[Canaloplasty ab interno - a Minimally Invasive Alternative]. / Kanaloplastik ab interno ­ eine minimalinvasive Alternative.

Purpose Description and evaluation of the technique and efficacy of canaloplasty ab interno (ABIC) in patients with open angle glaucoma (POAG). Methods In this monocentric series of consecutive cases, patients with cataract and open angle glaucoma (combined operation) and pseudophacic patients (mean age: 78 years, range 66-90 years), and suffering from POAG were included. All of them were operated with ABIC by using the iTrack™ 250 µ-microcatheter (Ellex Medical Lasers Pty Ltd, Adelaide, Australia), in order to circumferentially vasodilate Schlemm's canal without implanting a suture to increase tension. Primary endpoints were the mean IOP (intraocular pressure) after 1, 3, 6, 9 and 12 months surgery. Results Twenty-three patients (23 eyes) were included in the study. Mean IOP without a preoperative wash-out phase was reduced from 18.8 ± 5.63 mmHg preoperatively to 14.9 ± 2.90 mmHg (n = 22), 13.82 ± 2.98 (n = 19), 14.69 ± 2.36 mmHg (n = 13), 16.0 ± 2.09 (n = 11) and 14.73 ± 2.97 (n = 11) at 1, 3, 6, 9 and 12 months after surgery. Mean medication was reduced from 1.69 to 0.21 at the last follow-up. The only complication was limited descemetolysis near the limbus. Conclusion The initial results in this study indicate that ABIC reduces IOP and that the dependance on medication is comparable to that with ab externo canaloplasty.

[Canaloplasty after trabeculectomy]. / Kanaloplastik nach Trabekulektomie.

BACKGROUND: Canaloplasty after failed trabeculectomy is an operation with differing individual surgical situations, which depend on the extent of scarring in the preexisting bleb area and on the site of the fistula in the chamber angle itself. OBJECTIVE: The results of 18 cases and the surgical technique are presented.

[Can an intrascleral implant and/or the combined cataract surgery improve the long-term outcome of viscocanalostomy in glaucoma?]. / Kann ein intrasklerales Implantat und/oder die kombinierte Katarakt-OP die Langzeitprognose der Viskokanalostomie beim Glaukom verbessern?

BACKGROUND: Beside the established methods in glaucoma surgery, several procedures have been developed in the recent past including viscocanalostomy as a non-penetrating surgery. The efficiency of a combination of this procedure with an intrascleral implant and/or with cataract surgery was examined in this retrospective study over a period to 60 months postoperatively. PATIENTS AND METHODS: 67 eyes from 49 patients with glaucoma were operated in two different operational groups. 39 eyes had a viscocanalostomy (Group "V"). 16 eyes in this group additionally got a T-Flux implant ("ViskoT"), 23 did not ("Visko"). A combined cataract extraction and viscocanalostomy was undertaken in 28 eyes (Group "VK"), 18 of which did not ("ViskoKa"), and 10 of which did receive a T-flux implant ("ViskoKaT"). RESULTS: The mean preoperative intraocular pressure was 27.1 ± 4.5 mmHg and went down to 17.4 ± 2.9 mmHg postoperative up to the point of 60 months: there was a significant difference in the overall postoperative intraocular pressure in comparison to the preoperative intraocular pressure. There was, however, no significant effect to be found until after 5 years on the postoperative intraocular pressure by cataract extractions and also not by the implantation of a T-Flux. However, significantly less medication was applied up to the postoperative point of 12 and 36 months in the group with cataract surgery (VK). This difference was lost in the course of time and was no longer detectable after 60 months. However, an overall rise in both medication and goniopuncture (31.3 %) of the Descemet using YAG laser was necessary in the course of time, in order to keep a constant level of the postoperative intraocular pressure. CONCLUSIONS: Viscocanalostomy represents a safe surgical antiglaucomatous method for improving the intraocular pressure. A respective clinical improvement could be observed during the follow-up period of up to 60 months. The prognosis of intraocular pressure does not improve by the use of intrascleral implants and viscocanalostomy with simultaneous cataract surgery, however.

[Canaloplasty. A new way in glaucoma surgery?]. / Kanaloplastik. Ein neuer Weg der Glaukomchirurgie?

Evaluation of the surgical treatment of open angle glaucoma depends on values, such as target pressure, success rates and complication rates. Canaloplasty is a new non-penetrating method for glaucoma surgery and the aim of this article is to present the surgical approach, indications, results and post-operative therapy. During the operation a viscocanalostomy according to Robert Stegmann is performed. Subsequently a microcatheter with an outer diameter of 200 µ is used to circumferentially dilate Schlemm's canal. During the dilation microvolumes of a high viscosity ophthalmic viscosurgical device (OVD) (sodium hyaluronate) are injected. After successful dilation the catheter is retracted and at the same time a 10.0 Prolene suture is placed in the canal and closed tightly to apply permanent tension to the trabecular meshwork.

