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Biomedical subjects

G Sallet

Publications and source records attributed to G Sallet.

17 recordsLinked to original sources
PubMed2004

[Malaria modelling].

The purpose of this article is to describe various models used for the study of malaria. The type of models depends on the focus of study. Until now the most models have been designed to study malaria transmission. In addition to giving a basic description of a few classic models, we show how simulation can be useful despite the inherent simplicity of models. In our opinion it is urgent to develop models for use in public health based on recent advances in computer, automation, and mathematical techniques.

Animals↗
PubMed2001

Comparison of optical and ultrasound central corneal pachymetry.

In 100 eyes of 50 patients central corneal thickness was measured comparing optical to ultrasound pachymetry. With optical pachymetry the values were 1 to 40 micrometer (microns) lower in 64 eyes compared to ultrasound pachymetry. With ultrasound pachymetry the values were 1 to 18 microns lower in 26 eyes compared to optical pachymetry. In 10 cases no difference in pachymetry readings was seen between both techniques. The mean difference of optical pachymetry compared to ultrasound was 9 microns. Optical pachymetry is a no-touch form of corneal thickness measurement, with quick and precise central alignment, and can easily be done by a technician.

Cornea↗
PubMed2000

The correlation between IOP measurement, central corneal thickness and corneal curvature.

In a prospective study we measured the intraocular pressure (IOP), the central corneal thickness (CCT) and the central corneal curvature in 172 myopic eyes before and after LASIK treatment. We find a significant decrease in intraocular pressure. Statistical evaluation reveals a linear correlation between the IOP decrease and the amount of stromal ablation. The IOP and corneal curvature are measured in 21 hyperopic eyes before and after LASIK treatment. We do not find a change in the IOP. In a retrospective study of 47 myopic eyes before and after RADIAL KERATOTOMY we find no change in IOP. We conclude that CCT is important in evaluating the IOP and that corneal curvature has little effect on IOP measurement.

Cornea↗
PubMed1998

Lasik learning curve: clinical study of 300 myopic eyes.

We present a retrospective analysis of the short term results of our first 300 myopic eyes which have been corrected by LASIK refractive surgery using the Automated corneal shaper and the NIDEK EC 5000 excimer. We will discuss our technique and outcome based on the evaluation of the safety of the procedure and the predictability of the postoperative result. We discuss all the complications we have encountered during this learning curve.

Astigmatism↗
PubMed1997

A 8 months indocyanine angiographic follow-up of a patient with serpiginous choroidopathy.

BACKGROUND: Serpiginous choroidopathy is a rare progressive disorder which affects both the choroid and the retinal pigment epithelium. PURPOSE: To analyze the fluorescein and indocyanine green angiographic evolution in a patient affected by serpiginous choroidopathy with a one year follow-up. METHODS: A patient affected by serpiginous choroidopathy was examined with fluorescein angiography and indocyanine green angiography with a follow-up of 8 months. CONCLUSION: Fluorescein angiography shows clearly the active and healed lesions in serpiginous choroidopathy while indocyanine green angiography seems to be more useful in detecting the extent of the choroidal involvement and may prove to be a useful tool in indicating the direction of future disease extension.

Adult↗
PubMed1996

Indocyanine green angiography and age-related serous pigment epithelial detachment.

BACKGROUND: Fundus fluorescein angiography has shown that pigment epithelial detachment in age-related macular degeneration is often associated with choroidal neovascularisation (CNV). Indocyanine green angiography (ICG-A) provides a better visualisation of choroidal circulation and of CNV than fluorescein angiography (FA). METHODS: We studied the ICG angiograms of 58 eyes presenting age-related pigment epithelial detachment, either with signs of occult CNV (48 eyes) or without signs of CNV (10 eyes) on FA. In selected cases the neovascular complex defined on the ICG angiogram was photocoagulated. RESULTS: ICG-A revealed hyperfluorescence interpreted as CNV in 46 of 48 eyes with fluorescein angiographic signs of occult choroidal neovascularisation. The neovascular complex seen on the ICG angiogram was well delineated in 29 eyes and ill defined in 17 eyes. ICG-A revealed CNV in 2 of 10 eyes without signs of CNV on FA. In these two cases the neovascular complex was ill defined. Photocoagulation in selected cases resulted in stabilisation or even improvement of visual acuity and flattening of the pigment epithelial detachment in 9 of 18 cases. CONCLUSION: ICG-A may offer a better definition of the neovascular complex associated with pigment epithelial detachment in age-related macular disease and be helpful in guiding laser treatment. In some cases FA still outlines more clearly the lesions to be treated. FA and ICG-A should thus be used concurrently to determine treatment strategy.

