Alexandra Luksch

Medical University of Vienna, Vienna, Vienna, Austria

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Publications (49)137.54 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine whether nifedipine, an L-type calcium channel blocker, alters choroidal blood flow (ChBF) regulation during isometric exercise in healthy subjects. The study was carried out in a randomized, placebo-controlled, double-masked, two-way crossover design. Fifteen healthy male subjects were randomly assigned to receive either placebo or nifedipine on two different study days. Subfoveal ChBF was measured with laser Doppler flowmetry while the study participants performed isometric exercise (squatting). This was performed before drug administration and during infusion of nifedipine and placebo, respectively. Mean arterial pressure (MAP) and intraocular pressure (IOP) were measured noninvasively, and ocular perfusion pressure (OPP) was calculated as &frac23; MAP-IOP. MAP and OPP increased significantly during all squatting periods (P < 0.01). The increase in ChBF was less pronounced than the increase in OPP during isometric exercise. Nifedipine did not alter the OPP increase in response to isometric exercise, but it significantly augmented the exercise-induced increase in ChBF (P < 0.001 vs. placebo). Although ChBF increased by a maximum of 14.2% ± 9.2% during the squatting period when placebo was administered, the maximum increase during administration of nifedipine was 23.2% ± 7.2%. In conclusion, the data of the present study suggest that nifedipine augments the ChBF response to an experimental increase in OPP. In addition, it confirms that the choroidal vasculature has a significant regulatory capacity over wide ranges of OPPs during isometric exercise. (ClinicalTrials.gov number, NCT00280462.).
    Investigative ophthalmology & visual science 12/2011; 53(1):374-8. · 3.43 Impact Factor
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    ABSTRACT: The performance of a primary posterior capsulorhexis (PPC) with and without posterior optic buttonholing (POBH) may significantly influence the intraocular pressure (IOP) after cataract surgery in age-related cataract patients. The prospective randomized clinical study was performed at the department of Ophthalmology, Medical University of Vienna, Austria. Thirty consecutive cataract patients with bilateral same-day cataract surgery (60 eyes) under topical anesthesia were enrolled. In randomized order, cataract surgery with combined PPC/POBH was performed in one eye; in the other eye, cataract surgery was performed with PPC and in-the-bag implantation of the intraocular lens (IOL). Standardized IOP measurements by Goldmann applanation tonometry were performed preoperatively, 1, 2, 4, 6, 8 and 24 hours postoperatively, as well as 1 week and 1 month postoperatively. During the first 24 hours after surgery, all IOP measurements were significantly lower in eyes with combined PPC/POBH when compared to eyes with solitary PPC (p < 0.001). No IOP peaks of more than 27 mmHg were observed with combined PPC/POBH. In contrast, in eyes with PPC and in-the-bag IOL implantation, seven patients had an IOP peak of more than 27 mmHg and four IOP peaks of more than 30 mmHg. One week and 1 month postoperatively, IOP measurements were statistically comparable, and no significant differences could be observed between the two groups (p > 0.05). Postoperative IOP peaks after cataract surgery with sole PPC can be effectively prevented by the buttonholing of the IOL through the posterior capsulorhexis.
    Albrecht von Graæes Archiv für Ophthalmologie 11/2010; 248(11):1595-600. · 1.93 Impact Factor
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    ABSTRACT: Cardiovascular risk factors such as smoking, hypertension, and atherosclerosis seem to play an important role in the development of choroidal neovascularization (CNV). Recent studies have also provided evidence suggesting that choroidal and retinal blood flow is decreased in patients with AMD. On the basis of these results, the hypothesis for this study was that lower choroidal blood flow is associated with an increased risk of CNV in patients with AMD. Forty-one patients with unilateral choroidal neovascular AMD were included in this observational longitudinal study. The fellow eyes of the patients served as study eyes. Subfoveal choroidal blood flow (FLOW) and fundus pulsation amplitude (FPA) were assessed with laser Doppler flowmetry and laser interferometry, respectively. A multivariate COX-regression model was used to test the hypothesis that low choroidal perfusion parameters are associated with the development of CNV. Of the 37 patients that were followed up until the end of the study, 17 developed CNV and 20 did not. The univariate COX-regression analysis shows that lower FLOW, systolic blood pressure, intraocular pressure, and FPA are risk factors for development of CNV. Moreover, the more advanced the AMD in the study eye, the higher the risk for CNV to develop in the fellow eye. Multivariate COX regression analysis indicated that only FLOW (P = 0.0071), FPA (P = 0.0068), and staging (P = 0.031) had statistically significant influences on the progression to CNV. The present study indicates that lower choroidal perfusion is a risk factor for the development of CNV in the fellow eye of patients with unilateral CNV.
