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Biomedical subjects

G Soubrane

Publications and source records attributed to G Soubrane.

At least 19 recordsLinked to original sources
PubMed1998

The epsilon4 allele of the apolipoprotein E gene as a potential protective factor for exudative age-related macular degeneration.

PURPOSE: Apolipoprotein E (ApoE) is a polymorphic protein that plays a central part in plasma metabolism of lipids and in central nervous system lipid homeostasis. Our purpose was to evaluate the potential role of ApoE polymorphism in the occurrence of exudative age-related macular degeneration associated with drusen, which contain lipids. METHODS: We analyzed apolipoprotein E genotypes in 116 unrelated patients with exudative age-related macular degeneration in one eye and hard drusen (n = 39) or soft drusen (n = 77) in the other eye, and compared the results with those of age-matched and sex-matched control subjects (n = 168). Apolipoprotein E alleles were detected by a ploymerase chain reaction-based method. RESULTS: A lower frequency of the epsilon4 allele carriers was observed in the exudative age-related macular degeneration group compared with control subjects (12.1% vs 28.6%, respectively; P < .0009). The epsilon4 allele was less frequent in the age-related macular degeneration group compared with control subjects (0.073 vs 0.149, respectively; P < .006). This decreased frequency of the epsilon4 allele was mainly observed in the soft drusen subgroup compared with control subjects (0.045 vs 0.149, respectively; P < .0009). CONCLUSION: This lower relative frequency of the epsilon4 allele supports the hypothesis that the ApoE gene is a genetic protective factor identified in age-related macular degeneration.

Aged↗
PubMed1998

Macular dystrophy, diabetes, and deafness associated with a large mitochondrial DNA deletion.

PURPOSE: To report the mitochondrial DNA in a 17-year-old patient with diabetes, deafness, cataract, and maculopathy. METHOD S: Ophthalmologic examination, fluorescein angiography, and electroretinogram were performed. Detection of deletion was analyzed by polymerase chain reaction and Southern blot, and screening for the A3243G mitochondrial DNA mutation was performed. RESULTS: A short fragment of approximately 8.5 kb corresponding to deleted mitochondrial DNA was detected. The A3243G mitochondrial DNA mutation was not found. CONCLUSIONS: A 7-kb heteroplasmic deletion of the mitochondrial genome was found in this patient. No mitochondrial DNA deletion has been reported previously in association with macular dystrophy.

Adolescent↗
PubMed1998

[Radiotherapy of occult neovascularization in senile macular degeneration: initial results of a pilot study].

BACKGROUND: AMD is the leading cause of legal blindness in people aged of more than 50 in industrialized countries. Occult neovascularization accounts for more than 70% of all exsudatives forms of AMD. Radiotherapy has been proposed as a possible treatment for retrofoveal neovascularization. We present the first results of a pilot study actually ongoing at the AMD Center in Creteil. PATIENTS AND METHODS: 44 patients (46 eyes) presenting occult choroidal neovascularization involving the fovea, aged of > 50 years and with a minimal visual acuity of at least 0.1 were included. They received a total dose of 16 Gy in 4 sessions of 4 Gy. All the patients were checked after 3 months. RESULTS: Visual acuity was globally maintained (> 0.1 in 93% of the eyes). Only one eye suffered a significant loss of vision (> 6 lines) and 11% suffered a moderate loss of vision (> 3 lines). Moreover 67% of eyes still had a near vision of 0.5 or more with reading glasses. On fluorescein angiography 17.5% of the eyes experienced an increase of the size of the occult neovascularization of > 0.5 Disk Area (DA), 76% showed no modification and 6.5% demonstrated a decrease in size of > 0.5 DA. CONCLUSIONS: As it has been shown that the antimitotic action of radiotherapy is most effective after 3 months, the present results suggest better evolution than natural history. However, as occult choroidal neovascularization is a slow-evolving disease further follow-up is needed to confirm it.

Aged↗
PubMed1997

Indirect scatter laser photocoagulation to subfoveal choroidal neovascularization in age-related macular degeneration.

BACKGROUND: Occult choroidal neovascularization (CNV), poorly defined on fluorescein angiography, is present in the majority of patients with exudative complications of age-related macular degeneration. For patients who present with this type of subfoveal CNV but who have useful visual acuity, no form of treatment is of proven benefit. Accordingly, a pilot randomized trial of indirect laser treatment was performed. The rationale of this treatment was to inhibit the CNV through laser-induced effects on the retinal pigment epithelium. METHODS: Patients with occult subfoveal CNV without retinal pigment epithelial detachment and with visual acuity of 20/200 or better were randomized to treatment or control groups. A grid of laser burns was applied to the macula beyond the area of serous retinal detachment and of angiographically defined occult CNV. RESULTS: After an average follow-up of 38 months, there was no difference in mean final visual acuity (0.12 treated, 0.14 control) or clinical outcome between treated and untreated groups. Fluorescein angiography showed gradual enlargement in the occult CNV in 58% of eyes in both groups. A decrease in visual acuity to worse than 20/200 (54% of treated, 50% of control eyes) was associated with ingrowth of well-delineated CNV (6 treated, 7 control eyes) or progression to a fibroglial or atrophic scar (11 treated, 8 control eyes). CONCLUSIONS: No benefit was demonstrated for scatter photocoagulation of the macula in patients with age-related macular degeneration and occult subfoveal CNV with initially good visual acuity. There were, however, no complications related to treatment.

