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Biomedical subjects

G Coscas

Publications and source records attributed to G Coscas.

At least 325 records · Page 18Linked to original sources
PubMedDate not supplied

Macular grid photocoagulation in persistent macular edema due to central retinal vein occlusion.

AIM: Macular edema is still the main cause of poor visual prognosis in central retinal vein occlusion (CRVO). This study was designed to establish whether grid photocoagulation is effective in the management of this disorder. METHODS: The records of 16 patients who had undergone macular grid photocoagulation for persistent macular edema due to CRVO were reviewed retrospectively. Pre-treatment visual acuity ranged from 20/400 to 20/40, and laser treatment was done six months or more after the onset of the disease. RESULTS: Biomicroscopy and fluorescein angiography showed the improvement or disappearance of macular edema in 14/16 patients (87.5%). Improved visual acuity was observed in eight (50%) and no improvement or reduced vision in the other eight (50%). A poorer prognosis was statistically correlated with older age (p < 0.03), macular ischemia (p < 0.001), foveal avascular zone larger than 1/2 disc diameter (p < 0.05) and pigmentary clumps in the foveal area (p < 0.05). Laser treatment was ineffective for most patients with systemic vascular risk factors and pre-treatment visual acuity below 20/200. CONCLUSION: Macular grid photocoagulation may be effective for drying up, or at least reducing, macular edema due to CRVO and some improvement of vision can be expected in half the cases.

Adult↗
PubMedDate not supplied

Long-term visual outcome of choroidal neovascularization in pathologic myopia: natural history and laser treatment.

UNLABELLED: This retrospective study was designed to help clarify the visual prognosis during long-term follow-up (5-10 years) of myopic choroidal neovascularization (CNV) with and without laser treatment in a referral population. PATIENTS AND METHODS: A group of 50 consecutive non-treated eyes and a group of 50 consecutive treated eyes were selected retrospectively. Inclusion criteria were: fluorescein angiographic documentation of CNV not involving the center of the fovea, visual acuity (VA) > or = 20/200, age less than 60, onset of symptoms < or = 6 months and at least five years of follow-up. The mean decrease in VA in non-treated and treated eyes during the follow-up was analysed on the basis of subgroups with the same initial VA. RESULTS: Considering both groups (100 eyes) at presentation, 89% of CNV spared the center of the fovea but were located in the foveolar area (< 200 microns) and only 11% were extrafoveal (> or = 200 microns). In the natural history group, after five years all CNV involved the center of the fovea and mean VA was 20/160. In the treated group, at the end of the five year follow-up and after one or more laser session, 64% of eyes had a dry scar and mean VA was 20/74. Nevertheless there was a very high rate of recurrences (72%) and at the end of follow-up 36% of treated eyes had a subfoveal recurrence with a mean decrease in VA to 20/154. The difference between the mean decrease in VA of the treated and non-treated groups was statistically significant at two years. At five years (100 eyes), the difference persisted only for eyes with initial VA better than > or = 20/40 (P < 0.05). At eight years (76 eyes) and ten years (24 eyes), this difference was no longer significant. COMMENTS: This study confirms that CNV accompanying degenerative myopia has an extremely poor prognosis. Nevertheless analysis of final VA in both groups suggests that eyes with high initial VA gain more from treatment.

Adult↗
PubMedDate not supplied

Two novel missense mutations in the peripherin/RDS gene in two unrelated French patients with autosomal dominant retinitis pigmentosa.

PURPOSE: To report the identification of two novel RDS mutations in the peripherin/RDS gene of two unrelated French patients affected by autosomal dominant retinitis pigmentosa (ADRP). METHODS: Fifty-eight unrelated patients affected by ADRP were analyzed. Our diagnostic for RP were bilateral fundus involvement, concentric depression of the visual field and severe involvement on electroretinogram. Transmission of the trait was unambiguous. Our strategy was to analyze the coding sequence of the gene using a combination of single-strand conformation polymorphism (SSCP) and direct sequence analysis of the exons of the gene. Exons that displayed conformational polymorphisms were sequenced on an automated DNA sequencer. RESULTS: The sequence analyses revealed two previously unreported missense mutations: Cys165Tyr and Phe211Leu in exons 1 and 2, respectively. None of the 70 controls analyzed carried these base changes. Cosegregation of the base substitution with the disease could be tested in both families presenting the Cys165Tyr and Phe211Leu mutations. CONCLUSIONS: Several lines of evidence support the idea that these base substitutions are disease-causing mutations. To the best of our knowledge, no peripherin/RDS gene analysis has been previously reported in ADRP in France.

