Biomedical subjects

J Flammer

Publications and source records attributed to J Flammer.

At least 73 records · Page 4Linked to original sources

PubMed2000

Choroidal laser Doppler flowmetry in healthy subjects.

OBJECTIVE: To evaluate normal choroidal blood flow and its relationship with various factors such as age, systemic blood pressure, and intraocular pressure (IOP). METHODS: A total of 70 healthy subjects were recruited. Choroidal blood flow was assessed using a method based on laser Doppler flowmetry (LDF) technique. The LDF parameters of velocity, volume, and flux were obtained. The influence of age, mean systemic blood pressure, IOP, smoking, and sex on choroidal hemodynamic parameters was assessed in a multiple linear regression model. The correlations between interocular difference in IOP and interocular differences in the LDF parameters were assessed by means of the Pearson linear correlation factor. RESULTS: Velocity decreased significantly (P = .03) with advancing age of the subjects and volume increased significantly (P = .02) with increasing IOP. Mean blood pressure, smoking, and sex had no influence on the choroidal LDF parameters. Interocular difference in IOP correlated significantly with interocular difference in volume (R = 0.34, P<.005). CONCLUSION: Choroidal blood flow velocity decreased with increasing age of the subjects, while the volume of moving erythrocytes decreased with lower IOP.

Adolescent↗

PubMed2000

Regulation of connective tissue growth factor gene expression in retinal vascular endothelial cells by angiogenic growth factors.

BACKGROUND: Connective tissue growth factor (CTGF) is a novel, cysteine-rich secreted protein, which is implicated in fibrotic disorders and atherosclerosis. To elucidate the role of CTGF in fibrovascular proliferative retinopathy, we investigated the regulation of CTGF gene expression in a cell line of retinal vascular endothelial cells (RVEC) stimulated with fetal calf serum (FCS) and angiogenic growth factors, including vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), platelet-derived growth factor-BB (PDGF-BB), endothelial growth factor (EGF), transforming growth factor-beta 1 and -beta 3 (TGF-beta 1, TGF-beta 3), and insulin-like growth factor-I (IGF-I). METHODS: RVEC derived from Macaca mulatta (CRL-1780; ATCC) were stimulated with 10% FCS as well as with VEGF, bFGF, PDGF-BB, TGF-beta 1, TGF-beta 3, EGF, or IGF-I. Time-dependent CTGF gene expression was assessed by northern blot analysis. RESULTS: FCS, TGF-beta 1, TGF-beta 3, bFGF, and EGF induced an upregulation of CTGF gene expression in RVEC in a time-dependent manner. Highest expression was induced with TGF-beta 1. No response on CTGF gene expression could be detected to VEGF, PDGF-BB, or IGF-I. CONCLUSION: The present study demonstrates for the first time that CTGF mRNA is expressed at high levels in RVEC, and that the level of the temporal pattern of its expression is differentially regulated by angiogenic growth factors, indicating a significant role of CTGF in the pathological course of uncontrolled retinal angiogenesis.

Animals↗

PubMed2000

Nitric oxide production by isolated human and porcine ciliary processes.

BACKGROUND: In the kidney, the trachea, and the colon, nitric oxide (NO) can modulate transepithelial fluid transport. This study investigates whether isolated human and porcine ciliary processes produce NO. METHODS: Porcine ciliary processes and iris were used either fresh or thawed after storage at -70 degrees C. Post-mortem (8-12 h) human ciliary processes were used thawed after storage at -70 degrees C. NO was measured by placing a nafion-coated polymeric porphyrinic microsensor (differential pulse voltammetry) on the surface of the tissue. Measurements were conducted in the absence or in the presence of the NO formation inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME; 0.2 mM, 1 mM) or its biologically inactive D-enantiomer N(G)-nitro-D-arginine methyl ester (D-NAME; 1 mM). RESULTS: NO concentrations in porcine ciliary processes (1.27+/-0.25 microM) were higher (P=0.001) than those in the iris (0.00+/-0.02 microM) and were significantly (P<0.001) decreased by L-NAME (fresh specimen). From thawed porcine ciliary processes, NO concentrations measured (1.85+/-0.47 microM) were not significantly different (P=0.16) from those measured in fresh specimen and were also reduced (P <0.001) by L-NAME, but not by D-NAME. In human ciliary processes, NO concentrations measured (0.08+/-0.11 microM) were somehow lower but were again decreased (P<0.001) by L-NAME (thawed specimen). CONCLUSION: Reflecting the biological activity of a nitric oxide synthase, isolated human and porcine ciliary processes produce NO.

