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T Desmettre

Publications and source records attributed to T Desmettre.

At least 19 recordsLinked to original sources
PubMed2006

[Autosomal dominant syndrome of retinal arterial tortuosity].

INTRODUCTION: Autosomal dominant syndrome of retinal arterial tortuosity is a rare condition, often discovered after a benign macular hemorrhage. CASE REPORT: We report here the case of a 52-year-old man who was refereed to our center for an abrupt decrease in vision after an effort. The initial visual acuity was 2/10 for distance and Parinaud 6 for near vision. The biomicroscopic examination showed a small foveal hemorrhage associated with loops and bilateral vascular tortuosities limited to the arterioles. The aspect evoked inherited retinal arteriolar tortuosity. Questioning the patient revealed an antecedent of macular hemorrhage in the patient's sister that had spontaneously resolved. After a few months, redfree photographs were obtained from the two asymptomatic daughters of the patient, which showed a dominant arterial tortuosity in one of the two daughters, confirming the familial aspect of the disease. CONCLUSION: The case described here illustrates the advantage of biomicroscopy in establishing the diagnosis and the usefulness of questioning the patient further to disclose family history. Imagery studies complement the examination to eliminate other causes for the decrease in vision. Some recently published data suggest an advantage to including at least the search for a microscopic or macroscopic hematuria during the assessment.

Genes, Dominant↗
PubMed2005

[Hypothesis on the role of nutritional factors in ocular hypertension and glaucoma].

Recent notions in connection with oxidative stress and the fat balance of long chain polyunsaturated fatty acids (PUFA) families have brought new insight to a probable role of nutritional factors in glaucoma and intraocular hypertony. The modifications of the extracellular matrix of the trabecula could be influenced by oxidative stress. On the one hand, collagen apoptosis and remodeling (associated with an increase in intraocular pressure) are mainly influenced by hydrosoluble antioxidants such as glutathione. On the other hand, elastin apoptosis and remodeling (correlated with the occurrence of optic atrophy) are particularly influenced by liposoluble antioxidants such as vitamin E. In addition, the dietary ratio of omega3/omega6PUFA intake could influence the balance of intraocular pressure. Omega-3 PUFA could influence cyclooxygenase competition. A diet with increased omega-3 and decreased omega-6 could thus favor an increase in intraocular pressure reducing synthesis of PG-F2, leading to a decrease in uveoscleral outflow. The true importance of these factors has not yet been solidly determined and studies are in progress to clarify the real implication of these nutritional factors.

Animals↗
PubMed2004

[Photodynamic therapy follow-up: when to retreat, when to observe, or when to propose an alternative treatment?].

Clinical and angiographic progression after photodynamic therapy (PDT) is usually slow, sometimes fluctuating and therefore difficult to evaluate. After several sessions of PDT, angiographic follow-up remains the basis for therapeutic management involving either a new PDT session or an alternative treatment. It remains difficult, however, to evaluate the activity and progression potential of the remaining neovessels. Imaging (angiography, optical coherence tomography) and functional data both contribute to the therapeutic decision. Certain patients require several sessions for a progressive reduction of the exudation. For others, the persistence of metamorphopsias and accentuation of the scotoma despite the treatment may entail alternative treatment. Thus, a perifoveal photocoagulation can be proposed to limit the extension of the scotoma if after a reasonable number of sessions, central visual acuity is not recovered; direct photocoagulation of a persistent active neovascular contingent, distant from the fixation zone (foveal or exenterated) can be proposed if it remains on the border of a stabilized lesion; the treatment of a feeder vessel can be proposed if it becomes visible and is associated with active neovessels with a persistent central serous detachment of the neuroretina. Lastly, performance status and patient wishes are important elements in the overall therapeutic project, especially if the eye involved is the second eye, in view of quickly initiating low-vision rehabilitation.

Fluorescein Angiography↗
PubMed2004

[Nutrition and age-related macular degeneration].

The nutritional factors involved in the pathogenesis of age-related macular degeneration (AMD) include antioxidants or antioxidant cofactors: vitamins A, C, etc.; zinc, etc.; anti-free-radicals such as beta-carotene and carotenoids, including lutein and zeaxanthin; micronutrients protecting from blue light such as lutein and zeaxanthin; and finally components of the membranes of the photoreceptors docosahexaenoic acid (DHA). These nutritional factors are closely related to environmental risk factors such as smoking and chronic blue light exposure. Although the experimental and epidemiological data are concordant and coherent, the protective role of these micronutrients is not clearly established, mainly because there are very few clinical studies. However, a first observation study showed positive effects at stages 3 and 4 of AMD. Report #8 of the Age-Related Eye Disease Study (AREDS) provides important results for preventing complications of AMD (secondary prevention), and the cocktail of micronutrients proposed even encourages complementary studies on, for example, lutein and zeaxanthin instead of beta-carotene. The outcome of observation studies including a supplementation of long-chain polyunsaturated fatty acids (PUFA) of the omega-3 family (DHA) is also important, as it addresses primary prevention of the disease. A supplementation of omega-3 PUFAs could be proposed to certain subjects at risk for AMD for primary prevention and a supplementation with an antioxidant cocktail of micronutrients could be proposed to patients presenting AMD at stages 3 or 4 or to subjects with a nutritional imbalance. These conceivable supplementations are compatible with simple dietary advice. The supplements currently proposed could be optimized to increase their advantages. New research and new clinical studies are necessary to definitively validate these formulations in order to grant them an authentic drug status.