Video fluorescein angiography: method and clinical application.

Video fluorescein angiography, combined with a picture analyzing system, is a clinically applicable, objective method of evaluating the retinal blood-flow parameters. Optical density measurements were performed on videorecordings of fluorescence angiograms by means of a picture-analyzing system in order to determine the circulation parameters of the retina. These included: the arm-retina time (ART), the arteriovenous passage time (AVP), and the mean arterial dye-bolus velocity (MDV). Normal values for these parameters were derived from measurements in 75 healthy volunteers. The mean arm-retina time (ART) was 11.2 +/- 3.3 s, the mean arteriovenous passage time (AVP) 1.45 +/- 0.4 s and the mean arterial dye-bolus velocity (MDV) 6.39 +/- 1.7 mm/s. No significant correlation could be shown between pulse or blood pressure and one of the retinal circulation parameters. A group of ten healthy volunteers was examined twice in order to obtain the intraindividual variation for the measuring parameters. The coefficient of variation for the ART was 18%, 10% for the AVP, and 26% for the MDV.

Measurement of retinal blood flow in various pathological conditions by video fluorescence angiography.

Many ophthalmological disorders are due to poor local microcirculation, examples being central retinal vein occlusion, acute retinal artery occlusion, and ischaemic eye disease. Generalized changes have been found in arterial hypertension, diabetes mellitus, and arteriosclerosis. It is only at a few places that the microcirculation can be investigated non-invasively in man, and in this connection the retina is of particular interest because it is one of the regions supplied by the intracranial part of the internal carotid. The retinal blood supply is divided into four clearly separate quadrants, normally not communicating via anastomoses. The time of the arteriovenous passage (AVP) can therefore serve as a good indicator of retinal microcirculation. This parameter was measured before and after treatment in patients with diabetic retinopathy, angiosclerosis of the fundus, and lacunar stroke. Video fluorescence angiography reveals the abnormalities of the microcirculation in the area supplied by the carotid artery and can be used to check on therapeutic effects.

Microcirculation in the conjunctival capillaries of healthy and hypertensive patients.

To study the impact of hypertension on conjunctival circulation, one group of healthy individuals and three groups of hypertensive patients (different stages of disease) were examined. Each participant had to undergo videomicroscopy to determine erythrocyte velocity in conjunctival capillaries, reactive hyperaemia and the diameter of the erythrocyte column within the vessels. Compared to healthy subjects, erythrocyte velocity and the diameter of the erythrocyte column were markedly increased in hypertensive patients. Furthermore the normalization of the erythrocyte velocity after a period of hypoxia was impaired in the hypertensives. These results indicate that changes in microcirculation due to hypertension can be detected by video microscopy.

Microcirculation and hemorheology of children with type I diabetes.

A group of 53 children, suffering from diabetes mellitus type I and a group of 12 healthy children were compared. In both groups the following data were determined: Haemoglobin A1C, retinal blood flow (video fluorescence angiography), erythrocyte velocity in finger nailfold capillaries (video capillaroscopy), capillary tortuosity, plasma viscosity, erythrocyte rigidity, and haematocrit. The degree of capillary tortuosity was significantly elevated and erythrocyte velocity was significantly diminished in the group of diabetic children in comparison to the healthy children. Regarding rheological data there was a significant decrease in erythrocyte deformability for the diabetic children. Diabetic children with good stabilization presented better rheological parameters than the poorly stabilized ones. Although these findings provided sufficient information, it will be necessary to cover a long follow up period to judge the prognosis of good and poorly stabilized diabetic children.

Circulatory parameters of the retina in patients with lacunar stroke.

Ophthalmological data were obtained in 40 patients presenting with lacunar stroke. The stroke was verified clinically as well as by computed tomography. Vision was tested and the visual field, intraocular pressure, retinal arteriovenous passage time, arm-retina time, and erythrocyte flow velocity in the conjunctival capillaries were all determined; ophthalmoscopy was also carried out. Microcirculatory parameters were obtained from 21 patients. Significant disturbances of the retinal arteriovenous passage time were observed, but there were no significant disturbances of the conjunctival erythrocyte flow velocity. The concurrently measured haemorheological parameters were all pathological with the exception of the haematocrit. Ophthalmoscopic examination revealed arteriosclerotic alterations in 38 of 40 patients. These angiological and rheological findings confirm the importance of disturbed microcirculation in lacunar stroke.

[Television fluorescence angiography and image analysis: clinical use with a case example]. / Fernsehfluoreszenzangiographie und Bildanalyse: Klinische Anwendung mit Fallbeispiel.

