Predictability of morphological changes of the anterior chamber angle after laser iridotomy by ultrasound biomicroscopy.

BACKGROUND: Laser peripheral iridotomy is a useful method in primary angle-closure eyes to prevent angle-closure attack and development of glaucomatous optic nerve damage. The aim of this study was to quantify morphological changes after LPI and their impact on intraocular pressure, and to evaluate predictive parameters for enlarging the anterior chamber angle after laser peripheral iridotomy. PATIENTS AND METHODS: Ultrasound biomicroscopy images and intraocular pressure before and after laser peripheral iridotomy from 62 eyes of 34 patients with primary angle-closure were retrospectively analysed. Anterior chamber angle, anterior chamber depth, lens thickness, iris curvature and a newly defined parameter, the end-iris-lens vault were measured. RESULTS: In each quadrant anterior chamber angle was on average significantly larger (at 12 o'clock: from 10.1° to 15.0°; at 3 o'clock: from 13.4° to 19.8°; at 6 o'clock: from 12.2° to 18.5°; at 9 o'clock: from 12.9 to 17.9°; p<0.001) and iris curvature significantly smaller (at 12 o'clock: from 0.26 mm to 0.10 mm; at 3 o'clock: from 0.21 mm to 0.08 mm; at 6 o'clock: from 0.25 mm to 0.08 mm; at 9 o'clock: from 0.21 mm to 0.08 mm; p<0.001) after laser peripheral iridotomy. Anterior chamber depth, lens thickness and end-iris-lens-vault did not significantly change. Anterior chamber angle in each quadrant (p<0.05), and iris curvature at 3 and 6 o'clock positions (p<0.05) were highly predictive for the enlargement of the anterior chamber angle after laser peripheral iridotomy. Intraocular pressure was slightly lower after laser peripheral iridotomy (from 16.6 mmHg to 16.1 mmHg). CONCLUSION: In primary angle-closure eyes, laser peripheral iridotomy enlarges the angle and flattens the iris significantly. This study demonstrated that a small anterior chamber angle and a large iris curvature are predictive parameters for a greater enlargement of the anterior chamber angle after laser peripheral iridotomy. These new findings underline the importance of the ultrasound biomicroscopy and may help in counselling patients about laser peripheral iridotomy.

Comparing Short-Duration Electro-Oculograms with and without Mydriasis in Healthy Subjects.

BACKGROUND: In order to obtain artifact-free electro-oculogram recordings the subject's cooperation is necessary. The aim of our study is to evaluate the recording characteristics of short-duration EOG and to compare the effect of mydriasis on electro-oculogram recordings in a cohort of controls. PATIENTS AND METHODS: Electro-oculogram recordings were performed on a light-emitting diode stimulus screen using a RETI-port gamma plus2 system (RETIscan™, Roland Consult). Fast oscillations were set at 1.5 sec (6 cycles; total duration 75 sec).The dark phase included: pre-adaptation (6 min), alternate fixation (4 min), fixation-rest (20 sec), 100 sweeps. The light phase included: light adaptation (4 min), alternate fixation (10 min), fixation-rest (20 sec), 250 sweeps. The amplifier band pass was filtered at 0.1÷50 Hz. The background illumination in mydriasis was 100 cd/m2 and in miosis--450 cd/m2. RESULTS: A total of 55 controls participated and were divided into three age groups [number; mean (years, y); ±SD]: group 1: 18-20 years (19; 19.49 years; ±0.89); group 2: 20-40 years (18; 27.91 years; ±5.39) and group 3: 40-60 years (18; 48.66 years; ±4.00). The Arden ratio, dark-trough and light-peak did not differ between recordings with or without mydriasis (p=0.914; p=0.880; p=0.680, linear mixed-effects model). The age did not influence the Arden ratio, dark-trough, light-peak (p=0.206; p=0.112; p=0.155). Arden ratio, dark-trough, light-peak were comparable between tested eyes (p=0.934; p=0.193; p=0.270). CONCLUSIONS: Short-duration electro-oculograms allow successful recording, furthermore, the application of mydriasis does not influence the quality of the recording.

Analysis of risk factors for long-term glaucomatous damage development.

