressure-lowering effect of latanoprost in combined therapy with other ocular hypotensive agents.

Latanoprost, a prostaglandin F2 alpha analogue prodrug, has been shown to be an effective ocular hypotensive agent when used alone on ocular hypertensive or open angle glaucoma patients. In various studies, the ocular hypotensive effects of latanoprost have also been evaluated when used in addition to, or in combination with, other ocular hypotensive agents. Latanoprost produces an additional reduction of intraocular pressure (IOP) when used in combination with timolol, pilocarpine, acetazolamide and dipivefrin. These represent four different classes of glaucoma drugs-beta-adrenergic antagonists, cholinergic agonists, carbonic anhydrase inhibitors, and adrenergic agonists-all of which reduce the IOP by different mechanisms (reduction of aqueous humor production, increased outflow facility, or by a mixed effect on aqueous humor dynamics). All the available evidence shows that latanoprost produces a clinically significant additive ocular hypotensive effect when used in combination with any currently available ocular hypotensive agent.

Design of low cost glaucoma screening.

In 1991 the Netherlands Glaucoma Patient Association organized a glaucoma screening survey. This survey was designed to evaluate the effectiveness of a low cost screening setting. During a screening period of 8 days, 1259 subjects over the age of 49 years were examined by a team of non-ophthalmologically trained students. The following screening methods were used: visual field analysis (Henson CFS3000 perimeter), retinal nerve fiber layer photography (Canon non-mydriatic camera), intraocular pressure measurement (Pulsair non-contact tonometer) and determination of the peripheral anterior chamber depth (slitlamp biomicroscope, the van Herick method). In a later stage, subjects with glaucomatous abnormalities in the visual field and/or the photograph were re-examined by a glaucoma specialist using applanation tonometry, gonioscopy, ophthalmoscopy and Humphrey 30-2 visual field analysis. The time taken to conduct the individual screening tests in a subject varied from 1 to 5 min: perimetry took 5 min, photography 2 min, tonometry 3 min and angle-width determination 1 min. Fifty-six (4.4%) subjects showed glaucomatous defects in perimetry and/or photography. Thirty-seven could be re-examined and glaucoma was diagnosed in 16 subjects. Visual field defects and glaucomatous abnormalities in the photograph were confirmed by Humphrey perimetry in 72.7% and 35.7% respectively. Sixty-seven (5.3%) subjects had an intraocular pressure above 21 mm Hg, while no cases of angle closure glaucoma were found in this population. The costs of this screening setting were estimated at F1. 48,60 per screen. A future low cost screening survey might be limited to non-contact tonometry and visual field analysis with the Henson CFS3000 perimeter or a similar device, using suprathreshold testing with a limited number of points. Screening might be performed by non-medically trained employees. The costs of such a screening program may be estimated at F1. 16,- per screen and F1. 1.989,- per glaucoma case using a mobile screening unit (addendum).

Choroidal haemodynamics in glaucoma.

AIM: Quantification of haemodynamics of the peripapillary choroid in and the assessment of possible differences between normal subjects (N), ocular hypertensive (OHT), primary open angle (POAG), and normal pressure glaucoma (NPG) patients. METHODS: Video fluorescein angiograms (Rodenstock SLO 101) were made in 22 N subjects, 12 OHT, 48 POAG, and 46 NPG patients. The angiographically derived dye build up curves were described by means of an exponential model. One of the model parameters is the time constant tau theoretically reflecting local blood refreshment time; the blood refreshment time tau is the time needed to replace the blood volume in the choriocapillaris, inversely proportional to the local choroidal blood flow. Other variables are maximal fluorescence (Fdt) and time of first fluorescence (t0). Mean variable values were calculated for disc area and circular areas around the disc. RESULTS: Fdt of the disc was significantly lower in the POAG and NPG patients. There was no statistical difference in t0 between the study groups. The choroidal blood refreshment time was significantly longer in NPG patients and to a lesser extent in the POAG patients compared with the normal controls. The slowest choroidal blood refreshment can be found in the NPG group. The median choroidal blood refreshment times (25th-75th percentile) in the controls, OHT, POAG, and NPG patients were 4.1 (3.7-4.5), 4.4 (3.7-6.4), 5.8 (4.3-6.8), and 7.1 (5.5-9.3) seconds respectively. CONCLUSIONS: With the help of parametrisation of dye curves, using a one compartmental model, choroidal haemodynamics can be quantified. The blood refreshment time of the peripapillary choriocapillaris was found to be significantly prolonged especially in NPG patients; this may indicate slower choroidal haemodynamics in NPG patients.

Study of choroidal blood flow by comparison of SLO fluorescein angiography and microspheres.