Aged↗

PubMed2000

Relationship between ocular perfusion pressure and retrobulbar blood flow in patients with glaucoma with progressive damage.

PURPOSE: To evaluate the relationship between ocular perfusion pressure and color Doppler measurements in patients with glaucoma. MATERIALS AND METHODS: Twenty patients with primary open-angle glaucoma with visual field deterioration in spite of an intraocular pressure lowered below 21 mm Hg, 20 age-matched patients with glaucoma with stable visual fields, and 20 age-matched healthy controls were recruited. After a 20-minute rest in a supine position, intraocular pressure and color Doppler measurements parameters of the ophthalmic artery and the central retinal artery were obtained. Correlations between mean ocular perfusion pressure and color Doppler measurements parameters were determined. RESULTS: Patients with glaucoma showed a higher intraocular pressure (P <.0008) and a lower mean ocular perfusion pressure (P <.0045) compared with healthy subjects. Patients with deteriorating glaucoma showed a lower mean blood pressure (P =.033) and a lower end diastolic velocity in the central retinal artery (P =.0093) compared with normals. Mean ocular perfusion pressure correlated positively with end diastolic velocity in the ophthalmic artery (R = 0.66, P =.002) and central retinal artery (R = 0.74, P <.0001) and negatively with resistivity index in the ophthalmic artery (R = -0.70, P =.001) and central retinal artery (R = -0.62, P =.003) in patients with deteriorating glaucoma. Such correlations did not occur in patients with glaucoma with stable visual fields or in normal subjects. The correlations were statistically significantly different between the study groups (parallelism of regression lines in an analysis of covariance model) for end diastolic velocity (P =.001) and resistivity index (P =.0001) in the ophthalmic artery, as well as for end diastolic velocity (P =.0009) and resistivity index (P =. 001) in the central retinal artery. CONCLUSIONS: The present findings suggest that alterations in ocular blood flow regulation may contribute to the progression in glaucomatous damage.

Aged↗

PubMed2000

Interocular difference in progression of glaucoma correlates with interocular differences in retrobulbar circulation.

PURPOSE: To evaluate the correlation between interocular difference in progression of glaucomatous damage and interocular differences in retrobulbar blood flow. METHODS: On the basis of a retrospective analysis of visual fields, progressive damage was identified in 20 patients with primary open-angle glaucoma. As a parameter of interocular difference in progression of visual field damage, the angle (gamma) between the regression lines of the visual field index mean defect over time per eye was calculated for each subject. The relationship between the angle gamma and interocular differences in intraocular pressure and retrobulbar color Doppler imaging parameters was analyzed by a multiple linear regression analysis in a stepwise forward approach. RESULTS: With larger interocular differences in progression of glaucomatous damage, lower mean blood flow velocities in the ophthalmic artery (partial r = -.69; P <. 0016), higher resistivity indices in the central retinal artery (partial r =.48; P <.0456), and higher peak systolic velocities in the ophthalmic artery (partial r =.52; P <.0285) were noted in the eyes with more marked progression of damage (multiple r =.71; P <. 0099). Interocular differences in progression of visual field damage were not related to intraocular pressure or extent of visual field damage. CONCLUSION: Independent of the extent of the interocular difference in glaucomatous damage and intraocular pressure, interocular difference in progression of glaucomatous visual field damage correlates with interocular difference in retrobulbar hemodynamic parameters.

Blood Circulation↗

PubMed2000

Correlation between apolipoprotein B and endothelin-1-induced vasoconstriction in humans.

Low-density lipoprotein (LDL) concentrations have been linked to altered responses to endogenous vasodilators and vasoconstrictors. We evaluated retrospectively the relationship between LDL and vasoconstrictor (endothelin-1, phenylephrine) responsiveness of the forearm vasculature in 15 elderly healthy volunteers with apolipoprotein B and LDL levels in the normal range. In contrast to phenylephrine, changes in forearm vascular resistance induced by endothelin-1 were correlated with apolipoprotein B, LDL, and total cholesterol concentrations in women but not in men. These findings might suggest that lipids may increase vascular tone through both impaired endothelial vasodilation and increased vasoconstriction to endothelin-1 at least in women.

Aged↗

PubMed2000

In glaucoma, should enthusiasm about neuroprotection be tempered by the experience obtained in other neurodegenerative disorders?

