Prevalence, incidence, and risk factors of primary open-angle glaucoma - a cohort study based on longitudinal data from a German public health insurance.

BACKGROUND: This study estimates the prevalence and incidence rates of primary open -angle glaucoma (POAG) as well as risk factors based on a dataset from the largest German health insurance company. METHODS: A random sample of 250,000 persons at age 50+ of the Allgemeine Ortskrankenkasse (AOK) from 2010 to 2013 was used. Selected risk factors of POAG incidence were analyzed using multivariate Cox proportional hazard models. RESULTS: The age-standardized prevalence of POAG at age 50+ in 2010 was 2.79% (95%-CI: 2.72-2.85%). The age-standardized total incidence rate was 0.38 (0.36-0.39) per 100 person-years. Sex differences were significant for total prevalence and total incidence rates, with higher prevalence and incidence rates for women compared to men. The Cox model revealed a strong age effect, a significantly 19% higher incidence for women (p ≤ 0.001), injuries of the eye and orbit (175%, p ≤ 0.001), degeneration of iris and ciliary body (155%, p = 0.022), myopia (155%, p ≤ 0.001), retinal vascular occlusions (134%, p ≤ 0.001), hypertension (13%, p ≤ 0.001) and diabetes mellitus (23%, p ≤ 0.001). CONCLUSION: Health claims data are an important data source for estimating POAG occurrence and help overcome the problems of small sample sizes. These results may help to understand the causal pathways of POAG and to develop intervention strategies to increase the awareness of patients and physicians with the aim of reducing POAG incidence.

[In vivo imaging of the corneal nerve plexus : From single image to large scale map]. / In-vivo-Bildgebung des kornealen Nervenplexus : Vom Einzelbild zur großflächigen Darstellung.

The sub-basal nerve plexus (SNP) of the cornea provides the possibility of in vivo and non-invasive examination of peripheral nerve structures by corneal confocal microscopy (CCM). Thus morphological alterations of the SNP can be directly detected and quantified. A single CCM image is insufficient for a well-founded diagnosis because of the inhomogeneous distribution of the nerve fibers; therefore, there is a demand for techniques for large area imaging of the SNP. This article provides an overview of published approaches to the problem. Current developmental work at the Karlsruhe Institute of Technology and the University of Rostock Eye Clinic is expected to lead to a simplified handling of the technology and a further improvement in the image quality.

[Morphometric characterization of the subbasal nerve plexus : Detection and analysis of networks of nerve fibers]. / Morphometrische Charakterisierung des subbasalen Nervenplexus : Detektion und Analyse von Nervenfasernetzwerken.

Confocal laser scanning microscopy is a versatile tool in medical research and enables noninvasive in vivo imaging of the corneal subbasal nerve plexus. The aim of this work is to provide a structured overview about the detection and quantification of nerve fibers of the subbasal nerve plexus from images acquired by confocal laser scanning microscopy. Relevant steps are explained and potential factors influencing the quality of the results are pointed out. Information obtained from the quantification of subbasal nerve fiber structure can be potentially used as clinical parameters in the context of diagnostics and therapy control of diabetic neuropathy.

Femtosecond laser cutting of human corneas for the subbasal nerve plexus evaluation.

Assessment of various morphological parameters of the corneal subbasal nerve plexus is a valuable method of documenting the structural and presumably functional integrity of the corneal innervation in health and disease. The aim of this work is to establish a rapid, reliable and reproducible method for visualization of the human corneal SBP using femtosecond laser cut corneal tissue sections. Trephined healthy corneal buttons were fixed and processed using TissueSurgeon-a femtosecond laser based microtome, to obtain thick tissue sections of the corneal epithelium and anterior stroma cut parallel to the ocular surface within approximately 15 min. A near infrared femtosecond laser was focused on to the cornea approximately 70-90 µm from the anterior surface to induce material separation using TissueSurgeon. The obtained corneal sections were stained following standard immunohistochemical procedures with anti-neuronal ß-III tubulin antibody for visualization of the corneal nerves. Sections that contained the epithelium and approximately 20-30 µm of anterior stroma yielded excellent visualisation of the SBP with minimal optical interference from underlying stromal nerves. In conclusion, the results of this study have demonstrated that femtosecond laser cutting of the human cornea offers greater speed, ease and reliability than standard tissue preparation methods for obtaining high quality thick sections of the anterior cornea cut parallel to the ocular surface.

