Niklas Plange

Use of colour Doppler imaging in ocular blood flow research.

The main objective of this report is to encourage consistent quality of testing and reporting within and between centres that use colour Doppler imaging (CDI) for assessment of retrobulbar blood flow. The intention of this review is to standardize methods in CDI assessment that are used widely, but not to exclude other approaches or additional tests that individual laboratories may choose or continue to use.

Colour Doppler imaging and fluorescein filling defects of the optic disc in normal tension glaucoma

Aim: To investigate the relation between blood flow parameters of the retrobulbar vessels measured by means of colour Doppler imaging (CDI) and fluorescein filling defects of the optic nerve head in patients with normal tension glaucoma (NTG) and control subjects. Methods: 29 patients with NTG and 29 age and sex matched control subjects were included in this study. Blood flow velocities—peak systolic velocity (PSV), end diastolic velocity (EDV), and resistive indices (RI) of the ophthalmic artery (OA), the central retinal artery (CRA), and of the temporal and nasal short posterior ciliary arteries (TPCA, NPCA)—were measured with CDI. Fluorescein angiograms were performed with a scanning laser ophthalmoscope. The extent of absolute fluorescein filling defects of the optic nerve head in relation to the optic nerve head was assessed. Results: The PSV of the OA, the PSV and EDV of the CRA, and of the TPCA and NPCA were significantly reduced in NTG (p<0.05). The RI of the CRA, the TPCA and NPCA were significantly increased in NTG (p<0.01). The optic nerve head fluorescein filling defects were significantly larger in NTG (p<0.01). The filling defects were significantly negatively correlated (p<0.05) with the PSV and EDV of the CRA (PSVCRA: r = −0.41; EDVCRA: r = −0.34), with the PSV and EDV of the NPCA (PSVNPCA: r = −0.34; EDVNPCA: r = −0.38), and with the EDV of the TPCA (r = −0.29). A significant positive correlation (p<0.05) was found with the RI of both PCAs (RINPCA: r = 0.28; RITPCA: r = 0.29). Conclusion: Patients with NTG had reduced blood flow velocities and higher resistive indices in most retrobulbar vessels. Optic nerve head fluorescein filling defects were larger compared to controls. The filling defects were correlated with end diastolic velocities and resistive indices of the PCAs and with blood flow velocities of the CRA. Capillary loss of the optic nerve head may be related to higher downstream resistance and reduced blood flow velocities of the retrobulbar vessels.

Capillary density and retinal diameter measurements and their impact on altered retinal circulation in glaucoma: A digital fluorescein angiographic study

Aim: Normal pressure glaucoma (NPG) patients exhibit prolonged retinal arteriovenous passage times in fluorescein angiography and colour Doppler imaging suggests increased resistance downstream from the central retinal and posterior ciliary arteries. The aim of the study was to elucidate the morphological source of decreased perfusion and increased resistance of the ocular circulation in NPG. Methods: Retinal arteriovenous passage time (AVP) and peripapillary arterial and venous diameters were measured in digital scanning laser fluorescein angiograms. For estimation of retinal capillary density the area of the foveal avascular zone (FAZ) and the perifoveal intercapillary area (PIA) was quantified. 36 patients with NPG (mean age 57 (SD 13) years) and 21 healthy subjects (mean age 51 (13) years) were enrolled in the comparative study. Results: In NPG patients the AVP (2.55 (1.1) seconds) was significantly prolonged (p<0.001) when compared with healthy subject data (AVP: 1.70 (0.39) seconds). No differences for arterial or venous diameter, FAZ, and PIA were observed in NPG patients compared with healthy subjects. FAZ, PIA, arterial and venous diameter were not correlated with visual field indices (except venous diameter with PSD, r=0.35 (p<0.05)) or cup to disc ratios. AVP was significantly correlated (p<0.05) with the size of the optic nerve head (r=−0.28), visual field indices (MD: r=−0.3; PSD: r=0.3; CPSD: r=0.3), and contrast sensitivity (r=−0.34}. Conclusion: AVP times are significantly prolonged in NPG. The slowing of the retinal transit does not result from capillary dropout, or changes of peripapillary arterial or venous diameters with increased vascular resistance.

Pathogenetic aspects of the glaucomatous optic neuropathy: fluorescein angiographic findings in patients with primary open angle glaucoma.

