Peripheral exudative hemorrhagic chorioretinopathy: a clinical, angiographic, and histologic study.

PURPOSE: To describe the clinical and angiographic characteristics of peripheral exudative hemorrhagic chorioretinopathy, an uncommon chorioretinal mass lesion, important for its differential diagnosis to choroidal melanoma, but only rarely described in the literature. DESIGN: Retrospective, institutional chart review. METHODS: Institutional chart review of 45 patients (56 eyes) diagnosed with peripheral exudative hemorrhagic chorioretinopathy to describe the clinical findings and those obtained by fluorescein angiography (FA) and indocyanine green angiography (ICGA), in addition to a review of the histologic findings of an enucleated eye. RESULTS: Peripheral exudative hemorrhagic chorioretinopathy typically was characterized by increased age of the patient (mean, 77 years; range, 60 to 91 years), female preponderance (69%), frequent pigment epithelium detachment, temporal equatorial location, and a highly hemorrhagic and exudative presentation, sometimes extending to the macula. Bilateral involvement (24%) was associated with multiples lesions in the same eye (P < .001) and with nasal extension (P < .001). A neovascular origin was suspected on FA, but was more evident on ICGA. Histologic examination of the enucleated eye did not reveal a neovascular network. CONCLUSIONS: Peripheral exudative hemorrhagic chorioretinopathy is a characteristic peripheral degenerative disorder, frequently with benign outcome, although it can be vision threatening because of hemorrhage or exudation. Clinical features are helpful for its diagnosis. FA and ICGA contribute valuable evidence to the hypothesis of a neovascular origin, but further histologic studies are needed to prove this hypothesis.

Ecology and evolution of soil nematode chemotaxis.

Plants influence the behavior of and modify community composition of soil-dwelling organisms through the exudation of organic molecules. Given the chemical complexity of the soil matrix, soil-dwelling organisms have evolved the ability to detect and respond to these cues for successful foraging. A key question is how specific these responses are and how they may evolve. Here, we review and discuss the ecology and evolution of chemotaxis of soil nematodes. Soil nematodes are a group of diverse functional and taxonomic types, which may reveal a variety of responses. We predicted that nematodes of different feeding guilds use host-specific cues for chemotaxis. However, the examination of a comprehensive nematode phylogeny revealed that distantly related nematodes, and nematodes from different feeding guilds, can exploit the same signals for positive orientation. Carbon dioxide (CO(2)), which is ubiquitous in soil and indicates biological activity, is widely used as such a cue. The use of the same signals by a variety of species and species groups suggests that parts of the chemo-sensory machinery have remained highly conserved during the radiation of nematodes. However, besides CO(2), many other chemical compounds, belonging to different chemical classes, have been shown to induce chemotaxis in nematodes. Plants surrounded by a complex nematode community, including beneficial entomopathogenic nematodes, plant-parasitic nematodes, as well as microbial feeders, are thus under diffuse selection for producing specific molecules in the rhizosphere that maximize their fitness. However, it is largely unknown how selection may operate and how belowground signaling may evolve. Given the paucity of data for certain groups of nematodes, future work is needed to better understand the evolutionary mechanisms of communication between plant roots and soil biota.

Comparison of fundus autofluorescence between fundus camera (Topcon) and confocal scanning laser ophthalmoscope (HRA) in various pathologies

Purpose: To investigate the differences between Fundus Camera (Topcon TRC-50X) and Confocal Scanning Laser Ophthalmoscope (Heidelberg retina angiogram (HRA)) on the fundus autofluorescence (FAF) imaging (resolution and FAF characteristics). Methods: 105 eyes of 56 patients with various retinal diseases underwent FAF imaging with HRA (488nm exciter/500nm barrier filter) before fluorescein angiography (FFA) and Topcon Fundus Camera (580nm exciter/695nm barrier filter) before and after FFA. The quality of the FAF images was compared for their resolution and analysed for the influence of fixation stability and cataracts. Hypo-and hyper-FAF behaviour was analysed for the healthy disc, healthy fovea, and a variety of pathological features. Results: HRA images were found to be of superior resolution in 18, while Topcon images were estimated superior in 29 eyes. No difference was found in 58 eyes. Both poor fixation (p=0.009) and more advanced cataract (p=0.013) were found associated with better image quality by Topcon. Images acquired by Topcon before and after FFA were identical (100%). The healthy disc was usually dark on HRA (72%), but showed mild autofluorescence on Topcon (85%). The healthy fovea showed in 100% Hypo-FAF on HRA, while Topcon showed in 53% Iso-FAF, in 43% mild Hypo-FAF, and in 4% Hypo-FAF as on HRA. No difference of FAF was found for geographic atrophy, pigment changes, and drusen, although Topcon images were often more detailed. Hyper-FAF due to serous exudation showed better on HRA. Cystic edema was visible only on HRA in a petaloid hyper-FAF pattern in 83%, while only two eyes (17%) showed similar behavior in both HRA- and Topcon images. Hard exudates caused Hypo-FAF only on HRA, hardly visible on Topcon. Blockage phenomenon by blood however was identical. Conclusions: The filter set of Topcon and the single image acquisition appear to be an advantage for patients with cataract and poor fixation respectively. Preceding FFA does not alter the Topcon FAF image. Regarding the FAF behavior, there are differences between the 2 systems which need to be taken into account when interpreting the images.