Amino Acid Sequence↗
PubMedDate not supplied

[Recent findings on the etiopathogenesis of subretinal neovascularization].

The proliferation of new vessels originating from the choriocapillaris, constitute the turning point in Age Related Macular Degeneration. Vaso-proliferative, or better vaso-modulator, factors have an effect upon the subsequent steps of angiogenesis. Receptors especially for the fibroblast growth factor have been identified on ocular vascular endothelial cells. Basement membranes are the storage site of the factor. In vitro, vaso-proliferative factors, as Fibroblast growth factors, and vaso-inhibitor factors, as Transforming Growth Factor B, were identified in cell cultures of pigment epithelium. On the other hand, proliferations of pigment epithelium cells surround the neovascular sprouts and induce involution of experimental subretinal new vessels. Experimentally and clinically, inflammatory cells are found in the vicinity of the new vessels. Their effect could add or initiate new vessel proliferation. Angiogenesis is an extremely complex phenomenon but results of research on the role of pigment epithelium and vaso-modulators factors help to clarify it partially.

Animals↗
PubMedDate not supplied

[Significance of the digital image in the diagnosis and classification of macular drusen].

Macular drusen, hard or soft, have been often observed at the early stages of age-related macular degeneration. Clinically, it has been shown that soft drusen and macular subretinal new vessels are associated in a statistically significative manner. The question is to recognize and to determine drusen at greatest risk for developing choroidal neovascularization? To answer to this question, a method of digital images analysis of fluorescein angiography had been perfected. About ten eyes, preliminary results show, an objective and quantitative difference of the evolution of the grey level during the same angiogram between the different retinal structures. This method would bring a prognostic feature for the long term follow-up of patients with drusen.

Fluorescein Angiography↗
PubMedDate not supplied

[Transforming growth factor beta in the vitreous of patients with epiretinal proliferation].

Recent evidence suggests that TGF beta, a substance synthetized and released by Retinal Pigment Epithelial (RPE) cells, might play a role in fibrotic preretinal proliferation. We measured the concentration of this factor by radioreceptor assay in samples of vitreous obtained from 17 patients by vitrectomy. Seven had uncomplicated Retinal Detachment (RD) and 10 had either Proliferative Vitreoretinopathy (PVR) or Epimacular Membranes (EM). In the RD group, the mean concentration of TGF beta was 0.06 p mole/ml of vitreous, and in the PVR group, 0.21 p mole/ml. The total mitogenic activity of native vitreous and the amounts of a and b FGF in each sample were also measured, but were not different in the 2 groups. These results suggest that TGF beta is involved in the mechanism of excessive repair which characterises preretinal proliferation.

Cell Division↗
PubMedDate not supplied

[Prognosis in idiopathic retinal periphlebitis. Apropos of 14 cases].

Fourteen patients (26 eyes) suffering from idiopathic retinal periphlebitis were followed during a mean time of 6 years (2 to 11 years). At the first examination, five eyes presented with irreversible loss of vision (tractional retinal detachment, neovascular glaucoma). At the end of follow-up, the visual acuity was inferior to 0.1 in 6 eyes, between 0.1 and 0.5 in 7 eyes, superior to 0.6 in 13 eyes. In 70% of cases, initial visual acuity was maintained or ameliorated. New vessels were present in association with significant capillary closure in 18 eyes (70%). Cystoid macular edema appeared in 7 eyes (27%). Steroid therapy, or immunosuppressants in few cases, were usefull to suppress intraocular inflammation. Laser photocoagulation was performed in 18 eyes in order to prevent or reduce ocular neovascularization; beneficial results were obtained in 13 eyes.

Adrenal Cortex Hormones↗