Some in vitro and in vivo evidence, as well as rare observations in human eyes with glaucoma, suggests that retinal ganglion cells could be lost by apoptosis during the course of glaucomatous optic neuropathy. There exist also observations indicating that in the vitreous of patients with glaucoma it is possible to measure an increased concentration of glutamate (an excitotoxic amino acid known to induce neuronal apoptosis in animal models). These observations, among others, suggest the possibility of an excitotoxicity mechanism in the pathogenesis of glaucoma and as a consequence the potential for a neuroprotective approach to treating this disorder. Amazingly, not only in glaucoma but also in other neurodegenerative disorders (Parkinson's disease, amyotrophic lateral sclerosis, stroke, etc.) it has been postulated that neurons could be lost through an excitotoxic mechanism. In these non-glaucomatous disorders, quite a large number of clinical trials have already been conducted to determine the potential benefit of different neuroprotective therapies. Unfortunately, with a few rare exceptions, the results of these clinical studies have been very disappointing (in contrast to encouraging results obtained in preclinical trials). The experience acquired in other neurodegenerative disorders should probably be kept in mind when addressing the question of neuroprotection in glaucoma. In particular, the hope raised by preclinical studies showing that drugs could have a beneficial effect on the survival of retinal ganglion cells should certainly be tempered until such an effect is confirmed by clinical trials conducted in patients with glaucoma.

Apoptosis↗

PubMed2000

Vasorelaxing properties of carteolol in isolated porcine ciliary arteries.

INTRODUCTION: Carteolol is a topical beta-blocker used in ophthalmology to decrease the intraocular pressure. This study investigates the vasoactive effect of carteolol in isolated porcine ciliary processes. MATERIAL AND METHODS: With a myograph system isometric force measurements, quiescent vessels or vessels either precontracted with endothelin-1 (0.03 microM) or the thromboxane A2 analog U 46619 (0.3 microM) were exposed, in cumulative manner, to increasing concentrations of carteolol (10 microM-3 mM). Vessels that had a functional endothelium were compared with vessels that had a non functional endothelium (intentionally and mechanically damaged). RESULTS: In quiescent vessels carteolol did not induce contractions. In contrast, in precontracted arteries, carteolol evoked marked relaxations which were endothelium-independent. CONCLUSIONS: In vitro, carteolol has a marked vasorelaxing effect on porcine ciliary arteries, however the clinical relevance of this observation for the care of glaucoma patients requires further evaluation.

Adrenergic beta-Antagonists↗

PubMed2000

[Membrane potential depolarization in the porcine ciliary epithelium evoked by nitric oxide].

BACKGROUND: The present work studies if in porcine ciliary body epithelium the intracellular signal transduction pathway nitric oxide (NO)--guanylate cyclase (GC)--3',5'-cyclic guanosinemonophosphate (cGMP) can change the membrane potential of the epithelium of the ciliary body. MATERIAL AND METHODS: Recordings of membrane potentials were done by means of intracellular microelectrodes in the presence of the NO donor Sodium Nitroprusside (SNP; 100 microM; n = 5) or the membrane permeable cGMP analogue 8-parachlorophenyl-thioguanosine-3',5' cyclic monophosphate (8-pCPT-cGMP; 100 microM; n = 5). To test whether the GC is involved in this process, recordings were repeated in both groups in presence or in absence of the GC inhibitor 1-H-(1,2,4)oxadiazole-(4,3-a)quinoxalin-1-one (ODQ; 10 microM; n = 4). RESULTS: SNP and 8-pCPT-cGMP both induced significant membrane potential depolarizations (7.7 +/- 1.8 mV and 13.1 +/- 1.3 mV, mean +/- SEM). Membrane depolarizations induced by SNP were significantly inhibited by ODQ (p < 0.01), whereas depolarizations induced by 8-pCPT-cGMP were not altered by the presence of ODQ (p > 0.2). CONCLUSIONS: Nitric oxide induces depolarizations of the membrane potential in the isolated porcine ciliary body. This process is transduced by activation of the GC. We conclude that nitric oxide might be involved in the regulation of permeability of the cellular membrane for ions in the ciliary body.

Animals↗

PubMed2000

Altered gene expression in lymphocytes of patients with normal-tension glaucoma.

