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At least 1,495 records · Page 83Linked to original sources
PubMed1993

[Pupillary dilatation with Eckardt iris retraction sutures within the scope of vitreoretinal surgery. A follow-up study].

In cases of complicated vitreoretinal surgery, maximal mydriasis is necessary. Preexisting or intraoperatively occurring miosis in aphakic eyes can be remedied by the iris suture by Eckardt. In our hospital, the iris suture technique was carried out in 31 cases. The postoperative situation depends on the extent of retraction of the iris sutures and the general course of the disease. At maximal retraction, the iris is forced against the ciliary body, causing persisting synechias; therefore, to us it seems important to separate all synechias after opening the iris sutures. The formation of anterior loops is also possible. Thus, it is essential to release the endangered segments behind the ciliary body and at the base of the vitreous body from tractive elements immediately after opening the iris sutures. Based on our present experience, we think non-maximal retraction of the iris is desirable. It offers enough view of the fundus and reduces the complications mentioned above.

Diabetic Retinopathy↗
PubMed1993

Eales' disease with progressive spastic paraparesis.

Eales disease is a disease of unknown aetiology characterised by ophthalmic changes and often neurological involvement as in multiple sclerosis. We are reporting a case of Eales' disease in a 27 yr old male with chronic progressive non compressive motor myelopathy.

Adult↗
PubMed1996

[Responsibility of incomplete retinal photocoagulation in the indication of vitrectomy in proliferative diabetic retinopathy].

PURPOSE: We report an epidemiologic study about prophylactic photocoagulation of ischaemic diabetic retinopathy in order to avoid proliferative stage and severe vitreous haemorraghe. METHODS: We studied retrospectively 42 eyes of 32 diabetic patients who underwent a vitrectomy in 1993. For each patient several items were analyzed: nationality, sex, age, type, duration and clinical course of diabetes, and other risk factors. Slit lamp and ocular fundus examination were noted; in particular lens, iris and vitreoretinal framework. RESULTS: Almost all patients had an inadequate laser photocoagulation: in 26 eyes (62%) it was insufficient or non-existent, uncomplete in 12 eyes (29%), and non confluent for 18 eyes (43%). Only four eyes have had complete and confluent panphotocoagulation. CONCLUSION: Photocoagulation appears to be the priority therapy to avoid most severe complications of proliferative diabetic retinopathy. Laser photocoagulation must be started from preproliferative retinopathy, confluent on the useless ischaemic retinal areas, and dense elsewhere.

Adult↗
PubMed1995

[In vivo fundus fluorescence measurements in patients with age related macular degeneration].

UNLABELLED: This study was performed to measure and characterize the intrinsic fluorescence of the ocular fundus in patients with age-related macular degeneration (AMD). METHOD: Fluorescence spectral measurements from discrete retinal locations were made using the fundus spectrophotometer with excitations at 470 and 510 nm. Two normal subjects and seven patients with different stages of AMD were investigated. RESULTS: The spectral characteristics of fundus fluorescence are consistent with those of lipofuscin in the retinal pigment epithelium (RPE). The fluorescence spectrum is broad, with a maximum at about 620 nm. The shape and intensity of the fluorescence spectra are affected by age, site of measurement, pathology, ocular media absorption, and excitation wavelength. Spectra from areas with drusen reveal an additional fluorophore, with maximum around 560 nm, probably emanating from drusen and Bruch's membrane. Measurements in atrophic reveal a decrease of lipofuscin fluorescence and/or a contribution likely due to choroidal and sclera collagen fluorescence. Fluorescence from lipofuscin is more efficiently excited at 510 nm, whereas that of drusen and subretinal structures is relatively more efficient with 470 nm excitation, allowing for discrimination of various fluorophores. CONCLUSION: The spectral characteristics of RPE lipofuscin could be identified and quantified in AMD patients. In addition, the spectra are affected by other fluorophores such as drusen and choroid contributions in atrophy. Fluorescence spectra measurements in AMD patients allow for discrimination of lipofuscin fluorescence, drusen fluorescence, and choroidal or scleral fluorescence. The non-invasive measurement of lipofuscin and drusen fluorescence in AMD may be helpful in monitoring the disease, understanding its evolution, and testing therapeutic concepts.

Aged↗
PubMed1996

[Hemoglobinopathies and retinopathies in Lomé UHC].