PURPOSE: The aim of this study was to analyze predictors of long-term glaucoma progression. PATIENTS AND METHODS: We followed 17 primary open angle glaucoma patients (POAG) and 25 ocular hypertensives (OHT) over three years, with regular follow-up examinations of both eyes every 6 months. Glaucoma damage was quantified by optical coherence tomography (retinal nerve fiber layer - OCT RNFL) and by perimetry. Corneal and hand temperature (infrared thermometer), corneal hysteresis, pachymetry and ocular pulse amplitude (OPA) readings were taken at baseline, and applanatory intraocular pressure and retinal vessel analysis recordings were made at baseline and follow-up visits. Forward-stepwise multiple regression analysis was performed. RESULTS: With OCT-RNFL progression as the dependent variable, the model selected initial diagnosis (OHT less probable of progressing), baseline RNFL thickness, retinal arterial and venous diameter and arterial flicker response as significant damage predictors. For visual field damage progression, these were: corneal temperature, OPA, initial diagnosis and venous flicker response (all p<0.05). CONCLUSION: Initial damage and vascular factors are strong predictors of future glaucoma progression.

Hemorrhagic descemet membrane detachment after classic canaloplasty.

PURPOSE: Canaloplasty is a safe and effective alternative in glaucoma surgery, avoiding the risk for hypotony and bleb-related complications. Two cases of hemorrhagic Descemet membrane detachment (DMD) after canaloplasty are reported in patients who did not have previous surgery. RESULTS: Two patients with primary open-angle glaucoma underwent canaloplasty because of medically uncontrolled intraocular pressure (IOP). Canaloplasty was performed using a flexible microcatheter, viscoelastic material and a tensioning suture. The day after surgery, hemorrhagic DMD was observed in the inferior quadrants in both patients on slit-lamp biomicroscopy. THERAPY: For the size and location (occlusion of the visual axis), aspiration of blood and descemetopexy with air tamponade were performed promptly. In both cases, a small translucent scar remained. CONCLUSIONS: Circumferential cannulation and viscodilation of the Schlemm canal increases the risk for DMD, which may be aggravated by blood reflux resulting from the tensioning suture and low postoperative IOP. Surgeons should be aware of this specific and potentially sight-threatening complication in classic canaloplasty. Immediate intervention is recommended for good visual prognosis.

[Analysis of retinal vein motion in glaucoma patients]. / Analyse der Venenbewegungen in der Netzhaut von Glaukompatienten.

BACKGROUND: Analysis of retinal vein amplitude in eyes of glaucoma patients. PATIENTS AND METHODS: Motion of retinal veins was captured by Retinal Vessel Analyzer in duration of 30 seconds. Inferotemporal vein segments of 500 micrometers length in the immediate vicinity of, as well as away from the optic disc were chosen. Time behavior of the average segment diameter was analyzed by the self made software: dominating frequency (heart rate) was determined by Fourier analysis, and based on this an average pulse form was produced. Difference between the highest and lowest diameter point was the subject of analysis in 25 eyes of 25 glaucoma patients and 25 age-sex-matched healthy controls. RESULTS: Pulse amplitude of retinal veins in healthy eyes was higher than in glaucoma patients: in the optic disc vicinity the pulse amplitude relative to baseline was 2.6 ± 2.1% in control eyes and 1.4 ± 0.8% in glaucoma eyes (t-test, p = 0.009). Away from the disc, it was 1.7 ± 1.0% and 1.1 ± 0.5% respectively (p = 0.01). CONCLUSIONS: Retinal veins in glaucoma eyes demonstrate lower pulse amplitudes than healthy eyes, indicating disturbance in venous outflow and increased intraluminal venous pressure.

Retinal neurovascular coupling in patients with glaucoma and ocular hypertension and its association with the level of glaucomatous damage.