    Investigative ophthalmology & visual science 08/2010; 51(8):4220-5. · 3.43 Impact Factor
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    ABSTRACT: It has been shown that retinal blood flow is autoregulated, meaning that flow is independent of perfusion pressure within a certain range. We tested the hypothesis that nitric oxide (NO) synthase inhibition alters the response of retinal arterial and venous vessels during isometric exercise. In this study, nine healthy subjects were included. Each subject received the NO synthase inhibitor Ng-monomethyl-l-Arginine (l-NMMA, the α-receptor agonist phenylephrine or placebo intravenously on three study days. Retinal vessel diameter was assessed with the retinal vessel analyser (RVA), at baseline and during a squatting period of 6-7 min in absence or presence of l-NMMA, phenylephrine or placebo. Mean arterial pressure (MAP) and pulse rate (PR) increased significantly during all pretreatment squatting periods (p < 0.001) Retinal venous and arterial diameters showed a continuous decrease during squatting (p < 0.001). Phenylephrine increased MAP and PR but did not alter the retinal vessel diameter response to squatting. Administration of l-NMMA lead to a significant decrease in venous diameter before isometric exercise (p = 0.004). In addition, the retinal venous diameter response during administration of the NO synthase inhibitor was less pronounced than during phenylephrine or placebo (p < 0.001). Our study confirms that NO plays an important role in the control of retinal vascular tone at rest. In addition, the present data indicate a role of NO in retinal autoregulation, because the response of retinal venous diameters was altered after NO synthase inhibition. The nature of involvement, however, appears to be complex and requires further studies.
    Acta ophthalmologica 07/2010; 90(4):362-8. · 2.44 Impact Factor
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    ABSTRACT: There is evidence from several vascular beds that acute alcohol consumption causes ocular hypotension and peripheral vasodilatation. The current study investigated the effects of intravenously administered ethanol on retinal vessel diameters and on flicker induced retinal vasodilatation. For this purpose, ethanol (0.35 g/kg) or placebo (physiologic saline solution) was administered intravenously for 40 min in a randomized, double masked, two way cross-over design to 12 healthy male volunteers. Retinal vessel diameters and flicker induced vasodilatation were measured before administration of ethanol as well as 30, 50, 90 and 130 min after the start of infusion with a retinal vessel analyzer. Intraocular pressure, systemic blood pressure and blood ethanol concentration were determined at the same time points. Intravenous administration of ethanol increased blood ethanol concentration from 0.0 g/l to 0.56+/-0.10 g/l. Ethanol reduced IOP, but did not change ocular perfusion pressure. After cessation of the infusion blood ethanol concentration started to drop reaching a blood ethanol concentration of 0.22+/-0.06 g/l 130 min after the start of infusion. Retinal arterial diameters increased significantly after administration of ethanol by a maximum of +4.2+/-4.0%, whereas no change was observed in retinal veins. Neither arterial nor venous diameters were influenced by administration of placebo. Flicker stimulation induced a significant dilatation in both arterial and venous diameters. Ethanol did not change flicker responses in arteries or in retinal veins. In conclusion, intravenous administration of ethanol increases retinal arterial diameters, whereas venous diameters remained unchanged. Whether this is related to a direct vasodilator effect or to a hitherto unidentified mechanism remains to be clarified.
