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Provisioning services from grassland ecosystems are strongly linked to physical and chemical grassland traits, which are affected by atmospheric CO2 concentrations ([CO2]s). The influences of increased [CO2]s ([eCO2]s) are typically investigated in Free Air Carbon dioxide Enrichment (FACE) studies via destructive sampling methods. This traditional approach is restricted to sampling plots and harvest dates, while hyperspectral approaches provide new opportunities as they are rapid, non-destructive and cost-effective. They further allow a high temporal resolution including spatially explicit information. In this study we investigated the hyperspectral predictability of 14 grassland traits linked to forage quality and quantity within a FACE experiment in central Germany with three plots under ambient atmospheric [CO2]s, and three plots at [eCO2]s (∼20% above ambient [CO2]s). We analysed the suitability of various normalisation and feature selection techniques to link comprehensive laboratory analyses with two years of hyperspectral measurements (spectral range 600–1600 nm). We applied partial least squares regression and found good to excellent predictive performances (0.49 ≤ leave one out cross-validation R2≤ 0.94), which depended on the normalisation method applied to the hyperspectral data prior to model training. Noteworthy, the models' predictive performances were not affected by the different [CO2]s, which was anticipated due to the altered plant physiology under [eCO2]s. Thus, an accurate monitoring of grassland traits under different [CO2]s (present-day versus future, or within a FACE facility) is promising, if appropriate predictors are selected. Moreover, we show how hyperspectral predictions can be used e.g., within a future phenotyping approach, to monitor the grassland on a spatially explicit level and on a higher temporal resolution compared to conventional destructive sampling techniques. Based on the information during the vegetation period we show how hyperspectral monitoring might be used e.g., to adapt harvest practices or gain deeper insights into physiological plant alterations under [eCO2]s.

The course of N-NO 3 concentrations in soil, N transfer from the catch crops Vicia sativa L. and Trifolium resupinatum L. to the companion grass Lolium multiflorum ssp. gaudinii (Parl.) Schinz et Keller, and the preceding crop effect on Lolium multiflorum ssp. italicum (A. Br.) Volkart were studied in a field experiment. Catch crops were sown in pure stands and grass/legume swards (= two species in alternating rows) at two sowing dates and harvested at different dates from August to November. Vicia sativa was more effective concerning N 2 fixation than Trifolium resupinatum, this was also evident from above ground N yield and N-NO 3 amount of the soil. The factor sowing date had the greatest influence on N yield. N transfer to the companion grass was generally low. Early sown legumes in pure stands and in mixture temporarily caused slightly increased N-NO 3 amounts in soil compared with unfertilized grass in winter and following spring, whereas late sown legumes apparently had no effect on N-NO 3 amounts. Both legumes had a considerable preceding crop effect in the mixture and in the pure stand for both sowing dates.

Regarding the estimation of the energy concentration or digestibility of herb-dominated forage and plant samples from winter pastures, it could be expected that the estimation is only reliable when in vitro methods with rumen fluid as inoculum (= gas production techniques) are used. For the verification of this thesis based on logical reflections, an in vitro-method with rumen fluid added as inoculum, as well as chemical, and enzymatic methods were applied under consideration of existing estimating functions. As a possible reason for the observed divergence of the methods, effects of fungal infections or, respectively, secondary compounds in herbs are discussed. At the present state of knowledge, it is adequate to estimate the energy concentration in vitro by gas tests, as far as fattening types like suckler cows and beef cattle are concerned, maybe in contrast to the forage evaluation for dairy cows.

