Predictability of success and open conjunctival revision rates in the subsequent eye after XEN45 Gel Stent implantation according to lens status.

PURPOSE: To determine the predictability of success and the risk of open conjunctival revision in the subsequent eye after XEN45 Gel Stent implantation according to lens status. METHODS: This was a retrospective single-centre study involving 132 eyes of 66 participants who had undergone intraocular pressure (IOP)-lowering XEN45 Gel Stent implantation, either as a standalone procedure in phakic and pseudophakic eyes or in combination with phacoemulsification. Successful surgery was defined by three scores: IOP at follow-up < 21 mmHg (score A) or < 18 mmHg (score B) and an IOP reduction > 20% or IOP ≤ 15 mmHg and an IOP reduction ≥ 40% (score C). In all scores, one open conjunctival revision was allowed, and additional repeat surgery was considered a failure. The predictability of success and revision rate depending on the outcome of the first eye were calculated using Bayes' theorem. RESULTS: IOP-lowering did not differ significantly between the first and second eyes. Success rates of standalone surgery in the second eye after successful surgery in the first eye significantly exceed rates after prior failure. For the combined procedure, the rates did not differ significantly. For score A, we determined a 76.6% chance of success following a prior success and a 57.9% chance, if prior surgery failed. The corresponding probabilities were 75% and 59.1% for score B, while 66.7% and 15.7% for score C, respectively. We calculated a 60% risk for revision surgery in the standalone phakic group. If the first eye was not revised, the risk of revision in the subsequent eye was 20%. The corresponding risks were 72.7% and 5% for the standalone procedure in pseudophakic patients and 38.4% and 41.7% for the combined procedure, respectively. CONCLUSION: The results of our study offer a tool to predict the outcome of subsequent eye surgeries based on either the outcome in the initial eye and the type of surgery performed, owing to the high predictive potential.

Impact of failed ab-interno trabeculectomy (trabectome) on subsequent XEN45 gel stent implantation in pseudophakic eyes.

PURPOSE: To determine the impact of failed ab-interno trabeculectomy on the postoperative outcome of subsequent XEN45 gel stent (Allergan, CA, USA) implantation in pseudophakic eyes. METHODS: In this retrospective single-center study, we included 60 pseudophakic eyes from 60 participants who underwent XEN45 gel stent implantation. Thirty eyes each underwent primary stent implantation (control group) or had previously undergone a failed ab-interno trabeculectomy (trabectome group). The groups were matched at a 1:1 ratio based on the following criteria: preoperative and maximum Intraocular pressure (IOP), preoperative medication score, cup/disk-ratio, follow-up time, best-corrected visual acuity at baseline, age, and the proportion of patients classified as primary open angle glaucoma or exfoliation glaucoma. We defined a successful surgery by the following three scores: an IOP reduction > 20% and IOP at the longest follow-up < 21 mmHg (Score A) or < 18 mmHg (Score B) or IOP ≤ 15 mmHg and an IOP reduction ≥ 40% (Score C). One open conjunctival revision was allowed in all scores, and a repeat surgery was considered a failure. RESULTS: Following an average follow-up period of 22 ± 12 months, we observed a mean IOP reduction of 38%, from 23.5 ± 5.2-14.5 ± 5.0 mmHg. Comparative analyses between the groups did not reveal a significant difference in the postoperative IOP, postoperative medication score, side effects, revision rate, repeat surgery rate, or success rate. CONCLUSIONS: Trabectome is a viable first-line procedure for medically uncontrolled glaucoma before filtering ab-interno microstent surgery is considered.

The effect of additional trabecular aspiration to phacoemulsification and trabectome as a triple procedure in pseudoexfoliation glaucoma: a case-matched study.

