[Use of antiglaucomatous drugs in the urban adult population : New Insights into the prevalence of glaucoma from the Hamburg City Health Study]

BACKGROUND

Glaucoma is a widespread ophthalmological disease. Knowledge about the spread of the disease in the population is necessary with respect to further questions on comorbidities, risk factors and the provision of care.

OBJECTIVE

An analysis of the use of glaucoma medications and the prevalence of glaucoma in an urban adult population was carried out.

MATERIAL AND METHODS

The Hamburg City Health Study (HCHS) is a prospective, long-term, population-based cohort study that includes a random sample of 45,000 participants aged between 45 and 79 years from the general population of Hamburg, Germany. Apart from various medical parameters, data include premedication and the medical history of the participants. The use of antiglaucomatous medication among the first 10,000 study participants was analyzed and the prevalence of glaucoma was estimated according to the use of medications as well as by the self-reported history of glaucoma. Descriptive analysis and logistic regression analysis were performed to analyze the data and to calculate correlations by age and gender.

RESULTS

In the study population 319 persons were on medication to lower the intraocular pressure (IOP, mean age 67.1 years, SD = 7.57 years), which is equivalent to an estimated prevalence of 3.35% (95% confidence interval, CI 3.00-3.70%). A positive correlation was observed between age and the use of IOP-lowering medication, which is statistically highly significant (p = < 0.001). The analysis by gender showed a slightly higher prevalence among women, which was not statistically significant. The estimated prevalence according to glaucoma medication and history were only partly congruent.

DISCUSSION

This estimated prevalence of glaucoma is comparable to other epidemiological studies. The study results cover not only patients with manifest glaucoma but also persons who were treated for ocular hypertension. The inconsistency between the prevalence of glaucoma medication and the diagnosis of glaucoma can be explained by different treatment strategies and also by information deficits.

Telemedical cardiac risk assessment by implantable cardiac monitors in post-infarction patients with autonomic dysfunction (SMART-MI-DZHK9): gender differences and outcomes

Background

Cardiac autonomic dysfunction identifies high-risk patients after myocardial infarction (MI). Telemedical cardiac risk assessment by implantable cardiac monitors (ICM) after MI was recently identified as an effective method to early detect subclinical, but prognostically relevant serious arrhythmic events (SArE). Clinical complications in female patients after MI usually present with atypical symptoms. Therefore, early detection of prognostically relevant SArE in females would be of great clinical interest.

Purpose

In this pre-specified analysis of the SMART-MI trial we aimed to assess the impact of gender on detection of SArE and subsequent clinical complications.

Methods

SMART-MI was a prospective, randomised trial. Survivors of acute MI with preserved left-ventricular ejection fraction (LVEF 36–50%) and abnormal periodic repolarization dynamics (≥5.75deg2) and/or deceleration capacity (≤2.5ms) were randomly assigned to ICM-based telemedical monitoring or conventional follow-up. Primary endpoint was time to detection of SArE defined as the composite of atrial fibrillation ≥6 minutes, atrioventricular block ≥IIb, or fast non-sustained (&gt;187 bpm;≥40 beats)/sustained ventricular tachycardia/fibrillation. Clinical complications were defined as the composite of mortality, stroke, systemic arterial thromboembolism, and hospitalization for decompensated heart failure. The effect of intervention on the primary endpoint was tested using Cox-regression analysis. The effect of SArE on clinical complications was evaluated by introducing SArE as time-dependent covariate.

Results

Between May 12, 2016, and July 20, 2020, 1305 individuals were screened and 400 patients were randomly assigned to ICM-implantation (N=201; 49 females) or conventional follow-up (control group; N=199; 29 females). During a median follow-up of 21±23 months, SArE were detected in 60 (30%; 12 females) patients in the ICM and 12 (6%; 1 female) patients in the control group. In both males and females ICM-implantation was associated with a higher detection rate of SArE (HR 6.33; 3.28–12.23; p&lt;0.001 in males and HR 8.49; 1.10–65.66; p=0.040 in females; p-interaction = 0.790; Figure 1). In both male and female patients, detection of SArE was prognostic for subsequent clinical complications (HR 3.64; 1.89–7.02; p&lt;0.001 in males and HR 16.19; 4.76–55.11 in females; p&lt;0.001). The association between SArE and clinical complications was significantly higher in females than males. Among the 13 females with detected SArE, 6 developed clinical complications within a median period of 25±18 months, compared to 12 complications out of 59 SArE within 18±13 months among males (Figure 2; p-interaction = 0.030).

Conclusion

Telemedical monitoring with ICM was highly effective in early detection of subclinical, prognostically relevant SArE in both female and male patients. However, the association of a detected SArE with a subsequent clinical complication was significantly higher among females.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Deutsches Zentrum für Herz und Kreislaufforschung (DZHK) and Medtronic Bakken Research Center

Suppression of natural lens fluorescence in fundus autofluorescence measurements: review of hardware solutions

Fluorescence lifetime imaging ophthalmoscopy (FLIO), a technique for investigating metabolic changes in the eye ground, can reveal the first signs of diseases related to metabolism. The fluorescence of the natural lens overlies the fundus fluorescence. Although the influence of natural lens fluorescence can be somewhat decreased with mathematical models, excluding this influence during the measurement by using hardware enables more exact estimation of the fundus fluorescence. Here, we analyze four 1-photon excitation hardware solutions to suppress the influence of natural lens fluorescence: aperture stop separation, confocal scanning laser ophthalmoscopy, combined confocal scanning laser ophthalmoscopy and aperture stop separation, and dual point confocal scanning laser ophthalmoscopy. The effect of each principle is demonstrated in examples. The best suppression is provided by the dual point principle, realized with a confocal scanning laser ophthalmoscope. In this case, in addition to the fluorescence of the whole eye, the fluorescence of the anterior part of the eye is detected from a non-excited spot of the fundus. The intensity and time-resolved fluorescence spectral data of the fundus are derived through the subtraction of the simultaneously measured fluorescence of the excited and non-excited spots. Advantages of future 2-photon fluorescence excitation are also discussed. This study provides the first quantitative evaluation of hardware principles to suppress the fluorescence of the natural lens during measurements of fundus autofluorescence.