Purpose There is little information about exposure to dosages below 500 mSv. This pilot study aimed at investigating the effects of low dose radiation on lens transparency in occupationally exposed interventional cardiologists and radiologists. Methods Physicians who have performed fluoroscopically guided procedures for at least 5 years were recruited in the areas of Cologne-Bonn and Rhine-Main together with their non-exposed colleagues. A questionnaire has been developed to estimate occupational exposure. Exclusion criteria comprised corticosteroid treatment, radiotherapy, chemotherapy and glaucoma. Changes in lens transparency and cataract formation were determined by slit lamp microscopy including LOCS III grading, slit lamp photography and Scheimpflug/Pentacam® imaging. Results The prevalence of lens opacification mainly found in the nuclear region was 52% (95% CI: 30-74%) among interventional physicians and 31% (95% CI: 9-61%) among their non-exposed colleagues. Densitometric analysis of the cornea demonstrated a mean value 52,8% (SD: 7,4) in exposed participants compared to 45,9 % (SD: 7,2) in non-exposed colleagues. In the lenses layers 4 (deep cortex) and 5 (supra-nuclear layer) evidenced higher mean densities (40,5% (SD: 3,9%) vs. 31,6% (SD: 6,9%) in layer 4 and 27,5% (SD: 1,9%) vs. 23,7% (SD: 4,3%) in layer 5). Conclusion The data from the ophthalmological examinations demonstrated generally normal findings. However, classification of the mostly small cataracts and densitometric analysis of cornea and lens evidenced that low dosage exposure to ionizing radiation has an effect on corneal and lenticular transparency, albeit on a subclinical level.

Background: Light scattering properties of the cornea and lens change in relation to age. This process is influenced by noxious factors which may induce the formation of cataracts. Four different camera types based on the Scheimpflug principle have been developed for documentation and evaluation of light scattering in the eye, Topcon SL-45, Zeiss SLC, Oxford CASE 2000, Nidek EAS 1000. Only the SL-45 and EAS 1000, however, have found a wider application in clinical and experimental studies. Material and Methods: Documentation of the eye with a Scheimpflug system is performed in a dark room after mydriasis induction.The rotating axis of the camera is aligned to the optical axis of the eye with fixation devices. Four meridians have been found appropriate for routine documentation. Image analysis is based on peak height and distance evaluation of 2 layers in the cornea and 10 layers in the lens. Standardization devices allow correction of technical differences in the recording process. Results: Evaluation of the ageing properties of the lens has evidenced typical density developments for each individual layer, the cortex increasing in density earlier than the nucleus. Cataract classification using a Scheimpflug camera provides an objective characterization of cataract type and progression. The outcome of surgical procedures changing the refractive power of the eye can be evaluated with a Scheimpflug camera as well. Its application in studies dealing with the ocular effects of Quinolones and HMG-CoA-reductase inhibitors, has demonstrated that Scheimpflug photography is the method of choice for establishment of a safety profile for a new drug. Conclusions: Scheimpflug photography has proven to be ideal for objective documentation of the anterior eye segment in human and animal eyes, although both documentation and image analysis demand technical expertise to be reproducible.

To investigate normal light scattering and cataract formation, the anterior eye segments of farmed Atlantic salmon (Salmo salar) reared in fresh water and sea water were documented in vivo for the first time with a Topcon SL-45 Scheimpflug camera. A total of 40 fish from the fresh-water-rearing period, obtained from 2 groups of identical age but showing a different growth rate, and 24 fish from the sea-water-rearing period, sampled from 2 groups with identical age but being fed different food brands, were included in this study. The fish were anaesthetized before examination. Due to the naturally wide pupil, no mydriatic compound was applied. All fish were removed from the water for photography, which was performed for each eye in 0° = vertical slit position. Images were recorded on Kodak Tmax 400 black-and-white film. Microdensitometric image analysis of all negatives was performed using a Joyce-Loebl online microdensitometer. In spite of the virtual absence of an anterior chamber gap between cornea and lens and very little light scattering in the normal fish lens, a small number of distinct layers could be reproducibly identified in the lens. While there was little abnormal light scattering which could point to cataract development in young fish from the fresh water period, the evaluation of the lenses from the 2 sea water groups showed the presence of specific forms of cataract especially in the cortical and supranuclear layers. There were significant differences between the groups fed different food brands at the sea water site. In conclusion, Scheimpflug photography proved to be applicable to eye research in fish in vivo. It is suggested that this method should be employed for reproducible documentation as an extension to slit lamp monitoring in experimental research to reveal causative factors for cataracts in farmed fish.