BACKGROUND: In glaucoma there is a loss of retinal ganglion cells. There is evidence that this loss can occur by apoptosis. The signal transduction leading to retinal ganglion cell apoptosis in glaucoma is not yet clear. The present study compares the gene expression in lymphocytes of normal tension glaucoma patients (NTG-patients) with the one of healthy controls. METHODS: Subtractive hybridization was used to compare mRNA in lymphocytes of six vasospastic NTG-patients with six age and sex matched healthy subjects. RESULTS: Genes coding for p53-protein, NTP (neural thread protein) and 20 S proteasome subunit XAPC7 were overexpressed, whereas those coding for XPGC (Xeroderma pigmentosum gene), the survivin protein as well as one type of ABC transport protein were underexpressed. CONCLUSION: In comparison to healthy controls, patients with vasospastic NTG seem to over- as well as under-express certain genes in their lymphocytes.

ATP-Binding Cassette Transporters↗

PubMed2000

Absolute rate constants for the quenching of reactive excited states by melanin and related 5,6-dihydroxyindole metabolites: implications for their antioxidant activity.

The triplet-excited state of benzophenone and the singlet-excited state of 2,3-diazabicyclo[2.2.2]oct-2-ene (Fluorazophore-P) have been employed as kinetic probes to obtain information on the antioxidant activity of the skin and eye pigment melanin and its biogenetic precursors 5,6-dihydroxyindole (DHI) and 5,6-dihydroxyindole-2-carboxylic acid (DHICA). The excited states were generated by the laser-flash photolysis technique and their reaction kinetics was examined by time-resolved transient absorption or fluorescence spectroscopy, respectively. The reaction between triplet benzophenone and DHI produced with unit efficiency the corresponding 6O-centered semiquinone radical, which was characterized by its characteristic transient absorption. The quenching rate constants for DHI (3.1-8.4 x 10(9) M-1 s-1) and DHICA (3.3-5.5 x 10(9) M-1 s-1) were near the diffusion-controlled limit, indicating excellent antioxidant properties. Kinetic solvent effects were observed. The reactivity of synthetic melanin, assessed through the quenching rate constant of Fluorazophore-P and normalized to the number of monomer units, was more than one order of magnitude lower (2.7 x 10(8) M-1 s-1) than that of its precursors. The trend of the quenching rate constants, i.e. DHI > DHICA approximately alpha-tocopherol > melanin, along with the preferential solubility of DHICA in aqueous environments, serves to account for several experimental results from biochemical studies on the inhibition of lipid peroxidation by these natural antioxidants.

Antioxidants↗

PubMed2000

Interocular differences in optic disc topographic parameters in normal subjects.

PURPOSE: To test the interocular differences in optic disc topography in normal subjects by means of confocal scanning laser ophthalmoscopy. METHODS: Topographic measurements of the optic disc were evaluated by means of confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph) in 314 eyes of 157 healthy volunteers. The examination was started randomly either with the right eye or the left eye. Differences between right and left eyes in disc area, cup area, cup volume, cup/disc area ratio, rim area, rim volume, maximum cup depth, cup shape measure, retinal nerve fiber layer thickness, and retinal nerve fiber cross section area for 360 degrees and for the temporal and nasal regions of the optic nerve head were evaluated by means of Student t-test. The same parameters were assessed in a subgroup of 80 elderly (age> 50 years) healthy subjects. Holm's sequentially rejective method was used for significance correction of multiple comparisons. RESULTS: Significant interocular differences in the average retinal nerve fiber layer thickness (p = 0.0010) and retinal nerve fiber layer cross section area (p = 0.0036) were found, with the right eye showing, on the average, lower values. The left eye showed a larger retinal nerve fiber layer thickness in 94 subjects (59.87%) and a larger retinal nerve fiber cross section area in 101 subjects (64. 33%). In the temporal optic disc area there were no statistically significant differences in topometric data (p> 0.05). In the nasal area, significant interocular differences in the retinal nerve fiber layer thickness (p = 0.0002) and retinal nerve fiber layer cross section area (p = 0.0003) were found. Similar results were found when the group of subjects older than 50 years was considered. CONCLUSIONS: This study demonstrates systematic interocular differences in optic disc topometric data. Such a finding, be it due to methodological or biological reasons, should be taken in consideration in clinical trials.

Adolescent↗

PubMed2000

NO/cGMP pathway activation and membrane potential depolarization in pig ciliary epithelium.