Morphological characterization of the human corneal epithelium by in vivo confocal laser scanning microscopy

Background

Regarding the growing interest and importance of understanding the cellular changes of the cornea in diseases, a quantitative cellular characterization of the epithelium is becoming increasingly important. Towards this, the latest research offers considerable improvements in imaging of the cornea by confocal laser scanning microscopy (CLSM). This study presents a pipeline to generate normative morphological data of epithelial cell layers of healthy human corneas.

Methods

3D in vivo CLSM was performed on the eyes of volunteers (n=25) with a Heidelberg Retina Tomograph II equipped with an in-house modified version of the Rostock Cornea Module implementing two dedicated piezo actuators and a concave contact cap. Image data were acquired with nearly isotropic voxel resolution. After image registration, stacks of en-face sections were used to generate full-thickness volume data sets of the epithelium. Beyond that, an image analysis algorithm quantified en-face sections of epithelial cells regarding the depth-dependent mean of cell density, area, diameter, aggregation (Clark and Evans index of aggregation), neighbor count and polygonality.

Results

Imaging and cell segmentation were successfully performed in all subjects. Thereby intermediated cells were efficiently recognized by the segmentation algorithm while efficiency for superficial and basal cells was reduced. Morphological parameters showed an increased mean cell density, decreased mean cell area and mean diameter from anterior to posterior (5,197.02 to 8,190.39 cells/mm²; 160.51 to 90.29 µm²; 15.9 to 12.3 µm respectively). Aggregation gradually increased from anterior to posterior ranging from 1.45 to 1.53. Average neighbor count increased from 5.50 to a maximum of 5.66 followed by a gradual decrease to 5.45 within the normalized depth from anterior to posterior. Polygonality gradually decreased ranging from 4.93 to 4.64 sides of cells. The neighbor count and polygonality parameters exhibited profound depth-dependent changes.

Conclusions

This in vivo study demonstrates the successful implementation of a CLSM-based imaging pipeline for cellular characterization of the human corneal epithelium. The dedicated hardware in combination with an adapted image registration method to correct the remaining motion-induced image distortions followed by a dedicated algorithm to calculate characteristic quantities of different epithelial cell layers enabled the generation of normative data. Further significant effort is necessary to improve the algorithm for superficial and basal cell segmentation.

In vivo Histology of the Cornea - from the "Rostock Cornea Module" to the "Rostock Electronic Slit Lamp" - a Clinical "Proof of Concept" Study

INTRODUCTION

Confocal in vivo microscopy is an established method in ophthalmology research. As it requires contact coupling and calibration of the instruments is suboptimal, this method has been only rarely used in clinical routine work. As a result of close collaboration between physicists, information scientists and ophthalmologists, confocal laser scanning microscopy (CLSM) of the eye has been developed in recent years and a prototype can now be used in patients. The present study evaluates possible clinical uses of this method.

MATERIAL AND METHODS

The essential innovations in CLSM are (1) a newly designed coupling element with superficial adaptation to corneal curvature and (2) the use of a dual computerised piezo drive for rapid and precise focusing. In post-processing and after elastic imaging registration of the individual images parallel to the surface, it is also possible to produce sagittal sections resembling a split lamp and with resolution in the micrometer range. The concept was tested on enucleated pig bulbi and tested on normal volunteers and selected patients with diseases of the cornea.

RESULTS

Simultaneous imaging in planes parallel to the surface and in sagittal planes provided additional information that can help us to understand the processes of wound healing in all substructures of the cornea and the role of immune competent cells. Possible clinical uses were demonstrated in a volunteer with healthy eyes and several groups of patients (keratoconus after CXL, recurrent keratitis, status after PRK). These show that this new approach can be used in morphological studies at cellular level in any desired and appropriate test plane.

CONCLUSIONS

It could be shown that this new concept of CLSM can be used clinically. It can provide valuable and novel information to both preclinical researchers and to ophthalmologists interested in corneal disease, e.g. density of Langerhans cells and epithelial stratification in ocular surface diseases.

Comparison of algorithms to suppress artifacts from the natural lens in fluorescence lifetime imaging ophthalmoscopy (FLIO)

Fluorescence lifetime imaging ophthalmoscopy (FLIO) has developed as a new diagnostic tool in ophthalmology. FLIO measurements are taken from 30° retinal fields in two spectral channels (short spectral channel (SSC): 498-560 nm, long spectral channel (LSC): 560-720 nm). Because of the layered structure of the eye, the detected signal is an interaction of the fluorescence decay of the anterior part and of the fundus. By comparing FLIO measurements before and after cataract surgery, the impact of the natural lens was proven, despite the application of a confocal laser scanning (cSLO) technique. The goal of this work was to determine the best algorithmic solution to isolate the sole fundus fluorescence lifetime from the measured signal, suppressing artifacts from the natural lens. Three principles based on a tri-exponential model were investigated: a tailfit, a layer-based approach with a temporally shifted component, and the inclusion of a separately measured fluorescence decay of the natural lens. The mean fluorescence lifetime τ_m,12 is calculated using only the shortest and the intermediate exponential component. τ_m,all is calculated using all three exponential components. The results of tri-exponential tailfit after cataract surgery were considered as a reference, because the implanted artificial lens can be assumed as non-fluorescent. In SSC, the best accordance of τ_m,all of the reference was determined with τ_m,12 of the tailfit before surgery. If high-quality natural lens measurements are available, the correspondence of τ_m,12 is best with τ_m,all of the reference. In LSC, there is a good accordance for all models between τ_m,12 before and after surgery. To study the pure fundus fluorescence decay in eyes with natural lenses, we advise to utilize fluorescence lifetime τ_m,12 of a triple-exponential tailfit, as it corresponds well with the mean fluorescence lifetime τ_m,all of eyes with fluorescence-less artificial intraocular lenses.