The density characteristics of the anterior and posterior surfaces of the lens, although of primary importance for its optical quality, are difficult to determine. Scheimpflug photography, however, allows distinct density measurements from the optical axis towards the periphery with the only limitation of a sufficient mydriasis, so that a 3-dimensional scatter profile of both capsular surfaces can be calculated via multilinear densitometric evaluation of a sufficient number of meridians. On this methodical basis, we analysed Scheimpflug images recorded with the Topcon SL-45 on Kodak T-Max 400 film from 25 patients in an age range between 19 and 63 years. Images from the 0 degree + 45 degree meridians were scanned with multilinear microdensitometry and the data computed to get a density profile. In general, most scattering profiles show a marked interindividual variability. Nevertheless, a general trend can be established between the periphery and the center of the anterior and posterior capsules: (a) the anterior capsule generally has a higher density than the posterior; (b) in most cases, the center of the posterior capsule has a higher density than the periphery; (c) the anterior capsule has a more uniform spatial density distribution in all cases. From the cases evaluated, it can be concluded that the density of the peripheral posterior capsule is more importantly influenced by shading effects of the iris, so that geometrical correction is needed.

Lens density has been followed-up in 32 healthy volunteers (mean age 65 years) over a period of 3.5 years. The negatives of Scheimpflug-photos (Topcon SL-45) were evaluated by linear microdensitometry in three measure planes (Joyce Loebl 3 CS). Correlation coefficients, curves of regression as well as calculations of the percentage of density change made obvious, that a minimal increase in lens density occurred in the anterior cortical region.

The present study deals with a prospective investigation on the optical density of the eye lenses of 32 volunteers with initially normal eyes (mean age 65 years) over a period of 3.5 years. The negatives of the Scheimpflug photographs (Topcon SL-45) were evaluated by linear densitometry in 3 measure planes (Joyce Loebl 3CS). The evaluation of the coefficient of correlation, the representation of the regression straight line as well as the evaluation of the percent changes in lens density showed that during the observation period of 3.5 years a minimum increase in density took place mainly in the anterior cortex.

Purpose Evaluation of the effects of different anti-diabetic therapies on light scattering in the lenses of type II diabetic patients compared to data from age-matched normal patients. Methods The anterior eye segment of 53 patients (20 males and 33 females, mean age 68,23 years) from a private practice, 25 of which were on insulin therapy and 28 on oral anti-diabetic therapies, were photographed with a Topcon SL-45 Scheimpflug camera on Kodak Tmax 400. After standard development the images were digitized and evaluated in respect to density in defined lens layers. Statistical comparison was performed with regression analysis between diabetics and normal patients for 9 defined lens layers. Results Density data in lens layers 1 – 3 and 5 – 8 did not differ between the 2 treatment groups, whereas in layer 4 (anterior lens cortex) light scattering was significantly lower than in the group of patients on oral anti-diabetic therapy. Gender had no influence on the data evaluated in this study. Conclusion In contrast to other, larger studies comparing different anti-diabetic therapies, this study shows a trend indicating that insulin might provide a better protection of lens crystallins against non-enzymatic glycosylation than oral anti-diabetic medication. Further studies are needed to differentiate between various oral anti-diabetic drugs.

Ultraviolet (UV) filter photography with the Topcon SL-45 Scheimpflug camera has provided valuable informations about age-related and cataract-type-dependent changes in the spectral properties of the human lens. The present study deals with the same phenomenon in normal lenses of the Brown-Norway rat and in those with true diabetic and naphthalene cataracts. The lenses of all animals of the 3 groups were photographed at the middle and final examination of a 6-week experiment on Kodak Tri-X-pan ASA 400 black-and-white film, using visible light (xenon flash) and UV-filtered light (320-390 nm transmission) from the same light source for recording. The results clearly demonstrate that both cataract models exhibit characteristic fluorescence properties, different from each other and from normal rat lenses. The naphthalene cataract shows the most drastic increase in fluorescence in the cortex, compared to the increase in scattering with visible light. The versatility of the method in preclinical research and the versatility of the cataract models open new aspects of drug-related research in drug toxicity studies.

