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Biomedical subjects

H Hamard

Publications and source records attributed to H Hamard.

At least 19 recordsLinked to original sources
PubMed1992

[Hemo-rheology of glaucomatous neuropathy].

The vascular participation to the optic nerve pathogenesis has been contradicted. The red blood cell velocity in the optic nerve capillary with a laser Doppler velocimeter, an atraumatic and reliable method, and the aggregability was determined with an erythroaggregameter to know whether an erythrocyte hyperaggregability could slow down the optic nerve blood flow as it has been previously demonstrated in an experimental study. The experiment on the open angle glaucoma patients showed that their optic nerve blood flow was reduced, and their erythrocyte aggregability significantly increased. The two parameters were not significantly correlated, certainly because of a local papillary autoregulation and of the papilla vessels variability, those two factors could modulate the blood flow response to blood qualitative changes. The erythrocyte hyperaggregability could be explained by erythrocyte membrane modifications that could agree with the glaucoma heredity.

Animals↗
PubMed1990

[Cyclodiathermy: is it effective in the treatment of glaucoma?].

The authors describe the non penetrating technique of cyclodiathermy in the treatment of different types of glaucoma and publish the results and the complications of the application of this technique on thirty three eyes among their patients. These eyes included congenital glaucoma (8 eyes), aphakic glaucoma (5 eyes), after silicone surgery (5 eyes), neovascular glaucoma (4 eyes), traumatic glaucoma (4 eyes), secondary glaucoma (3 eyes), Sturge-Weber-Krabbe (2 eyes) and open angle glaucoma (2 eyes). Their study with a mean follow up of 2.5 years shows an overall success rate of 60%. The success is defined as an ocular tension less than or equal to 22 mmHg in the absence of serious complications. All the encountered complications are mentioned. Phtysis occurred in not more than 3% of cases (1 eye). They establish a comparison with the published results and complications of the other cyclodestructive procedures: Sonocare, transcleral laser Yag, transcleral laser Ruby and cyclocryotherapy. This comparison does not prove the superiority of these other procedures with regard to the non penetrating cyclodiathermy. They conclude that this non penetrating cyclodiathermy is a non expensive procedure which still have its good therapeutic value.

Electrocoagulation↗
PubMed1990

[Diagnostic procedures in optic neuropathies].

Functional disturbance and ophthalmoscopic feature are the most important parameters to diagnose optic neuropathy. Swelling of the optic disc is produced by 2 aetiologies: inflammation and ischaemia. The most frequent cause of retrobulbar neuritis remains multiple sclerosis.

Fluorescein Angiography↗
PubMed1990

[Toxicity of ethylene oxide on the crystalline lense in an occupational milieu. Difficulty of epidemiologic surveys of cataract].

Ethylene oxide is a sterilizing gas for heat-sensitive materials. Eight cases of subcapsular cataract were attributed to this compound from 1982 to 1985. This epidemiological study was conducted in 55 persons to determine the prevalence of lens opacities and cataracts in workers exposed to this gas. The 21 persons of more than 45 years of age were then compared to 16 non-exposed persons matched for age and gender. Lens opacities (independently of visual acuity) were observed in 19 of the 55 exposed. Among exposed and non-exposed persons of more than 45 years of age, there were no significantly differences with regard to the following characteristics of lens opacities: prevalence (13 in the 21 exposed; 10 in the 16 non-exposed), distribution of the localisations, morphology and importance of the cortical opacities. No link was found between the characteristics of the lens opacities and the characteristics of the exposure: habitual exposure and accidental overexposures. For cataracts, defined by the association of lens opacities and a visual acuity less than 20/25 (this loss not being attributable to another cause), their prevalence differed significantly (p less than 0.05) between the exposed (6 of 21) and the non-exposed (0 of 16). There was no relation between their existence and accidental overexposures. The risk of lens opacification by ethylene oxide, established in cases of massive exposures as previously described, could also exist during chronic exposure to low concentrations, but is to be confirmed by other studies. It could be explained by saturation of the protective mechanisms against alkylating action of this product. This study prompted us to discuss the epidemiological difficulties in studies of cataracts.

Animals↗
PubMed1990

[Effects and complications of Nd YAG laser posterior capsulotomy after ECA + PCI (extracapsular extraction and posterior chamber implantation)].