PURPOSE: To investigate whether in isolated porcine ciliary processes, stimulation of the nitric oxide (NO)-guanylate cyclase (GC)-3',5'-cyclic guanosine monophosphate (cGMP) pathway modulates ciliary epithelial transmembrane potential. METHODS: Changes in transmembrane potential induced by the two NO donors, sodium nitroprusside (SNP; 100 microM) and S-nitroso-N-acetyl-penicillamine (SNAP; 100 microM), or by the cGMP-analogue 8-para-chlorophenylthioguanosine-3', 5'-cyclic guanosine monophosphate (8-pCPT-cGMP; 100 microM) were measured with microelectrodes in the presence or in the absence of the GC-inhibitor 1-H-(1,2,4)oxadiazole(4,3-alpha)quinoxalin-1-1 (ODQ; 10 microM). The effect of 8-pCPT-cGMP was also assessed in the presence of the anion channel inhibitors niflumic acid (100 microM), diisothiocyanatostilbene-2,2' disulfonic acid (DIDS; 1 mM), anthracene-9-carboxylic acid (9-AC; 1 mM), or the K+ channel blocker tetraethylammonium chloride (TEA; 10 mM). cGMP production was measured by immunoassay. RESULTS: Significant membrane depolarizations (P < 0.05-0.001; n = 5-8) were induced by SNP (6 +/- 1 mV; mean +/- SEM), SNAP (8 +/- 1 mV), or 8-pCPT-cGMP (13 +/- 1 mV). In presence of ODQ, the effect of SNP and SNAP were significantly inhibited (-2 +/- 0 mV and 0 +/- 0 mV, respectively; P < 0.05; n = 5-6), but not depolarizations elicited by 8-pCPT-cGMP. These were prevented (P < 0.05-0.01; n = 5) by niflumic acid (1 +/- 1 mV), DIDS (1 +/- 1 mV), or 9-AC (5 +/- 1 mV), but not by TEA (12 +/- 2 mV). The increase in cGMP production induced by SNP (9.5-fold) was inhibited by ODQ (P < 0.001; n = 6). CONCLUSIONS: Activation of the NO-GC-cGMP pathway modulates epithelial transmembrane potential in isolated porcine ciliary processes.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗

PubMed2000

Expression of connective tissue growth factor (CTGF) mRNA in plaques of human anterior subcapsular cataracts and membranes of posterior capsule opacification.

PURPOSE: To investigate the correlation between connective tissue growth factor (CTGF) mRNA expression and immunohistochemical characteristics of anterior subcapsular cataract (ASC) formation as well as posterior capsule opacification (PCO) development (expression of type I collagen, alpha-smooth muscle actin and tenascin) under in vivo and under in vitro conditions in human and porcine lens epithelial cells. METHODS: CTGF mRNA expression was investigated using in situ hybridization and RT-PCR. Expression of type I collagen, alpha-smooth muscle actin and tenascin was detected by immunohistochemical staining. RESULTS: CTGF mRNA was expressed in human cataractous plaques of ASC and human PCO membranes, and appeared simultanously with the expression of type I collagen, alpha-smooth muscle actin and tenascin. CONCLUSION: The predominant expression of CTGF mRNA in human ASC and human PCO membranes suggests a significant role of CTGF in the pathological course of these ocular disorders.

Actins↗

PubMed1999

Is vascular regulation in the central retinal artery altered in persons with vasospasm?

OBJECTIVE: To assess the relation between ocular perfusion pressure and blood flow velocity in the central retinal artery in patients with acral vasospasm. SUBJECTS AND METHODS: Eighteen otherwise healthy subjects with acral vascular dysregulation, as demonstrated by nail-fold capillaroscopy, and 18 age- and sex-matched healthy volunteers without vasospasm were recruited. After subjects had rested for 20 minutes in a supine position, intraocular pressure and blood flow velocity in the central retinal artery were determined by applanation tonometry and color Doppler imaging, respectively. The peak systolic velocity, end-diastolic velocity, and resistivity index were assessed. Correlations between the mean ocular perfusion pressure (2/3 x [2/3 x diastolic blood pressure + 1/3 x systolic blood pressure] - intraocular pressure) and blood flow velocities in the central retinal artery were determined by the Pearson linear correlation factor. The Student t test was used to evaluate differences between controls and subjects with vasospasm. RESULTS: The mean +/- SD ocular perfusion pressure was 42.0 +/- 7.4 mm Hg in the group with vasospasm and 47.1 +/- 6.5 mm Hg in the control group (P= .04). In the subjects with vasospasm, the peak systolic and end-diastolic velocities and the resistivity index of the central retinal artery correlated significantly with the mean ocular perfusion pressure (R = 0.49, P = .04 P = .01; and R = -0.67, P = .002, respectively). Such correlations were not found in the control group. CONCLUSIONS: An altered blood flow regulation is suggested in the ocular circulation of patients with acral vasospasm.