Scheimpflug photography has become the basic method for documentation of lens transparency changes in clinical and experimental ophthalmology, due to its high reproducibility. In animal cataract studies, the reproducibility is strongly influenced by the handling characteristics of the camera used, due to limited cooperation of the animal. The reproducibility of the Zeiss SLC system, which offers a direct quality control of the image on the video screen, was tested with 2 animal cataract models, the ultraviolet B (UVB)-induced cataract and the true diabetic cataract in the Brown-Norway rat. 10 rats each of the 2 cataract models and of an untreated control group were photographed in a random order on 3 occasions on the same day by the same photographer. Quality control and densitometry were performed by the same system operator, the measurement window was positioned standardly, coincident with the optical axis of the eye. Statistical comparison was carried out in the capsular layer, that is the area of initial cataract development in both models, and in the cortical layer, into which the diabetic cataract progresses during its later stages of development. The nuclear layer was also evaluated, but has no direct relation to one of the models employed. The results clearly indicate that the reproducibility is predominantly influenced by the homogeneity or inhomogeneity of the cataract model employed. The system operator and the photographer provided that they are well trained, have minor influence on the reproducibility of the Zeiss SLC system.

To investigate normal light scattering and cataract formation, the anterior eye segments of farmed Atlantic salmon (Salmo salar) reared in fresh water and sea water were documented in vivo for the first time with a Topcon SL-45 Scheimpflug camera. A total of 40 fish from the fresh-water-rearing period, obtained from 2 groups of identical age but showing a different growth rate, and 24 fish from the sea-water-rearing period, sampled from 2 groups with identical age but being fed different food brands, were included in this study. The fish were anaesthetized before examination. Due to the naturally wide pupil, no mydriatic compound was applied. All fish were removed from the water for photography, which was performed for each eye in 0 degrees = vertical slit position. Images were recorded on Kodak Tmax 400 black-and-white film. Microdensitometric image analysis of all negatives was performed using a Joyce-Loebl online microdensitometer. In spite of the virtual absence of an anterior chamber gap between cornea and lens and very little light scattering in the normal fish lens, a small number of distinct layers could be reproducibly identified in the lens. While there was little abnormal light scattering which could point to cataract development in young fish from the fresh water period, the evaluation of the lenses from the 2 sea water groups showed the presence of specific forms of cataract especially in the cortical and supranuclear layers. There were significant differences between the groups fed different food brands at the sea water site. In conclusion, Scheimpflug photography proved to be applicable to eye research in fish in vivo. It is suggested that this method should be employed for reproducible documentation as an extension to slit lamp monitoring in experimental research to reveal causative factors for cataracts in farmed fish.

Light scattering properties of the cornea and lens change in relation to age. This process is influenced by noxious factors which may induce the formation of cataracts. Four different camera types based on the Scheimpflug principle have been developed for documentation and evaluation of light scattering in the eye. Topcon SL-45. Zeiss SLC, Oxford CASE 2000, Nidek EAS 1000. Only the SL-45 and EAS 1000, however, have found a wider application in clinical and experimental studies.Documentation of the eye with a Scheimpflug system is performed in a dark room after mydriasis induction. The rotating axis of the camera is aligned to the optical axis of the eye with fixation devices. Four meridians have been found appropriate for routine documentation. Image analysis is based on peak height and distance evaluation of 2 layers in the cornea and 10 layers in the lens. Standardization devices allow correction of technical differences in the recording process.Evaluation of the ageing properties of the lens has evidenced typical density developments for each individual layer, the cortex increasing in density earlier than the nucleus. Cataract classification using a Scheimpflug camera provides an objective characterization of cataract type and progression. The outcome of surgical procedures changing the refractive power of the eye can be evaluated with a Scheimpflug camera as well. Its application in studies dealing with the ocular effects of Quinolones and HMG-CoA-reductase inhibitors, has demonstrated that Scheimpflug photography is the method of choice for establishment of a safety profile for a new drug.Scheimpflug photography has proven to be ideal for objective documentation of the anterior eye segment in human and animal eyes, although both documentation and image analysis demand technical expertise to be reproducible.