NWChem: Past, present, and future

Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support and guide experimental efforts and for the prediction of atomistic and electronic properties. In this regard, electronic structure packages have played a special role by using first-principle-driven methodologies to model complex chemical and materials processes. Over the past few decades, the rapid development of computing technologies and the tremendous increase in computational power have offered a unique chance to study complex transformations using sophisticated and predictive many-body techniques that describe correlated behavior of electrons in molecular and condensed phase systems at different levels of theory. In enabling these simulations, novel parallel algorithms have been able to take advantage of computational resources to address the polynomial scaling of electronic structure methods. In this paper, we briefly review the NWChem computational chemistry suite, including its history, design principles, parallel tools, current capabilities, outreach, and outlook.

[Efficiency and Therapy Safety of Fractionated Cyclophotocoagulation with up to Ten Laser Spots for Advanced Primary Open-Angle and Pseudoexfoliation Glaucoma]

BACKGROUND

Various procedures are available for the treatment of advanced glaucoma. We examined the efficacy and safety of fractionated cyclophotocoagulation (CPC) with up to ten laser spots for advanced primary open-angle glaucoma (POAG) and pseudoexfoliation (PEX) glaucoma treated with maximal topical therapy or eye-drop intolerance.

MATERIAL UND METHODS

This retrospective study evaluated data from 297 eyes with advanced POAG and PEX glaucoma which received 10 applications of CPC between February 2012 and June 2017. Intraocular pressure (IOP), number of topical eye drops and postoperative complications were evaluated. Data were collected preoperatively, four weeks postoperatively, and at the last documented contact (six months postoperative visit). The paired Wilcoxon rank sum test was used to analyse the changes.

RESULTS

The IOP for open-angle glaucoma decreased from 16.66 ± 4.36 mmHg preoperatively to 13.87 ± 3.59 mmHg at the last visit (6 months postoperative visit; p < 0.05). The IOP for the PEX glaucoma decreased significantly from 20.76 ± 9.55 mmHg preoperatively to 15.50 ± 5.93 mmHg at the last visit (p < 0.003). The number of hypotensive agents in the POAG was 2.51 ± 1.00 preoperatively and at the last visit 2.27 ± 1.03. In PEX glaucoma, the number of hypotensive agents was 2.46 ± 1.07 preoperatively and at the last visit 1.88 ± 0.97. Treatment-related complications occurred in three eyes - two cases of postoperative macular oedema, which were treated well with systemic steroids, and one case of pretreated anterior chamber irritation with hyphema, which was also treated with topical steroids.

CONCLUSION

In our group of patients, the mild CPC performed by us with a maximum of 10 applications (vs. the conventional 20 - 30 applications) produced a good reduction of intraocular pressure, as well as a reduction in topical medication, with a low complication rate.

Correlations and incipient antiferromagnetic order within the linear Mn chains of metallic Ti4MnBi2

We report measurements on Ti4MnBi2, where a crystal structure involving linear chains of Mn ions suggests one-dimensional magnetic character. The electrical resistivity is metallic, consistent with the results of electronic-structure calculations that find a robust Fermi surface albeit with moderate electronic correlations. A Curie-Weiss fit to the magnetic susceptibility suggests that the Mn moments are in the low-spin S = 1/2 configuration. Neutron diffraction measurements detect weak antiferromagnetic order within the Mn chains, with further evidence for the small staggered moment coming from the entropy associated with the ordering peak in the specific heat as well as from the results of spin-polarized electronic-structure calculations. The antiferromagnetic moments are apparently associated with thed x 2 - y 2 and d xy orbitals of Mn while the remaining Mn orbitals are delocalized and nonmagnetic. Strong quantum fluctuations, possibly related to an electronic instability that forms the Mn moment or to the one-dimensional character of Ti4MnBi2, nearly overcome magnetic order.

Schlafstörungen und schlafassoziierte Erkrankungen beim Glaukom

Das gleichzeitige Auftreten von Schlafstörungen und Glaukom könnte in einem Zusammenhang stehen. Es gibt bisher keine konkreten Studien darüber, wie häufig und warum Schlafstörungen bei Glaukompatienten auftreten, jedoch liegen verschiedene Ansätze vor, die sowohl einen Zusammenhang zwischen dem Auftreten von Schlafstörungen im Verlauf einer Glaukomerkrankung als auch zwischen dem Auftreten eines Glaukoms und bestimmten Schlafgewohnheiten herstellen.

Association between optical coherence tomography based retinal microvasculature characteristics and myocardial infarction in young men

Incident myocardial infarction (MI) is a leading cause of adult mortality in the United States. However, because MI has a relatively low incidence in the young population, little information exists on the disease in younger adults. Because the retina has the unique quality that its vasculature is readily and noninvasively visible, the retina is frequently studied to evaluate correlations between vessels and cardiovascular diseases. In the current study, we evaluated the retinal microvasculature of patients who had experienced an MI before 50 years of age (n = 53 subjects) and age- and sex-matched patients who had not experienced an MI (n = 53 patients). We used circular optical coherence tomography (OCT) scans to image peripapillary venules and arterioles. The diameter of each vessel was measured and the respective arterial-venous ratio (AVR) was calculated. We did not detect any significant differences between MI and control subjects in retinal vessel calibre or AVR.