BACKGROUND: There are few publications concerning retinal complications of hemoglobinopathies in our country. We studied recruited patients to evaluate these complications. MATERIAL AND METHODS: From October 1993 to August 1995, 66 patients were recruited among clinical hematology out patients; all of them underwent acetate electrophoretic diagnosis and fluorescein angiographic examination. RESULTS: The mean age of the patients was 26,92 years, ranging from 5 years to 50 years; the genotypic forms were 34 SC (51.51%), 15 SS (22.72%), 11 AC (16.66%), 2 AS (3.03%), 2 CC (3.03%), and 2 A2F (3.03%). Thirty eight patients (57.57%) had retinopathies. The majority were proliferative retinopathies in 55,26% cases and in 44,73% non proliferarive retinopathies. These retinopathies were essentially present with SC (26 cases for 34 SC, 76.47%), predominantly proliferative forms (21 cases for 26 SC, 80.76%). CONCLUSION: Retinal complications are common in Togolese sickle cell patients; clinical course usually leads to proliferations. Early screening could help improve prevention, including laser photocoagulation.

Adolescent↗
PubMed1996

[Macular surgery].

Macular surgery has made great strides in the past few years, particularly to treat some age-related maculopathies. Epimacular membranes, which occur after posterior vitreous detachment, must be operated if they result in loss of visual acuity, metamorphopsia or disturbance of binocular vision. Visual improvement is obtained in more than 70% of the cases. Macular holes, which are related to a vitreous traction on the macula, can be closed surgically in 70 to 90% of the cases. Choroidal neovascularisation and submacular haemorrhages may be operated on when laser photocoagulation is impossible.

Choroid↗
PubMed1996

[Stages of cell proliferation in an experimental model of vitreoretinal proliferation following injection of platelet-rich plasma].

PURPOSE: To understand the pathophysiogenesis of the proliferative retinopathies, with a simple and valuable tool, for pathophysiologic and therapeutic assays. METHODS: We prepared a 10 million platelet concentrate from the same donor in 30 microliters, directly injected into the right eye of 46 pigmented and 14 albino rabbits. Animals were sacrificed at days 7, 14, 21 and one month after injection. Before histopathological analysis, all animals were followed clinically to evaluate the vitreoretinal proliferation, scored according to a 6 grade classification. RESULTS: Vitreoretinal proliferation started at day 5 or 8 after injection and increased during the 3 following weeks. Eighty per cent of the eyes showed at the end of the first month a tractional retinal detachment. histopathology revealed intense cell migration and proliferation close to ciliary body appearing from the 7th day, then further increasing rapidly. Immunostaining showed cell infiltrates expressing vimentin and cytokeratin. Overexpression of vimentin was also found in ciliary and retinal epithelia, and in Müller cells. CONCLUSION: This simple and valuable model can reproduce some characteristics of human vitreoretinal proliferations, such as the involvement of the ciliary body and the retinal pigment epithelium, inflammatory mechanisms occurring together with cell proliferation, and significant disturbances of cytoskeleton within deep ocular structures. Furthermore, this study is a first step on the way of antiproliferative assays, and for a better understanding of pathogenesis of intraocular proliferative disorders.

Animals↗
PubMed1995

[Massive subretinal hemorrhage in the course of age-related macular degeneration: preliminary study].

We retrospectively studied 58 eyes with a subretinal haemorrhage > or = 5 disc areas related to age-related macular degeneration. The subretinal new vessels which caused the haemorrhage were occult or mixed except in 2 cases of well-defined new vessels where the haemorrhage appeared after a trauma. A pigment epithelium detachment was present in 1/3 of the cases before the haemorrhage. 36% of the patients had one or more important haemorrhagic recurrences. In 32% of the cases, the visual acuity before the haemorrhage was > or = 4/10. The final evolution resulted in an important fibroglial and atrophic central scar with a dramatic loss of visual acuity (85% VA < 0,1).

Aged↗
PubMedDate not supplied

Endothelial and glial cell interaction in diabetic retinopathy via the function of vascular endothelial growth factor (VEGF).

