[Work sampling in ophthalmological clinical studies. A multicenter field study]. / Zeiterfassung in ophthalmologischen klinischen Studien. Eine multizentrische Feldstudie.

BACKGROUND: Work in clinical studies is generally more elaborate and therefore more time-consuming in comparison to the clinical routine. The purpose of this study was to systematically investigate the time consumption in the German ophthalmological clinical trial centers. METHODS: The members of the working group of the German Ophthalmology Society clinical study centers (Arbeitsgemeinschaft DOG Klinische Studienzentren) were asked to fill in three questionnaires about best estimations for the time spent on study-related procedures and administration. Additionally, work sampling was performed for each employee at each study center over a period of 3 weeks. RESULTS: The questionnaires were completed by 9 of the 11 centers. Overall, 5504 working hours were recorded. On an average working day, the time spent for both documentation and administration averaged 4 h each. Operative interventions consumed a significant amount of time (2.8 h), as did ophthalmological examinations (2.5 h) and obtaining informed consent (1.5 h). The recorded time consumption for visual acuity testing, informed consent and documentation was well aligned with the best estimates of the three questionnaires. By contrast, interventions, ophthalmological examinations and biomaterial sample handling were underrated in the best estimations. DISCUSSION: A considerable amount of time in clinical studies is spent on documentation and administration. From work sampling, ophthalmological examinations and biomaterial sampling turned out to be surprisingly time consuming. This is probably due to preparation and postprocessing tasks. It is important to consider this when calculating the overall costs of a clinical study. In addition, many administrative activities cannot be attributed to specific patients and can therefore not be compensated on the basis of case payments alone. Additional remuneration is required to fully cover the costs in an ophthalmological study center.

[Acute bilateral impaired vision with central scotoma in an 11-year-old boy]. / Akute bilaterale Visusminderung mit Zentralskotom bei einem 11-jährigen Jungen.

This article presents a case of acute bilateral impaired vision and central scotoma in an 11-year-old boy. Looking directly into a laser beam of a laser pointer for only a few seconds can cause retinal damage in the form of lesions of the retinal pigment epithelium and the photoreceptor layer, up to retinal hemorrhage. Patients often complain about impaired vision and a central scotoma of the affected eye.

[Ocular signs of a mitochondrial trifunctional protein defect. A long-term follow-up]. / Okuläre Zeichen eines mitochondrialen trifunktionalen Proteindefekts. Eine Langzeitbeobachtung.

A 13-year-old boy presented with a defect of the mitochondrial trifunctional protein (MTP). The MTP complex catalyses ß-oxidation of long chain fatty acids. Disorders of this multienzyme complex result in accumulation of hydroxylated long chain fatty acids which leads to chorioretinopathy. Ophthalmoscopic findings in these patients include fine hyperpigmentation while autofluorescence reveals hyperfluorescent granules at the posterior pole. Visual acuity, visual fields and electroretinography are within the normal range. A special long chain fatty acid-reduced diet seems to delay the progression of chorioretinopathy.

[Effect of intravitreal bevacizumab on pigment epithelial detachment in occult choroidal neovascularization]. / Effekt von Bevacizumab auf die Abhebung des retinalen Pigmentepithels bei okkulter choroidaler Neovaskularisation.

PURPOSE: This study aimed to investigate the effect of bevacizumab on pigment epithelial detachment (PED) in occult choroidal neovascularization (CNV) in patients with age-related macular degeneration (AMD) and to determine predictive factors. METHODS: 73 eyes of patients with AMD and PED due to CNV with subretinal and/or intraretinal fluid were assessed. Patients were treated with 1.25 mg of intravitreal bevacizumab. RESULTS: After 30.6 weeks, the mean visual acuity (VA) increased from 0.53 to 0.49 logMAR (p=0.170). The mean PED height decreased from 354.4 µm to 277.4 µm (p=0.004). Although 53.4% of the eyes showed a reduction in PED, this did not correlate with a significant change in VA. Predictive factors were a high baseline PED and VA <0.32. CONCLUSION: Half of the patients showed PED flattening. Especially in patients with distinctive PED, a response to intravitreal bevacizumab may be expected. This therapy can stabilize VA, but PED flattening does not essentially correlate with an increase in VA.

[High-resolution fluorescence microscopy of retinal pigment epithelium using structured illumination]. / Hochauflösende Fluoreszenzmikroskopie des retinalen Pigmentepithels mittels strukturierter Beleuchtung.