[Quality of Glaucoma Care in the Greater Hamburg Area]

Background There is insufficient data on the quality of health services and health-related quality of life of patients with glaucoma. The purpose of this study was to investigate the extent to which the health services for glaucoma patients in the Greater Hamburg area conform to the guidelines set by the German Ophthalmological Society (DOG). Materials and Methods 196 glaucoma patients were offered an interview-administered questionnaire during their inpatient diurnal IOP measurement. The quality of glaucoma care and examinations recommended by the DOG were analysed. The results of the questionnaire were correlated with glaucoma severity, according to the stage of visual field defects. The correlation to the type of glaucoma was also analysed. Results The frequency of visits to the ophthalmologist was 5.1 per year. Most patients reported quarterly medical consultations. The majority of patients reported short waiting periods, because appointments were made in advance. In 92 % of cases, an intraocular pressure measurement was performed with each medical consultation. Half of the patients stated that their intraocular pressure had been measured at different times of the day. The visual field was tested a mean of 0.9 times per year at the ophthalmology clinic, but 1.4 times per year in the outpatient area. Further measures for glaucoma diagnostic testing were carried out 0.8 times per year at the ophthalmology clinic, and 0.4 times per year in the outpatient area. For the majority of patients, there were no additional costs for outpatient glaucoma diagnostic testing. Only 4 % of patients had to pay more than 100 € per year for these services. Conclusions For the majority of glaucoma patients in the Greater Hamburg area, the glaucoma health services conform to the guidelines set by the German Ophthalmological Society. Intraocular pressure measurements were performed on almost all patients at the regular check-ups and visual fields were examined as recommended. However, for about one-fifth of the patients, regular procedures for optic nerve analysis do not take place. The date of the next appointment was arranged immediately, allowing close follow-up, with little or no additional costs for the majority of patients.

An Automated Approach for Localizing Retinal Blood Vessels in Confocal Scanning Laser Ophthalmoscopy Fundus Images

In this work, we present a rules-based method for localizing retinal blood vessels in confocal scanning laser ophthalmoscopy (cSLO) images and evaluate its feasibility. A total of 31 healthy participants (17 female; mean age: 64.0 ± 8.2 years) were studied using manual and automatic segmentation. High-resolution peripapillary scan acquisition cSLO images were acquired. The automated segmentation method consisted of image pre-processing for gray-level homogenization and blood vessel enhancement (morphological opening operation, Gaussian filter, morphological Top-Hat transformation), binary thresholding (entropy-based thresholding operation), and removal of falsely detected isolated vessel pixels. The proposed algorithm was first tested on the publically available dataset DRIVE, which contains color fundus photographs, and compared to performance results from the literature. Good results were obtained. Monochromatic cSLO images segmented using the proposed method were compared to those manually segmented by two independent observers. For the algorithm, a sensitivity of 0.7542, specificity of 0.8607, and accuracy of 0.8508 were obtained. For the two independent observers, a sensitivity of 0.6579, specificity of 0.9699, and accuracy of 0.9401 were obtained. The results demonstrate that it is possible to localize vessels in monochromatic cSLO images of the retina using a rules-based approach. The performance results are inferior to those obtained using fundus photography, which could be due to the nature of the technology.

[The Limits of Selective Laser Trabeculoplasty in Glaucoma Therapy]

Introduction: The aim of this study was to evaluate the efficacy of selective laser trabeculoplasty (SLT) in the University Eye Hospital Hamburg Eppendorf. Material and Methods: We conducted a retrospective analysis of 113 eyes of 113 consecutively treated patients who underwent SLT treatment between 03/2011 and 01/2014 and had a follow-up of at least 4 months. Results: Intraocular pressure was reduced by 1.08 mmHg (7 % reduction) on average. In 43.7 % of the treated eyes, additional medical or surgical glaucoma treatment was necessary within 12 months. Conclusion: SLT is not effective as monotherapy in pre-treated eyes with low target pressure.

[Diverse effectiveness of the trabectome for different types of glaucoma]

PURPOSE

Ab interno trabeculotomy using the trabectome device is a intraocular pressure (IOP) decreasing operation by ablation of the trabecular meshwork and the inner wall of Schlemm's channel. This prospective study analyses the effectiveness of the trabectome operation in 122 patients.

PATIENTS AND METHODS

The operation was conducted when topical medication was maxed out with the intraocular pressure (IOP) remaining above the desired target range. In addition to the evaluation of the whole study group further analysis concerned the effectiveness of the trabectome in different subclassifications of glaucoma. In some cases the procedure was combined with cataract surgery and subsequently the results were compared to the plain trabectome OP. The results were split into two groups: "complete success" (without postoperative medication) and "qualified success" (with medication). The evaluation was processed for the IOP levels ≤ 21 mmHg, ≤ 18 mmHg, ≤ 15 mmHg und ≤ 12 mmHg. Follow-up dates were 6 and 12 months after surgery.

RESULTS

Baseline IOP was 20.15 ± 7.1 mmHg. After 6 months the average IOP of all patients was 16.53 ± 5.89 mmHg, after 12 months the IOP amounted to 15.6 ± 4.45 mmHg. At both follow-ups approximately 90 % of the "complete success" group exhibited an IOP ≤ 18 mmHg. Also at both follow-ups 75 % of the "qualified success" group achieved a range ≤ 18 mmHg - whereas 50 % gained an IOP ≤ 15 mmHg. In secondary glaucoma an IOP decrease of 36 % was achieved. In open-angle glaucomas and those with dysgenetic altered angles the operation evoked a pressure loss of ca. 20 %. The trabectome-only group as well as the group of combined surgery exhibited a significant lowering of IOP. This was accomplished by a significant reduction of eye drops. After surgery nearly half of all patients required none or 1 eye drop at most.

CONCLUSION

The trabectome offers a safe and significant lowering of IOP for around 36 % and seems to be very effective in secondary glaucomas. In dysgenetic alterations and open-angle glaucoma a moderate lowering of IOP (ca. 20 %) may be expected. The amount of eye drops can be reduced for about 42 %. After surgery every second patient requires at most 1 eye drop. The technique can be combined with cataract surgery and permits a penetrating operation at a later date.