Comparative quantitative assessment of the human corneal sub-basal nerve plexus by in vivo confocal microscopy and histological staining.

PurposeThis study was designed to compare and contrast quantitative data of the human corneal sub-basal nerve plexus (SBP) evaluated by two different methods: in vivo confocal microscopy (IVCM), and immunohistochemical staining of ex vivo donor corneas.MethodsSeven parameters of the SBP in large-scale IVCM mosaicking images from healthy subjects were compared with the identical parameters in ex vivo donor corneas stained by ß-III-tubulin immunohistochemistry. Corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), average weighted corneal nerve fiber tortuosity (CNFTo), corneal nerve connection points (CNCP), average corneal nerve single-fiber length (CNSFL), and average weighted corneal nerve fiber thickness (CNFTh) were calculated using a dedicated, published algorithm and compared.ResultsOur experiments showed significantly higher values for CNFL (50.2 vs 21.4 mm/mm2), CNFD (1358.8 vs 277.3 nerve fibers/mm2), CNBD (847.6 vs 163.5 branches/mm2), CNFTo (0.095 vs 0.081 µm-1), and CNCP (49.4 vs 21.6 connections/mm2) in histologically staining specimens compared with IVCM images. In contrast, CNSFL values were higher in IVCM images than in histological specimens (32.1 vs 74.1 µm). No significant difference was observed in CNFTh (2.22 vs 2.20 µm) between the two groups.ConclusionsThe results of this study have shown that IVCM has an inherently lower resolution compared with ex vivo immunohistochemical staining of the corneal SBP and that this limitation leads to a systematic underestimation of several SBP parameters. Despite this shortcoming, IVCM is a vital clinical tool for in vivo characterization, quantitative clinical imaging, and evaluation of the human corneal SBP.

[Magnetic Resonance Microscopy of the Accommodative Apparatus]. / Magnetresonanzmikroskopie des Akkommodationsapparats.

Magnetic resonance microscopy (MRM) at ultra-high magnetic fields allows acquisition of high resolution MR images in the micrometre range. The use of ultra-high magnetic fields opens the possibility of user-independent and artefact-free detailed characterisation of the anatomical tissue of the human eye, which is not achievable with classical imaging techniques. This article correlates MRM of the anterior eye segment and the accommodative apparatus at 9.4 Tesla with conventional histology.

Quantitative assessment of central and limbal epithelium after long-term wear of soft contact lenses and in patients with dry eyes: a pilot study.

PurposeAnalysis of microstructural alterations of corneal and limbal epithelial cells in healthy human corneas and in other ocular conditions.Patients and methodsUnilateral eyes of three groups of subjects include healthy volunteers (G1, n=5), contact lens wearers (G2, n=5), and patients with dry eyes (G3, n=5) were studied. Imaging of basal (BC) and intermediate (IC) epithelial cells from central cornea (CC), corneal limbus (CL) and scleral limbus (SL) was obtained by in vivo confocal microscopy (IVCM). An appropriate image analysis algorithm was used to quantify morphometric parameters including mean cell area, compactness, solidity, major and minor diameter, and maximum boundary distance.ResultsThe morphometric parameters of BC and IC demonstrated no significant differences (P>0.05) between groups. Comparison between three corneal locations (CC, CL, and SL) within the groups showed significant differences (P<0.05) with mean values of cell area, compactness, solidity, and major and minor diameter of BC that increase from CC to limbus. The BC were round and regular in the central cornea (P<0.05) compared with CL and SL.ConclusionsIVCM enables high-quality confocal images from central corneal and limbal epithelium. This quantitative study demonstrated morphological differences in the basal and intermediate epithelium between limbus and central cornea, and found no differences between contact lens wearers, dry eyes, and normal subjects.

[Diffusion Weighted Magnetic Resonance Imaging and its Application in Ophthalmology]. / Diffusionsgewichtete Magnetresonanztomografie und ihre potenziellen Anwendungsmöglichkeiten in der Ophthalmologie.

