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G Soubrane

Publications and source records attributed to G Soubrane.

At least 91 records · Page 5Linked to original sources
PubMed1996

Retinitis punctata albescens associated with the Arg135Trp mutation in the rhodopsin gene.

PURPOSE: To screen for mutations in the rhodopsin, peripherin/RDS, and ROM1 genes in a family affected with retinitis punctata albescens. Because clinical heterogeneity was observed in this family, with some members affected with retinitis punctata albescens and one member affected with features typical of retinitis pigmentosa, we analyzed the apolipoprotein E gene to elucidate this unusual intrafamilial heterogeneity. METHODS: The coding sequences of these genes were analyzed with a combination of single-strand conformation polymorphism and direct sequence analysis. Haplotypes of the apolipoprotein E gene were analyzed by polymerase chain reaction and enzymatic digestion. RESULTS: The Arg135Trp mutation in the rhodopsin gene was observed in all affected members of this family, but no mutation was detected in the peripherin/RDS or ROM1 genes. The e4 allele of the apolipoprotein E gene apparently cosegregated with the albescens phenotype in this family. CONCLUSIONS: The albescent phenotype in retinal dystrophy appears to not be caused exclusively by a peripherin/RDS gene mutation, and we suggest that the apolipoprotein E gene may play a role in the albescent phenotype.

Adolescent↗
PubMed1996

Etiology of choroidal neovascularization in young patients.

BACKGROUND: Choroidal neovascularization (CNV) is a common cause of legal blindness in developed countries. In patients younger than 50 years of age, CNV can be due to various causes, but to the authors' knowledge there has been no large epidemiologic study to compare the relative incidence of the various causes of CNV in this younger-aged group. METHODS: A retrospective study was performed of patients seen over a 30-month period to precisely define the relative incidence of the various etiologies of CNV in patients younger than 50 years of age who had been referred to a tertiary care ophthalmology department in western Europe. RESULTS: Clinical charts and angiograms of 363 patients were reviewed. The etiology of CNV was high myopia in 225 (62%) patients, pseudo-presumed ocular histoplasmosis syndrome in 42 (12%), angioid streaks in 17 (5%), and miscellaneous hereditary or traumatic or inflammatory disorders in 16 (4%). Choroidal neovascularization could not be related to any etiology in 63 (17%) patients, and was considered to be idiopathic lesions. Choroidal neovascularization was subfoveal in 62% of the patients due to myopia versus 30% to 36% in patients due to other etiologies. Laser photocoagulation was applied in the majority of patients due to all etiologies except myopia. CONCLUSION: These data provide the relative incidence of the various etiologies of CNV in young patients and emphasize the importance of myopia as an etiology of CNV in such patients. In addition, an apparent preferential localization of CNV to the subfoveal region in myopic eyes precludes its treatment with photocoagulation.

Adolescent↗
PubMed1995

Imaging of chorioretinal anastomoses in vascularized retinal pigment epithelium detachments.

OBJECTIVE: To identify specific features of pigment epithelium detachments with limited hyperfluorescent lesions (hot spots). DESIGN: One hundred eighty-two consecutive patients (186 eyes) who had vascularized pigment epithelium detachments and recent onset of symptoms were examined with indocyanine green and fluorescein videoangiography using the scanning laser ophthalmoscope. The choroidal neovascularization complex and macular retinal vessels were studied. The natural history and the effect of laser treatment were evaluated. RESULTS: Fifty-four eyes had hot spots on indocyanine green angiography. In 50 of these 54 eyes, the video analysis showed an anastomosis of one or more retinal vessels, with the choroidal neovascularization within the hot spot. One or two retinal veins or arteries or both filled with both dyes and were seen to enter into the hot spot. Results of indocyanine green-guided photocoagulation of the hot spot in 28 eyes were disappointing. CONCLUSION: Continuous recording of the early phases of fluorescein and indocyanine green angiography allowed identification of chorioretinal anastomoses in vascularized pigment epithelium detachments with hot spots at an early exudative stage of age-related macular degeneration in 50 (26.8%) of 186 eyes. The poor outcome of laser photocoagulation could be related not only to the development of an overlying pigment epithelium detachment, but also to the retinal and choroidal vascularization of the lesion.