Aged↗
PubMed1995

Indocyanine green angiography of choroidal tumors.

BACKGROUND: Fluorescein angiography (FA) has been widely used in the diagnostic evaluation of choroidal tumors. Indocyanine green angiography (ICG-A), which permits better visualization of choroidal vasculature than FA, has been recently introduced into clinical practice. Only few reports exist on the ICG-A characteristics of choroidal tumors. METHODS: The fluorescein and indocyanine green angiograms of 61 patients were assessed. These included 14 patients with choroidal nevi, 30 with malignant melanomas, 7 with suspected melanomas or atypical nevi, 5 with hemangiomas and 5 with metastases. RESULTS: The outline of pigmented tumors was more accurate on ICG-A than on FA. Characteristic patterns were seen in all intra-ocular tumors with ICG-A, so it was possible to distinguish hemangiomas from malignant lesions. Characteristic features of malignant melanomas include abnormal vascular pattern and marginal late dye leakage. None of the benign lesions showed these features. In suspected melanomas, the presence of abnormal choroidal vascular patterns and/or late dye leakage on ICG-A may indicate malignancy. CONCLUSION: The study suggests that ICG-A can yield additional information that is useful in differentiating amongst choroidal tumors. Better delineation of pigmented lesions with ICG-A allows more accurate treatment planning and follow-up.

Choroid Neoplasms↗
PubMed1995

Ophthalmoscopic visualization of the inferior ophthalmic vein through a chorioretinal coloboma.

PURPOSE/METHODS: In a patient with a coloboma of the optic nerve, inferior retina and choroid, and deep portions of the sclera, a retrobulbar vessel moved irregularly relative to the retinal vessels, which moved contiguously with the posterior globe. RESULTS/CONCLUSION: Fluorescein angiography showed the retrobulbar vessel filling slightly later than overlying retinal vessels. We conclude that the retrobulbar vessel was a vein situated inferiorly to the optic nerve.

Adult↗
PubMed1995

Radiation choroidal vasculopathy: an indocyanine green angiography study.

An indocyanine green angiography (ICG-A) study of choroidal vasculature in the irradiated peritumoral zone in 16 eyes treated with 106Ru/106Rh brachytherapy for choroidal melanoma was performed between 4 and 72 months following treatment. The earliest changes observed were peritumoral atrophy of the retinal pigment epithelium and choriocapillaries. With time, the larger choroidal vessels progressively became non-perfused. There was only minimal staining of the smaller vessels. However, at 2 years or more after radiotherapy the larger choroidal vessels showed progressive vascular wall staining with ICG ('perivasculitis') associated with continuing closure. Previous histopathological studies of radiation damage to the choroid have demonstrated atrophy and occlusion of the vasculature but have shown no evidence of vasculitis. It is suggested that ICG staining of the choroidal vascular wall in radiation choroidopathy is due to radiation-induced endothelial cell loss or dysfunction rather than a true vasculitis. Subsequent progression results in vascular occlusion, and development of new clusters of abnormal choroidal vessels.

Angiography↗
PubMed1995

Discrepancy between indocyanine green and fluorescein angiography in occult choroidal neovascularization.

Six eyes without or with minimal evidence of choroidal neovascularization on fluorescein angiography are presented. All six eyes have marked retinal pigment epithelial alterations. Indocyanine green angiography reveals extensive hyperfluorescence, indicative of choroidal neovascularization undermining the macula in these six eyes. It is surprising that three eyes are asymptomatic and two others have a relative good visual acuity. It is suggested that hyperfluorescence observed by indocyanine green angiography without or with minimal late dye diffusion on fluorescein angiography could indicate a slow progression and thus a better prognosis of the maculopathy.

