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Biomedical subjects

G Coscas

Publications and source records attributed to G Coscas.

At least 199 records · Page 11Linked to original sources
PubMed1985

[Hypereosinophilic syndrome with ocular involvement].

The authors report a case of idiopathic hypereosinophilia with Löffler endocarditis in a 19 year old male. Retinal arteriolar occlusions were observed in the pre-equatorial region and documented by angiography. Histologic examination of the globes showed obliteration of the arterioles by a fibrinous coagulum without signs of vasculitis. Clinical data appears to suggest an embolic origin of the occlusions rather than thrombosis in situ.

Adult↗
PubMed1985

[Ocular complications of Lyell's syndrome: recent concepts apropos of 26 cases].

Acute ocular lesions are usual during Toxic Epidermal Necrolysis (T.E.N.) and may induce persistent alterations. These were thought to be of cicatricial nature. 26 patients recovering from TEN had a systematic ophthalmological follow-up of at least six months after the acute stage (mean: 3 years). 11 of 26 patients (42%) exhibited a dry eye, associated in 7 with decreased salivary flow. The sicca syndrome appeared during the acute phase of TEN or, more often, a few weeks later. The reduction of the lacrymal flow induced corneal lesions in all 11 patients and 6 patients suffered permanent visual impairment. Biopsies of labial accessory salivary glands showed a lymphocytic infiltration of the glandular tissue in 5 of 7 cases. In 2 cases the lymphocytic infiltrate was nodular, grade III of Chisholm's classification, considered as pathognomonic of Sjogren's syndrome. The occurrence of Sjogren-like syndrome in patients recovering from TEN suggests an auto-immune pathogenesis for TEN, and is one more analogy between TEN and graft-versus-host disease.

Conjunctival Diseases↗
PubMed1984

Acute sectorial choroidal ischemia.

Four eyes (of three patients) with sectorial choroidal ischemia by temporal arteritis or carotid obstruction underwent fluorescein angiography during and after the acute phase. In all cases hypoperfusion affected the whole temporal choroid; however, disturbance of retinal pigment epithelium was much less extensive. In two cases the retinal pigment epithelium became necrotic and scarred within a limited area that was typically triangular in shape; in the third case scarring was limited to some pigmented streaks, and in the fourth case, retinal pigment epithelium remained normal. The triangular scar that appeared after episodes of choroidal hypoperfusion did not seem to be a true reflection of the extent of the choroidal artery obstruction in the acute phase. Our observations suggest that the deficient choroidal perfusion involved more than the choroidal artery supplying the triangular area of pigment epithelium disturbance. Several mechanisms (for example, retrograde venous filling, restoration of perfusion) reduce the deleterious effects of ischemia. Thus the necrosis of the retinal pigment epithelium would appear in only those sectors where ischemia was particularly severe or prolonged.

Acute Disease↗
PubMed1984

Natural course of nonaphakic cystoid macular edema.

We evaluated the longterm natural history of nonaphakic cystoid macular edema (CME) in a retrospective study of 130 out of 557 CME cases recorded in the past ten years. A listing of causes was provided and the cases divided into two groups: those with perifoveal leakage and those with deep subretinal leakage. In cases of diabetic retinopathy, 60 patients who were followed up for more than three years had noncystoid or cystoid macular edema. The occurrence and persistence of a large central foveal cyst usually resulted in a severe decrease in visual acuity. Hard exudates, present in 60% of cases, seemed to influence visual prognosis when they were inside the foveal avascular zone. In cases of venous occlusion, chronic CME increased the risk of a central cyst and was the major cause of a macular scar. In cases of uveitis and vasculitis, the restoration of macular capillary wall competence was possible when inflammation decreased. Disturbances in the macular pigment epithelium were also shown to produce poor visual acuity.

Choroid Neoplasms↗
PubMed1984

[Toxoplasmic choroiditis and subretinal neovessels].