PURPOSE: To analyze neurovascular coupling in the retina of untreated primary open-angle glaucoma (POAG) and ocular hypertension (OHT) patients. PATIENTS AND METHODS: Maximal vessel dilation in response to flicker light was analyzed with Retinal Vessel Analyzer (RVA) in temporal superior/inferior arterioles and veins in 51 POAG patients, 46 OHT and 59 control subjects. RVA parameters were compared between groups, between contralateral POAG eyes, and correlated to intraocular pressure, visual field mean defect and retinal nerve fiber layer thickness. RESULTS: POAG eyes demonstrated generally smaller response of all vessels to flicker light than the other two groups (ANOVA p=0.026; mean arterial flicker response in percent of baseline, averaged superior and inferior was 3.48 ± 2.22 % for controls , 2.35 ± 2.06 % for POAG patients , and 2.97 ± 2.35 % for OHT patients; corresponding values for venules were 3.88 ± 1.98 %, 2.89 ± 1.72 %, 3.45 ± 2.77 %). There was no difference in flicker response between the eye with more and less advanced damage in each patient of the POAG group (ANOVA p=0.79). Correlation of flicker response to intraocular pressure (IOP) was borderline at best, correlations to the level of glaucomatous damage were not significant. Correlation of flicker response of superior and inferior vessels of the same eye was significant for the arteries (Pearson r=0.23, p=0.004), as well as venules (r=0.52, p<0.001). CONCLUSION: General vessel response to flicker light was decreased in POAG patients, compared to normal controls and OHT patients. In contrast to significant correlation between the two contralateral eyes of the flicker response itself, only its borderline correlation to IOP was seen. There was no correlation to the level of damage, altogether indicating a systemic dysregulation phenomenon. GRANTS: Swiss National Foundation Grant 3200B0-113685, Velux Stiftung Grant, Freie Akademische Gesellschaft (FAG) Grant, Pfizer Inc. Grant CLINICAL TRIAL REGISTRATION REFERENCE NUMBER: ClinicalTrials.gov NCT00430209.

The 2-global flash mfERG in glaucoma: attempting to increase sensitivity by reducing the focal flash luminance and changing filter settings.

PURPOSE: To test a new 2-flash multifocal electroretinogram (mfERG) paradigm in glaucoma using a reduced light intensity of the m-frame flash as opposed to the global flash, as it has been suggested that this may increase the responses induced by the global flash, which has been the part of the mfERG response where most changes have been noted in glaucoma. METHODS: A mfERG was recorded from one eye of 22 primary open angle glaucoma (POAG) patients [16 normal tension glaucoma (NTG), 6 high tension glaucoma (HTG)] and 20 control subjects. A binary m-sequence (2^13-1, Lmax 100 cd/m2, Lmin<1 cd/m2), followed by two global flashes (Lmax 200 cd/m2) at an interval of 26 ms (VERIS 6.0™, FMSIII), was used. The stimulus array consisted of 103 hexagons. Retinal signals were amplified (gain=50 K) and bandpass filtered at 1-300 Hz. For each focal response, the root mean square was calculated. We analyzed 5 larger response averages (central 15° and 4 adjoining quadrants) as well as 8 smaller response averages (central 10° and 7 surrounding response averages of approximately 7° radius each). Three epochs were analyzed: the direct component at 15-45 ms (DC) and the following two components induced by the effects of the preceding focal flash on the response to the global flashes at 45-75 ms (IC-1) and at 75-105 ms (IC-2). Statistical analysis was performed using linear mixed effects models adjusted for age. RESULTS: Responses differed significantly between POAG patients and controls in all central response averages. This difference was larger for the central 10° than for the response average of the central 15°. While these observations held true for all response epochs analyzed, the DC differed least and the IC-1 most when POAG was compared to control. For POAG, the most sensitive differential measure was IC-1 of the central 10° with an area under the ROC curve of 0.78. With a cutoff value of 12.52 nV/deg2, 80% of the POAG patients (100% HTG, 69% NTG) were correctly classified as abnormal, while 77% of the control subjects were correctly classified as normal. When the results of the mfERG were compared to the visual fields, there was a tendency for the mfERG to decrease as the mean defect increased. However, this correlation was only significant in the superior nasal quadrant when the IC-1 of the mfERG was compared to the corresponding area of the visual field. CONCLUSION: When compared to findings from previous studies, reducing the luminance of the m-frame flash in the 2-global flash paradigm did not increase the sensitivity and specificity of the mfERG to detect glaucoma further.