PURPOSE To identify and quantify the role of retinal circulation, capillary leakage and/or nonperfusion of the optic nerve head in digital fluorescein angiography in normal subjects and patients with open angle glaucoma. METHODS Eighteen patients with primary open angle glaucoma (POAG) and 18 healthy age matched subjects were included. Fluorescein angiograms were performed using the scanning laser ophthalmoscope. The arteriovenous passage time (AVP) was assessed by dye dilution technique and describes the shortest passage through a retinal vascular segment. Optic nerve head nonperfusion was marked manually in early angiographic images and is given as percentage of the optic disk area. The fluorescence of the optic nerve head (as measure of the disruption of the blood-brain barrier) and the surrounding retina (ratio of leakage) was measured using digital imaging analysis in the late phases of the angiogram (9-10min). RESULTS The AVP time was significantly prolonged ( P=0.001) in patients with open angle glaucoma (AVP 2.29+/-0.32 s) compared to healthy subjects (AVP 1.37+/-0.42 s). The mean percentage of the optic nerve head nonperfusion was 16%. The ratio of optic nerve head fluorescence compared to retinal reference loci was significantly increased (P = 0.02) in patients with glaucoma (1.32+/-0.25) compared with normal subjects (1.32+/-0.19). CONCLUSIONS Fluorescein angiography revealed altered retinal perfusion along with optic nerve head nonperfusion and increased vascular leakage in open angle glaucoma patients. These factors appear to influence each other, with ultrastructural changes of the lamina cribrosa accompanying changes in the vasculature and nerve fibers. Longitudinal and interventive studies should help better elucidate the relationship between circulatory and neural loss, adding vasoprotective therapeutic approaches to interfere with the glaucomatous neurodegenerative chain of events.

Fluorescein filling defects of the optic nerve head in normal tension glaucoma, primary open-angle glaucoma, ocular hypertension and healthy controls

Background:  To evaluate fluorescein filling defects of the optic nerve head in normal tension glaucoma (NTG), primary open‐angle glaucoma (POAG), ocular hypertension (OHT) and controls.

Retrobulbar haemodynamics and morphometric optic disc analysis in primary open-angle glaucoma

Background: Previous studies confirmed reduced retrobulbar haemodynamics in primary open-angle glaucoma (POAG). Aim: To investigate a correlation between retrobulbar haemodynamics and morphometric neuroretinal rim analysis in patients with POAG. Methods: 51 patients with POAG (mean (standard deviation (SD)) age 65 (11) years) were included in this clinical study. Blood flow velocities (peak systolic velocity (PSV) and end-diastolic velocity (EDV)) of the ophthalmic artery, central retinal artery (CRA), posterior ciliary arteries (PCA) and central retinal vein were measured using colour Doppler imaging (Siemens Sonoline Sienna, Erlangen, Germany). Optic disc morphometry was carried out using scanning laser tomography (Heidelberg Retinal Tomograph II Heidelberg Egineering Heidelberg, Germany). The stereometric parameters of the neuroretinal rim (rim area, rim volume, cup shape measure and retinal nerve fibre layer (RNFL) cross-sectional area) were used for analysis. Results: The PSV of the CRA was significantly (p<0.001) correlated with rim area (r = 0.50) and rim volume (r = 0.51). The minimum velocities of the central retinal vein were significantly (p<0.001) correlated with rim volume (r = 0.56) and RNFL cross-sectional area (r = 0.49). No correlations were found for the flow velocities of the ophthalmic artery and PCAs. Conclusion: Retrobulbar haemodynamics of the central retinal artery and vein are correlated with the neuroretinal rim damage in POAG.

Accuracy of intraocular lens power calculation using partial coherence interferometry in patients with high myopia.

Citation information: Roessler GF, Dietlein TS, Plange N, Roepke A‐K, Dinslage S, Walter P, Mazinani BAE. Accuracy of intraocular lens power calculation using partial coherence interferometry in patients with high myopia. Ophthalmic Physiol Opt 2012, 32, 228–233. doi: 10.1111/j.1475‐1313.2012.00903.x

Effects of brinzolamide on ocular haemodynamics in healthy volunteers.