BACKGROUND: Trabectome surgery combined with phacoemulsification is effective in lowering (intraocular pressure) IOP in pseudoexfoliation glaucoma. Trabectome surgery usually aims to remove two to four clock hours of the trabecular meshwork. When adding trabecular aspiration, the remaining meshwork can be treated as well, and therefore 360 degrees of the meshwork can be reached. This study was conducted to investigate the additional benefits and risks of adding trabecular aspiration to the combination of phacoemulsification and trabectome as a triple procedure. METHODS: Two groups of patients from two centres were compared. The first group underwent phacoemulsification and trabectome (Freiburg), and the second group underwent additional trabecular aspiration (Düsseldorf). Using a case-matched retrospective study design, 50 patients were included into each group. The clinical endpoint was the intraocular pressure at follow up. RESULTS: The mean follow up was 22 months. Mean intraocular pressure decreased in all 100 patients from 25.0 (SD 4.3) to 14.9 mmHg (SD 4.0). Comparing the two groups, the IOP reduction was from 25.0 (SD 5.0) to 14.1 (SD 4.4) mmHg in the triple procedure group compared to a reduction from 25.0 (3.6) to 15.7 (SD 3.4) mmHg in the phaco/trabectome group. The difference was statistically significant (p = 0.03). The number of medication after surgery was reduced from 2.2 (SD 0.9) to 1.7 (SD 0.9) while in the phaco/trabectome group the medication score was reduced from 2.2 (SD 1.0) to 1.1 (SD 0.1) (p < 0.001). CONCLUSIONS: This study shows that the combination of trabectome surgery and phacoemulsification leads to a clinically significant reduction of IOP over several years in patients with pseudoexfoliation glaucoma. The addition of trabecular aspiration as a triple procedure results in further lowering of IOP without causing more side effects. This finding might be biased by the higher medication score in the triple procedure group.

[Clinical Results after Implantation of Epiretinal Visual Prostheses]. / Klinische Ergebnisse epiretinaler Sehprothesen.

Epiretinal visual prostheses have already been implanted in blind retinitis pigmentosa (RP) patients. Here we report on clinical experience with the Argus® II device and the EPIRET 3 device, on the basis of data from patients operated in Germany. Twenty-eight patients were implanted with the Argus II device and followed for up to three years. EPIRET 3 was implanted in six patients for a period of four weeks. With Argus II, an improvement in visual performance was achieved in the majority of cases, as demonstrated by improved localisation of a light spot and a better perception of moving targets. Mobility and self-confidence improved. The main complications were conjunctival erosion due to the combined extra- and intraocular concept of the device. Among the 28 implanted systems, two needed to be removed because complications refractive to treatment. In contrast, EPIRET 3 is a fully intraocular epiretinal system. During a four week implantation, period thresholds were recorded and exhibited high variability between subjects. However, patients were able to recognise simple patterns. Epiretinal implants for electrical stimulation of the retina should be considered to treat advanced photoreceptor degeneration, and thus to restore basic visual functions at an acceptable rate of complications.

[Trabeculotomy Combined with Cataract Surgery in Glaucoma: Outcome in a Rural Setting]. / Trabekulotomie kombiniert mit Phakoemulsifikation als operative Glaukomtherapie: Ergebnisse im ländlichen Versorgungsbereich.

Purpose: Intensive postoperative care is essential for the outcome of trabeculectomy. However, in a rural setting, repeated visits to the operating theatre are often not requested or possible. The objective of this study was to examine the outcome of trabeculotomy combined with cataract surgery in patients with glaucoma. Patients and Methods: 142 patients with glaucoma and cataract were included in a retrospective clinical study. All patients were operated on from November 2005 to December 2008 by a single surgeon and with a minimum follow-up of 2 months. Intraocular pressure (IOP), number of antiglaucomatous medications and surgical success rate were assessed at 2 months and at the longest follow-up (at least 1 year). Results: IOP was significantly reduced from 24.1 ± 8.3 mmHg preoperatively to 14.9 ± 3.3 mmHg at 2 months (p < 0.0001) and to 15.1 ± 3 mmHg at the longest follow-up (3.71 ± 1.5 years). The number of IOP-lowering medications was lowered from 1.35 ± 1 preoperatively to 0.73 ± 1 at the longest follow-up. Complete surgical success (no IOP-lowering medications, longest follow-up) was achieved in 51.3 % (IOP < 22 mmHg) and 47.5 % (IOP < 19 mmHg) of patients, respectively. Conclusions: Trabeculotomy combined with cataract surgery is a safe and effective surgical option to treat combined cataract and glaucoma without the need of intensified postoperative treatment.

[The Influence of Intravitreal Injections on Outpatient Cataract Operations in Germany]. / Der Einfluss der intravitrealen Injektionen auf die ambulante Intraokularchirurgie in Deutschland.