[Psoriasis-associated keratitis: case report]

Psoriasis is a common skin disease, which is associated with multiple extracutaneous manifestations. This article presents a case report of a rare ocular manifestation of psoriasis; psoriasis-associated keratitis. In a 37-year-old man we could show that systemic immunomodulatory therapy led to a rapid improvement of the ocular symptoms.

Vascular dysfunction in ocular blood flow regulation: impact of reactive oxygen species in an experimental setup

PURPOSE

Glaucoma is associated with an altered blood flow and increased levels of reactive oxygen species (ROS). Reactive oxygen species can have opposing influences on the tone of a vessel; depending on the condition and type of the vessel, ROS can induce vasodilation or vasoconstriction. In the present study, we investigated the impact of ROS on the tone of rat ophthalmic arteries under various conditions and present data on the underlying mechanisms.

METHODS

Freshly dissected rat ophthalmic arteries were pressurized in a perfusion setup to 80 mm Hg, at which a stable myogenic tone was observed. After various pretreatments (e.g., removal of endothelium, partial depolarization to -41 mV, blocking of the Na(+)/Ca(2+)-exchanger (NCX) in reverse mode by KB-R7943, or blocking of the Na(+)/K(+)-ATPase by ouabain), the vessels were exposed to ROS. Vessel diameter was continuously recorded and values before and after treatment compared.

RESULTS

Stable myogenic tone of vessels with and without endothelium was established at a pressure of 80 mm Hg. At the physiological resting membrane potential, ROS exposure led to a significant vasodilatation, which was significantly reduced by pretreatment with ouabain. After depolarization to -41 mV, ROS exposure led to vasoconstriction. Blocking the NCX in reverse mode using KB-R7943 completely abolished this ROS-induced vasoconstriction.

CONCLUSIONS

At resting potential, ROS provoke dilation; however, in precontracted vessels they act synergistically and induce further vasoconstriction. In diseases involving altered blood flow through altered vascular tone (e.g., vasospasms), ROS may influence blood flow and may thereby contribute indirectly to further disease progression.

[Astigmatism after keratoplasty: influence of orthotopic transplantation]

BACKGROUND

Patients undergoing corneal transplantation often suffer from postoperative reduced vision due to high astigmatism. This retrospective study analyzed the influence of heterotopic or orthotopic transplantation on astigmatism and visual outcome.

PATIENTS AND METHODS

In this study 373 eyes of 334 patients were analyzed. Group 1 (OT) contained 186 eyes, which underwent orthotopic transplantation (side of recipient and donor corresponded), whereas group 2 (HT) included 187 heterotopic keratoplasties (donor cornea placed in the recipient's contralateral side). After 1, 3, 6, 12 and 24 months the median of keratometric astigmatism, objective astigmatism, topographic astigmatism and best corrected visual acuity (BCVA) were assessed and compared between groups.

RESULTS

The long-term results showed no statistically significant differences regarding keratometric and objective astigmatism, whereas topographic astigmatism differed significantly (p = 0.04) after 3 months. We observed a lower astigmatism of 5.7 dpt (range 3.08-7.78 dpt) in group OT than in the group HT with 7.1 dpt (range 3.9-10.7 dpt). No differences were found at the other time points. The BCVA showed a significantly better effect after 1 month (p = 0.01) in the OT group of 0.2 (0.1-0.3) than in HT group of 0.1 (0.05/0.25). In the postoperative course no additional significant dissimilarities were documented.

CONCLUSIONS

Heterotopic and orthotopic keratoplasty show no significant long-term differences in astigmatism and visual outcom.

Depression, anxiety, and disturbed sleep in glaucoma

Although it has been suggested that glaucoma is associated with circadian misalignment, sleep disorder, anxiety, and depression, these comorbid conditions have not received much attention. This study provides evidence for a significantly higher prevalence of depression, trait anxiety, and sleep disturbances in patients with progressed glaucoma, as compared with glaucoma patients with no or minor visual field defects (VFD). Logistic-regression analyses suggest that severe VFD constitute a significant predictor of depression, trait-anxiety, and sleep disturbance. Results indicate the necessity of regular screening and psychochronobiological treatment in glaucoma patients.

[Long-term follow-up after deep sclerectomy]

BACKGROUND

The aim of this study was to evaluate the long-term outcome of deep sclerectomy (DS) with a follow-up of up to 8 years.

PATIENTS AND METHODS

All patients who underwent a deep sclerectomy between February 2004 and October 2005 and who attended a follow-up visit between August 2009 and October 2011 were included in this study.

RESULTS

This study evaluated 74 eyes of 65 patients with a mean postoperative follow-up of 76.28 ± 10.6 (53.65-92.02) months. Preoperative IOP was 18.37 ± 6.36 mmHg, postoperative IOP at the last follow-up was 12.85 ± 3.5 mmHg, corresponding a 30 % reduction. The number of IOP-lowering eye drops was reduced from 2.36 ± 1.24 to 1.66 ± 1.21 after more than 6 years (p < 0.05). The visual fields showed a mean deviation of - 9.16 ± 8.48 dB initially and - 9.43 ± 8.07 dB at the last follow-up (p > 0.05). Complete success (IOP ≤ 15 mmHg without eye drops or additional surgery) was achieved in 5 % of patients. Qualified success (IOP ≤ 15 mmHg with eye drops or additional surgery) was achieved in 81 %. 53 % (n = 39) underwent cyclophotocoagulation and 20 % (n = 15) needed revision surgery during the follow-up period.

CONCLUSION

DS is an effective long-term IOP-lowering procedure leading to visual field stabilisation.