Thirty six cases of toxoplasma chorioretinitis with fundus scars were studied. Subretinal neovascularization occurred in 7 cases out of 36. Angiographically, the new vessels were located either directly on the border of scar (5 cases) or at distance with feeder vessels arising from the scar. The identification of subretinal new vessels is easy during the early phase of angiography. At the late phase, the leakage from the membrane is usually difficult to distinguish from the staining of the scar. Leakage from these new vessels can cause a sudden decrease of visual acuity (from 0.4 to central scotoma) that is not associated with inflammatory signs. The natural history of these juxtafoveolar new vessels allows a useful final acuity (0.18 after a follow-up period from 5 to 42 months). The visual outcome of toxoplasmosis choroiditis without subretinal new vessels is usually around 0.5. In 3 eyes photocoagulation of new vessels was performed with improvement in the mean final acuity (0.3). In our cases the occurrence of subretinal new vessels happened only when the healing process was achieved, from 1 to 26 years after the acute chorioretinitis.

Adolescent↗
PubMed1984

[Effects of red krypton and monochromatic green argon lasers in the foveal region. A clinical and experimental study].

The destruction of senile neovascular membranes in the central avascular region of the macula using argon laser is difficult and associated with complications. Yellow pigment in this region absorbs the blue component of the conventional argon laser radiation. In this study, we compared laser of different wavelenghts: red krypton and green argon. Light and electron microscopic studies on non-human primates were performed at one hour and three weeks following laser burns. With the red krypton laser maximum damage was seen at the level of choriocapillaris and the choroïd, although the pigment epithelium was also destroyed. With the green argon laser the maximum absorption occurred at the level of the pigment epithelium. A clinical and angiographic study showed that the destruction of juxtafoveal neovascular membranes by both these lasers was possible after one or several treatment sessions. After an average follow-up period of 45 months, visual acuity was stable or improved in 10 out 17 eyes treated with the green argon laser and in 27 out of 53 eyes treated with the red krypton laser. Our results suggest that the red krypton laser offers a better alternative for the treatment of neovascular membranes located near the foveola since less unnecessary damage is induced. Outside the xanthophyllic area there is no major difference between the different wavelengths.

Animals↗
PubMed1984

[Angiographic aspects of senile macular degeneration: spontaneous course].

Between 1971 and 1981, 45 patients (50 eyes) with a senile macular degeneration were seen at an early stage of the disease. These patients were followed for 6 to 72 months (mean follow-up 32 months). The early morphological features and evolution of the lesions were analysed by fluorescein angiography. Three different angiographic types of subretinal new vessels were identified in this study. These were: angiographically visible vascular networks (27 cases) subretinal new vessels hidden behind retinal pigment epithelium modifications (9 cases); and subretinal new vessels associated with pigment epithelial detachment (14 cases). In the first group subretinal new vessels were clearly visible on the angiogram, as a distinct network of cart wheel-like capillary plexuses which fill very early in the arterial phase. Progressive leakage of dye hides this capillary plexus during the late phase. In the second group a pigment epithelial detachment, usually identified on biomicroscopic examination, was associated with neovascularization visible as a hyperfluorescent hot spot or as an uneven hyperfluorescence on the border of the RPE detachment. Other angiographic features are a non-circular shape, irregular filling of the pigment epithelial detachment, and uneven late hyperfluorescence. In the third group, occult neovascularization was usually located behind the retinal pigment epithelium. When subretinal neovascularization was suspected by the presence of a disciform lesion, angiography, showed an irregular pattern of delayed hyperfluorescence with late leakage. These features permit putative diagnosis without precise localization. This clinical study attempted to establish the evolution and prognosis of three clinical forms of subretinal new vessels, in order to more accurately establish the indications of photocoagulation treatment.

Aged↗
PubMed1984

[Indications, technics and results of argon laser photocoagulation of macular subretinal neovascularization].