The value of diffusion-weighted magnet resonance imaging (DWI-MRI) has been demonstrated for an ever growing range of clinical indications. DWI is sensitive to the diffusion of water molecules and probes their random displacement within tissue. DWI provides both qualitative and quantitative information on tissue characteristics, e.g. tissue cellularity. This review provides an overview of diffusion-weighted imaging and its emerging applications in ophthalmology. The basic physics and technical foundations of DWI are introduced. The emerging applications of DWI are surveyed, particularly in diseases of the eye, orbit and optical nerve.

[Visual analysis for an early detection of diabetic neuropathy]. / Visuelle Analyse zur Früherkennung einer diabetischen Neuropathie.

Diabetic neuropathy is the most common long-term complication of diabetes mellitus. It comes along with significant nerve dysfunction, which is not reversible. Hence, it is essential to detect nerve fibre abnormalities as early as possible. In this paper, we investigate markers describing degradation of corneal nerves. We apply statistical computations and visual analysis to identify those variables of two clinical studies that separate DN patients from a control group. In this way, the diagnosis of DN patients is supported. The visual analysis is based on different representations visualizing both the statistical results and the gathered multi-variate data. The user can interactively manipulate the views, or select data that will be shown by further displays. In this way, the understanding of the data and its classification is supported. Ambiguous categorisations can be identified and grouped into a so-called "fuzzy group". For this group, further investigations are needed to decide about diabetic neuropathy.

[Current progress of the artificial accommodation system]. / Fortschritte des Künstlichen Akkommodationssystems.

In case of presbyopia or cataract the "artificial accommodation system" represents one future possibility to durably restore the ability to accommodate. The work presented describes recent progress in the development of the artificial accommodation system. Major advances were achieved in the fields of the actuator system for the active optics, the pupil near reflex sensor, the communication system, the power supply system as well as in system integration. Beside the technical advances, first trials were performed to implant the artificial accommodation system into animals. These trials showed that the new lens shaped design and the C-shaped haptics are beneficial for implantation and secure fixation of the implant inside the capsular bag.

[Optimisation of the visualisation technique for optical paths through intraocular lenses for characterisation of multifocal imaging properties of Fresnel-zone plates]. / Optimierung der Visualisierungstechnik für Strahlenverläufe durch Intraokularlinsen zur Charakterisierung multifokaler Abbildungseigenschaften von Fresnel-Zonenplatten.

The utilisation of the diffractive properties of Fresnel zone plates offers the possibility of intraocular lens designs with multiple foci. Such intraocular lenses can be manufactured by two-photon polymerisation (2PP). This paper explains the underlying concept and shows the principles for visualisation of the focus properties of such implants.

[Effect of pseudophacic mini-monovision as an option for independence of spectacles in everyday life]. / Der Effekt der pseudophaken Minimonovision als Option einer Brillenunabhängigkeit im Alltag.

BACKGROUND: Modern day patients who undergo bilateral cataract surgery expect to be spectacles-independent after surgery. The options that are available to attain this goal are pseudophakic monovision, implanting multifocal IOLs or alternatively accommodative IOLs. The aim of this study is to establish the suitability in daily life when attaining minor monovision, named hereafter mini-monovision. MATERIAL/METHODS: In this clinical retrospective study 30 patients were examined. These subjects where bilaterally pseudophake and received either AcrySof®-IOL or Acreos® Adapt-IOL with a slight anisometropia of between 0.5 and 1.75 D and with a maximal astigmatism up to 1.5 D. Visual acuity (VA) for distance (ETDRS), intermediate (Jaeger 80 cm) and near (Jaeger 40 cm) as well as defocus curves were assessed. Furthermore were examined: the reading speed using the font size of the Radner reading chart, anisoconia (FA Oculus according to Esser), stereopsis (Titmus), subjective patient satisfaction (adapted VF-14-questionnaire) and the subjective dependence on having to wear spectacles. RESULTS: The median anisometropia was at 0.75 D; the age was between 61 and 80 (median being at 73 years). 12 patients were male and 18 female. When examined with binocular vision 100 % could attain distance VA of at least decimal 1.0 (LogMAR 0) and an intermediate VA of at least decimal 0.8 (LogMAR 0.1), up to 86.57 % a near VA of at least Jaeger 5, (LogMAR 0.4); up to 63.33 % even managed at least Jaeger 3 (LogMAR 0.3). The median average reading speed for binocular uncorrected reading under photopic conditions was 145 words/minute and under mesopic conditions 117 words/minute. The critical font size was LogRAD 0.60 (Jaeger 5-6), the anisoconia at 2 % and stereopsis at 80 arc seconds. The general dependence on glasses was reduced from 100 % preoperatively to 13 %, postoperatively. Simultaneously a high patient satisfaction score of 93.18 in the VF-14 questionnaire was attained. The result is comparable to those quoted in the literature on full monovision and mulitifocal IOLs. CONCLUSION: To attain spectacles independency, pseudophake mini-monovision is a cost efficient alternative to multifocal lenses for well selected patients. A relative reduction in near VA must be taken into account. To establish the refractive target further examinations are required. Establishing the accurate depth of vision will be helpful in attaining this.