    Microvascular Research 07/2009; 78(2):224-9. · 2.93 Impact Factor
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    ABSTRACT: To investigate in patients with neovascular age-related macular degeneration (ARMD) the changes in ocular perfusion caused by single treatment with photodynamic therapy (PDT) by different non-invasive methods; to evaluate correlations between relative changes of ocular haemodynamic parameters after PDT among each other and compared to morphological parameters; and to assess this in relation to early changes of visual acuity. Study population: 17 consecutive patients with subfoveal choroidal neovascularization (CNV) caused by ARMD scheduled for PDT without previous PDT treatment (four patients with predominantly classic CNV and 13 patients with occult CNV). best-corrected visual acuity (before PDT, 6 and 8 weeks after PDT), fundus photography, fluorescein angiography, haemodynamic measurements with laser Doppler flowmetry (LDF), laser interferometry and ocular blood flow (OBF) tonometry (baseline and 1, 2, 6 and 8 weeks after treatment). choroidal blood flow (CHBF), fundus pulsation amplitude (FPA), pulsatile ocular blood flow (POBF), visual acuity. Changes smaller than 20% were considered clinically irrelevant. Results: Ocular haemodynamic parameters did not change significantly in the follow-up period. Changes of haemodynamic parameters showed no correlation to treatment spot, morphological changes or visual acuity. Changes of visual acuity were comparable to results of earlier studies. Single treatment with PDT did not modify ocular blood flow parameters above 20% as assessed with different non-invasive methods.
    Acta ophthalmologica 04/2009; 87(6):631-7. · 2.44 Impact Factor
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    ABSTRACT: To evaluate the effect of primary posterior continuous curvilinear capsulorhexis (PCCC) with and without posterior optic buttonholing (POBH) on the anterior chamber reaction after small-incision cataract surgery. Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. Consecutive patients with age-related cataract having cataract surgery in both eyes under topical anesthesia were prospectively enrolled in a randomized clinical trial. In randomized order, cataract surgery with combined primary PCCC and POBH was performed in 1 eye; in the other eye, cataract surgery was performed with primary PCCC and in-the-bag implantation of an intraocular lens. Intraocular flare was measured with an FC-1000 laser flare-cell meter preoperatively and postoperatively at 1, 4 to 6, and 24 hours, 1 week, and 1 month. Thirty patients (60 eyes) were evaluated. The peak of intraocular flare was 1 hour postoperatively in all study eyes. In both groups, the response steadily decreased thereafter. Anterior chamber flare was statistically significantly higher in eyes with primary PCCC without POBH than in eyes with combined primary PCCC-POBH at all postoperative testing points (P<.001), including at 1 month (P = .01). Cataract surgery with combined primary PCCC-POBH led to significantly lower postoperative anterior chamber reaction than conventional in-the-bag implantation during a 4-week follow-up. The tight capsule-optic diaphragm effectively prevented the ophthalmic viscosurgical device captured behind the optic from entering the anterior chamber postoperatively.
    Journal of Cataract and Refractive Surgery 03/2009; 35(3):480-4. · 2.75 Impact Factor
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    ABSTRACT: Breathing of 100% oxygen causes vasoconstriction in retinal vessels paralleled by a decrease in blood flow. The mechanism underlying this effect is still unclear, but may be related to the increased generation of reactive oxygen species during hyperoxia. Thus, the purpose of the present study was to investigate whether vitamin C, an agent with strong antioxidative properties, modifies the retinal vasoconstrictor response to hyperoxia. A randomized, double-masked, placebo controlled, two-way crossover study was performed in 12 healthy young volunteers. 100% oxygen was administered via a breathing mask for 12 min. Retinal blood flow was measured before and during oxygen breathing in the presence of either ascorbic acid (3 g) or placebo on two different study days. Retinal blood flow was determined based on measurement of retinal vessel diameters and red blood cell velocity. Breathing of 100% oxygen induced a pronounced reduction of retinal arterial (-7.6%+/-6.5%) and venous diameters (-12%+/-6%). Hyperoxia induced vasoconstriction was not altered by co-administration of vitamin C (-8.6%+/-4.8% in arteries and -15%+/-7% in veins). Likewise, RBV and retinal blood flow decreased in response to oxygen by -24%+/-53% and -38%+/-42%. Again, the reduction of retinal hemodynamic parameters was not altered by co-administration of vitamin C. Oxygen induced blood flow response in the human retina is not altered by a single dose of vitamin C in healthy, young subjects. Whether this indicates that ROS are not involved in hyperoxia induced vasoconstriction of retinal vessels or is related to other factors has yet to be determined.