PURPOSE: The number of outpatient operations in Germany is not registered in a centralised manner. To estimate the development of the outpatient intraocular surgery especially since the implementation of the intravitreal injections, surveys among ophthalmic surgeons were analysed. METHODS: Between 2006 and 2013 surveys were done among ophthalmic surgeons in Germany using questionnaires. An average of 318 completed questionnaires were sent back. The mean participation ratio was 37 %. RESULTS: Between 2006 and 2013 an extrapolated mean of 347 564 cataract operations and 139 946 intravitreal injections were reported. Whereas the number of cataract operations was constant in the observation period, the number of injections increased considerably from 35 135 in 2006 to 274 714 in 2013. CONCLUSION: A saturation in the development of the numbers of the intravitreal injections could not yet be observed. Other outpatient operations, especially cataract procedures were not replaced by the increase of the injections in the recent years.

Towards the bionic eye--the retina implant: surgical, opthalmological and histopathological perspectives.

Degenerations of the outer retina such as retinitis pigmentosa (RP) lead to blindness due to photoreceptor loss. There is a secondary loss of inner retinal cells but significant numbers of bipolar and ganglion cells remain intact for many years. Currently, no therapeutic option to restore vision in these blind subjects is available. Short-term pattern electrical stimulation of the retina using implanted electrode arrays in subjects blind from RP showed that ambulatory vision and limited character recognition are possible. To produce artificial vision by electrical retinal stimulation, a wireless intraocular visual prosthesis was developed. Images of the environment, taken by a camera are pre-processed by an external visual encoder. The stimulus patterns are transmitted to the implanted device wirelessly and electrical impulses are released by microcontact electrodes onto the retinal surface. Towards a human application, the biocompatibility of the utilised materials and the feasibility of the surgical implantation procedure were stated. In acute stimulation tests, thresholds were determined and proved to be within a safe range. The local and retinotopic activation of the visual cortex measured by optical imaging of intrinsic signals was demonstrated upon electrical retinal stimulation with a completely wireless and remotely controlled retinal implant. Potential obstacles are reviewed and further steps towards a successful prosthesis development are discussed.

Effect of physical activity on human potassium metabolism in a hot and humid environment.

Previous investigations have suggested that there are high potassium losses during heavy physical activities in hot climates. In order to determine if high levels of potassium losses could be offset by potassium loading, this study was conducted with five long-distance track runners who had trained in hot and humid environments. The liquid supplements containing 4.3, 98.0, and 0.0 mEq/liter of potassium were given 1 to 2 hr before physical activity. The daily diet contained 2.6 g of potassium. A sodium and potassium balance study was conducted in which stool, urine, and dermal losses were measured. In order to determine if there was a change in the distribution of body potassium during physical exercise, seven subjects total body potassium was estimated before and after exercise. This measurement was performed by counting 40K in a whole body counter. Although the subjects with potassium supplementation and higher urinary sodium and potassium losses, the 98 mEq/liter of potassium supplement resulted in a positive potassium balance. The subjects' potassium requirements exceeded the National Research Council suggested dietary intake. The total body potassium measurements indicated that the counting efficiency of 40K increases significantly immediately after the period of vigorous exercise.

Effects of chemotherapy (busulfan-hydroxyurea) and interferon-alfa on bone marrow morphologic features in chronic myelogenous leukemia. Histochemical and morphometric study on sequential trephine biopsy specimens with special emphasis on dynamic features.

We performed a retrospective clinicopathologic study on sequential biopsy specimens from 90 patients with Philadelphia chromosome-positive chronic myelogenous leukemia to study therapy-specific effects of busulfan (28 patients), hydroxyurea (32 patients), and interferon-alfa (IFN-alfa; 30 patients). Bone marrow specimens were evaluated by morphometry after silver impregnation and staining with monoclonal antibodies to identify reticulin fibers, nucleated erythroid precursors, megakaryocytes, and macrophages. To compute dynamics of histopathology implicating corresponding changes in time, relevant indices were calculated. Quantification of megakaryocytopoiesis and its precursor cell population showed a significant increase in the IFN-alfa and busulfan groups compared with the hydroxyurea group. These changes were associated with a development of myelofibrosis during therapy. Although a significant increase in fiber density was detectable in the busulfan group, the progression index proved to be twice as high after IFN-alfa therapy. In contrast, a considerable number of patients displayed a regression of myelofibrosis after hydroxyurea treatment. The general association of the megakaryocyte lineage with myelofibrosis was in line with experimental findings. The mature macrophage population and its activated subfraction revealed a marked proliferation (IFN-alfa group) during treatment. Growth and activation of macrophages may be compatible with their putative function during erythrocytopoietic regeneration and with stimulation of their phagocytic properties.

