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Biomedical subjects

G Renard

Publications and source records attributed to G Renard.

At least 199 records · Page 11Linked to original sources
PubMed1991

Biocompatibility of a refractive intracorneal PMMA ring.

Intrastromal ring (ISR) implantation is a promising concept in refractive corneal surgery. In theory, it has two main advantages: eccentric corneal surgery and reversibility after ISR explanation. We present our first experimental data on histobiocompatibility after implantation of a 0.2/1.0 mm vaulted polymethylmethacrylate (PMMA) ISR of 7.5 mm diameter with a specially designed "puzzle lock" using a suction-guided stromal channelling device. Ninety-six rabbit eyes were implanted and enucleated after a 24-h to 8-month follow-up to be period and processed for histology (n = 51), scanning electron microscopy (n = 30) and transmission electron microscopy (n = 9). In this study, the histological data are reported. Two main histopathological phases of stromal reaction were observed: (1) up to 3 months: mild inflammation, mostly mononuclear cell reaction with some macrophages; (2) over 3 months: moderate fibrosis surrounding the ISR filling irregularities of the stromal channel. Mild scarring and rare circumscribed vascularization occurred at the sutured peripheral insertion site of the ISR. Persistent epithelial atrophy without erosion or ulceration was regularly observed over the bulging shoulder of the ISR. There was no significant endothelial surgical trauma due to ISR placement. Major complications occurred in 11 cases (11.5%): stromal abscess starting from the incision (n = 8) and massive neovascularization (n = 3). However, the incidence of complications regressed with improved surgical technique. In conclusion, there is good middle-term tolerance of the PMMA ring with a transparent central cornea.

Animals↗
PubMed1991

Surgical management of corneal perforation with expanded polytetrafluoroethylene (Gore-Tex).

We report a series of six patients with spontaneous corneal perforations successfully treated with a temporary graft of expanded polytetrafluoroethylene (Gore-Tex) until a definitive penetrating keratoplasty could be performed. Two other patients had a paralimbic perforation treated with an artificial lamellar Gore-Tex graft. No infection or extrusion developed, and the artificial graft kept the anterior chamber tight in all cases. Gore-Tex appears to be a safe and effective material for use in treating acute central and peripheral corneal perforation.

Adult↗
PubMed1990

[Combined operation of glaucoma and cataract. Comparison between 2 operative techniques].

In this retrospective study of combined surgery we compared patients who underwent Trabeculectomy (Trab.) + Intracapsular cataract extraction (EIC) +/- Intraocular lens (IOL) with patients who underwent Trabeculectomy + Extracapsular cataract extraction (EEC) +/- IOL. All the patients presented with primary open angle glaucoma with a senile cataract. Each group studied included 20 eyes. After 24 months we confirmed that the mean postoperative intraocular pressure (IOP) showed a decrease of 7.4 mmHg in the first group (EIC + Trab.) and 5.46 mmHg in the second group (EEC + Trab.) of patients. A statistically significant difference was observed between the two groups (p less than 0.05). On the basis of IOP the 1st group showed a success rate of 85% after an average period of 23.55 months (6-43 months). The 2nd group presented a success rate of 90% after an average period of 18.3 months (4-37 months). The mean visual acuity after 24 months improved in the 1st group from 0.10 to 0.50 and in the second group from 0.13 to 0.50. Seventy percent of the eyes recovered a visual acuity greater than or equal to 0.4 in each of the two groups. In both groups of patients, surgery allowed a reduction in the prescription of drugs. We therefore verified that, in the first group, combined surgery allowed us to more effectively control the IOP while achieving a greater improvement in visual acuity. However, it must be stressed that intracapsular cataract extraction is associated with a higher complication rate.

Aged↗
PubMed1990

[Treatment of dry eye by temporary punctum plug. Comparison with a control group].

35 patients with chronic dry eye were treated with punctum plug on one side only. The other side was a control: after simulation dilatation, the patient underwent a simulation insertion. This is an open study in which only the patient ignored the reality of treatment. The study was prospective. 28 females and 7 males were enrolled in this study. The age' average was 53. The follow-up average is 5.3 months. The etiologies were: idiopathic dry eye: 10 cases, Sjögren's syndrome: 11 cases, drug induced dry eye: 6 cases, filamentous keratitis: 4 cases. Other: 4 cases. Enrollment criteria were: functional symptomatology not answering to topical therapy (physiological serum drops) associated with one or more of the following items: positive Rose Bengal staining and/or Schirmer lower than 5 mm in 5 min and/or filamentary keratitis. Subjective improvement is significantly better after closing the two puncta on the same side (77%) than the other side (placebo) (17%) (p less than 0.001). This difference is also demonstrated for the improvement of Rose Bengal staining (p = 0.068) and for Schirmer's test (p = 0.002). These results demonstrated the effectiveness of this therapy versus placebo. Results after closing the 2 puncta on the same side are better than after closing one punctum.