    Microvascular Research 01/2009; 77(3):256-9. · 2.93 Impact Factor
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    ABSTRACT: To investigate the fluctuations of ocular blood flow parameters over 13 h in patients with primary open-angle glaucoma (POAG) and in healthy eyes, and to relate these fluctuations with variations in intraocular pressure (IOP) and mean ocular perfusion pressure (OPP). 15 patients with POAG and 15 control subjects were included. Measurements of systemic blood pressure (SBP), fundus pulsation amplitude (FPA), choroidal blood flow (CHBF), optic nerve head blood flow (ONHBF) and IOP were performed at 08:00, 12:00, 17:00 and 21:00. OPP was calculated from IOP and SBP. The coefficient of variation (CV) was calculated for all individual parameters to assess their variability. The time response of the ocular haemodynamic variables was not different between the groups. Most of the outcome variables showed significantly larger fluctuations in patients with POAG compared with healthy controls (CV: FPA: 0.085 (SD 0.033) vs 0.054 (0.029), p = 0.012; CHBF: 0.082 (0.030) vs 0.052 (0.023), p = 0.005; ONHBF: 0.086 (0.044) vs 0.059 (0.032), p = 0.063). These changes were not associated with OPP or IOP. Changes over time correlated among the different ocular haemodynamic outcome measures in patients with POAG (r = 0.678, r = 0.557, r = 0.545; p<0.04) but not in the control subjects (r = 0.336, r = -0.227, r = -0.130; p>0.22). Patients with POAG show a larger diurnal fluctuation of ocular blood flow parameters. These fluctuations appear not to be related to a higher statistical error of the applied measurement techniques in POAG patients. These data support the hypothesis that POAG is associated with vascular dysregulation.
    The British journal of ophthalmology 12/2008; 93(4):486-91. · 2.92 Impact Factor
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    ABSTRACT: The aim of the present study was to investigate the reproducibility and potential diurnal variation of optic nerve head and retinal blood flow parameters in healthy individuals over a period of 12 hr. We measured optic nerve head and retinal blood flow parameters in 16 healthy male non-smoking individuals at five time-points during the day (08:00, 11:00, 14:00, 17:00 and 20:00 hr). Outcome parameters were perimacular white blood cell flux (as assessed with the blue field entoptic technique), blood velocities in retinal veins (as assessed with bi-directional laser Doppler velocimetry), retinal arterial and venous diameters (as assessed with the retinal vessel analyser), optic nerve head blood flow, volume and velocity (as assessed with single point and scanning laser Doppler flowmetry) and blood velocities in the central retinal artery (as assessed with colour Doppler imaging). The coefficient of variation and the maximum change from baseline in an individual were calculated for each outcome parameter. No diurnal variation in optic nerve head or retinal blood flow was observed with any of the techniques employed. Coefficients of variation were between 1.6% and 18.5% for all outcome parameters. The maximum change from baseline in an individual was much higher, ranging from 3.7% to 78.2%. Our data indicate that in healthy individuals the selected techniques provide adequate reproducibility to be used in clinical studies. However, in patients with eye diseases and reduced vision the reproducibility may be considerably worse.
    Acta ophthalmologica 11/2008; 87(8):875-80. · 2.44 Impact Factor
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    ABSTRACT: Scattering of blood flow data as assessed with laser Doppler flowmetry (LDF) in humans is a problem in many studies using this technique. We set out to reduce variability in LDF data by eliminating the effect of the total returning light level (DC) on LDF parameters in the choroid through partial regression analysis. In 20 healthy subjects, choroidal blood flow parameters were measured at different DC values using a portable confocal LDF device. We used two different strategies to reduce scattering of data eliminating the effect of yield, which is defined as DC/gain. On the one hand, we used a previously described method based on a third-order polynomial fit, which combines all obtained data. On the other hand, we applied a new method based on a linear fit for each individual subject. Variability of data during changes in DC is higher for LDF parameters volume and flow than for velocity. Both methods were successful in reducing scattering of LDF parameters with varying DC. The present study indicates that both methods to correct for changes in yield were successful in reducing the variability of LDF measurements. When systematic changes in DC occur after an intervention, one needs to be careful in interpreting the obtained data and it remains to be shown if either of the two techniques is capable of correcting for this effect. The approach presented here may, however, represent an effective, easily applicable and valid approach to reduce scattering of data from using LDF to assess blood flow in the posterior pole of the human eye.