Dynamics of retinal vessel response to flicker light in glaucoma patients and ocular hypertensives.

PURPOSE: To analyze dynamics of retinal vessel dilation response to flicker light in patients with glaucoma and ocular hypertension. PATIENTS AND METHODS: Response to flicker light was measured in retinal vessels by means of Retinal Vessel Analyzer. After the baseline 50 seconds long diameter recording of inferior and superior temporal artery and vein, three flicker stimulations of 20 seconds duration was applied, with a 80 seconds break in between. Area under the curve of the vessel diameter (AUC) was compared during 3 flicker periods in the open angle glaucoma patients group (POAG, n = 47) and ocular hypertensives (OHT, n = 46) and age-matched healthy controls (n = 56) RESULTS: POAG eyes demonstrated smaller response of all vessels to flicker light in general than the other two groups (p = 0.0008), but the response dynamics was significantly different between the groups (p = 0.038), showing in three flicker periods a delayed increasing response in the POAG and OHT groups, and remaining stable in healthy subjects. CONCLUSION: General vessel response to flicker light was decreased in POAG patients despite the slow improvement in repeated flicker stimulation, indicating an altered response pattern.

Relationship between peripheral blood flow in extremities and choroidal circulation.

BACKGROUND: The aim of this study was to explore the relationship between subjectively estimated and objectively measured finger temperature on the one, and choroidal blood flow on the other side. PATIENTS AND METHODS: We measured submacular choroidal blood flow (CBF) in 73 healthy subjects. Based on the history of cold hands and feet, they were divided in three groups, reporting "never", "sometimes" and "always" having cold extremities. As an objective measure of finger temperature, it was recorded at the fingertips with an infrared thermometer (IRT). Analysis of variance for CBF based on the group selection and with blood and intraocular pressures as covariates was performed, as well as the correlation between CBF and IRT. RESULTS: There were 37 subjects in the group with "never" cold extremities, 20 in the group with "sometimes", and 16 subjects in the group with "always" cold extremities. Average age was 44.2 ± 12.9 years. CBF was 11.5 ± 7.3 AU (arbitrary units), 13.6 ± 6.1 AU and 14.3 ± 4.6 AU in the three groups, respectively. The ANOVA p-value was 0.04. Pearson's R for correlation between CBF and IRT was - 0.51, p < 0.001. CONCLUSION: Subjectively and objectively, colder extremities are associated with higher CBF, possibly due to the redistribution of blood flow.

Olfactory function in primary open-angle glaucoma patients.

PURPOSE: The aim of this study was to assess the olfactory function of primary open-angle glaucoma patients. PATIENTS AND METHODS: We analyzed odour threshold, identification, and discrimination in 30 primary open-angle glaucoma patients and 30 age- and gender-matched healthy control subjects. The "Sniffin' Sticks" test battery was applied sequentially on both sides, scores of two nostrils were averaged and means were compared with Mann-Whitney U-test between the groups. RESULTS: Scores for odour threshold were 5.9 +/- 2.2 and 7.4 +/- 2.1 in glaucoma and control group, respectively (p = 0.01), for odour discrimination 10.5 +/- 2.0 and 10.8 +/- 1.6 (p = 0.65), and for odour identification 11.8 +/- 2.1 and 10.6 +/- 1.6 (p = 0.008). Comparing within glaucoma group between those with (n = 18) and without history (n = 12) of cold hands and feet, the former had significantly better odour threshold scores, 6.6 +/- 1.5, than the latter, 4.8 +/- 2.6 (p = 0.036); no difference in other two olfactory modalities were detected. CONCLUSION: Changes of olfactory function have been described in neurodegenerations such as Alzheimer and Parkinson diseases. Complex alterations of olfactory performance seem to be present in POAG patients as well.

Volumetric blood flow measurement in the ophthalmic artery using colour Doppler.