VEGF, which is also known as vascular permeability factor (VPF), is a recently identified specific mitogen for endothelial cells, and has been paid much attention for the critical participation in the physiological and pathological angiogenesis/vasculogenesis in retinas. To investigate whether retinal glial cells (RGCs) synthesize VEGF under hypoxic state (2%) in vitro and in retinas in vivo of streptozotocin-induced diabetic rats, VEGF mRNA and activity expressed by cultured RGCs were assessed with Northern blot analysis and in vitro angiogenesis assay, and the in vivo expression of VEGF mRNA and protein was examined in diabetic retinas by in situ hybridization and immunohistochemistry using rabbit anti-IgG against human VEGF. Cultured RGCs synthesized and released VEGF and this VEGF production was markedly enhanced by hypoxia through the activation of AP-1 promotor gene. However, the expression of bFGF mRNA by RGCs was not enhanced under the hypoxic condition. Retinal capillary endothelial cells (RECs) expressed flt-1 mRNA. Therefore, conditioned media harvested from RGCs under hypoxic condition significantly accelerated not only thymidine incorporation by RECs but also in vitro angiogenesis, namely, the formation of capillary-like tubes by RECs in type I collagen gels. In normal rat retinas astrocytes located just beneath the inner limiting membrane revealed immunohistochemically the weak expression of VEGF, while in diabetic retinas six months after the streptozotocin treatment, the enhanced expression of VEGF mRNA and protein mainly by glial cells such as Muller cells and astrocytes, was confirmed by immunohistochemistry and in situ hybridization. These diabetic retinas were associated with the hyperpermeability of albumin, but not angiogenic retinopathy. These findings indicate that VEGF expressed by RGCs under hypoxia or diabetic condition plays an integral role in the maintenance of retinal circulation via the VEGF-VEGF receptor (flt-1) interaction.

Animals↗
PubMed1997

[Potential of photodynamic therapy with a second-generation sensitizer: mono-L-aspartyl chlorin e6].

We evaluated the potential for photodynamic therapy of a new photosensitizer, mono-L-aspartyl chlorin e6 (NPe6), whose tissue uptake and clearance are rapid. Firstly, NPe6 solution was exposed to a diode laser at 664 nm that fits the maximum absorption of NPe6. Immediately after laser exposure, the solution was subjected to electron spin resonance (ESR) to detect generation of activated oxygen species. With ESR, O2-, .OH, and 1O2 were detected in the NPe6 solution. O2- and .OH disappeared when superoxide dismutase was added to the solution. Next, the fundi of pigmented rabbits were irradiated with the diode laser after administration of NPe6. Histopathologically, there was necrosis of endothelial cells and vascular occlusion in the choroid, especially in the choriocapillaris. Retinal pigment epithelial cells were also injured. In contrast, the sensory retina was undamaged even after use of a large amount of dye. This new combination of NPe6 and diode laser at 664 nm enables us to occlude choroidal vessels efficiently by generating various activated oxygen species. Thus, photodynamic therapy with NPe6 is potentially useful in treating retinochoroidal involvement.

Animals↗
PubMed1997

[Geometrical distribution of newly formed blood vessels in diabetic retinopathy].

Outbreak sites of newly formed blood vessels (NFVs) in proliferative diabetic retinopathy (PDR) were analyzed geometrically. A montage was made of fluorescein fundus angiography photographs of 109 eyes and applied to a two dimensional x-y plane in which the center of the optic disc was taken as the origin. Thus each NFV acquired a coordinate value (x, y). After a coordinate transformation of this x-y plane designed to correct the parafoveal distortion of vascular distribution, a polar coordinate value (r, theta) of the NFV was calculated. The frequencies of NFVs were analyzed statistically relating to both theta, which is the angle around the origin, and r, which is the distance from the origin. The average theta was 2.74 +/- 1.72 (mean +/- standard deviation) radians and the outbreak frequency of NFVs showed a homogeneous distribution which was not influenced by any difference in theta. As for r, the frequency corrected as a truncated distribution at r = 0 showed a normal distribution with an average of 1.45 +/- 0.8. The outbreak of NFVs in PDR is a phenomenon in which accidental elements are strongly concerned and it is thought to be difficult to predict the site at early stage of retinopathy.

Adult↗
PubMed1997

[Concentration of vascular endothelial growth factor within the subretinal space and vitreous fluid in rhegmatogenous retinal detachment].

To determine the increased production and release of vascular endothelial growth factor (VEGF) from the retina in the eye with non-angiogenic retinal detachment in which relative blood supply disturbance may be present, the concentration of VEGF in subretinal fluid and vitreous fluid collected from the eyes was investigated by enzyme linked immunospecific assay. The average concentration of VEGF was 0.5 +/- 1.1 ng/ml (mean +/- standard deviation) in nine samples of vitreous fluid collected from proliferative retinal detachment, and was 1.2 +/- 1.2 ng/ml in eleven samples of subretinal fluid from rhegmatogenous retinal detachment. The concentration of VEGF in six samples of vitreous fluid from angiogenic diabetic eyes (5.0 +/- 2.8 ng/ml) was significantly higher than in the samples from eyes with retinal detachment. The results suggest that the relative ischemic insult to the detached retina increases the release of VEGF into the vitreous cavity and subretinal space. The increased concentration of VEGF does not induce remarkable angiogenesis since the concentration is lower than the biological threshold, or the effect is modulated by inhibitors.

Adolescent↗