[Comparison of dysphotopsia effects in phakic and pseudophakic eyes using Rostock glare perimeter]. / Vergleich von Dysphotopsieeffekten bei phaken und pseudophaken Augen mit dem neuen Rostock Glare Perimeter.

BACKGROUND: Pseudophakic dysphotopsia as unwanted side effect after cataract surgery are becoming increasingly important. The so-called glare perimetry allows a realistic quantification of these phenomena. The article presents the method on the example of healthy subjects and pseudophakic patients. PATIENTS AND METHODS: Using glare perimetry phakic and pseudophakic subjects were examined for differences in disability glare. For this, data from 60 phakic persons of different ages (45 ± 17.1 years) were used. As pseudophakic subjects 31 carriers of monofocal lenses (70 ± 6.7 years) and 25 carriers of multifocal lenses (71 ± 8.5 years) were tested. RESULTS: Disability glare was significantly smaller in the phakic group (1.00 ± 0.336°) than in the pseudophakic group (1.56 ± 0.622°). Among the pseudophakic eyes those with a multifocal lens (1.69 ± 0.367°) were significantly more sensitive to glare than those with a monofocal lens (1.43 ± 0.492°). CONCLUSION: Glare perimetry allows an objective quantification of effects of dysphotopsia under realistic conditions. Pseudophakic eyes show a higher sensitivity to glare than eyes with the natural clear lens. Here, eyes with multifocal lenses prove to be particularly sensitive to glare.

[Characterisation of tear film dynamics after application of trehalose for treatment of dry eye]. / Charakterisierung der Tränenfilmdynamik am Beispiel einer Trehaloseapplikation zur Behandlung des Trockenen Auges.

The implementation of additional modalities for tear film break-up time characterisation expands the application range of the Oculus® Keratograph 5M. The aim of the present study was to evaluate the possibilities for non-invasive break-up time analysis using this device. Furthermore we applied the Oculus® Keratograph 5M to characterise possible modifications of tear break-up time after application of Thealoz® eye drops (Théa Pharma). The device allowed for a precise and solid topographical analysis of tear film dynamics. We could show that at four weeks after treatment, trehalose solution was a better treatment for dry eye compared with saline. These results are in agreement with our previous in vitro findings concerning the protective role of trehalose on desiccation-caused cell death in a corneal epithelial model.

[New concepts for pressure-controlled glaucoma implants]. / Neue Konzepte für druckgesteuerte Glaukomimplantate.

In industrialized countries glaucoma is one of the most common causes that leads to blindness. It is also the most common cause of irreversible blindness worldwide. In addition to local treatment of intraocular pressure and filtering glaucoma surgery, alloplastic implants are increasingly being used in glaucoma therapy. As long-term results published in the literature of commonly used implants are unsatisfactory, it seems useful to search for new concepts. In order to avoid the well-known short-term and long-term postoperative complications a pressure-controlled microstent with antiproliferative surface modifications was developed. Additionally, the functionality of such a microstent should be investigated using an animal glaucoma model. This paper describes the concept of a microstent which drains aquous humour from the anterior chamber into the suprachoroidal space. In addition, the glaucoma models described in the literature are discussed. Unfortunately, none of the methods could be reproduced permanently. First results show a correct implantation of a coated microstent with valve where the anti-proliferative effect could be demonstrated histologically. The promising results should lead to further investigations and the final goal will be the testing of the stent in the human eye.