BACKGROUND: The accumulation of autofluorescent bodies in retinal pigment epithelium (RPE) cells has an impact on the pathogenesis of retinal diseases, including age-related macular degeneration. While current in vivo fluorescence microscopy allows a lateral resolution of fluorophores in a micrometer range, with ex vivo microscopy a lateral resolution down to 200 nm is possible. For the first time, we used structured illumination microscopy for ex vivo high-resolution fluorescence microscopy of RPE cells. METHODS: Histological sections were prepared from a 68-year-old patient. With epifluorescence microscopy, fluorescent RPE cells were detectable. Structured illumination uses inhomogeneous illumination for resolution of previously nonresolvable structures, similar to the Moiré effect. Images were taken from RPE cells at different excitation wavelengths (488, 568, and 647 nm) and were reconstructed with special software. The different excitation patterns of the fluorescent granules in the RPE cells were colour-coded and analysed. RESULTS: With structured illumination microscopy, autofluorescence signals of RPE cells were detectable, and a lateral resolution of 110 nm could be achieved. Using varying wavelengths, different pigments were excitable. Lipofuscin gave the highest signals, at 488 and 568 nm. The improved resolution showed inhomogeneous intragranular fluorophore patterns. CONCLUSION: Structured illumination microscopy enabled us to generate images of fluorescent structures in RPE cells ex vivo with a lateral resolution of 110 nm. With the use of different excitation wavelengths, intracellular fluorescence patterns in single cell compartments are visible and allow further differentiation.

[Primary intrastromal iris cysts]. / Primäre stromale Iriszysten.

BACKGROUND: Cysts of the iris are uncommon and most of them occur secondarily after surgery or penetrating injury. The minority of the iris cysts is primary without a reasonable cause. They are classified into the more common pigment epithelial cysts and the rare cysts of iris stroma ("intrastromal cysts"). These intrastromal iris cysts are generally diagnosed in children and often cause symptoms such as a decrease of visual acuity because of ingrowth into the optical axis. A diagnosis of stromal cysts in adults is very rare. Most of these patients remain without any symptoms and do not need treatment. The cellular origin is so far unknown. Mesoderm, neuroectoderm and surface ectoderm have been discussed in this context. CASE REPORTS: Two patients with primary intrastromal iris cysts are presented, a 5-year-old boy and a 65-year-old woman. In both cases, the cyst affected the optical axis and was removed by sector iridectomy. In histological and electron-microscopic examinations both cysts presented a typical epithelial structure. Immunohistochemical examination revealed positivity for epithelial markers and negativity for mesenchymal and neuroectodermal markers. CONCLUSION: Primary intrastromal iris cysts can occur in advanced age and may cause symptoms due to progressive growth. The cellular origin of primary intrastromal iris cysts is controversially discussed in the literature. On electron microscopy and immunohistochemistry, the iris cysts presented here showed characteristic features of surface ectodermal origin.

Treatment of peripapillary choroidal neovascularization with intravitreal bevacizumab.

PURPOSE: Peripapillary choroidal neovascularization (CNV) is an uncommon condition and often shows a growth tendency towards the fovea during spontaneous progression that threatens visual acuity. Treatment of peripapillary CNV is difficult. The authors report results of intravitreal bevacizumab therapy for peripapillary CNV. METHODS: Four patients with CNV located in the temporal or superior peripapillary area received intravitreal bevacizumab injections. Ophthalmologic examinations including OCT were performed at baseline and at 6-week intervals. Fluorescein angiography was performed at baseline and depending on clinical and OCT findings. The mean follow-up was 34+/-20 (22-69) weeks. RESULTS: The patients received an average of 3.5+/-3.1 (1-8) injections. In all patients fluorescein angiography showed inactivation of peripapillary CNV. No further increase in size was observed in any of the patients. The OCT showed a decrease of intraretinal and subretinal fluid. No intraocular or systemic side effects were observed. CONCLUSIONS: In this series of patients, intravitreal bevacizumab appears to be efficacious. A progression of peripapillary CNV could be prevented in all patients and the lesion was successfully inactivated. Anti-VEGF treatment with bevacizumab represents a promising therapy option for peripapillary CNV.

[Light exposition in vitreoretinal surgery. I. Basics]. / Lichtexposition bei vitreoretinaler Chirurgie. I. Grundlagen.

Due to its function of light perception, the eye is exposed to high levels of radiation of the optical spectrum. Most of the ultraviolet and infrared radiation is absorbed in the cornea and lens, and mostly only radiation of the visible spectrum can reach the retina. Visible light can cause retinal damage by photomechanical, photothermal, and photochemical mechanisms. The most important mechanism of light damage to the retina under daily conditions or when using ophthalmologic light sources is the photochemical light toxicity caused by light-induced chemical reactions. The extent of damage depends on several factors, such as wavelength, exposure time, and irradiance. Particularly the shorter portion of the visible light spectrum (blue light) is responsible for photochemical damage to the retina.