Aged↗
PubMed1995

Indocyanine green angiography in cases of inflammatory chorioretinopathy.

We studied 13 patients with various chorioretinal inflammatory diseases, comparing fluorescein angiography and indocyanine green angiography. The study included cases of presumed ocular histoplasmosis syndrome, Birdshot chorioretinopathy, serpiginous choroiditis and acute posterior multifocal placoid pigment epitheliopathy. Based on our findings and comparing them to the few previous reports, we try to better understand the pathogenesis of these inflammatory chorioretinopathies.

Adult↗
PubMed1994

[Diffuse bilateral proliferation of uveal melanocytes. Apropos of an uncommon case].

Diffuse bilateral uveal melanocyte proliferation is a rare paraneoplastic syndrome causing severe visual impairment. We report the case of a 58 year old man with progressive visual loss due to multiple retinal pigment epithelial lesions with a serous detachment of the posterior pole in both eyes. Visual acuity improved with systemic corticoids. Two years later, he again experienced visual loss. Meanwhile this patient had undergone a resection of a large cell anaplastic lung carcinoma. The fundus appeared unchanged except for the appearance of multiple naevoid lesions. The choroid was diffusely thickened. Visual acuity improved again with systemic corticoids. This case is quite exceptional as the visual acuity was well preserved during a follow up of more than two years. The case is compared with those published previously and the differential diagnosis is discussed.

Cell Division↗
PubMed1993

Hypofluorescence in infrared angiography.

We selected from the infrared angiograms taken in the department of Ophthalmology of the University of Ghent showing hypofluorescence. We differentiate masking from choroidal vascular filling defect. The etiologies and the differences between these are qualitatively discussed. Based on these findings we try to better appreciate the dynamics of infrared angiography.

Angiography, Digital Subtraction↗
PubMed1993

Follow up of suspected choroidal naevi.

The correct diagnosis of small pigmented choroidal tumours is often difficult. We reviewed 16 cases with a mean follow-up of 58 months and illustrate the difficulties which can be encountered in correctly diagnosing small to medium-sized pigmented tumours. Of those 16 cases, 4 cases ultimately progressed and needed appropriate therapy. Some suspected melanomas grew initially but then stayed stationary for a long period of time. In doubtful cases, it is essential to document the evolution with echography, fundoscopy, fundus photographs, fluorescein-angiography, visual fields and eventually ICG-angiography. If progression is documented, appropriate treatment has to be considered.

Adult↗
PubMed1993

The value of medical imaging techniques in the diagnosis of extra-ocular extension of malign melanoma of the choroid: a case report.

The major goal in the evaluation of posterior uveal tumours is to determine whether an intra-ocular malignancy is present and whether intervention is necessary. Small uveal pigmented tumours can safely be managed by observation until growth is documented. However, extensive evaluation for each suspicious lesion is necessary in order not to miss any signs of malignancy. A case is presented of a 41 year old male patient with orbital pain as initial symptom of a choroidal melanoma. Fluorescein-angiography revealed signs of double circulation. Abnormal choroidal vessels inside the tumour showed up clearly on indocyanine-green angiography. By ultrasonography we were able to detect scleral perforation and extra-scleral extension. Computed tomography confirmed the extra-scleral extension. As there were no signs of metastasis, an orbital exenteration with sparing of the eyelids was performed. Histopathology is compared with the results of clinical investigation.

Adult↗
PubMed1992

Radiation-induced optic neuropathy.

Radiation-induced optic neuropathy is a well-known complication of cranial radiotherapy. We describe four cases. In two cases, the diagnosis was made on MRI. After administration of Gadolinium-DTPA, there was an enhanced captation at the level of the optic nerve. In addition we reviewed 47 cases reported in the literature. Visual prognosis is less than 1/10 in 78% of affected eyes. In case of associated brain necrosis, the mortality rate is 62%.

Adult↗