[The relevance of diabetes for patients with glaucoma]

Although there are some hints for a correlation between diabetes and primary open angle glaucoma (POAG), it remains unclear in which way diabetes influences eye pressure (IOP) and glaucoma. Despite this, the main reason for neovascular glaucoma in diabetes is proven to be retinal ischaemia due to diabetic vessel damage. Primary open angle glaucoma is more frequent than neovascular glaucoma, but neovascular glaucoma is very aggressive and difficult to treat. The mainstay of the treatment is panretinal photo- or cryocoagulation. The next treatment options are cryodestructive procedures followed by filtering surgeries. In most cases a combination of treatments is necessary. In end-stage neovascular glaucoma sometimes enucleation is the only possible therapy when the IOP cannot be controlled or phthisis bulbi occurs.

[Post-surgical treatment after non-penetrating glaucoma surgery: the goniopuncture]

Non-penetrating glaucoma surgery was primarily developed as an alternative to the widely applied trabeculectomy. Since the anterior chamber in non-penetrating surgery is not directly opened, common postoperative complications such as hypotony are rare. The most frequently applied technique in this group is the deep sclerectomy. After having prepared a superficial scleral flap a deeper scleral flap is performed and excised unroofing Schlemm's canal. The trabecular meshwork is then peeled leaving a residual trabeculodescemet membrane. As a consequence aqueous humour diffuses via the trabeculodescemet membrane under the scleral flap and subsequently under the conjunctiva. One of the reasons for a postoperatively high IOP is seen in the resistance of the residual trabculodescemet membrane. A solution to this problem lies in its puncture, the so-called goniopuncture. Goniopunctures are done in approximately 50 % of cases after deep sclerectomy and are also applied in cases of canaloplasty and viscocanaloplasty. Usually a 1064 nm Nd : YAG laser is used. A potential risk of iris incarceration is described. Two studies have shown that an equally IOP lowering effect can be achieved by treating the trabeculodescemet membrane with a frequency-doubled 532 nm Nd : YAG laser (SLT). No complications were detected in those cases. In conclusion, goniopuncture should be considered as the first line treatment for postoperative IOP increase in cases of non-penetrating glaucoma surgery. It should therefore be preferred to a (re)start of topical treatment.

Thirty years of cornea cultivation: long-term experience in a single eye bank

PURPOSE

To evaluate donor demographics, trends in donor tissue procurement and tissue storage over a long period.

METHODS

A retrospective, longitudinal, descriptive analysis was undertaken of data from the Hamburg Eye Bank Data Base (HEB-DB) that had been collected between 1981 and 2010. Data on 54 parameters of cornea donors [including clinical history, age, death cause, gender and death-to-explantation interval (DEI)] and of cultivated corneas (endothelial quality and development in culture, cultivation period, microbiological contamination) were retrieved. These data were analysed statistically, focusing on the historical development of the eye bank.

RESULTS

At the time of retrieval (June 2010), the HEB-DB contained data on 10 943 corneas (5503 donors). Most donors were men (65%) and had died from cardiopulmonary (n = 801)/cerebral (n = 261) failure or as the result of a polytraumatic accident/suicide (n = 602). Within these years, donor age, DEI and storage time increased. The percentage of stored corneas suitable for transplantation displayed a variable but increasing trend; in 2007, almost 75% of the stored corneas were transplanted. Between 1995 and June 2010, the median microbiological contamination rate was 5.3%. A change in the procurement procedure from enucleation to corneoscleral explantation in 2008 led to a briefly increased contamination rate.

CONCLUSION

  Donor demographic data run parallel to the general demographic development. Our analysis indicates a dynamic development of the eye bank over the last 30 years and emphasizes the need for an active quality management in coping with the challenges of modern eye banking.

European proficiency study with control serum for the tumor marker CA 19-9 measured on different test systems

BACKGROUND

Reliable and precise CA 19-9 testing is required for the long-term follow-up of patients with pancreatic carcinoma during therapy. The aim of this longitudinal proficiency study was to evaluate the comparability, linearity, and precision of CA 19-9 determinations performed in different laboratories using currently available test systems under routine conditions.

METHODS

During the one year study period, 15 laboratories applied 7 different tests and included a liquid BIOREF control serum with pancreatic carcinoma derived CA 19-9 in their routine testing and quality control procedures. The results were collected centrally and evaluated statistically.

RESULTS

The comparability of CA 19-9 results is limited especially when different tests are used, albeit, some tests show a good correlation: The CA 19-9 values obtained by different laboratories using different test systems vary up to a factor of 2. The precision of CA 19-9 determinations was acceptable in most laboratories with coefficients of variation ranging between very low 3.2% and high 17.8%. The imprecision was slightly increased when automatic dilution procedures of the analysers were used.

CONCLUSIONS

The comparability of CA 19-9 test results must be improved. The precision is acceptable in most cases. In order to monitor key performance parameters, every laboratory should participate in external quality assessment schemes and should perform a routine internal quality control with a control serum independent from the test kit manufacturer.

[Canaloplasty : a new alternative in non-penetrating glaucoma surgery]

BACKGROUND

Canaloplasty provides a new option in non-penetrating glaucoma surgery. The aim of this study is to examine its early postsurgical safety and efficacy.

PATIENTS AND METHODS

This was a retrospective study of canaloplasties performed at our institution in 2009 (n=46, 13 of which were combined with cataract surgery). The mean follow-up was 6.0±3.4 months. The most important parameters examined were intraocular pressure (IOP), number of topical medications, postoperative complications, and required additional surgery.

RESULTS

Mean presurgical IOP: 18.2±5.8 mmHg on a mean of 2.3±1.2 applied topical medications. Mean postsurgical IOP: 12.3±5.1 mmHg at 3 months, 11.7±3.0 mmHg at 6 months, and 12.6±2.4 mmHg at 12 months. Number of postsurgical medications: 0.8±1.1 at 3 months, 1.2±1.3 at 6 months, and 1.0±1.1 at 12 months. The most frequent postoperative complications were transient hypotension (32.6%), bleb leakage (26.1%), and microhyphema (23.9%). Revision surgery was required in 8.7% of all patients.

CONCLUSIONS

Canaloplasty showed a good IOP-reducing effect. Complications occurred mostly temporarily and were of a controllable nature.