Induced responses to herbivory and jasmonate in three milkweed species

We studied constitutive and induced defensive traits (latex exudation, cardenolides, proteases, and C/N ratio) and resistance to monarch caterpillars (Danaus plexippus) in three closely related milkweed species (Asclepias angustifolia, A. barjoniifolia and A. fascicularis). All traits showed significant induction in at least one of the species. Jasmonate application only partially mimicked the effect of monarch feeding. We found some correspondence between latex and cardenolide content and reduced larval growth. Larvae fed cut leaves of A. angustifolia grew better than larvae fed intact plants. Addition of the cardenolide digitoxin to cut leaves reduced larval growth but ouabain (at the same concentration) had no effect. We, thus, confirm that latex and cardenolides are major defenses in milkweeds, effective against a specialist herbivore. Other traits such as proteases and C/N ratio additionally may be integrated in the defense scheme of those plants. Induction seems to play an important role in plants that have an intermediate level of defense, and we advocate incorporating induction as an additional axis of the plant defense syndrome hypothesis.

Evanescent vaso-occlusive choroidal pseudo-tumor with acute painful onset: a presumed vortex vein occlusion.

PURPOSE: The aim of our study was to describe the clinical presentation of an unusual evanescent, exudative, choroidal pseudo-tumor with acute painful onset, and propose a pathogenesis. METHODS: We carried out a retrospective, observational study using the case series of three patients presenting with an evanescent, exudative, choroidal pseudo-tumor with acute painful onset. Ultra-widefield fluorescein and indocyanine green angiography (ICGA) using the Heidelberg Retina Angiograph and the Staurenghi 230 SLO Retina Lens were used to propose a pathogenesis of this unusual entity. RESULTS: In all three cases, acute ocular pain led to discovery of an exudative, partially hemorrhagic choroidal mass (thickness 2.4 mm-4.1 mm on ultrasound) that quickly regressed within weeks. In the subacute phase, all patients showed choroidal circulation abnormalities on dynamic wide-field ICGA in the affected quadrant, with delayed arterio-venous filling in two patients, and a poorly-defined vortex vein in the third. The choroidal circulation abnormalities resolved within 8-12 weeks, simultaneously with the spontaneous resolution of the choroidal pseudo-tumor. The findings evoked a self-resolving vortex vein occlusion in the corresponding quadrants with acute, painful choroidal exudation. CONCLUSIONS: An evanescent, exudative, hemorragic choroidal pseudo-tumor with acute painful onset may be caused by a vortex vein occlusion. Future patients need to be studied with ICGA in the acute phase to confirm this hypothesis.

Plants respond to pathogen infection by enhancing the antifungal gene expression of root-associated bacteria.

Plant health and fitness widely depend on interactions with soil microorganisms. Some bacteria such as pseudomonads can inhibit pathogens by producing antibiotics, and controlling these bacteria could help improve plant fitness. In the present study, we tested whether plants induce changes in the antifungal activity of root-associated bacteria as a response to root pathogens. We grew barley plants in a split-root system with one side of the root system challenged by the pathogen Pythium ultimum and the other side inoculated with the biocontrol strain Pseudomonas fluorescens CHA0. We used reporter genes to follow the expression of ribosomal RNA indicative of the metabolic state and of the gene phlA, required for production of 2,4-diacetylphloroglucinol, a key component of antifungal activity. Infection increased the expression of the antifungal gene phlA. No contact with the pathogen was required, indicating that barley influenced gene expression by the bacteria in a systemic way. This effect relied on increased exudation of diffusible molecules increasing phlA expression, suggesting that communication with rhizosphere bacteria is part of the pathogen response of plants. Tripartite interactions among plants, pathogens, and bacteria appear as a novel determinant of plant response to root pathogens.