Antioxidants↗
PubMed2004

[Transpupillary thermotherapy and age-related macular degeneration].

Transpupillary thermotherapy (TTT) has been proposed over the last a few years for the treatment of subfoveal occult choroidal neovessels resulting from age-related degeneration (AMD) when they are symptomatic and associated with exudation. Several pilot studies have shown how this technique can decrease or slow down the progression of exudation related to choroidal neovessels. Based on these pilot studies, a randomized study (TTT4CNV) is in progress to evaluate the efficacy of TTT. While the inclusion of the patients in this study has come to an end, the therapeutic context of AMD has recently been changed with a permit to market Visudyn for photodynamic therapy (PDT) for some types of subfoveal occult choroidal neovessels. Moreover, the clinical studies in progress on photodynamic therapy and antiangiogenic drugs now make it possible to consider combined treatments possibly including TTT. This paper aims to provide a report on the current place and potential of TTT within the therapeutics available or soon available for subfoveal occult choroidal neovessels of AMD.

Angiogenesis Inhibitors↗
PubMed2003

[Status of low-vision rehabilitation for age-related macular degeneration by orthoptists in the North of France].

AIM OF THE STUDY: To evaluate the status of low-vision rehabilitation carried out by the orthoptists in the North of France. This study was a preliminary step in setting up a network between different vision professionals for the management of age-related macular degeneration (AMD) the North of France. METHODS: The ASO (Association Septentrionale d'Ophtalmologie) conducted a survey funded by the URCAM (Union Régionale des Caisses d'Assurance Maladie) with the FAQSV (fond d'aide à la qualité des soins de ville). The survey was based on the analysis of two forms sent to orthoptists of the North region of France. RESULTS: The survey analyzed 46 responses (a representative sample with 69% responses) providing a description of the orthoptists of the North of France: 19% males, 81% females whose mean professional experience was 13.3 years. Thirty-four percent of the orthoptists have had training in low-vision rehabilitation. This training was given during the university courses for 21% of responders and during a postgraduate course for 79%. Of the orthoptists surveyed, 64% worked in a private context, 9% in a public context, and 27% in both public and private contexts. Their main activity was in their own private practice for 60%, in an ophthalmologist's office for 20%, in a public institution for 16%, and a private institution for 4%. The mean number of patients treated was 70 per week per orthoptist, with 21% working mostly with children, 36% working mainly with adults between 16 and 60 years of age, and 7% with the elderly, whereas 36% reported no specificity related to patient age. The mean number of patients dealt with for low vision related to AMD was 4.1 per month per orthoptist. The average number of patients dealt with for low vision with no relation to AMD was 1.5 per month. The prescriber of low-vision rehabilitation was an ophthalmologist for 88.9% of the orthoptists and a general practitioner for 11.1%. Questions addressed to AMD patients: at the beginning of the survey, 83.8% of the patients did not have sufficient visual acuity to be able to read a text of current size (Parinaud 4); 40.4% of the patients required help for everyday life, and 59.6% were autonomous. For 7.1% of the patients, low-vision rehabilitation was carried out less than 1 month after the stabilization of retinal lesions, but in 35.3%, rehabilitation was carried out more than 2 years after lesions were stabilized. The main request of the patients involved improvement of near vision (89.9%). CONCLUSION: This survey will be a preliminary step in setting up a regional health network coordinating the ophthalmological and orthoptic management of AMD.

Aged↗
PubMed2001

Heat shock protein hyperexpression on chorioretinal layers after transpupillary thermotherapy.

PURPOSE: To assess a biological effect induced by temperature elevation during transpupillary thermotherapy (TTT). METHODS: Six pigmented rabbits were anesthetized, and TTT was performed on the right eye using an 810-nm diode laser installed on a slit lamp (spot size, 1.3 mm; duration, 60 seconds; power, 92-150 mW). A series of laser pulses were aimed at the posterior pole of the retina. The left eyes were used as the control. Twenty-four hours after laser irradiation, a histologic study was performed on the chorioretinal layers. Tissue samples were fixed in formalin and embedded in paraffin. A monoclonal antibody was used to detect heat shock protein (Hsp)70 immunoreactivity, followed by a biotinylated goat anti-mouse antibody, revealed by the avidin-biotin complex and the 3-amino-9-ethyl-carbazole (AEC) chromogen. Retinal structures were further identified by hematoxylin erythrosin saffron (HES) coloration. RESULTS: The photocoagulation threshold was found to be at the 150-mW laser power. Under this threshold, Hsp70 immunostaining was the strongest at the 127-mW power, with staining of some choroidal cells, including capillary endothelial cells. No Hsp70 immunoreactivity was observed on the retina. At the 107-mW power, Hsp70 reactivity was observed only in occasional choroidal cells. At the 98-mW power, only mild, diffuse Hsp70 immunoreactivity was observed in the choroid. At the 92-mW power, as in nonirradiated eyes, no Hsp70 immunoreactivity was detected. CONCLUSIONS: Subthreshold transpupillary 810-nm laser irradiation induces choroidal Hsp hyperexpression. This confirms that choroidal Hsp hyperexpression can be induced during TTT, as has been recently hypothesized by several investigators.