Alpha-1-Fetoprotein (AFP): international proficiency study with different test systems

BACKGROUND

The present proficiency study aimed to elucidate the comparability and reliability of test systems for the determination of AFP concentrations.

METHODS

25 laboratories using 8 different commercial test systems used liquid BIOREF-AFP control serum in their routine internal quality control over a period of one year. For statistical analysis the results were collected centrally.

RESULTS

The statistical analysis of the test results revealed considerable variation for the different laboratories. The deviations of the mean values of different laboratories from the overall mean value varied between 0.1 and 26.1%, and for most of the laboratories the deviation was round about 10%. The precision of measured values in the individual laboratories was in most cases acceptable: Nevertheless, the coefficients of variation of the individual laboratories ranged from 13 to 16.1%.

CONCLUSIONS

In conclusion, this study indicates that AFP results vary between different laboratories albeit an international standard for AFP is available. Therefore, every laboratory should participate in external ring studies and should use a quality control serum independent of the test kit manufacturer for the internal quality control.

Precision and long-term stability of different estradiol immunoassays assessed in a multi-center quality control study

BACKGROUND

Because of the vast range of physiological relevant estradiol concentrations the requirements to be met by an estradiol assay are high. In the present study the performance of various commercially available estradiol assays was evaluated with regard to imprecision and long-term stability.

METHODS

Precision and long-term stability of 7 commercially available estradiol immunoassays were assessed in a multi-centre quality control study based on the repeated measurement of liquid BIOREF estradiol control sera by 18 laboratories during a 14-month study period.

RESULTS

The mean estradiol concentrations determined in 594 runs performed for each control level were 71 pg/ml, 349 pg/ml and 676 pg/ml. A high variation was found for the method specific mean values calculated from all results measured with the same method, which ranged between 32 - 90 pg/ml, 187 - 392 pg/ml and 373 - 790 pg/ml, resulting in a similar high inter-laboratory variation with coefficients of variation (CVs) of 25.0%, 16.7% and 17.5%. In contrast, the intra-laboratory variation of estradiol values as well as the variation of values measured with the same method were found to be considerably lower with coefficients of variation < 10% for most laboratories and methods; only the low control level was measured with CV values > 10% by the majority of laboratories and methods. For none of the laboratories a tendency was observed in the results from beginning to end of the 14 month study period indicating a high uniformity in assay production and a good long-term stability of the control material used.

CONCLUSIONS

The present data demonstrate that also with the currently available estradiol immunoassays the comparability of results measured with different methods is limited. With most assays very low estradiol concentrations, as observed in postmenopausal women, can be determined only with a precision which is not adequate for clinical assessment.

[Stem cell-based in vitro models as alternative methods for toxicity and efficacy tests in animals]

Regarding toxicity and efficacy tests of pharmacological and chemical substances (REACH legislation in Europe), there is a strong need to develop alternative methods for animal in vivo studies, in particular for human in vitro models. Here we present results from early phases of projects exploring the potential of embryonic stem cell models, with a special emphasis on embryo toxicity and neuronal stress.We have been able to demonstrate key functional read-outs of neural hESC models, in addition to representing mechanistic aspects which are characteristic for ischemia or excitotoxicity. There is agreement that these mechanisms underlie a variety of human neurodegenerative diseases. We discuss the possibilities to develop more precise endpoints on the molecular level and present an example of a protein biomarker signature emerging from a European FP6 project about embryo toxicity (www.reprotect.eu), employing murine and human embryonic stem cell models.

Protective effects of nebivolol on oxygen free radical-induced vasoconstrictions in vitro

BACKGROUND

Disturbed ocular hemodynamics and vasospasms might be involved in the pathogenesis of glaucoma. On a clinical level there are indications for an optimization of ocular perfusion parameters in hypertensive glaucoma patients by switching a beta-adrenoceptor-antagonist therapy to nebivolol. Aim of the present study is to investigate vasoactive properties of nebivolol on ocular vasculature in vitro. Besides vasorelaxing effects, the impact of nebivolol on oxygen free radical-induced vasoconstrictions is studied.

MATERIAL/METHODS

The experiments were carried out with ring preparations from porcine ciliary arteries. The preparations were placed in a myograph system and were kept under physiological conditions (pH 7.4, 37 degrees C, Krebs-Henseleit-Buffer, 1.75 mM Ca2+) and were stimulated by K+ depolarizations. The experiments were performed at a Nernst potential of -41 mV, which reflects half-maximal activation. For radical exposure, the preparations were superfused for 20 s in a specifically designed set-up with hydroxyl radicals generated by the Fenton reaction from H2O2 and Fe3+. NO synthase activity was modulated by adding L-arginine to the buffer.

RESULTS

At a concentration of 10-5 M nebivolol leads to a reduction of vascular tone by -8.5+/-3.4% (n=11; P=0.016) vs. +2.6+/-1.9% (n=11; n.s.) in presence of its solvent DMSO. Nebivolol (10-5 M) reduces hydroxyl radical-induced vasoconstrictions by 53+/-10% (n=11; P<0.001). Stimulation of the NO synthase by L-arginine saturation potentiates this effect.

CONCLUSIONS

Nebivolol combines vasorelaxing properties with protection against oxidative stress-induced vasoconstrictions. Both effects may be attributed to NO-releasing properties of nebivolol independently of its beta-adrenoceptor-blocking effect.

Effects of the systemic beta-adrenoceptor antagonist nebivolol on ocular hemodynamics in glaucoma patients

BACKGROUND

Systemic antihypertensive treatment in glaucoma patients with hypertension carries the potential risk of an additional deterioration in ocular hemodynamics due to the reduction in ocular perfusion pressure. Nebivolol is a beta1-selective adrenoceptor antagonist with known peripheral vasodilatory effects due to NO-releasing properties. The effect of a switch in systemic beta-blocker treatment to nebivolol on retrobulbar hemodynamics in glaucoma patients with arterial hypertension was therefore investigated.