BACKGROUND: Herewith we present a new method for measurement of the volumetric blood flow in absolute units in the ophthalmic artery. PATIENTS AND METHODS: A Philips EnVisor HD ultrasound unit with a 12 - 3 MHz linear transducer was used to measure flow in the ophthalmic artery in 8 healthy young subjects. The transducer was mounted on a custom-made holder which enabled precise and reproducible positioning in 3 axes as well as in rotation angle. Blood flow velocity and vessel diameter were measured during 10 consecutive heartbeats. The measurements were ECG-gated. Blood vessel diameter and blood flow velocity were calculated in an average heartbeat cycle. Hence blood volume over time within a heartbeat cycle as well as blood flow in mL/min were determined. Simultaneously, cardiovascular parameters have been recorded by Finapres. Short time reproducibility (5 measurements on day 1) and long time reproducibility (5 days once daily) as well as interindividual coefficient of variation were evaluated. RESULTS: Average blood flow in the ophthalmic artery in all measurements was 39.7 mL/min. The short-term intraindividual coefficient of variation was 24.1 +/- 9.2 %, the long-term coefficient 32.0 +/- 13.8 %. Interindividual coefficient of variation was 32.8 %. CONCLUSIONS: Our method allows volumetric blood flow measurements in the ophthalmic artery in absolute units, reproducible to a limited extent.

Retinal vessels in patients with multiple sclerosis: baseline diameter and response to flicker light stimulation.

BACKGROUND: Transparency of ocular media enables the precise quantitative analysis of vessels of retina, a neuronal tissue which can be affected by multiple sclerosis (MS). PATIENTS AND METHODS: Eyes with no history of optic neuritis (non-ON eyes) of 21 patients with MS were examined with Retinal Vessel Analyzer. Segments of vessels of 500 microm length were measured proximal and distal from the optic disc and compared to those of 21 age- and gender-matched controls. Baseline diameters and peak response to flicker light stimulation of retinal vessels were analyzed. RESULTS: MS eyes had thinner arterioles (p = 0.02) and thicker venules (p = 0.008) than controls: arterioles 111 +/- 14 microm (proximal), 99 +/- 11 microm (distal) in MS eyes and 121 +/- 15 and 107 +/- 9 in controls, respectively. Values for venules were 157 +/- 18 and 136 +/- 20 (MS); 147 +/- 15 and 119 +/- 20 (controls). Peak response was higher in MS eyes than in controls for arterioles (p = 0.007), but comparable for venules (p = 0.35). CONCLUSION: Narrower arterioles and wider venules might be a consequence of subclinical swelling of optic nerve axons in eyes with negative history of ON in MS patients.

Rigidity of retinal vessels in patients with multiple sclerosis.

PURPOSE: The aim of this study was to analyze pulse wave propagation in the ocular circulation by assessing the phase delay between retinal arterioles and venules and calculating the pulse delay between the retinal and choroidal circulations in MS patients and in control subjects. SUBJECTS AND METHODS: Twenty patients with multiple sclerosis (38.3 +/- 6.2 years) and twenty healthy subjects (37.4 +/- 15.2 years) were examined with the Retinal Vessel Analyzer. In addition, an average peripapillary RNFL (retinal nerve fiber layer) thickness was measured by means of ocular coherence tomography in MS patients. The phase delay between the arteriole and venule pulsations was assessed at three sites: in the close retinal vicinity of the disc, 1 - 2 disc diameters and 3 - 4 disc diameters away from the disc. Assuming that venules are counterphased to the choroidal circulation, a choroid-to-retina pulse delay was calculated. RESULTS: The choroid-to-retina pulse delay was 0.26 +/- 0.11, 0.27 +/- 0.13 and 0.34 +/- 0.15 sec in eyes with history of optic neuritis (ON-eyes); in eyes of MS patients without such a history (non-ON eyes) the corresponding values were 0.27 +/- 0.14, 0.29 +/- 0.11 and 0.30 +/- 0.15 sec, and in control eyes 0.32 +/- 0.19, 0.38 +/- 0.16 and 0.45 +/- 0.20 sec, respectively, at three sites centrifugal from the disc. The choroid-to-retina pulse delay was significantly longer in healthy control eyes than both in ON eyes (p = 0.012) and non-ON eyes of MS patients (p = 0.004). The interocular difference of the choroid-to-retina pulse delay and OCT RNFL thickness showed a significant correlation in MS patients (Pearson r = 0.54, p = 0.015; Spearman R = 0.66, p = 0.0016). CONCLUSION: Patients with multiple sclerosis seem to demonstrate an increased rigidity of the retinal vessels. The interocular difference in retinal vessel rigidity was significantly correlated with the interocular difference in RNFL thickness in MS patients.