Aged↗
PubMed1997

Indocyanine green angiography of drusen.

PURPOSE: To analyze the indocyanine green angiographic findings of drusen in the early stages of age-related macular degeneration. METHODS: Sixty-nine eyes of 53 consecutive patients with drusen but without exudative complications of age-related macular degeneration were studied. Drusen were classified into four groups: hard drusen, drusen derived from clusters of hard drusen (hard cluster-derived drusen and soft cluster-derived drusen), membranous drusen, and regressing drusen. An additional category was constituted by reticular pseudodrusen that could be associated with drusen of either the inner or outer macula. Results of contact lens biomicroscopy and fluorescein angiography were compared with findings on indocyanine green angiography. RESULTS: Hard drusen, either isolated hard drusen or hard cluster-derived drusen, were hyperfluorescent during indocyanine green angiography; in contrast, all sizes of soft drusen derived from clusters of hard drusen were hypofluorescent throughout the angiogram. Membranous drusen, visible on biomicroscopy and fluorescein angiography, were not visible during indocyanine green angiography. Regressing drusen may have showed hyperfluorescence at the early stages of indocyanine green angiography, but associated calcium and pigmentation were hypofluorescent. Reticular pseudodrusen were visible on red-free photographs; on midphase and late-phase indocyanine green angiography using the scanning laser ophthalmoscope only, reticular pseudodrusen were seen as a pattern of hypofluorescent dots. CONCLUSION: The indocyanine green angiographic findings add to and support the clinicopathologic classification of drusen. Indocyanine green angiography may help to distinguish the different types of drusen and may thus be of use in evaluating the risk of progressive age-related macular degeneration in patients with drusen.

Adult↗
PubMed1996

[Age-related macular degeneration].

Age-related macular degeneration is the leading cause of non treatable blindness in industrialized countries. The impairment of visual acuity is preceded by the occurrence of "precursors" some of which are the witness of aging and others are the first symptoms of age-related degeneration of the macular retina. The disease involves both eyes with time resulting in a major handicap. Eventually, central visual acuity is destroyed, making reading, writing and recognition of faces impossible. Different clinical types are identified: the atrophic form for which there is at present no possibility of treatment, and the neovascular form in which the destruction of the new vessels with laser photocoagulation is beneficial. However, only an early diagnosis and treatment may allow a preservation of central vision. New possibilities of angiographic diagnosis, new therapeutic approaches (macular surgery or transplantation) based on physiopathogenic research, provide new hopes.

Age Factors↗
PubMed1996

[Hereditary retinal diseases].

Hereditary retinal dystrophies can be subdivised into central (macular) and peripheral degenerations. Stargardt disease, Best disease, cone dystrophy and retinoschisis, affecting children or young adults, are the 4 commonest macular dystrophies. Retinitis pigmentosa, with primary affects photoreceptors, presents a wide clinical, genetic and molecular heterogeneity. It is certainly the most representative cause of peripheral degeneration. Recent advances in molecular biology allow a more complete clinical definition of these inheritable retinal diseases.

Adolescent↗
PubMed1996

Indocyanine green angiographic features of pathologic myopia.

PURPOSE: To analyze indocyanine green angiographic findings of pathologic myopia and compare them with those of fluorescein angiography, with particular reference to the usefulness of indocyanine green angiography in the management of neovascular complications. METHODS: Thirty-two consecutive patients (52 eyes) with pathologic myopia underwent a complete ophthalmologic examination including fluorescein and indocyanine green angiography. RESULTS: Retrobulbar arteries and veins were visualized solely on indocyanine green angiography in 33 (63%) of 52 eyes. Choroidal arteries appeared attenuated and reduced in number. In the area of staphyloma, choroidal veins were less numerous, and in all eyes an absence of the normal choroidal flush caused by the choriocapillaris filling was observed. Subretinal and retinal hemorrhages were present in 28 (54%) of 52 eyes. Choroidal neovascularization was diagnosed in 16 eyes on fluorescein angiography and in 18 eyes on indocyanine green angiography. In seven eyes, indocyanine green angiography disclosed lacquer cracks (without choroidal neovascularization), appearing in the late phases as hypofluorescent lines, as the probable cause of the subretinal and retinal hemorrhages. In only one eye did indocyanine green angiography fail to disclose choroidal neovascularization detectable on fluorescein angiography. In two eyes, neither dye could clarify the origin of the hemorrhages. CONCLUSIONS: Indocyanine green angiography allows identification of retrobulbar arteries and veins, and analysis of the altered choroidal vasculature. Moreover, indocyanine green angiography is a useful diagnostic tool to differentiate lacquer cracks from choroidal neovascularization in retinal and subretinal hemorrhages.

Adolescent↗
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↗