Choroidal hemodynamics estimated with parameters describing the dye build-up curves obtained with video fluorescein angiography, were compared with a classical regional blood flow measurement: radioactively labelled microspheres. Video fluorescein angiograms (Rodenstock's SLO 101) and microspheres blood flow measurements were made in 13 anaesthetized pigmented rabbits. Ocular perfusion pressures were varied from 60 to 15 mmHg by changing the intraocular pressure. The angiographically derived dye build-up curves were described by means of an exponential model. One of the model parameters is the time constant tau theoretically reflecting local blood refreshment time. Labelled microspheres act as a non-recirculating blood flow indicator, enabling the estimation of regional blood flows. The relation between choroidal blood flow and perfusion pressure is nearly linear, suggesting the passive nature of choroidal vasculature. There is a significant correlation between tau and microspheres flow (R = 0.67, P < 0.01). According to the rheological model the product of blood flow and tau corresponds to the relevant blood volume. Hence, a function for the volume of the choriocapillaris as a function of perfusion pressure was established. The model parameter tau can be interpreted as the local blood refreshment time. Since the parameter tau, unlike microspheres, can be used clinically, tau may be used to retrieve information on choroidal hemodynamics in clinical practice. Information on the spatial distribution of choroidal hemodynamics is also obtained.

Reduction of intraocular pressure with treatment of latanoprost once daily in patients with normal-pressure glaucoma.

PURPOSE: Currently available ocular hypotensive agents often fail to lower intraocular pressure (IOP) in patients with normal-pressure glaucoma (NPG). The authors evaluated the IOP-reducing potential and side effects of latanoprost, a newly developed ocular hypotensive agent, in this patient group. METHODS: A randomized, double-masked, placebo-controlled cross-over study was performed in 30 patients with NPG, 29 of whom completed the study. During three periods of 3 weeks each, patients received, in a random order, 50 micrograms/ml latanoprost once daily, 15 micrograms/ml latanoprost twice daily, and placebo. Per dose, one drop of the study medication was applied topically in both eyes. At the end of each treatment period, diurnal IOP measurements were obtained. General and ocular symptoms were recorded, and a detailed ocular examination was performed on each visit to monitor side effects. RESULTS: Average IOP reduction after 50 micrograms/ml latanoprost once daily, 15 micrograms/ml latanoprost twice daily, and placebo was 3.6 +/- 1.9 mmHg (21.3%, P < 0.001), 2.4 +/- 1.5 mmHg (14.2%, P < 0.001), and 0.4 +/- 1.8 mmHg (2.4%, not significant), respectively. The difference between the two latanoprost dose regimens was significant (P = 0.001). Efficacy of latanoprost correlated with initial IOP (r2 = 0.76, P < 0.001). A mild, but statistically significant, increase in conjunctival hyperemia was observed in both latanoprost treatment groups. CONCLUSION: Both latanoprost regimens significantly reduce IOP in patients with NPG, but 50 micrograms/ml latanoprost once daily is more effective in reducing IOP than 15 micrograms/ml latanoprost twice daily. Lowering the concentration did not result in an improved side effects profile. Latanoprost is more effective at higher IOP levels.

Retinal nerve fiber layer assessment by scanning laser polarimetry and standardized photography.

PURPOSE: To determine whether, in a clinical setting, scanning laser polarimetry and retinal nerve fiber layer photography provide equivalent information on the retinal nerve fiber layer. METHODS: We prospectively studied 60 patients with glaucoma or ocular hypertension and 24 healthy subjects. With scanning laser polarimetry, an estimate of the cross section of the retinal nerve fiber layer was obtained. By using a photographic reference set, we quantified photographs of the retinal nerve fiber layer. Visual fields were used to relate the results of both methods to functional damage. RESULTS: The scanning laser polarimetry measurements yielded reproducible cross-section values (coefficient of variation, 6.6%). Comparison of cross-section values and photograph scores gave Pearson correlation coefficients smaller than r = .4 (P < .01), improving to a maximum of r = .53 after compensation for offset. When cross-section values were compared to the mean deviation of the visual field, the Spearman correlation coefficients varied from an r of -.34 to -.53 (P < .01). Correction for offset resulted in an r of -.54 to -.65. When photograph scores and mean deviation of the visual field were compared, the Spearman correlation coefficients varied from an r of -.65 to -.71 (P < .01). CONCLUSIONS: Because r was maximal at .53, the information on the retinal nerve fiber layer obtained with scanning laser polarimetry and photography seems not equivalent. This result could not have been because of lack of reproducibility. Although the results suggested possible offset in scanning laser polarimetry, other methodologic differences must be considered to explain the differences between the two techniques.

Evaluation of the peripapillary circulation in healthy and glaucoma eyes with scanning laser Doppler flowmetry.