Iron studies in hemophilia.

Although iron deficiency is not recognized as a usual complication of hemophilia, we questioned whether intermittent occult loss of blood in urine or stool might predispose hemophiliacs to chronic iron deficiency. Seven men with factor VII and one with factor IX deficiency were studied. Blood studied, bone marrow aspirates, urine and stool samples, and ferrokinetics with total-body counting up to five months were examined. These data showed no excessive loss of blood during the study period; however, marrow iron stores were decidedly decreased, being absent in four subjects. We suggest that in some hemophiliacs, iron deposits in tissues such as synovial membranes may form a high proportion of the body's total iron stores.

Determination of uranium and thorium concentrations in unprocessed soil samples.

An assay technique that directly determines the amount of 238U and 232Th in unprocessed, bulk soil samples has been developed. In this technique, a sample consisting of a 125-mL plastic bottle full of contaminated, moist, unprocessed soil is irradiated with gamma rays from 57Co. Induced U and Th K alpha fluorescent x rays are detected using a high-purity intrinsic germanium planar detector. Because of sample irradiation geometry, the fluorescent x-ray peaks lie on top of a large Compton backscatter peak. Spectral data are first fit to a combination polynomial and ERFc-step-function background that is subtracted from the peak data. The remaining peak data are fit to a Voigt Profile to properly determine peak area. The Voigt Profile, which is the convolution of the Gaussian response of the detector system and the Lorentzian energy distribution of x rays, describes the spectral peak better than a simple Gaussian distribution. A mathematical point-node model of the source-target-detector system, which includes fluorescent x-ray production by singly scattered Compton gamma s, calculates the predicted x-ray peak area per Bq cm-3 of target contamination. Soil attenuation coefficients, which are measured for each sample, are used by the model to properly transport gamma s and x rays through the soil sample. The sample 238U and 232Th concentrations are then calculated by dividing the measured peak areas by the model-predicted peak areas per Bq cm-3. No "soil standards," no assumptions about progeny equilibrium, and no sample preparation are required for this technique.

Indoor radon progeny exposure in the Florida phosphate mining region: a review.

This paper reviews the data generated in studies of land radioactivity and indoor airborne radon progeny associated with mined and reclaimed phosphate lands in Florida. Highest indoor radon progeny levels are associated with the slab-on-grade type of construction. Concentrations exceeding 0.03 WL are associated with overburden soils, deposits and fill, while concentrations up to about 0.03 WL are associated with tailings. The lower limit for distinguishing increases above non-enhanced natural concentrations is on the order of 0.01-0.02 WL. Results of this study show that about 25% of the land produced by present methods of mining and reclamation practices would require restrictions on the type of construction or would require special construction methods. It is projected that with modification of mining and tailings disposal practices, virtually all of the land produced by mining and reclamation would be satisfactory for unrestricted construction use.

Application of a canine 238Pu biokinetics/dosimetry model to human bioassay data.

Associated with the use of 238Pu in thermoelectric power sources for space probes is the potential for human exposure, primarily by inhalation and most likely as 238PuO2. Several models have been developed for assessing the level of intake and predicting the resulting radiation dose following human exposure to 239Pu. However, there are indications that existing models do not adequately describe the disposition and dosimetry of 238Pu following human exposure. In this study, a canine model that accounts for these differences has been adapted for use with human excretion data. The model is based on existing knowledge about organ retention of plutonium. An analysis of the sensitivity of the model to changes in aerosol-associated properties indicated that predictions of urinary excretion are most sensitive to changes in particle solubility and diameter and in the ratio of fragment:particle surface area. Application of the model to urinary excretion data from seven workers exposed to a 238Pu ceramic aerosol gave estimated intakes of 390-8,200 Bq and associated initial pulmonary burdens of 80-1,700 Bq. The resulting 50-y dose commitments to critical organs per Bq of 238Pu intake were estimated to be 0.5 mSv for the thoracic region, 0.2 mSv for the liver, and 1 mSv for the bone surfaces.