Aged↗
PubMed1995

Indocyanine green videoangiography of angioid streaks.

PURPOSE: The fluorescein angiographic features of angioid streaks are variable, and angioid streaks and their main complication, choroidal neovascularization, can sometimes be difficult to visualize in the presence of diffuse pigment migration, diffuse atrophy of the retinal pigment epithelium, or hemorrhage. The objective of the present investigation was to define the indocyanine green angiographic features of angioid streaks and to compare them with findings on fluorescein angiography. METHODS: For this prospective study, we recruited 22 consecutive patients, 21 of whom had angioid streaks and one who had typical peau d'orange appearance of the fundus. Complete ophthalmologic examination, fluorescein angiography, and indocyanine green videoangiography by the means of scanning laser ophthalmoscope were performed on all patients. RESULTS: In 21 patients with angioid streaks and in one patient with peau d'orange appearance of the fundus, indocyanine green videoangiography showed angioid streaks in the form of hyperfluorescent lines with numerous associated hyperfluorescent foci. The angioid streaks were more clearly visualized and were seen to be more numerous and larger by indocyanine green videoangiography than with red-free images or fluorescein angiography. Choroidal neovascularization was suspected in six eyes but could be precisely localized by fluorescein angiography in only three eyes. Indocyanine green angiography allowed precise localization of choroidal neovascularization in all six of these eyes. CONCLUSIONS: These findings indicate that indocyanine green videoangiography provides different information than fluorescein angiography in the evaluation of angioid streaks and can more precisely localize their neovascular complications.

Adolescent↗
PubMed1995

[Effect of rheological factors on diabetic microangiopathies: is there an effective medical treatment for diabetic retinopathy?].

Rheologic abnormalities, observed in type I and type II diabetes, have been implicated in the onset and progression of microangiopathy and of diabetic retinopathy. This theory of pathogenesis, proposed by Farhaeus in 1921, and developed by Little, takes into account complex abnormalities of blood viscosity, platelet and erythrocyte aggregation, fibrinolysis, coagulation and oxygen fixation by hemoglobin. The correction of these abnormalities might delay or prevent the onset or the progression of diabetic microangiopathy, most notably of retinopathy. No study, however, has demonstrated an therapeutic effect of molecules acting on the different rheologic factors. In contrast, strict long-term control of glycemia leads to a partial or complete correction of some of these rheologic abnormalities.

Blood Coagulation↗
PubMed1995

[Laser photocoagulation treatment of diabetic maculopathy].

Diabetic retinopathy is the main cause of decreased visual acuity in non-proliferative or proliferative diabetic retinopathy. The frequency of maculopathy rises with age and the duration of diabetes, and now represents the major therapeutic problem following the control of neovascular proliferation through pan-retinal photocoagulation. Oedematous maculopathy, focal or diffuse, and cystoid macular oedema are improved by laser photocoagulation, either focal or grid. Laser photocoagulation is not indicated for predominantly ischaemic maculopathy. The laser treatment should be carried out early in the stage of clinically significant oedema, and applied either focally or in a grid depending on the clinical and angiographic features of the diabetic maculopathy. If pan-retinal photocoagulation is also indicated it should be performed after the focal macular treatment. Laser treatment should always be accompanied by a general medical assessment, emphasising optimal glycemic control and control of associated risk factors, especially arterial hypertension.

Aging↗
PubMed1994

Superoxide inhibits proliferation and phagocytic internalization of photoreceptor outer segments by bovine retinal pigment epithelium in vitro.