    Albrecht von Graæes Archiv für Ophthalmologie 10/2008; 247(1):67-71. · 1.93 Impact Factor
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    ABSTRACT: To evaluate possible changes in macular morphology after cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing in comparison to conventional in-the-bag intraocular lens (IOL) implantation. Prospective randomized study. Fifty consecutive age-related cataract patients with normal macular morphology and function waiting for bilateral cataract surgery were enrolled. Cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing was performed in one eye; in the fellow eye cataract surgery was performed with in-the-bag IOL implantation, leaving the posterior lens capsule untouched. Optical coherence tomography measurements were performed one week and one month postoperatively. During follow-up, no statistically significant changes of macular morphology could be observed in any of the tested patients. Mean central retinal thickness, minimum and maximum retinal thickness, and central retinal volume were all statistically comparable between the eyes with combined primary posterior capsulorhexis and posterior optic buttonholing and the control eyes (P > .05). Best-corrected visual acuity was full in all patients (Snellen 20/25 and better). No cases of subclinical macular edema were observed. Cataract surgery with combined primary posterior capsulorhexis and posterior optic buttonholing apparently does not increase the risk for postoperative macular edema in patients with a normal macula, since no cases of biomicroscopically noticeable macular edema with visual loss were observed in the first 1,000 eyes with primary posterior capsulorhexis/posterior optic buttonholing cataract surgery and no case of subclinical macular edema was found in this prospective randomized study.
    American Journal of Ophthalmology 08/2008; 146(1):15-22. · 4.02 Impact Factor
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    ABSTRACT: To compare axial position changes of the intraocular lens (IOL) by measuring anterior chamber depth (ACD) after small-incision cataract surgery with primary posterior continuous curvilinear capsulorhexis (PPCCC) and posterior optic buttonholing (POBH) of the IOL and after conventional cataract surgery with phacoemulsification and in-the-bag IOL implantation. Department of Ophthalmology, Medical University of Vienna, Austria. This prospective comparative study comprised 23 patients (46 eyes) with age-related cataract who had bilateral cataract surgery and implantation of an acrylic IOL (YA-60BB, Hoya). In randomized order, cataract surgery with PPCCC and POBH of the IOL was performed in 1 eye of each patient. In the fellow eyes, conventional phacoemulsification cataract surgery with in-the-bag IOL implantation was performed. The ACD was measured 1 to 2, 6, and 24 hours as well as 7 and 30 days postoperatively using high-resolution partial coherence laser interferometry. A baseline measurement was taken preoperatively in all patients. Ten patients completed 10 to 12 months of follow-up. Postoperatively, the axial IOL position was stable in eyes with PPCCC-POBH (P>.05). In contrast, a significant axial shift of the IOL in the anterior direction was observed in control eyes with in-the-bag IOL implantation (P<.001). The resulting refractive shift was significantly higher in control eyes than in eyes with PPCCC-POBH (P<.001). Combined PPCCC and POBH for cataract surgery significantly reduced postoperative anterior movement of the IOL.
    Journal of Cataract and Refractive Surgery 06/2008; 34(5):749-54. · 2.53 Impact Factor
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    ABSTRACT: To evaluate the effect of Viscoat (sodium chondroitin sulfate 4%-sodium hyaluronate 3%) and DuoVisc (Viscoat and Provisc [sodium hyaluronate 1%]) on postoperative intraocular pressure (IOP) after bilateral small-incision cataract surgery. Department of Ophthalmology, University of Vienna, Vienna, Austria. This prospective randomized study comprised 60 eyes of 30 consecutive patients with age-related cataract in both eyes. Each patient's eyes were randomly assigned to receive Viscoat or DuoVisc during cataract surgery. DuoVisc is a packet containing 2 ophthalmic viscosurgical devices (OVDs): the dispersive Viscoat, which was used for intraocular lens (IOL) implantation. In the Viscoat group, the Viscoat was used during the entire surgery. The intraocular pressure (IOP) was measured preoperatively as well as 1, 6, and 20 to 24 hours postoperatively. One and 6 hours postoperatively, the mean IOP was significantly higher in the Viscoat group than in the DuoVisc group (25.8 mm Hg and 20.5 mm Hg, respectively, at 1 hour and 24.7 mm Hg and 21.1 mm Hg, respectively, at 6 hours) (P<.05). At 20 to 24 hours, the mean IOP was not statistically significantly different between the 2 groups. Intraocular pressure spikes to 30 mm Hg or higher occurred in 4 eyes in the DuoVisc group and 11 eyes in the Viscoat group (P<.05). Viscoat caused significantly higher IOP increases and significantly more IOP spikes than DuoVisc in the early postoperative period. Therefore, if Viscoat is used during cataract surgery, an additional cohesive OVD should be used for IOL implantation.