Nursing in the People's Republic of China.

In June, 1994 Dr. Grayce Roessler led a group of nurses to China to attend and present at international nursing conferences in Beijing and Shanghai. Dr. Roessler, an internationally known transcultural nursing leader, has traveled extensively in China (some 36 trips over 20 years). Her first trip to China, focused on nursing, took place in the fall of 1981 as a member of the American Nurses Association (ANA). The ANA group was invited to China by the Chinese government and the Chinese Nurses Association (CNA). Subsequent to that visit, she became involved in working with the Chinese Ministry of Health, the Chinese Nurses Association, and several of the CNAs in various cities throughout China. In an effort to assist in the preparation of Chinese nurses as teachers and administrators in the evolving health care system, Dr. Roessler facilitated a one year (1985-86) study program in the United States (Golden West College, Huntington Beach, California) for a group of 20 Chinese nurses. It was the first time in history that a number of Chinese nurses had studied at one institution with American nurses in the United States. Dr. Roessler has since coordinated several international conferences in China and arranged for American nurse experts in various fields to present at these meetings. In addition, she has traveled independently as a teacher and consultant and has taken numerous nursing study tour groups to many countries as part of continuing educational experiences. In this issue of the Journal of Transcultural Nursing, Dr. Roessler presents her reflections on nursing in China from a historical and transcultural nursing leader's perspective.

The retina implant--new approach to a visual prosthesis.

Currently, no treatment is available for degenerative diseases of retinal photoreceptors. The patients are faced with a high risk of blindness. Biological approaches failed to prove efficacy. A new concept for the treatment of disorders like retinitis pigmentosa is electrical stimulation at various levels of the visual system. Therefore, devices were fabricated with stimulating electrodes contacting retinal or central neurons to elicit biological activity in these cells. It became possible to fabricate even complex devices with an external power supply encapsulated within biocompatible materials. Animal experiments showed that with implanted prototypes cortical activation could be achieved and first experiments in blind human subject also suggest that vision can be restored, however at present in a very low range of simply identifying spots of light. Further developments and also the continuation of animal experiments are necessary before the clinical application will become a standard procedure.

Development of a very large array for retinal stimulation.

Retina degeneration is one of the leading causes of blindness nowadays and cannot be cured in most cases. It has been shown that electrical stimulation of retinal ganglion cells can generate visual perceptions and therefore implantable electrode arrays can be possible treatment for these patients. Most implants developed for that purpose use electrode arrays with a size of a few millimeters squared and therefore could restore only a very small field of vision and hardly improve orientation in an unknown environment. In this paper we present results of the development of an implantable electrode array covering about 100 mm(2) of retinal tissue.

Implantation and explantation of an active epiretinal visual prosthesis: 2-year follow-up data from the EPIRET3 prospective clinical trial.

PURPOSE: The EPIRET3 retinal prosthesis was implanted in six volunteers legally blind from retinitis pigmentosa (RP) and removed after 4 weeks. Two years later, these subjects were re-examined to investigate ocular side effects and potential changes to quality of life. METHODS: Vision-related quality of life was recorded using the NEI-VFQ-25 questionnaire. Clinical data including interval history, visual acuity, and intraocular pressure were obtained. Anterior and posterior segments of the study eyes were examined and photographed; this included fluorescein angiography and optical coherence tomography (OCT). RESULTS: Data from five patients could be analysed. Life-quality score was consistent with results obtained at baseline. No unexpected structural alteration could be found in the study eyes. A moderate epiretinal gliosis was present in areas where the epiretinal stimulator had been fixated using retinal tacks. Angiography revealed no leakage or neovascularisation; OCT showed no generalised increase of central retinal thickness. CONCLUSIONS: Vision-related quality of life is low in patients suffering from end-stage RP. No further deterioration of life quality could however be detected within our monitoring period. Surgery was well tolerated by both patients and their eyes, without adverse events occurring during the follow-up period. Epiretinal gliosis is known to occur with retinal tacks, but seems of no major concern to the integrity of the study eyes. However, it may potentially interfere with functional aspects of active implants. Hence, alternative, possibly biochemical, fixation methods merit further research.