Animals↗
PubMed2001

[Choroidal heat shock overexpression in transpupillary thermotherapy: preliminary results].

PURPOSE: To assess retinochoroidal overexpression of heat shock proteins (HSP-70) induced by a transpupillary laser irradiation below the photocoagulation threshold. METHODS: Four pigmented rabbits were anesthetized and TTT was performed on the right eye using a 810nm diode laser (Iridis, Quantel-Medical, France) adapted on slit lamp (spot size: 1.3 mm, duration: 60 seconds; power 92-150 mW). Series of laser impacts were aimed at the posterior pole of the retina. Left eyes were used as control. Twenty-four hours after laser irradiation, a histological study was done on chorioretinal layers. Tissue samples were fixed in formalin and embedded in paraffin. A monoclonal antibody was used to detect HSP-70 immunoreactivity (mouse IgGl, SPA-810, Stress Gen, Canada), followed by a biotinylated goat antimouse antibody (Dako, Denmark), revealed by the avidin-biotin complex (Vectastain kit, Vector, USA) and the AEC chromogen. Retinal structures were further identified by HES coloration. RESULTS: The photocoagulation threshold was obtained for laser power at 150 mW. Under this threshold, HSP-70 immunostaining was the strongest for power 127 mW with a staining of some choroidal cells, including capillary endothelial cells. No HSP-70 immunoreactivity was observed on the retina. For the laser power 107 mW, HSP-70 reactivity was observed only in occasional choroidal cells. For the laser power 92 mW, as for nonirradiated eyes, no HSP-70 immunoreactivity was detected. CONCLUSIONS: Transpupillary 810 nm laser irradiation under the photocoagulation threshold induces choroidal HSP overexpression. This study concludes that choroidal HSP overexpression can be induced during TTT.

Animals↗
PubMed1999

Quantitative fluorescein angiography following diode laser retinal photocoagulation.

OBJECTIVE: An in vivo study was done to establish if laser-induced damage of the retina could be quantified using fluorescein angiography. METHOD: This study was carried out on rabbit eyes (n = 6) with an 810 nm diode laser (spot diameter: 500 microm, pulse duration: 1 second, power: 100 mW-400 mW) adapted on a slit lamp. Fluorescence measurements were performed with a fundus camera connected to a fluorescence imaging system. Fluorescence staining of the retina was evaluated by mathematical modeling. Lesions were correlated to laser parameters and to histologic data. RESULTS: Image analysis shows that the laser lesions stained progressively. Fluorescence appears first at the borders of the lesion exhibiting a fluorescent ring. A progressive increase of the fluorescence into the central zone is observed. The maximum fluorescence intensity into the center of the laser spot is obtained after a delay depending on the laser energy. Below 100 +/- 20 mW, lesions are detectable by fluorescence imaging only. A fluorescence plateau appears for a threshold light dose above 200 +/- 20 mW. Mathematical modeling demonstrates that quantitative assessment of laser-induced damage to the retina is feasible using fluorescence imaging. CONCLUSION: The quantification of fluorescence staining in terms of both intensity and time can contribute to a better quantification of laser-induced damage. At last, since laser damage may mimic naturally occurring pathology, this method should also be considered to quantify different types of lesions.

Animals↗
PubMed1998

Indocyanine green: physicochemical factors affecting its fluorescence in vivo.

This study reinvestigates the spectral properties of ICG (Indocyanine green) in vivo, the role of quenching, and the possibility of an interaction of ICG with blood components and/or vessel walls. ICG quenching as a function of concentration was studied by spectrophotometry on whole blood samples from golden hamsters. Fluorescence ICG characteristics were evaluated by front-face fluorometry. In vivo, fluorescence measurements were performed on the femoral artery of golden hamsters. In vitro, on whole blood samples, fluorescence intensity is modified by ICG quenching as concentration increases above 80 microgram/ml. The maximum fluorescence peak is not affected and remains centered at 832 nm. The in vivo measurements display a similar fluorescence intensity shape, which is affected only by ICG concentrations. However, the maximum fluorescence emission peak is modified significantly with time. Between 0 and 120 min, four phases can be distinguished in which a wavelength shift from 826 to 835 nm is observed. The wavelength shift with change in fluorescence intensity observed in vivo could be due to a localization of ICG molecules in sites more hydrophobic than serum proteins. It is possible to hypothesize the presence of an endothelium-bound form with a specific fluorescence spectrum. The amphiphilic properties of ICG are consistent with fixation of some ICG molecules on sites other than plasmatic proteins after injection. The process of fixation of ICG molecules on surface components or within the vascular endothelium could be due to a change in the microenvironment of some ICG molecules.

Animals↗