    Journal of Cataract and Refractive Surgery 03/2008; 34(2):253-7. · 2.53 Impact Factor
  • Klinische Monatsblatter Fur Augenheilkunde - KLIN MONATSBL AUGENHEILK. 01/2008; 225.
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    ABSTRACT: Combining primary posterior capsulorhexis (PPC) and posterior optic buttonholing (POBH) in cataract surgery is an innovative approach to prevent after-cataract formation effectively and to increase postoperative stability of the intraocular lens (IOL). The present study was designed to compare the postoperative intraocular flare after cataract surgery with combined PPC and POBH to conventional in-the-bag implantation of the IOL. Fifty consecutive age-related cataract patients with cataract surgery under topical anaesthesia in both eyes were enrolled prospectively into a prospective, randomised clinical trial. In randomised order, cataract surgery with combined PPC and POBH was performed in one eye; in the other eye cataract surgery was performed conventionally with in-the-bag IOL implantation keeping the posterior lens capsule intact. Intraocular flare was measured 1, 2, 4, 6, 12 and 24 h postoperatively, as well as 1 week and 1 month postoperatively, using a KOWA FC-1000 laser flare cell meter. The peak of intraocular flare was observed in POBH eyes and eyes with in-the-bag IOL implantation 1 h postoperatively. In both groups, the response was steadily decreasing thereafter. During measurements at day 1, small though statistically significant higher flare measurements were observed in eyes with in-the-bag IOL implantation (p<0.05). At 1 week and 1 month postoperatively, intraocular flare measurements were comparable again (p>0.05). Cataract surgery with combined PPC/POBH showed slightly lower postoperative anterior chamber reaction compared to conventional in-the-bag implantation during 4-week follow-up, indicating that POBH might trigger somewhat less inflammatory response. This could be explained by the posterior capsule sandwiching between the optic and the anterior capsule, preventing direct contact-mediated myofibroblastic trans-differentiation of anterior lens epithelial cells with consecutive cytokine depletion.
    British Journal of Ophthalmology 11/2007; 91(11):1481-4. · 2.73 Impact Factor
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    ABSTRACT: To evaluate the effect of intravenously administered clonidine on ocular blood flow in healthy volunteers. A randomised, double-masked, placebo-controlled, two-way crossover study was performed in 12 healthy young volunteers. Clonidine (0.2 microg/kg/min) or placebo was administered intravenously over 10 minutes. The effects of clonidine were studied at baseline and up to 150 minutes after infusion. Ocular haemodynamics were measured using laser Doppler flowmetry, laser Doppler velocimetry and a retinal vessel analyser. Clonidine significantly decreased mean arterial pressure (MAP) and intraocular pressure (IOP). Calculated ocular perfusion pressure decreased significantly by -8.7+/-8.7% after infusion of clonidine (p<0.01 vs placebo). Retinal arterial diameters increased by +4.4+/-2.7% (p = 0.012 vs placebo), whereas no significant change was observed in retinal veins. Red blood cell velocity decreased by -16+/-14% (p<0.01 vs placebo) after infusion of clonidine. Hence, calculated retinal blood flow decreased by -14+/-12% (p = 0.033 vs placebo). Choroidal blood flow increased by +18+/-19% (p<0.01 vs placebo) and optic nerve head blood flow increased by +16+/-23% (p = 0.046 vs placebo) 30 minutes after administration of clonidine but both returned to baseline thereafter. The short-time increase in choroidal and optic nerve head blood flow indicates a transient vasodilatory effect of clonidine due to an unknown mechanism. The decrease in retinal blood flow indicates clonidine-induced vasoconstriction in the retinal microvasculature.