[Response of retinal vessel diameter to flicker-light in vasospastics compared to healthy controls]. / Flickerlichtprovokation bei Vasospastikern verglichen mit gesunden Kontrollpersonen.

BACKGROUND: Vascular dysregulation is considered to be a risk factor in several ophthalmic diseases. The purpose of this study was to evaluate the reaction of retinal vessels to flicker light in otherwise healthy subjects with a vasospastic propensity. PATIENTS AND METHODS: Thirty healthy Caucasians, aged between 18-35 years were recruited for this study and grouped into vasospastics, based on a history of frequent cold hands, even in summer, with concordant findings in nailfold capillary microscopy, or as controls, if such a history was absent. The reaction of the retinal vascular diameter to flicker light was observed in a distance of two to three discs diameters away from the optic nerve head with the retinal vessel analyser. Three phases of flicker light of twenty seconds followed by baseline light phases of eighty seconds were recorded. The maximal vasodilatory amplitude of each flicker phase was determined and the results averaged. RESULTS: The maximal average dilatory amplitude at the arterial side reached (mean +/- SD) 2.9 +/- 1.7 % and 4.8 +/- 2.6 % of the baseline amplitude respectively in vasospastic subjects and in healthy controls (t = 2.34; p = 0.025). The reaction at the venous side was statistically comparable in both groups. CONCLUSIONS: Otherwise healthy, vasospastic subject disclosed an altered reaction of the retinal vasculature to flicker light in this study.

Relation of body mass index and blood pressure to subjective and objective acral temperature.

BACKGROUND: Vascular dysregulation, indicated by a positive history of cold extremities, has been postulated as a risk factor for a number of ocular diseases. In order to further characterize the phenotype of vasospastic persons, we tested the association between cold extremities, body mass index (BMI) and blood pressure (BP) in a cohort of healthy subjects. PATIENTS AND METHODS: Questionnaire data were collected from one hundred and seventeen healthy subjects. Based on the history of cold hands and feet they were divided in three groups, reporting "never", "sometimes" and "always" having cold extremities. BP was measured sphygmomanometrically and as an objective measure of finger temperature, it was recorded at the fingertips with an infrared thermometer (IRT). Two-way analysis of variance with gender as one, and group selection as the second factor was performed separately for BMI and mean BP. The correlation of finger temperature with BMI and BP was analyzed by the Pearson regression. RESULTS: Gender distribution was male/female = 41/16, 13/21 and 4/22, for the three groups, respectively, and average age 45.8 +/- 13.0 years. For BMI, factor groups was highly significant (p = 0.0012) with both genders behaving comparably (interaction p = 0.18). For BP the corresponding p values were: factor group p = 0.026, interaction p = 0.89. Correlation coefficients between IRT and BMI were 0.34 (p = 0.0002) and between IRT and BP 0.24 (p = 0.009). CONCLUSION: A statistical significant association is present in healthy subjects between body mass index and blood pressure on one, and cold extremities on the other side, defined subjectively as well as measured objectively. This relationship is gender-independent.

The potential value of natural antioxidative treatment in glaucoma.

Glaucomatous optic neuropathy implies loss of retinal ganglion cells, including their axons, and a major tissue remodeling, especially in the optic nerve head. Although increased intraocular pressure is a major risk factor for glaucomatous optic neuropathy, there is little doubt that other factors such as ocular blood flow play a role as well. Mechanisms leading to glaucomatous optic neuropathy are not yet clearly understood. There is, however, increasing evidence that both an activation of glial cells and an oxidative stress in the axons play an important role. Glial cells may be activated by mechanical stress via activation of the epidermal growth-factor-receptor, or by ischemic stress via an increase in endothelin. Several factors can systemically or locally increase oxidative stress. In glaucoma, an unstable ocular blood flow leading to repeated mild reperfusion seems to be most relevant in inducing oxidative stress. The simultaneous production of nitric oxide in the astrocytes and of superoxide in the mitochondria of the axons leads to the production of the damaging peroxynitrite. Therapeutically, we need to reduce intraocular pressure, stabilize ocular blood flow, and reduce oxidative stress. Various natural compounds possess potential antioxidative value. Reduction of oxidative stress at the level of mitochondria can be achieved by gingko biloba. Polyphenolic compounds, such as tea, red wine, dark chocolate, or coffee have antioxidative properties. Coffee contains 3-methyl-1,2-cyclopentanedione (MCP), capable of scavenging peroxynitirite. Red wine-polyphenols (e.g., resveratrol), exert vasoprotective effects by inhibiting the synthesis of endothelin-1. Dark chocolate decreases blood pressure and improves endothelium-dependant vasorelaxation. Anthocyanosides (bilberries) owe their antioxidant effects to their particular chemical structure. Other antioxidants include ubiquinone and melatonin.