In order to study peripapillary perfusion, one randomly selected eye of 34 of healthy volunteers and 40 glaucoma patients (27 suffering from primary open-angle glaucoma (POAG) 10 from normal pressure glaucoma (NPG) nd three from other types of glaucoma) was studied with a Heidelberg Retina Flowmeter. Temporal flow adjacent to the disc edge was significantly higher than the nasal flow (p < 0.01). It was reduced significantly in myopia both in controls (p < 0.05) and in glaucoma patients (p < 0.001). However, there was no difference between either controls and glaucoma patients or between POAG and NPG patients. It was independent of treatment type in glaucoma. Within the temporal peripapillary area extremely high flow values (values higher than the mean + 2 SD of the corresponding individual retinal flow) seemed to represent deep peripapillary vascular rings. They were significantly more frequent in glaucoma (72%) than in healthy volunteers (44%, p < 0.05). Their frequency was 83% in myopic and 23% in non-myopic eyes in the control group (p < 0.001). However, in glaucoma patients they were common both in myopic eyes (71%) and in non-myopic ones (75%). The results suggest that capillary perfusion adjacent to the temporal edge of the disc is significantly reduced in myopia. Deep peripapillary vascular structures can be measured on images focused on the surface of the retina, especially if the retina is thinner than normal (healthy myopic eyes and glaucomatous eyes independently of the refraction). This may mask a deficient function of the retinal capillary bed.

Scanning laser Doppler flowmetry in glaucoma.

Scanning laser Doppler flowmetry is a new means for the measurement of capillary perfusion. We studied the retinal and neuroretinal rim capillary perfusion with the Heidelberg Retina Flowmeter in one randomly selected eye of 31 healthy volunteers, 42 primary open angle glaucoma (POAG) patients and 17 normal pressure glaucoma (NPG) patients. The reproducibility of the measurements on the temporal and nasal retina and on the disc rim was 19%, 26% and 28% in the unselected control group, 12% in the POAG and 12%, 13% and 10% in the NPG group, respectively. Optic disc flow was significantly higher than retinal flow (p < 0.000001). Differences in corresponding flow values between healthy volunteers and glaucoma patients as well as between POAG and NPG patients were not statistically significant. There was no correlation between the temporal and nasal flow values of the same eyes. The average variation in flow between adjacent frame positions was 18.5%. Actual intraocular pressure and the type of treatment had no influence on the retinal flow. The results suggest that the position of the test-frame is very important for the final result. We could not find any significant difference in the perfusion between glaucomatous and control eyes with the Heidelberg Retina Flowmeter.

Functional characteristics of blue-on-yellow perimetric thresholds in glaucoma.

PURPOSE: Blue-on-yellow (B-on-Y) perimetry assesses the S-cone visual field under yellow adaptation. Glaucomatous field defects have been shown to appear earlier and to be larger in B-on-Y perimetry than in standard perimetry. An upper limit to the use of B-on-Y perimetry is set by the separation of the S-cones from the M- and L-cones. But, because the S-cones may also input to the luminance channel, the actual separation of the color and luminance channels is unknown. Here, the relative sensitivities of the color and luminance channels under B-on-Y test conditions are measured. METHODS: In 15 eyes with early glaucoma, 19 risk eyes, and 10 normal eyes, B-on-Y thresholds were measured from 0 degrees to 20 degrees eccentric and were compared to pure chromatic (B-in-Y) and achromatic (Y-on-Y) thresholds, obtained under identical yellow adaptation. RESULTS: In normals, B-on-Y thresholds were found to coincide with B-in-Y thresholds; Y-on-Y values were 0.5 log (at 20 degrees) to 0.9 log (at 0 degrees) higher. In the pathologic groups, the differences between B-in-Y and Y-on-Y thresholds were smaller. Pathologic threshold elevation is on average 1.8 times larger for chromatic than for achromatic stimuli. In some cases, the luminance channel takes over detection of the B-on-Y stimulus. CONCLUSIONS: In normals, the B-on-Y stimulus is mediated by the color channel. Takeover of detection by the luminance channel might impose limits on following color defects with B-on-Y perimetry. This takeover may occur before the S-cones become less sensitive than the M- and L-cones and might indicate S-cone input to the luminance channel.

Vascular concepts in glaucoma.

A relationship has been found among vascular risk factors, normal-tension glaucoma (NTG), and visual field progression. All these factors have been measured qualitatively. These factors are disc hemorrhages, peripapillary atrophy, myopic disc, choroidal sclerosis, slow filling of the choroid and veins, and vasospasms. Now we are in a transition period where more and more quantitative methods are becoming available: pulsatile ocular blood flow measurement (POBF), scanning laser angiography of the peripapillary choroid (SLAPPC), scanning laser angiography of the retinal circulation (SLARC), scanning laser Doppler flowmetry (SLDF), and color Doppler imaging. With POBF, SLAPPC, SLARC, and SLDF a deficient blood flow was found in at least 50% of patients with NTG. With these results a vascular pathogenesis of NTG becomes more and more evident.