Adolescent↗
PubMed1990

[Complications of punctum plug in the symptomatic treatment of dry eye].

76 patients with dry eyes were treated by mechanical obstruction of lacrymal puncta. The sex ratio is: 62 females and 14 males. The age average was 55, ranging from 12 to 88. The etiologies were: Sjögren's syndrome: 16 cases (21%); filamentous kerato-conjonctivitis sicca: 12 cases (15%); anxiolytical and anti-depressant treatments: 10 cases (13%); complicated viral kerato-conjonctivitis: 4 cases (5%); post radiotherapy dry syndrome: 3 cases (4%); idiopathic and various etiologies: 31 cases (40%). The 149 plugs are completely made of hydrophobic silicone; 20 had a barb inclined on the neck axis. Insertion was achieved after tropical anesthesia in 90% of the cases. 121 plugs (81%) did not lead to any anatomical complication (the average duration remaining on time interval of implantation per plug was of 5 months). Functional tolerance depends on the quality of plug-punctum adjustment. Plug protrusion is the main cause of intolerance and disappearance. The complications were: rupture of punctum during dilation: 1%; suppurative canaliculitis: 1.3%; disappearance: 16%; epiphora: 22%. No intra-canalicular migration was observed. We check canalicular permeability in 26 cases, after loss or removal: che was normal 23 times (average time-interval: 5 months). We had 3 cases of canalicular stenosis after 4 months, 5 months and 18 months of intubation.

Adolescent↗
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

[Ophthalmologic manifestations of AIDS in an African milieu. Report of 45 cases].

Acquired Immune Deficiency Syndrome (AIDS) is a pathological entity whose agent is a virus called HIV (Human Immunodeficiency Virus). The principal immunological deficit is the insufficience of immunity in mediation cell. Actually AIDS can be considered as the "bubonic plague" of the 20th century. Eye lesions caused by AIDS could present in 54 to 94% of patients of AIDS (3,19). Eye symptoms can be classified into four main categories or groups: retinal vascular lesions, eye opportunist infections, neoplasms of the eye surface and the orbit and finally neuro-ophthalmological anomalies. This study was realised at the university clinic of Mont Amba in Kinshasa, Zaire. A total of 45 cases were studied of which 42 cases with full blown AIDS (1 Congolese, 3 Ruandese, 1 Zambian and 37 Zaireans) and the other three were HIV positive (all were Zaireans). Among the 45 cases, 20 were studied retrospectively with a counting down of 5 years, and 25 others comprised of a prospective group of study or research. The patients were seen either in an ophthalmology Department/Service, or in a medical Service/Centre or in both. The criteria of diagnosis of AIDS were almost the same: skin anergy, infections and/or neoplasm opportunists, the lymphopenia T4, the report T4/T8 low or inversed and the HIV serology positive. A complete opthalmological test was undertaken, the indirect ophthalmoscopy and the retina fluorography were not done. A sex ratio is 1,64 (28 men for 17 women). The 45 patients were sexually active heterosexuals. None of them used drug intravenously. No accidental case of blood transfusion was revealed.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1990

[Rapid imaging in orbito-ocular pathology. Contribution of gadolinium].

To evaluate Gradient-Echo Imaging (GEI) in orbito-ocular pathology, 15 volunteers and 34 patients (40 lesions) were examined with GEA T1 and GEA T2 (0.5 T). Results were compared with SE T1 in all cases, with SE T2 in 20 cases and with other imaging modalities (CT). 30 patients were examined before and after injection of gadolinium. Final diagnosis was obtained by surgery or biopsy in 24 cases or by combined results of imaging and clinical findings in 16 cases. Compared with SE, GEA demonstrated a better visualisation of optic nerve, orbital muscles, choroidal-retinal layer, lens capsule and episclera and a better detection of small lesions. It is very helpful for characterisation of lesions containing hemorrhages or paramagnetic components (melanine, gadolinium) or of vascular nature (angioma). Gadolinium was useful for detection of small lesions or characterisation of a few lesions. Thus GEA seems to be an efficient method for the evaluation of orbito-ocular pathology.