Lens density has been followed-up in 32 healthy volunteers (mean age 65 years) over a period of 3.5 years. The negatives of Scheimpflug-photos (Topcon SL-45) were evaluated by linear microdensitometry in three measure planes (Joyce Loebl 3 CS). Correlation coefficients, curves of regression as well as calculations of the percentage of density change made obvious, that a minimal increase in lens density occurred in the anterior cortical region.

Some years ago, Nidek developed a new imaging system for the anterior eye segment, which offers the possibility of recording Scheimpflug and retroillumination images. The system consists of 2 different technical units, a camera unit for image recording and a computer unit for storage, system operation and image analysis. To evaluate the clinical use of the system and its reproducibility, a study with 31 volunteers/patients was performed that were photographed with the Nidek EAS 1000 at the meridians 0 degree, 45 degrees and 180 degrees. Two examinations with a 1-week interval were performed. In addition, a direct comparison of the EAS 1000 with the Topcon SL-45 was carried out with 32 volunteers that were photographed at 0 degree and 45 degrees; a retroillumination photo was additionally recorded. The video images were evaluated with the computer software, the SL-45 negatives were standardly measured with a Joyce-Loebl densitometer. The handling of the EAS 1000 in clinical use was found to be easy and comfortable for the patient, as the alignment is done with infrared light. Difficulties occur only with the retroillumination photography in that the infrared light for imaging may outshine the red fixation light during exposure. However, shadowing problems due to the eyelashes occur in oblique slit positions, especially in those patients with a pronounced front head. In studying the reproducibility, the mean values of the individual coefficients of variation for light scattering (density) were in a range between 3.6 and 5.06%, but more than 35% of the single values show a variation coefficient above 5% (maximum 20.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

A double-masked study was performed to investigate a possible side effect of the antiallergic substance Picumast dihydrochloride on lens transparency. 372 patients with Picumast dihydrochloride- or Ketotifen-treatment regularly underwent ophthalmologic examinations and Scheimpflug photography of the anterior eye segment. Results of slitlamp examinations as well as microdensitometric analyzes of the film negatives after one year treatment did not reveal any evidence that Picumast dihydrochloride compromised lens transparency in humans.

Topcon Tokyo manufactured the first series of SL-45 in 1980 and a second in 1982/83, which were completed in Bonn with all technical improvements developed so far. In 1987, the SL-45B was manufactured which included all previously added improvements. To compare both camera types, we carried out a test with 10 volunteers and the following technical variables for the SL-45: (1) miosis; (2) mydriasis; (3) flashbulb 1; (4) flashbulb 2; (5) film batch 1; (6) film batch 2, and (7) different types of film. Afterwards, 5 of these volunteers were photographed with the SL-45B. Photographer and reader were identical in all cases. Based on microdensitometry it could be demonstrated that, with the exception of a different film type, all variables can be compensated for by using the corneal peak as an external standard.

The ophthalmic examination of patients with hypertrophic cardiomyopathy treated with high doses of verapamil over a considerable period of time showed no evidence of a side effect of the drug, thus pr

Evaluation of various long-term studies on changes of different lens opacities, as had been rendered possible by microdensitometric image analysis of the film blackening of Scheimpflug photographs, showed that only in a few special cases an extension of the opacification to adjacent lens layers is to be expected within the observation period of 2–3 years. This means that one of the reasons for evaluating the densitometer curve by area planimetry is no longer valid and may be neglected. A further advantage of the measurement of film blackening by height evaluation (height of densitometer deflection above baseline, i.e., noise level) is the fact that it is highly independent of subjective factors and, therefore, ensures a far better reproducibility with respect to data acquisition. The results of both evaluation procedures, obtained by evaluating the identical film material (2 photoexaminations) of 14 volunteers, are presented, and the advantage of height measurement as opposed to planimetry is demonstrated.