Adult↗

PubMed1999

Relationship between corneal temperature and finger temperature.

BACKGROUND: Because the temperature of the body surface depends largely on local blood flow, temperature measurements might provide information on the latter. OBJECTIVE: To evaluate the relationship between corneal temperature and finger temperature. METHODS: Corneal, finger, and body core temperatures were measured in a relatively unselected population of 266 white persons. Excluded were persons taking topical eye medication or with corneal inflammatory signs. Corneal and finger temperatures were measured on 1 randomly selected side of the body by means of a noncontact infrared thermometer. As a measure of body temperature, the tympanic temperature was measured by means of a noncontact infrared ear thermometer. A total of 124 females and 142 males were examined. RESULTS: A correlation analysis in a least squares regression model was highly significant (R = 0.67; P<.001), with corneal temperature as the dependent variable and environmental, tympanic, and finger temperatures and age and sex as predicting variables. All variables contributed significantly to prediction of the corneal temperature. The corrected mean corneal temperature after adjusting for environmental, tympanic, and finger temperatures and for age of participants was 0.16 degrees C higher in male participants (P = .002). CONCLUSIONS: Corneal temperature correlates with finger temperature even after adjusting for environmental and tympanic temperatures and for the age and sex of participants. A possible cause for these findings are some parallelisms in blood-flow regulation in the finger and the eye.

Adolescent↗

PubMed1999

Psychological characteristics of patients with normal-tension glaucoma.

BACKGROUND: A study was carried out to evaluate the extent of psychosomatic complaints in patients with normal-tension glaucoma. METHODS: Twenty-four patients (M:F=3:21; mean age 58+/-15.3 years) with normal-tension glaucoma were rated according to the von Zerssen Symptom List (psychosomatic discomfort), the Maudsley Personality Inventory (MPI-N, emotional status and MPI-E, extroverted-introverted), the Beck Depression Inventory (BDI), and the Sixteen Personality Factor Questionnaire (16PF). An age- and sex-matched control group (n=24; M:F=3:21; mean age 56+/-13 years) without any ocular or other general chronic disease was selected. RESULTS: In comparison with the control group the patients with normal-tension glaucoma showed significantly more complaints (von Zerssen Symptom List) and were more emotionally unstable (MPI-N). No group differences were found regarding extroversion-introversion (MPI-E) and depression (BDI). In the 16PF, patients with normal-tension glaucoma were remarkable, only for a significant negative correlation between the duration of illness and psychic endurance. CONCLUSION: The results demonstrate that patients with normal-tension glaucoma show evident psychosomatic involvement. However, the sequence of the pathogenetic development remains unclear. Therefore, it is not known whether these psychological disturbances are factors contributing to the development of normal-tension glaucoma or whether they are a result of normal-tension glaucoma. Nevertheless, some patients with normal-tension glaucoma had these disturbances. Besides reduction of intraocular pressure and improvement of vascular condition, those who display psychological disturbances should receive psychological support, such as autogenic training.

Adult↗

PubMed1999

Retrobulbar and peripheral capillary blood flow in hypercholesterolemic subjects.

PURPOSE: To assess retrobulbar blood flow velocities and finger nailfold capillary blood flow velocities (two readily accessible vascular beds) in subjects with primary hypercholesterolemia before and during lipid-lowering therapy. METHODS: Retrobulbar blood flow velocities and finger nailfold capillary blood flow velocities were assessed in 15 hypercholesterolemic subjects and in 15 age-matched and sex-matched healthy control subjects. In addition, the change in blood flow velocities after a 3-month period of lipid-lowering therapy was evaluated. RESULTS: No alterations in retrobulbar blood flow velocities after lipid-lowering therapy could be observed in hypercholesterolemic patients. Nailfold capillary blood flow velocity was slower in hypercholesterolemic subjects than control subjects immediately after local cooling (P = .0052), but this vascular dysregulation did not improve after lipid-lowering therapy (P = .58). CONCLUSIONS: Blood flow alterations, potentially caused by perturbed vascular endothelial function, may occur in nailfold capillaries of hypercholesterolemic subjects. Such alterations were not seen in retrobulbar vessels, and blood flow measures did not change during lipid-lowering therapy.

Blood Flow Velocity↗