MATERIAL/METHODS

Peak systolic (PSV) and end-diastolic (EDV) velocity in the short and long posterior ciliary arteries (SPCA, LPCA), central retinal artery (CRA), and ophthalmic artery (OA) were recorded by color Doppler imaging (CDI) in 23 glaucoma patients with arterial hypertension using their primary systemic beta-blocker medication and four weeks after a switch to nebivolol.

RESULTS

Compared with the first recording under the primary antihypertensive medication, the CDI measurements after four weeks of nebivolol treatment revealed a significant acceleration of the PSV in the SPCA and LPCA and the EDV in the SPCA and CRA. No significant differences in flow velocities were found for the OA. Intraocular pressure and systemic blood pressure remained unchanged.

CONCLUSIONS

Switching blood pressure treatment to nebivolol in glaucoma patients with hypertension leads to accelerated blood flow in the small retrobulbar vessels. A stabilization of ocular perfusion might be of particular importance in this group of co-morbid patients.

[A comparison between absorbable and non-resorbable scleral implants in deep sclerectomy (T-Flux and SK-Gel)]

BACKGROUND

The intraocular pressure (IOP) lowering effects of deep sclerectomy (partially combined with phacoemulsification) with different scleral implants (T-Flux- or SK-Gel) were investigated.

PATIENTS AND METHODS

In a retrospective study, 72 patients with medically uncontrollable glaucoma underwent non-penetrating deep sclerectomy. Of these, 54 patients received T-Flux implants and 18 SK-Gel implants. Examinations were carried out shortly before and after surgery, as well as after 12 months.

RESULTS

Prior to surgery IOP was 18.4+/-5.5 mmHg (n=72) and 12 months after surgery it was 13.1+/-3.8 mmHg (n=65). The number of antiglaucomatous eyedrops used prior to surgery was 2.3+/-1.3 (n=72) and 12 months after surgery 0.2+/-0.6 mmHg (n=65). Secondary IOP-lowering surgery after 12 months was carried out on 15.3% of the operated eyes, and consecutive goniopunctures after 12 months were 25%. No significant differences were found between the two groups.

CONCLUSIONS

The short- and mid-term IOP lowering effects in deep sclerectomy with scleral implants were quite satisfying no matter which implant was used. There was no difference in deep sclerectomy whether or not combined with cataract surgery.

Retrobulbäre Hämodynamik bei Hochdruck- und Normaldruckglaukompatienten: Diagnostische Bedeutung von Tinnitus, Migräne und raynaudartigen Beschwerden

BACKGROUND

In the pathophysiology of open-angle glaucoma altered perfusion of the optic nerve head is of importance. Up to now these disturbances were presumed to be the chief cause of glaucomatous damage in patients with normal tension glaucoma showing other vascular disturbances like migraine or tinnitus.

PATIENTS AND METHODS

Peak systolic velocity (PSV) and end-diastolic velocity (EDV) were measured and the resistive index (RI) was calculated by colour Doppler imaging (CDI) in the ophthalmic artery (OA), central retinal artery (CRA) and in the short and long posterior ciliary arteries (SPCA, LPCA) in 18 patients with normal tension glaucoma (NTG), in 18 patients with high tension glaucoma (HTG) and in 18 normal control subjects.

RESULTS

In an upright sitting position both glaucoma groups showed statistically significant decreases in PSV and EDV in CRA and SPCA compared to the control subjects. HTG when compared to NTG and normal subjects showed statistically significant decreases of EDV and statistically significant increases of RI in LPCA. In addition, compared to normal subjects, HTG patients showed statistically significant increases of RI in both OA and SPCA.

DISCUSSION

Both glaucoma groups showed decreased blood flow velocities in the small retrobulbar vessels in an upright sitting position. Normal tension glaucoma patients with symptoms of vasospasms compared to patients with high tension glaucoma showed only small differences in ocular haemodynamics.

Influence of oxygen free radicals on the tone of ciliary arteries: a model of vasospasms of ocular vasculature

BACKGROUND

Altered regulation of vascular tone and particularly vasospasms are thought to be a risk factor for the progression of primary open angle glaucoma (POAG). Apoptosis of retinal ganglion cells and possibly vascular tone regulation in glaucoma might be caused by oxidative stress. The aim of the present study was to investigate the influence of oxygen free radicals on the tone of ciliary arteries.

METHODS

The experiments were carried out with fresh ring preparations from porcine ciliary arteries obtained from a slaughterhouse. The preparations were placed in a self-designed myograph system and were kept under physiologic conditions (pH 7.4, 37 degrees C, Krebs-Henseleit-Buffer, 1.75 mM Ca(2+)). The muscles were sub-maximally activated by depolarization to -41 mV Nernst potential for K(+). The pre-activated preparations were exposed to hydroxyl radicals generated by the Fenton reaction (4 mM H(2)O(2); 30 microM Fe(3+)). Exposure time varied between 10 s and 60 s in order to obtain different radical-time-doses. The developed force was evaluated relatively to the developed force at maximal depolarization to -4 mV.

RESULTS

Ten seconds of radical exposure result in an additional increase of the relative developed force from 0.35 +/- .08 to 0.62 +/- 0.12 (P = 0.003; n = 8). Comparable results were obtained for 20 s and 60 s radical exposures. The developed force of a maximal activation to -4 mV was not reduced after a 10 s radical exposure (0.84 +/- 0.13; P = 0.25; n = 5), but was significantly reduced after 20 s exposure (0.25 +/- 0.21; P = 0.005; n = 6) and was virtually 0 after 60 s exposure.

DISCUSSION

The data shows that oxygen free radicals induce transient contractions of isolated ciliary artery rings. The shape of these contractions shows parallels to vasospasms. Thus the established system may serve as an in vitro model of vasospasms.