Adolescent↗
PubMed1989

Terrien's disease: clinical and ultrastructural studies, five case reports.

Terrien's disease occurs in middle-aged patients and is characterised by an insidious thinning of the cornea near the limbus. In most cases, this results in a peripheral ectasia associated with a severe degree of astigmatism. Inflammatory signs are rarely observed in this marginal corneal degeneration which is of unknown aetiology. Electron and light microscopic studies have been performed on five specimens from penetrating keratoplasties. Anatomical and clinical correlations showed the marked marginal degenerations of the corneal stroma to be consistently associated with lipid deposits, but without inflammatory cell infiltrate. These changes are in agreement with previous reported pathological descriptions of Terrien's disease.

Adult↗
PubMed1989

Keratoconus associated with Terrien's marginal degeneration. A clinical and ultrastructural study.

A 59-year-old man presented with Terrien's marginal degeneration associated with keratoconus of his left eye. Penetrating keratoplasty of the left eye permitted an evaluation under optical microscopy, as well as transmission and scanning electron microscopy. An anatomical-pathological evaluation confirmed the co-existence of a central lesion due to keratoconus and a peripheral lesion due to Terrien's marginal degeneration. An absence of the knowledge of the etiology of either affliction does not allow one to define whether there exists one or two active degenerative processes.

Cataract Extraction↗
PubMed1989

Trifluorothymidine localization in the rabbit cornea by secondary ion mass spectrometry imaging microanalysis.

Imaging microanalysis by secondary ion mass spectrometry is a sensitive surface analytical technique that allows the detection and localization of elements and compounds in biological tissues. We report the detection by this approach of intracorneal trifluorothymidine following topical administration in rabbit with normal cornea. The presence of trifluorothymidine is revealed using 19F as a marker, allowing the acquisition of ultrastructural microanalytical images without using radioactive tracers.

Animals↗
PubMed1989

[Terrien's disease, apropos of 6 cases. Ultrastructural study].

Terrien's disease is characterized by slowly progressive thinning of the pre-limbal cornea in middle-aged patients. It usually leads to peripheral ectasia with marked astigmatism. It is rarely accompagnied by inflammation and its cause is unknown. Very few histopathologic examinations have been published, in particular those using electron microscopy We present detailed results concerning 6 patients in whom perforating keratoplasty permitted histopathologic and electron microscopic examination. Clinical and histological features reveal marked degeneration of the peripheral corneal stroma, with lipid accumulation unaccompagnied by significant inflammatory cellular infiltration in each case. Of interest is the association in one patient with keratoconus. The generally accepted pathogenic theories are fully discussed. The wealth of electron microscopic data provides a complete review of stromal degenerative changes.

Adult↗
PubMed1989

[Corneal perforation: a new solution...].

Two patients with perforation were treated with an inert vitrous teflon alloplast, expanded polytétrafluoroethylene (E.PTFE). Details of the surgical technique are discussed.

Adult↗
PubMed1988

Excimer laser keratectomy for myopia with a rotating-slit delivery system.

We performed argon fluoride excimer laser (193-nm) superficial keratectomy for myopia on human donor eyes and on a resected corneal disc. The laser beam was shaped by a rotating slit to produce a circular ablation 7.5 mm in diameter, with a mathematically defined profile to correct myopia. The fluence at the surface of the cornea was 200 mJ/cm2; the laser was fired at 20 Hz. Each 4.5-mJ laser pulse etched a 0.17-micron deep image of the slit in the cornea. Since the slit moved (0.03 Hz), each successive pulse etched an area adjacent to the previous one, reducing damage from repetitive pulses striking the same area. The slit scanned the cornea many times and the summation of these individual ablations produced the smooth myopic ablation profile, as shown by computerized keratographs and light and electron microscopy.

Cornea↗
PubMed1988

Phase II trial of menogaril in advanced colorectal cancer.

Menogaril, a new semisynthetic anthracycline antibiotic, was administered to 35 patients with advanced colorectal cancer. The drug was infused over 2 hr at a dose of 160 mg/sqm or 200 mg/sqm repeated every 4 weeks. Twenty-seven patients were evaluable for response and no objective responses were achieved. Myelosuppression, only leukopenia, was usually of mild-moderate degree and occurred in 63% of the patients. Twenty-seven percent of the patients experienced severe leukopenia. Local erythema and phlebitis were frequently observed and were severe in 13% of the patients. Nausea/vomiting (66%) and alopecia (50%) were. of mild-moderate degree. This study suggests that menogaril at these doses and schedule had no activity in advanced colorectal cancer.

Adult↗