The clinical application of TV fluorescein angiography with subsequent image analysis as performed on a patient with familial Mediterranean fever (FMF), who was suffering from an arterial branch occlusion, is discussed. In addition, the diagnostic relevance of rheologic parameters to the diagnostic evaluation of retinal circulatory disorders is emphasized.

The haemorheological features of lacunar strokes.

Clinical and haemorheological data were recorded in 40 patients with lacunar strokes confirmed clinically and by computed tomography. The following haemorheological variables were monitored: haematocrit, erythrocyte aggregation, erythrocyte deformability, plasma viscosity, fibrinogen concentration and yield shear stress. Clinically, most patients had case histories and features according to the description of Fisher. All haemorheological parameters with the exception of the haematocrit were pathological when compared with values obtained from a normal control group. In descending order of frequency the pathological changes were in erythrocyte aggregation, plasma viscosity and erythrocyte deformability.

The capillary tube plasma viscometer--an automatical instrument for measuring plasma viscosity.

A new capillary viscometer was developed to eliminate the measuring errors due to insufficient cleaning or the residue of cleaning solution in the capillary. A disposable polyurethane tube which can be discarded after each determination is used as a measuring chamber. This device has been constructed for bed-side application (light weight, dry, thermostat-controlled measuring capillaries, short measuring period, automated process, and easy operation). The PEARSON correlation coefficient for comparative measurements with the COULTER-HARKNESS viscometer was r = 0.979.

[Arterial retinal circulatory disorders: an urgent indication for Doppler sonographic study of the carotid flow system]. / Arterielle retinale Durchblutungsstörungen: eine dringende Indikation zur Doppler-sonographischen Untersuchung der Carotis-Strombahn.

Nineteen subjects with retinal strokes of different degrees of severity (amaurosis fugax, occlusion of individual retinal arteries or of the central retinal artery) were examined by continuous-wave Doppler sonography. Evaluation of periorbital Doppler flow and direct examination of the major neck vessels were performed. Twelve subjects presented with homolateral arteriosclerotic lesions at the carotid bifurcation. The ultrasonographic findings were confirmed by carotid arteriography. High-grade stenosis or occlusion of the internal carotid artery were found in approximately 50% of the patients; the remainder turned out to have low-grade stenoses or nonstenosing plaques. These findings emphasize the role of emboli from the major neck arteries in the pathogenesis of retinal and cerebral insults. Hemodynamic effects seem to be of minor significance. Continuous-wave Doppler sonography is a completely non invasive, but nevertheless reliable method for the detection of clinically relevant carotid lesions. Especially patients suffering from retinal insults should be examined by Doppler sonography, since they are at high risk for further cerebral stroke.

Measuring the microcirculation in the human conjunctiva bulbi under normal and hyperperfusion conditions.

We present a system consisting of a slit lamp stereomicroscope and an adapted video system for the examination of the conjunctival microcirculation. This system permits measurement of the flow of erythrocytes in the vessels of the bulbar conjunctiva. We present values obtained from clinically normal individuals under normal conditions and under conditions of hyperperfusion.

Quantification of characteristic blood-flow parameters in the vessels of the retina with a picture analysis system for video-fluorescence angiograms: initial findings.

Fluorescence angiograms of the retina were performed on 12 healthy, adult subjects between the ages of 20 and 52 years with a 30 degrees fundus camera (C. Zeiss), a low-light TV camera and a video recorder. Characteristic blood-flow parameters for the retina were obtained from the video recording using the picture-analysis system (Mikrovideomat 3, C. Zeiss). These included: the arm-retina time (ART), the arteriovenous passage time (AVP) and the arterial contrast-medium velocity (ACMV). Normal values for these parameters were derived for the four retinal quadrants and then discussed. In addition, the filling characteristics of venules were measured and discussed.

Rheologic findings in patients with acute central retinal artery occlusion.

The most important rheologic parameters were examined in six patients with acute occlusion of the central retinal artery. Blood samples were taken as part of the initial clinical examination on the day of the occlusion before the onset of therapy, and the following parameters were studied: (1) yield shear stress; (2) hematocrit; (3) plasma viscosity; (4) extent of erythrocyte aggregation; (5) erythrocyte deformability; (6) plasma fibrinogen concentration. A definite shear stress could be measured in all patients, something not possible in rheologically healthy volunteers. Hematocrit values were in the upper normal range; plasma viscosity was significantly increased. The extent of erythrocyte aggregation was greater than normal, erythrocyte deformability was markedly reduced, and the plasma fibrinogen was markedly higher than the normal level. Aside from the well-known pathologic findings in the carotid arteries of many patients with acute retinal vascular occlusion, rheologic factors seem to be of great importance in this disease.