The technique of Scheimpflug photography was used to measure changes in depth of the anterior chamber of the eye and of lens thickness in small laboratory animals (Sprague-Dawley [SD] and Brown-Norway [BN] rats). The data were recorded with two different systems: the Topcon SL-45 camera, combined with linear microdensitometry, and the Zeiss SLC system. Values were recorded from normal unaffected eyes, in streptozotocin-induced diabetic animals, in those with naphthalene cataracts, and in those with cataracts induced by ultraviolet B (UVB) irradiation. In addition, the effect of topically applied beta-blockers (befunolol, betaxolol, timolol) on chamber depth was tested. The chamber depth increased constantly in normal eyes over the whole 6 week experimental period, accompanied by a constant increase in lens thickness. Under diabetic conditions, the depth increased minimally in BN rats and even slightly decreased in SD rats, in both cases accompanied by a massive lens swelling, as reflected by a pro...

Les modifications de la diffusion de la lumiere au niveau du cristallin ne sont pas en rapport avec l'âge des patients, mais avec la duree du diabete et la glycemie a jeun

A double-masked placebo-controlled clinical trial with hard data evaluation by image analysis of Scheimpflug photographs taken at baseline and 6, 12 and 18 months after starting treatment was performed to assess the efficacy of bendazac lysine in four different types of senile cataract. The study had a classical split-plot design. For statistical evaluation, the analysis of variance and covariance for repeated measures were used for three different lens sections: anterior capsule and superficial layer, anterior cortex and nucleus. In the entire group of 53 evaluable patients (without separation into cataract-type subgroups), there was a significantly less increase over time in light scattering (i.e. film blackening) of the anterior cortex and nucleus with bendazac lysine than with placebo. There was also a strong trend in favour of the active drug at the anterior capsular level. Patients with water clefts and spokes showed a significantly less light scattering of the anterior capsule and cortex when treated with bendazac lysine. Those with nuclear changes also showed significantly less light scattering of the anterior cortex and nuclear region with the active drug than with placebo. The number of patients with subcapsular and wedge-shaped (cuneiform) cataracts was too small to be adequately assessed by statistical procedures. Nevertheless, there were indications of a beneficial effect of bendazac lysine on all the lens sections in patients with subcapsular cataracts and on the anterior cortical region in those with wedge-shaped cataracts. In conclusion, this study showed that the increase in light scattering over time, i.e. the progression of cataract, is less in bendazac lysine-treated patients than in those treated with placebo.

Experimental cataract development can be objectively monitored in rats by Scheimpflug slit-image photography and microdensitometric image analysis. Zeiss (Oberkochen, Federal Republic of Germany) has developed a new computerized slit-lamp measuring system that works according to the Scheimpflug principle; we have very successfully applied it to rats with streptozotocin-induced cataracta diabetica vera and with naphthalene-induced opacities. With these cataract models we tested the gyrase inhibitor compound, Ciprofloxacin (Bayer 09867), after 6 weeks' daily peroral application (20 mg/kg body weight) for differences in cataract progression indicating a possible cocataractogenic effect of the compound. When we compared the two different Scheimpflug methods, we found that the Zeiss-Scheimpflug measuring system SLC has some handling advantages with respect to animal cataract studies. If the equipment is to be fully used, complements to the program of the integrated computer part are necessary. The image-analytical results from the animals treated with Ciprofloxacin did not show any indication of cocataractogenic potential with respect to cataracta diabetica vera or naphthalene cataract.

Scheimpflug photos of 262 cataract patients, classified according to various forms of opacifications characteristic for senile cataracts were evaluated by biometric methods. The measured values on cornea thickness, depth of anterior chamber, lens thickness, and radii of curvatures of cornea and anterior lens surface show that a correlation between some of the parameters and certain forms of opacities must be assumed.