[Development of oculoplastic surgery in Kinshasa (capital of Democratic Republic of Congo)]. / Entwicklung der okuloplastischen Chirurgie in Kinshasa (Hauptstadt der Demokratischen Republik Kongo).

The partnership between Saint Joseph Hospital in Kinshasa (Capital city of DRC) and University Eye Clinic Rostock, Germany exists since 2000. The ophthalmologists from Rostock University performed 12 visits of St. Josef Hospital with the aim to perform oculoplastic surgery in complicated cases as well as to teach the local ophthalmologists. There they performed about 150 surgeries (entropion, ectropion, ptosis, repair of lid injuries, eye lid reconstruction and tumour management, lacrimal surgery) in joint teams. The programme of on-site training was established during this time. Meanwhile, the Kinshasa colleagues are able to perform the basic techniques by themselves. Two colleagues have obtained advanced training in oculoplastics in Rostock. The fruitful cooperation enabled the development of oculoplastic surgery in St. Josef Hospital in Kinshasa. The further education and training proccesses will support the continuous advancement in ophthalmological health care in DRC.

[Pathological conditions of the ocular surface -- a clinical and confocal laser-scanning microscopy study]. / Oberflächenerkrankungen des Auges unterschiedlicher Genese - klinische und konfokalmikroskopische Untersuchungen.

Confocal in vivo laser scanning microscopy is an established technique to visualise morphology of the cornea and conjunctiva, whereby the image interpretation needs experience. We report about changes of the ocular surface in the pathological conditions of infectious, metabolic and traumatic genesis and discuss their relevance. The micromorphology of the corneal epithelium and stroma in respect to pathogens (bacterial, fungal) is discussed. Metabolic disease induces multifaceted corneal alterations which can be visualised and used for assessment of the disease progression. Follow-up microscopic investigations allow for an assessment of the wound healing dynamics and enable a prognosis to be made for corneal recurrence. Taken together, confocal in vivo microscopy allows a non-invasive microscopy on the cellular level and thus complements clinical diagnostics.

[Diabetic retinopathy and diabetic foot syndrome in patients of a sub-Saharan megacity (Kinshasa, DR Congo)]. / Diabetische Retinopathie und diabetisches Fußsyndrom bei Diabetikern in Kinshasa (Demokratische Republik Kongo).

PURPOSE: The prevalence of diabetes mellitus is increasing worldwide especially in developing countries. Foot ulcerations in patients with diabetic neuropathy have a high impact in the overall amputation rate. In the present study we looked for the severity of diabetic retinopathy in patients with diabetic foot syndrome in a diabetic care unit in a sub-Sahara megacity (Kinshasa, Democratic Republic of Congo). METHOD: Forty-one patients with diabetes-related foot ulcerations (26 male, 15 female, mean age 45.6 years) were enrolled in the study. All patients underwent visual acuity evaluation and slit lamp biomicroscopy. Incidence and stage of retinopathy were evaluated by retinal funduscopy and documented by fundus photography. RESULTS: Twenty-seven eyes showed no signs of diabetic retinopathy. Forty-seven eyes were diagnosed as non-proliferative diabetic retinopathy (16 mild, 16 moderate, 15 severe). Seven eyes showed proliferative diabetic retinopathy. One patient had a unilateral central venous occlusion. In this case the classification of diabetic retinopathy was not possible because of the massive retinal bleedings. CONCLUSION: It was evident that there is a considerable discrepancy between partly extensive foot ulcerations and only mild to moderate diabetic retinopathy in most of the patients. This indicates that neuropathy-induced foot problems and microangiopathy-induced diabetic retinopathy are diabetic complications whose formal pathogenesis is only loosely correlated. Additional risk factors in local African conditions compared to Europe may play a major role in this discrepancy.