264 consecutive cases of ECCE are reviewed. In this series 28 cases of Nd YAG laser capsulotomy have been performed. Visual results are excellent: visual acuity is improved in 90% of cases. The rate of complications is low: 1 case of retinal detachment, 2 cases of IOP raise, no clinical CME. Laser therapy is performed when visual acuity decreases, prior to other extra clinical examination.

Aged↗
PubMed1989

[A case of MEWDS. "The multiple evanescent white-dot syndrome"].

A young white man developed acute bilateral visual loss with no previous general illness. Ophthalmoscopic examination showed multiple small yellow-white lesions scattered throughout the posterior poles and mild periphery fundus. There was also fine granularity of two foveal areas and one optic disc margin was blurred. Fluorescein angiography showed early hyperfluorescence of the lesions and late staining of the retinal pigment epithelium. Electrophysiologic abnormalities were transient, asymmetric, more marked in photopic than in scotopic. The origin could be in retinal bipolar cells. These lesions regressed, with return of normal visual function within several weeks. These clinical findings are different from others acute inflammatory diseases primarily involving retinal pigment epithelium and photoreceptors. This aspect is usually described as "multiple evanescent white dot syndrome". The etiology of this syndrome remains unknown with no evidence of systemic disease. A history of flulike illness is rare.

Adult↗
PubMed1988

[Histiocytofibroma of the sclerocorneal limbus].

A case of epibulbar benign fibrous histiocytoma is presented, with an optical microscopic study. A greyish vascularised nodule developed at the corneoscleral limbus in a 65 year-old male. The clinical diagnosis was confirmed by histopathologic evaluation. Complete surgical excision had a curative effect.

Aged↗
PubMed1988

[A glaucoma follow-up of 1500 persons over 20 years].

The parameters of glaucoma risk have been compiled and computer processed on 1,571 patients during 20 years at the C.P.E.M.P.N. (Medical Evaluation Center for the Aeronautic Staff) of Paris. The goal of this study is to follow in real time the évolution of these parameters and to determine their physiological variations across time in terms of age and professional categories. An average intra-ocular pressure of 15.1 mmHg as well as hypertonia and glaucoma percentages respectively of 3.88% and 0.6% have been recorded in this study. These results were below the results of other previous surveys due to the greater age range of our study the youngest being 15 years old. There was no significant difference among pilots and non pilots. The optic disc examination was not decisive for diagnostic screening.

Adolescent↗
PubMed1987

[Correction of presbyopia in users of video terminals by progressive half-spectacles].

Twenty one presbyopes of 48 years old and over (considered as emmetropes or light ametropes), and a young aphakik patient wearing contact lenses, working before visualization screens, were equipped with semi-framed Varilux 2. The correction of their Intermediary Vision was made precisely on the upper edged level of the frame; the correction of their Near Vision was made by an addition of strength reduced by half when compared to the usual graduation. This specific equipment was compared to the classical system of their choice, manufactured at the same time and offering the same strength in Near Vision. This comparative study resulted in the following conclusions which were in most cases: a "normalization" of the distance to the working screen, an improved distinctness of characters in the intermediate and near distances, a very definite improvement of the vertical scanning when alternating between the keyboard and the screen, and of the horizontal scanning when alternating between the keyboard, or the screen, and the documents, an obvious diminution of the time of tiredness, and less stiffness of the neck in its usual working position, the proposed progressive half spectacles remained essentially a working tool, but most participants of this study used them for spare time activities, large professional categories (musicians, painters, etc.), including ours, might benefit from them. The possible benefits obtained from their use by aviators will be published separately. These half-framed progressive spectacles seemed to be the best optical complement to propose to aphakic patients wearing contact lenses and to the pseudophakics.

Computer Systems↗
PubMed1987

[Surgical treatment of eye wounds with retinochoroidal metal foreign bodies. Apropos of 6 cases].

Six cases of intra-ocular metallic foreign bodies located into the retino-choroidal wall are presented. A surgical treatment was performed, and included a vitrectomy, a foreign body extraction with intraocular forceps, a primary or a secondary scleral buckling for the peripheral wound, and a retino-choroidectomy for one of the posteriorly located foreign bodies. In all the cases, we observed a cicatricial retraction of the retino-choroidal wound. When the wound was peripheral, the retina detached in the cases without buckling and it was necessary to do a secondary scleral buckling procedure. When the wound was located at the posterior pole, the retina remained flat in one case, with a 6 mm metallic body, probably because of the relaxing retinotomy performed to extract the foreign body. We think that it is better to perform a primary scleral buckle of the peripheral wounds. The various aspects of the treatment are discussed.

Adult↗