[Exposure to light during vitreoretinal surgery. II: Characteristics of endoilluminators]. / Lichtexposition bei vitreoretinaler Chirurgie. II. Physikalische Charakteristika von Endoilluminationssystemen.

PURPOSE: Light can cause phototoxic retinal damage. The aim of this study was to evaluate the risk of retinal hazard by endoilluminators during vitreoretinal surgery. METHODS: The spectra, radiance, and irradiance of six light sources with different associated fibre optics (20 G, 23 G, standard collimated, wide-angle diffuse) were measured and compared with thresholds published by international standardisation committees. RESULTS: The spectra of the endoilluminators differed significantly in the short wavelength band. The maximum radiance ranged from 15 mW to 190 mW and the calculated irradiance from 36 mW/cm2 to 1,130 mW/cm2 (distance 5 mm) and from 9 mW/cm2 to 376 mW/cm2 (distance 10 mm). Compared with published thresholds for surgery, time limits ranging from 0.7 min to 264 min (distance 5 mm) and 2.7 min to 1,052 min (distance 10 mm) seem to be safe. CONCLUSIONS: Light systems used for vitreoretinal surgery differ considerably in spectra, radiance, and irradiance; these differences have an impact on the maximum tolerable exposure times during surgery.

[Endothelial dysfunction of central retinal vessels: a prognostic parameter for diabetic retinopathy?]. / Endotheliale Dysfunktion zentraler Netzhautgefässe als Prognoseparameter der diabetischen Retinopathie?

BACKGROUND: Endothelial dysfunction as a possible prognostic parameter seems to play a role in the course of diabetic retinopathy. Flicker-induced endothelial NO release may be used as an indicator for endothelial functionality of the central retinal vessels. METHODS: Flicker-induced arterial vasodilation as well as complete internal medicine status were determined in 65 type 1 and 170 type 2 diabetics. Diabetic retinopathy was classified according ETDRS criteria. Furthermore, a group of 55 healthy subjects was used as control group. RESULTS: Diabetic subjects showed with 2.1+/-2.2 (type 1) and 2.2+/-2.4 (type 2) a significantly decreased percent arterial vasodilation in comparison to healthy subjects (3.6+/-2.1; p

[Subjective sensations after intravitreal injection of bevacizumab]. / Subjektives Empfinden nach intravitrealer Bevacizumab-Injektion.

BACKGROUND: The group of anti-VEGF drugs is a new option for ophthalmologists in the therapy for acute and chronic macular oedema. First studies have revealed a stabilisation and increase of best corrected visual acuity as well as a decrease of retinal thickness, objectively measured with optical coherence tomography. The effects on subjective sensations are not always correlated with the objective changes. PATIENTS AND METHODS: From May to July 2006, 43 patients were treated with 1.25 mg bevacizumab, administered by sterile intravitreal injection. 30 patients had an age-related macular degeneration, 9 patients a diabetic retinopathy with macular oedema, 3 patients had a chronic macular oedema caused by retinal vessel occlusion and one patient had a retinal pigment detachment. The age ranged from 45 to 84 years (median: 70 years). General and special ophthalmological anamnesis, best corrected visual acuity and retinal thickness measured by optical coherence tomography were taken. Complete follow-up examinations were performed four and eight weeks after injections. In these postoperative controls the patients were also asked about their subjective sensations after the injection of bevacizumab, controlled by means of a numerical rating scale. RESULTS: The best corrected visual acuity (ETDRS) decreased from 9.2 letters (range from 0 to 40) to 13.1 letters (range from 0 to 42; p < 0.05) after four weeks, further four weeks later to 15.8 letters (range from 0 to 44; p < 0.05). The subjective sensations increased significantly at four weeks (0.54 points; range from - 1 to + 3; p < 0.05) and at eight weeks light regression (0.28 points; range from - 3 to + 3; p < 0.05). All patients reported a brightening "dark central blot". The available metamorphopsias improved at four weeks (18 patients), and at eight weeks 5 patients reported improvement. For none of ther patients did the metamorphopsia disappear completely. CONCLUSIONS: The intravitreal injection of bevacizumab shows beneficial results in terms of an increase of best corrected visual acuity. However, on comparing these results with the subjective sensations after injections there is a discrepancy. The subjective sensations are found to be only slightly better. More investigations, also after repeated injections are necessary.