    British Journal of Ophthalmology 10/2007; 91(10):1354-8. · 2.73 Impact Factor
  • Eva Stifter, Alexandra Luksch, Rupert Menapace
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    ABSTRACT: To evaluate the natural course of intraocular pressure (IOP) after cataract surgery with combined primary posterior continuous curvilinear capsulorhexis (PPCCC) and posterior optic buttonholing (POBH) of the intraocular lens (IOL) in adult patients. Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. Fifty consecutive patients with age-related cataract awaiting cataract surgery under topical anesthesia in both eyes were enrolled prospectively. In randomized order, cataract surgery with combined PPCCC and POBH was performed in 1 eye. In the fellow eye, cataract surgery was performed conventionally with in-the-bag IOL implantation and the posterior lens capsule kept intact. Standardized IOP measurements by Goldmann applanation tonometry were performed 1, 2, 4, 6, 8, and 24 hours postoperatively. Follow-up IOP measurements were taken at 1 week and 1 month. Twenty-five patients received 1-time IOP-lowering medication immediately after cataract surgery; the other 25 did not receive IOP-lowering drops. During the first 24 hours postoperatively, no significant differences in IOP were observed between the PPCCC-POBH group and the conventional surgery group (P>.05). No IOP peaks greater than 27 mm Hg were observed in any eye. One week and 1 month postoperatively, no significant differences in IOP were found between groups (P>.05). The use of IOP-lowering drops significantly reduced postoperative IOP. However, no IOP spikes >27 mm Hg were found with and without the use of IOP-lowering drops. The course of IOP after cataract surgery with combined PPCCC and POBH showed the technique to be as safe as conventional cataract surgery with in-the-bag IOL implantation.
    Journal of Cataract and Refractive Surgery 09/2007; 33(9):1585-90. · 2.53 Impact Factor
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    ABSTRACT: To investigate the ocular blood flow response to systemic nitric oxide synthase inhibition in patients with primary open-angle glaucoma. In 12 patients with glaucoma and 12 age-matched control subjects, subfoveal choroidal blood flow, optic nerve head blood flow, ocular fundus pulsation amplitude, intraocular pressure, and systemic hemodynamic parameters were measured at baseline and after inhibition of nitric oxide synthase by intravenous administration of NG-monomethyl-L-arginine. The increase in blood pressure in response to NG-monomethyl-L-arginine was comparable between the 2 study cohorts. In patients with glaucoma, the decrease of optic nerve head blood flow (P = .03) and fundus pulsation amplitude (P<.001) during nitric oxide synthase inhibition was significantly less pronounced than in healthy control subjects. A tendency toward a reduced response in choroidal blood flow was seen (P = .051 between groups) in patients with glaucoma. This is the first in vivo study providing evidence for an altered ocular L-arginine/nitric oxide system in patients with glaucoma. Normalization of the ocular nitric oxide production may be beneficial in terms of normalization of ocular blood flow and neuroprotection of retinal ganglion cells.
    Archives of Ophthalmology 05/2007; 125(4):494-8. · 3.83 Impact Factor
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    ABSTRACT: Purpose: Ocular perfusion abnormalities have been implicated in the pathogenesis of primary open angle glaucoma (POAG). More specifically it has been reported that POAG is associated with vascular dysregulation and ischemia/reperfusion phenomena. In the present study we compared the twelve hour variability of ocular blood flow parameters in healthy subjects and patients with POAG.Methods: In 16 patients with POAG and 16 healthy age-matched controls ocular and systemic blood flow parameters and intraocular pressure was measured every 2 hours over 12 hours. Ocular hemodynamic measurements included optic nerve head blood flow and choroidal blood flow assessed with laser Doppler flowmetry, fundus pulsation amplitude assessed with laser interferometry and retrobulbar blood velocities with color Doppler imaging. A repeated measures ANOVA model was used to compare variability among these measurements between the two groups of patients.Results: Most of the outcome variables showed higher fluctuations in patients with PAOG than in healthy controls. These changes were not associated with ocular perfusion pressure or intraocular pressure. Changes over time were, however, correlated among the different ocular hemodynamic outcome measures in patients with POAG, but not in healthy controls.Conclusions: Patients with POAG show an abnormal diurnial fluctuation of ocular blood flow parameters. Since we observed correlations between these fluctuations as assessed with different methods this does not appear to be related to statistical errors associated with the measurement techniques. These data support the hypothesis of vascular dysregulation in POAG.
    Acta Ophthalmologica Scandinavica 01/2007; 85:0-0. · 1.85 Impact Factor

Publication Stats

670 Citations
137.54 Total Impact Points

Institutions

  • 2006–2011
    • Medical University of Vienna
      • Universitätsklinik für Klinische Pharmakologie
      Vienna, Vienna, Austria
  • 2000–2009
    • University of Vienna
      • Department of Internal Medicine III
      Wien, Vienna, Austria
  • 2004
    • IST Austria
      Klosterneuberg, Lower Austria, Austria
  • 2003
    • Vienna General Hospital
      Wien, Vienna, Austria