Prevalence of subfoveal nodules in Coat's disease

Purpose:Coats' disease is a non-hereditary condition characterized by idiopathic retinal telangiectasia, and exudative retinopathy. Although the exudation often spreads from the main areas of telangiectasia, there is a preferential accumulation of exudation in the macular area in Coats' disease. A subfoveal nodule has usually been described in the context of resolution of macular exudates after treatment of peripheral retinal telangiectasis. Nevertheless, a recent reports stressed out an uncommon prominent subfoveal nodule with peripheral exudates as initial presentation of Coats'disease. The purpose of this study was to report the prevalence of this presentation in a cohort of patients. Methods:All consecutive patients with Coats' disease referred to the Jules Gonin Eye Hospital between January 1979 and July 2006 were included. All charts were screened for a clear cut subfoveal circular lesion on fundus photographies at initial presentation. Results:95 patients suffering of Coat's disease were enrolled. 33 out of 95 patients had subtotal or total exudative retinal detachment, which impeded macular examination. 14 out of 62 (22.6%) resting patients presented with a clear cut prominent circular subfoveal lesion at initial presentation. All patients had unilateral disease. Mean age was 5.6 ± 3.5 year old at initial presentation. There were 4 females and 10 males. Pigmentation and size of the nodule were not homogenous. Mean diameter was 1.1 ± 0.5 optic disc diameter. Conclusions:The present study shows that subfoveal nodule is not such a rare primary presentation of Coats' disease in contrast to what it has been previously reported in the literature. Thus the initial finding of prominent subfoveal nodule associated with peripheral retinal findings made the diagnosis of Coats' disease highly likely.Physicians should be aware that a proeminent subfoveal nodule is a common initial presentation of Coats' disease as it can be confused clinically with Retinoblastoma.

Reemergence of dormant Coats disease after 30 years.

Purpose. We describe an atypical case of a patient with Coats disease that re-emerged after 30 years, illustrating a previously poorly understood long-term evolution of the disease. Methods. A 20-year-old man consulted for visual acuity (VA) decrease in the left eye (LE) to 0.3. Fundus examination revealed an exudative lesion with telangiectasias in the superior peripheral retina compatible with the diagnosis of Coats disease. Results. The patient was treated with cryotherapy and argon laser. Visual acuity improved to 0.5 and remained stable during a 1-year follow-up. The patient did not seek further clinical follow-up. Thirty years later, he returned complaining of a progressive VA decrease in the LE. Snellen VA was measured to counting fingers. Fundus examination revealed stage 3A Coats disease with macular exudation and a serous retinal detachment in the inferior quadrants requiring the placement of an encircling band, external drainage, and cryotherapy of the vascular lesions. After 10 additional sessions of argon laser on the vascular malformations, exudation regressed further and best-corrected VA increased to 0.1 at the end of the follow-up period. Conclusions. Coats disease must be considered as a chronic disease, which necessitates a very long-term follow-up even in the absence of subjective visual loss. The disease can reawaken and recur with force in previously unaffected areas of the retina several decades later. The gold standard treatment consists of cryotherapy and argon laser. However, in cases of very important retinal exudation, surgical management with subretinal drainage may be necessary.

Two-step postmortem angiography with a modified heart-lung machine: preliminary results.

OBJECTIVE: The purpose of this study was to adapt and improve a minimally invasive two-step postmortem angiographic technique for use on human cadavers. Detailed mapping of the entire vascular system is almost impossible with conventional autopsy tools. The technique described should be valuable in the diagnosis of vascular abnormalities. MATERIALS AND METHODS: Postmortem perfusion with an oily liquid is established with a circulation machine. An oily contrast agent is introduced as a bolus injection, and radiographic imaging is performed. In this pilot study, the upper or lower extremities of four human cadavers were perfused. In two cases, the vascular system of a lower extremity was visualized with anterograde perfusion of the arteries. In the other two cases, in which the suspected cause of death was drug intoxication, the veins of an upper extremity were visualized with retrograde perfusion of the venous system. RESULTS: In each case, the vascular system was visualized up to the level of the small supplying and draining vessels. In three of the four cases, vascular abnormalities were found. In one instance, a venous injection mark engendered by the self-administration of drugs was rendered visible by exudation of the contrast agent. In the other two cases, occlusion of the arteries and veins was apparent. CONCLUSION: The method described is readily applicable to human cadavers. After establishment of postmortem perfusion with paraffin oil and injection of the oily contrast agent, the vascular system can be investigated in detail and vascular abnormalities rendered visible.

Iontophoresis of dexamethasone in the treatment of endotoxin-induced-uveitis in rats.