Comet assay analysis of single-stranded DNA breaks in circulating leukocytes of glaucoma patients.

PURPOSE: To investigate the amount of single-stranded DNA breaks in circulating leukocytes of primary open-angle glaucoma (POAG) patients. METHODS: A comparative quantification of DNA breaks was performed in circulating leukocytes of POAG patients and healthy controls. The following groups of subjects were compared: (1) POAG patients having primary vascular dysregulation (PVD), (2) POAG patients without PVD, (3) healthy controls with PVD, and (4) healthy controls without PVD. The damage to DNA resulting in single-stranded breaks was assessed by means of the alkaline comet assay in which the damaged DNA migrates out of the nucleus forming a tail, which can be quantified using image analysis. Damage was quantified as the comet tail moment, which represents the extent of DNA damage in individual cells. RESULTS: Leukocytes of POAG patients exerted a significantly higher amount of comet tails, which are indicative of DNA damage, in comparison to control leukocytes (p<0.001). DNA breaks occurred particularly in the subgroup of POAG patients with PVD in comparison to glaucoma patients without PVD (p=0.002). In the control group, there was no significant difference between controls with PVD and controls without PVD (p=0.86). CONCLUSIONS: POAG patients with PVD have a significantly higher rate of DNA breaks than both POAG patients without PVD and healthy controls with and without PVD.

Detection of visual field progression in glaucoma.

BACKGROUND: The aim of this study was to compare an event analysis and a trend analysis for the detection of progression in glaucomatous visual field loss. PATIENTS AND METHODS: Excluding initial fields (Octopus, Haag-Streit AG, Köniz, Switzerland), baseline was defined as the average result of the second and third examinations. Eyes with at least 6 additional fields entered the study. The event analysis used the method of the Collaborative Normal Tension Glaucoma Study, and the trend analysis was based on a point-wise linear regression analysis. RESULTS: Of 251 glaucoma patients, 235 left eyes and 225 right eyes qualified for the study. Using the event analysis, 44 series suggested a progressive damage, while the point-wise regression approach disclosed only 14 progressing series. In 9 eyes, the two approaches were concordant. Among the latter, 1 - 5 additional fields were necessary in 7 series to disclose progression using the trend analysis. In one series, the event analysis showed progression 7 examinations later. CONCLUSIONS: The point-wise linear regression analysis classified fewer cases as progressing than the event analysis and determined progression later.

[Central corneal thickness and retrobulbar blood flow in glaucoma patients]. / Hornhautdicke und retrobulbärer Blutfluss bei Glaukompatienten.

BACKGROUND: A correlation between a thin cornea and the presence of vascular risk factors has recently been reported in normal-tension glaucoma patients. The present study intended to investigate the correlation between central corneal thickness and basal retrobulbar blood flow in glaucoma patients. PATIENTS AND METHODS: Corneal pachymetry and colour Doppler imaging (CDI) of the retrobulbar arteries (ophthalmic, central retinal and cilliary) were performed in 63 glaucoma patients. Linear mixed effect models were used to evaluate the association of central corneal thickness and retrobulbar blood flow. RESULTS: There was no significant correlation between central corneal thickness and blood flow in any of the assessed arteries (p = 0.13-0.88). CONCLUSIONS: A statistical relationship between central corneal thickness and retrobulbar blood flow could not be found in the examined sample of glaucoma patients.