Experiments were performed to investigate the effect of free radical damage on two aspects of retinal pigmented epithelium (RPE) metabolism, namely, proliferation and phagocytosis. Bovine RPE cells were maintained in monolayer cultures, either as passaged (for proliferation and lysosomal activity assays) or primary cultures (for phagocytosis measurements). Free radicals (superoxide anions) were generated by a xanthine oxidase (XO)-hypoxanthine (HX) reaction. Total phagocytosis (binding plus ingestion of rod outer segments (ROS)) was quantitated by radioimmunoassay using a specific anti-opsin antibody and iodinated secondary antibody. In some cases, agents with known or possible protective influences against oxidative damage, i.e., superoxide dismutase (SOD), vitamin E, and basic fibroblast growth factor (bFGF), were tested for their activity in this model system. RPE cell proliferation was inhibited in a HX-XO dose-dependent manner, in the absence of cell toxicity. Modifications of cell morphology were also noticed. Either simultaneous exposure of RPE cells to ROS membranes and HX-XO or pretreatment of ROS membranes with HX-XO prior to their addition to RPE monolayers led to a statistically significant 20-30% decrease in phagocytosis relative to control values. This decrease was essentially observed in the binding phase of phagocytosis, indicating damage to ROS surface molecules as the primary event. Addition of SOD or vitamin E prevented this loss of phagocytic activity, whereas bFGF had no effect. Superoxide radicals did not, however, affect phagocytosis when RPE cells were exposed to them alone, prior to incubation with ROS; nor did they alter a later stage in the phagocytic process, acid phosphatase activity. This tissue culture model represents a convenient system for analyzing free radical damage in different aspects of RPE-photoreceptor behavior and may be useful in studying this phenomenon in several retinal disorders.

Acid Phosphatase↗
PubMed1994

Visual function and course of basal laminar drusen combined with vitelliform macular detachment.

Basal laminar drusen (BLD) are small round yellow drusen that are more easily visualised angiographically than biomicroscopically, with a 'stars in the sky' pattern. Patients with BLD are predisposed to macular vitelliform detachment. Little is known about the course of the disease, but the prognosis for retention of useful central vision for patients with BLD is thought to be better than for patients with typical drusen. A retrospective analysis of clinical and angiographic charts of 19 patients with BLD combined with a vitelliform macular detachment was performed to precisely describe their course. In addition, nine patients were re-examined to allow an analysis of their visual function--that is, central visual field, contrast sensitivity, and colour vision. Eyes without choroidal new vessels retained a fair visual acuity (mean final visual acuity 0.5; follow up 4 to 69 months, mean 24 months). In 11 of these eyes visual function assessment disclosed a reduction of contrast sensitivity in high and medium spatial frequencies in nine eyes (81%), a blue-yellow dyschromatopsia in nine eyes (81%), and a mild reduction of foveal threshold in seven eyes (63%). Choroidal neovascularisation (CNV) was observed in 12 eyes (31%) with a poor final outcome (mean final visual acuity 0.1). Two thirds of cases of CNV were observed at the time of presentation; thus this finding may be a bias of a referring centre. However, the high prevalence of CNV suggests the need for a close follow up of patients with BLD.

Adult↗
PubMed1994

Basic fibroblast growth factor experimentally induced choroidal angiogenesis in the minipig.

Basic fibroblast growth factor (bFGF), a soluble mitogen, has been isolated and purified from various organs, including the retina. In vivo angiogenic activity of bFGF has been demonstrated with several assays. An experimental model of choroidal neovascularization was developed in the mini pig by perfusion of recombinant human bFGF through an osmotic minipump. Endogenous bFGF and bFGF receptors were localized in the normal pig retina by immunohistochemistry and autoradiography after binding. The perfusion of exogenous bFGF induced well-organized new vessels along the last 3 mm of the catheter in the suprachoroidal space. This neovascularization did not penetrate the normal Bruch's membrane. Vascular cells (identified by von Willebrand factor antibody staining) increased in number and in surface from the proximal part to the end of the intraocular catheter in all bFGF perfused eyes. In eyes perfused with phosphate buffered saline (controls), but not in the bFGF perfused eyes, an inflammatory response occurred (identified by a macrophage specific antibody). These results demonstrate that choroidal angiogenesis can be achieved without an inflammatory response by perfusing an excess of bFGF in the suprachoroidal space.

Animals↗
PubMed1994

[Albinism].

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Adolescent↗
PubMed1993

[Severe myopia or myopia-disease?].