The purpose of this study was to evaluate the efficacy of a Coulomb Controlled Iontophoresis system (CCI) in the local delivery of corticosteroids for the treatment of uveitis. The therapeutic efficacy of Dexamethasone (Dex) administered by CCI was compared to systemic injection and to topical application with the iontophoresis apparatus in the absence of electrical current. The evaluation was done in the treatment of the endotoxin-induced uveitis (EIU) model, and in the effect on TNF gene expression in the iris/ciliary body as well as in the retina and on TNF levels in aqueous humor and vitreous. Dex was administered either at the time of LPS injection or 5 hours later. For iontophoresis, we used a 1 ml reservoir-electrode covering the cornea, the limbus, and the first millimeter of the sclera. The applied electrical current was of 400 microA during four minutes with a total surface charge of 0.4 C cm-2. EIU was evaluated by clinical examination, by counts of intraocular inflammatory cells on histological sections, and by measuring the protein levels in the aqueous humor and in the vitreous. The TNF-alpha gene expression in the iris and ciliary body, and in the retina was evaluated by RT-PCR. The systemic effect of Dex delivered by CCI was evaluated on the level of serum TNF-alpha in EIU. Our results demonstrated that local administration of Dex by CCI inhibited anterior and posterior signs of intraocular inflammation as effectively as systemic administration, with no effect on systemic level of TNF. In the anterior and posterior segments of the eye, the protein exudation. TNF levels and the cellular infiltration were inhibited. The TNF-alpha gene expression was inhibited in the anterior as well as the posterior segment of the eye. No clinical nor histological damage were caused by the CCI apparatus. In conclusion, CCI administration of Dex allows for a therapeutic effect on the posterior as well as the anterior segment of the eye, and may present a viable alternative to systemic administration of glucocorticoids in severe ocular inflammations.

Comparison of Fundus Autofluorescence Between Fundus Camera (Topcon) and Confocal Scanning Laser Ophthalmoscope (HRA) in Various Pathologies

Purpose: To investigate the differences between the Fundus Camera (Topcon TRC-50X) and Confocal Scanning Laser Ophthalmoscope (Heidelberg retina angiogram (HRA)) on the fundus autofluorescence (FAF) imaging (resolution and FAF characteristics). Methods: Eighty nine eyes of 46 patients with various retinal diseases underwent FAF imaging with HRA (488nm exciter / 500nm barrier filter) before fluorescein angiography (FFA) and Topcon Fundus Camera (580nm exciter / 695nm barrier filter) before and after FFA. The quality of the FAF images was estimated, compared for their resolution and analysed for the influence of fixation stability and cataracts. Hypo- and hyper-FAF behaviour was analysed for the healthy disc, healthy fovea, and a variety of pathological features. Results: HRA images were found to be of superior quality in 18 eyes, while Topcon images were estimated superior in 21 eyes. No difference was found in 50 eyes. Both poor fixation (p=0.009) and more advanced cataract (p=0.013) were found to strongly increase the likelihood of better image quality by Topcon. Images acquired by Topcon before and after FFA were identical (100%). The healthy disc was usually dark on HRA (71%), but showed mild autofluorescence on Topcon (88%). The healthy fovea showed in 100% Hypo-FAF on HRA, while Topcon showed in 52% Iso-FAF, in 43% mild Hypo-FAF, and in 5% Hypo-FAF as on HRA. No difference of FAF was found for geographic atrophy, pigment changes, and drusen, although Topcon images were often more detailed. Hyper-FAF due to exudation showed better on HRA. Pigment epithelium detachment showed identical FAF behaviour on the border, but reduced FAF with Topcon in the center. Cystic edema was visible only on HRA in a petaloid pattern. Hard exsudates caused Hypo-FAF only on HRA, hardly visible on Topcon. Blocage phenomenon by blood however was identical. Conclusions: The filter set of Topcon and the single image acquisition appear to be an advantage for patients with cataract or poor fixation. Preceding FFA does not alter the Topcon FAF image. Regarding the FAF behaviour, there are differences between the two systems which need to be taken into account when interpreting the images.

Maligne Hypertonie: Klinische Zeichen von 7 Patienten Malignant Hypertension: Clinical Manifestations of 7 Cases.

Background: Malignant hypertension is defined by marked systemic arterial hypertension with retinal haemorrhages, exudation or papilloedema. Due to the rarity of this disease and due to its non-specific symptoms and lesions, the diagnosis can be challenging. Patients and Methods We investigated the types of symptoms and ocular lesions observed with ocular fundus examination, ocular fundus photography, fluorescein angiography and optical coherence tomography in a small case series of 7 patients with malignant hypertension. Results: Median systolic blood pressure (BP) was 205 mmHg ± 21. Median diastolic BP was 150 mmHg ± 16. Decrease in visual acuity (6/7 patients) and scotoma (5/7) were the main symptoms and Elschnig spot, flamed shaped haemorrhage, serous retinal detachment, cotton wool spots and optic nerve oedema were the five most frequently observed lesions. A regression of lesions was observed after therapy of systemic hypertension. Conclusion: The association of multiple lesions strongly suggests malignant hypertension. However even in cases with only one lesion malignant hypertension should be kept in mind.