New vessels in senile macular degeneration threaten central vision. To evaluate the effects of treatment a randomized prospective trial was undertaken between 1977 and 1981. This trial concerned destruction of subretinal new vessels by argon laser photocoagulation. The indications of photocoagulation depended on the location of new vessels in relation to the center of the fovea. New vessels amenable to this treatment were those that were clearly visible on angiography and located farther than 100 microns from the foveola. 60 patients were divided into 3 groups according to the distance of the new vessels from the fovea: 100-200 microns away; 200-400 microns away; and greater than 400 microns away from the center of the fovea. In each group patients were randomly assigned to treatment or no treatment. After at least one year follow-up, argon laser showed a statistically significant effect (p less of 0,01; Kolmogorow-Smirnov test) on the stabilization or the amelioration of visual acuity compared with the non treated group. There was no statistical difference in the 3 groups of new vessel location. In cases of failure, no differences in final visual acuity existed between the treated and the non-treated group.

Aged↗
PubMed1984

[Treatment of diabetic cystoid macular edema by argon laser photocoagulation].

Diabetic maculopathy remains the main cause of poor visual acuity in diabetic retinopathy either proliferative or non proliferative. Although photocoagulation in the macular area is known to be effective in treatment of exudates, results in treatment of cystoid macular edema (CME) are still questionable. 36 eyes with diabetic CME and non ischaemic capillary bed were treated with argon laser photocoagulation in the macular area. Two groups of patients were studied. Group I consisted of 16 eyes with CME and with circinate exudates in the paramacular area. Mild argon burns (50-200) were applied on the microvascular abnormalities and on the pigment epithelium in the center of the circinate exudates. The macula (1500 of diameter) was not treated in this group. As expected, results on the exudates rings were good. CME disappeared in 43% of the cases, and regressed in 23% of the cases. Nevertheless 3 years after treatment the mean visual acuity was found to be slightly worse than before the treatment. Group II consisted of 20 eyes with CME, exudates were absent or scattered. Mild argon burns were applied on the area of macular cysts avoiding only the foveal avascular zone (500 of diameter). Exudates when present disappeared in all cases. CME disappeared in 80% of the cases and regressed in 15% of the cases. Three years after treatment mean visual acuity remained identical. Extensive review of the literature concerning the treatment of diabetic maculopathy shows a wide range of techniques and evaluation procedures. We propose the following method of treatment: when exudate rings are present with CME, treatment should be aimed first towards focal microvascular abnormalities avoiding the macular area. When exudates are absent or in cases of unchanged CME after extramacular photocoagulation, treatment should be aimed towards the microcystic area avoiding the foveal avascular zone, if visual acuity is less than 0,5.

Aged↗
PubMed1984

[Retinal arterial macroaneurysms].

Nineteen eyes of 17 patients were examined for complications associated with a retinal macroarterial aneurysm. 13 of 17 patients were feminine and over 70 years of age and 15 had longstanding systemic hypertension. Visual loss associated with retinal macroarterial aneurysms was related to macular hemorrhage, exudate, or serous retinal detachment. Twelve eyes had retinal hemorrhages associated with the macroarterial aneurysm. Hemorrhages were subretinal and/or preretinal of which some diffused into the vitreous. Seven eyes were treated by direct argon laser photocoagulation of the aneurysm giving an arterial occlusion. Five eyes received perianeurysmal photocoagulation without occlusion of the arteriole. Five eyes received no laser treatment because their exudate or hemorrhage was not threatening the fovea and these evolved towards cicatrisation without a drop in visual acuity. Improvement in visual acuity was noted with both types of photocoagulation. But, direct photocoagulation was found less preferable since an absolute scotoma may be created by the area deprived of arterial flow. Perianeurysm photocoagulation was found to be effective, and is indicated in cases of deep exudate and edema that may threaten the fovea. Treatment is questionable when hemorrhage is the predominant complication.

Aged↗