Aim: A prospective, randomised study to evaluate effects of brinzolamide on ocular haemodynamics in healthy volunteers. Methods: 30 volunteers (12 men, 18 women; 28.3 (SD 7.8) years) were prospectively randomised to either brinzolamide or placebo during a 2 week double masked treatment trial. Examinations were performed at baseline and after 2 weeks of treatment. Intraocular pressure was measured and automatic static perimetry (Humphrey field analyser, 24-2) and contrast sensitivity (CSV 1000, Vector Vision) were performed. Retrobulbar blood flow velocities (peak systolic and end diastolic velocity) and resistive indices (RI) of ophthalmic artery, central retinal artery and of temporal and nasal short posterior ciliary arteries were measured by colour Doppler imaging (Sonoline Sienna Siemens). In video fluorescein angiograms (scanning laser ophthalmoscope, Rodenstock) arteriovenous passage time (AVP, dilution curves) and peripapillary diameters of retinal arterioles and venules were measured by means of digital image analysis. Results: Intraocular pressure was significantly decreased by brinzolamide (p<0.0001). Neither brinzolamide nor placebo changed visual field global indices after treatment. Contrast sensitivity at 3 cycles per degree was significantly higher in the placebo group (p<0.05). Apart from an increase of RI in ophthalmic artery under placebo treatment (p<0.05) there was no effect in retrobulbar haemodynamics in both groups. Brinzolamide therapy alone resulted in a significant reduction of AVP compared to baseline (p<0.05), while peripapillary retinal vessels diameters remained unaffected. Conclusions: Apart from the expected decrease of intraocular pressure brinzolamide showed no significant change in retrobulbar haemodynamics, but a significant shortening of AVP. Since in glaucoma AVP is prolonged indicating vascular dysfunction this effect might be beneficial in glaucoma therapy.

Retrobulbar haemodynamics in non-arteritic anterior ischaemic optic neuropathy

Aim: To compare retrobulbar haemodynamics in patients with acute non-arteritic anterior ischaemic optic neuropathy (NAION) and age-matched controls by colour Doppler imaging (CDI). Methods: 25 patients with acute NAION and 35 age-matched controls participated in this study. By means of CDI, the blood flow velocities of the ophthalmic artery, central retinal artery (CRA), and nasal and temporal short posterior ciliary arteries (PCAs) were measured. Peak-systolic velocity (PSV) and end-diastolic velocity (EDV) and Pourcelot’s resistive index were determined. Results: In the ophthalmic artery, no marked differences between patients with NAION and controls were detected. PSV and EDV of the CRA (p<0.001, p = 0.002) and PSV of the nasal PCA (p<0.05) were significantly decreased in patients with NAION compared with healthy controls. No marked differences between patients and controls were detectable for temporal PCAs. Conclusion: Blood flow velocities of the nasal PCA and the CRA are considerably reduced in patients with acute NAION compared with controls. Patients with NAION in part showed markedly different retrobulbar haemodynamics.

Performance of colour Doppler imaging discriminating normal tension glaucoma from healthy eyes

PurposePrevious studies have shown decreased retrobulbar blood flow in normal tension glaucoma (NTG) compared to healthy controls. This study evaluates the ability of colour Doppler imaging (CDI) to identify patients with NTG.MethodsSixty-two patients with untreated NTG (mean age 57±14 years) and 40 age-matched controls (mean age 58±9 years) were included in a prospective cross-sectional institutional study. Peak systolic velocity (PSV), end-diastolic velocity (EDV), and resistive indices (RI=(PSV–EDV)/PSV) of the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (PCAs) were measured by means of CDI. Using receiver operating characteristic (ROC) curves, sensitivity was determined at 90% specificity.ResultsPatients with NTG showed significantly decreased PSV (P<0.0001) and EDV (P<0.0001) of the CRA, significantly decreased EDV of the nasal (P=0.004) and temporal (P=0.002) PCA, and significantly increased RI of the temporal (P=0.003) PCAs compared to healthy controls. Sensitivity values at 90% specificity were calculated: PSV of the CRA, 30.6%; EDV of the CRA, 48.4%; EDV of the nasal PCA, 43.9%; EDV of the temporal PCA, 45.9%; and RI of the temporal PCA, 39.3%.ConclusionsThe power to identify NTG using CDI reaches 48% sensitivity at 90% specificity. Further longitudinal studies are needed to determine the prognostic value of CDI in glaucoma.