An increased axial length over 26 mm is one of the characteristics of highly myopic eyes. High myopia represents a marked type of the refraction disorders in which distance vision is impaired and leads to wear glasses in childhood. But this high myopia is also a degenerative myopia due to the distension of the whole envelopes of the ocular bulb mainly at the posterior part of it. Prevalence of high myopia in the general population ranges from 1 to 4%. The disease is usually inherited and transmitted in a dominant fashion. Degenerative myopic eyes are potentially blind eyes due to many complications occurring during lifetime at the choroidal or retinal level. Vision threatening retinal detachments are frequent and severe, and are sometimes related to a macular hole. Other diseases including glaucoma and cataract are more frequently encountered in those eyes but may be managed with higher success. Specific oculo-motor disturbances and strabismus are also encountered. At present, the main risk threatening central vision is macular disease with lacquer cracks and hemorrhages associated with subretinal new vessels growth. Only laser photocoagulation can halt the progression of the disease and avoid or delay severe loss of central vision.

Adolescent↗
PubMed1993

[The macula lutea in myopia].

High or degenerative myopia is associated to abnormalities of the posterior pole of the eye. Their expansion with time progresses to the occurrence of complications, especially neovascular ingrowth in the central macular area. The natural evolution of these new vessels results in loss of central vision at long term. Photocoagulation of the new vessels, sparing initially the center, has delayed the loss of central vision at 2 years in our randomized clinical trial. Only treated eyes retained useful acuity at 5 years. New therapeutic modalities will be possible when the mechanisms of occurrence of degenerative myopia are elucidated.

Humans↗
PubMed1991

Perifoveal laser treatment for subfoveal choroidal new vessels in age-related macular degeneration. Results of a randomized clinical trial.

In a controlled clinical trial, 160 eyes underwent "perifoveal" laser photocoagulation. All patients had age-related macular degeneration and subfoveal neovascularization (0.5 to 2.5 disc diameters), without detectable fibrous tissue, and visual acuity from 20/100 to 20/1000. At least 1 year of follow-up has been completed in 127 eyes. Visual acuity was maintained or improved in 12 (20.3%) of 59 untreated eyes vs 28 (41.1%) of 68 treated eyes (P = .04). Reading visual acuity (J4) with the use of low-vision aids was retained in 28 untreated eyes (47.4%) vs 50 treated eyes (73.5%) (P less than .01). Automated static perimetry showed an increased scotomatous area and/or depth with eccentric fixation in all but four patients. A flat atrophic scar was achieved in 53 of 68 treated eyes. Statistical analysis indicated that perifoveal photocoagulation has been effective in the short-term preservation of visual acuity.

Aged↗
PubMed1991

Clinical experience with digitized fluorescein angiography.

Directly acquired images of fluorescein angiography may be helpful in the treatment of retinal diseases. We report our experience with a commercially available image processing system. The major advantage of this system is that the pictures are instantly displayed on a television monitor allowing immediate treatment of the patient. However, further development of complementary software procedures is necessary to obtain an instrument capable of performing useful image-analysis of fundus lesions.

Equipment Design↗
PubMed1991

[FGF and physiopathological implications].

The role of FGF in retinal pathologies can be considered in two respects: 1-as a causative agent (for instance, stimulating aberrant growth or abnormally affecting some aspects of cellular behaviour), or 2-as a possible therapeutic drug (for instance, its ability to rescue neuronal cells from programmed or surgically-induced death), there is evidence for both: the retina, particularly the photoreceptors (PR), seems to be highly succeptible to a host of genetic defects, for instance, in the rat mutant RCS a defect in the pigmented epithelial cells (RPE) leads to the destruction of the PR. Transocular injection of FGF into RCS rats reduces the rate of PR cell loss. On the other hand, we have recently identify a difference in FGF-Receptor cell biology in the RCS mutant which may underline this particular dystrophy. Cultures of purified RPE cells were established from the dystrophic RCS rat and its congenic normal sighted control, and the number and affinity of cell surface FGF-R determined by incubation with 125I-bFGF. Scatchard analysis of the bining data indicated that whereas affinites were in both strains around 60pM, there was a large reduction in receptor number, about 70% in the mutant. Analysis of other FGF/FGF-R criteria, such as mitogenic activity, receptor molecular weight and the profile of FGF degradatoin showed no significant differences between the strains. Thus, defects in the FGF/FGF-R regulating system may actually led to retinal degeneration (RCS rat). But, once again, the underlying principles of FGF mechanisms of action in vivo are at present too incompletely understood to permit rationalization of these various observations.

Animals↗