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Biomedical subjects

J J de Laey

Publications and source records attributed to J J de Laey.

At least 19 recordsLinked to original sources

Combined hamartoma of the retina and retinal pigment epithelium associated with neurofibromatosis type-1.

BACKGROUND: Retinal tumors are occasionally seen in patients with neurofibromatosis type-1 (NF-1). These are usually astrocytic hamartomas or angiomas. Combined hamartoma of the retina and retinal pigment epithelium are tumors also described in NF-1, but this association has not been definitively established yet. METHOD: We report on a child with NF-1, who presented a combined hamartoma of the retina and retinal pigment epithelium in both eyes. RESULTS: The diagnosis of bilateral combined hamartoma of the retina and retinal pigment epithelium in our patient was performed on the basis of the ophthalmoscopic appearance of the lesions. NF-1 was diagnosed following the current international clinical criterion, supplemented by neuroimaging findings. CONCLUSION: Despite the extreme rarity of this association, we believe that it is not coincidental, as the presence of a hamartomatous retinal lesion in a patient with a systemic hamartomatous neuroectodermic disease would be, at least, rational. Thus, NF-1 must be excluded in patients with combined hamartoma of the retina and retinal pigment epithelium.

Child↗

Myelinated nerve fibers and retinal vascular abnormalities.

BACKGROUND/PURPOSE: Abnormal retinal vessels may develop in a region of myelinated nerve fibers, and these vessels may cause vitreous hemorrhages. METHODS: The clinical histories of seven patients with retinovascular abnormalities in a patch of myelinated nerve fibers are presented. None of the reported patients had other evidence of systemic disease. The cases were traced by a multicentric retrospective study. RESULTS: Retinal vascular abnormalities ranged from mild telangiectasis to frank neovascularization, with or without obstruction of the capillary network and signs of branch artery and vein occlusion. Age at diagnosis ranged from 15 to 68 years. Vitreous hemorrhages occurred in the four youngest patients and occurred at 15, 27, 27, and 43 years of age. Laser photocoagulation was applied in three patients and vitrectomy was performed in one. CONCLUSION: The authors' findings suggest that the abnormal structure of the myelinated nerve fibers and the thickened nerve fiber layer of the affected portions of retina may play a role in the onset of retinal vascular abnormalities and eventually cause telangiectasis, branch artery and vein occlusion, neovascularization, and vitreous hemorrhages. This suggestion is based on the absence of other causes of neovascularization or vitreous hemorrhage in all seven patients, and on the relatively young age of four of the patients with this association.

Adolescent↗

Antioxidant activity of plasma from subjects with and without senile cataract.

The relationship between overall plasma antioxidant activity and senile cataract was examined in 148 subjects aged 37-90 years. Antioxidant activity of plasma from 52 control and 96 patients with senile cataract was determined by a method which measures the capacity of plasma to inhibit auto-oxidation of bovine brain homogenate. In contrast to previous studies which demonstrated a relationship between decreased levels of antioxidant components in blood and the occurrence of lens opacities, the present study does not show any significant difference between subjects with and without senile cataract.

Adult↗

Diagnostic problems in chronic vitreous inflammation.

We reviewed 188 patients with chronic vitreous inflammation initially diagnosed as intermediate uveitis, who were seen at the Ghent Eye Clinic during the period 1978 to 1988. We were able to establish a more specific diagnosis in 55 patients. The different approaches that contributed to the diagnosis were analyzed, (comprehensive history-taking and clinical examination, laboratory tests and special investigations, vitrectomy, and following the evolution of the disease). No etiology was found in 133 patients (70.7%), subsequently diagnosed as idiopathic intermediate uveitis. The major characteristics of the disease were analyzed.

Adolescent↗

Cilioretinal artery occlusion in young adults with central retinal vein occlusion.

Ten patients, all younger than 50 years of age, had a temporal cilioretinal artery occlusion associated with a nonischemic central retinal vein occlusion. On fluorescein angiography, the cilioretinal artery eventually filled in all but one eye. The cilioretinal artery showed pulsations on fluorescein angiography in five eyes. The central retinal vein occlusion eventually resolved and the fundus assumed a normal appearance in all nine of the followed cases. Eight of nine eyes that underwent follow-up examination had final visual acuity of 20/30 or better. The occlusion of the central retinal vein produces an elevation of intraluminal capillary pressure because the central retinal artery continues to pump blood into the retina. Because the perfusion pressure of the cilioretinal artery is lower than the central retinal artery, it becomes relatively occluded. The prognosis for these patients is generally good unless the entire parafoveal capillary net is affected by the cilioretinal artery that is occluded.

Adult↗

Clinical application of indocyanine green angiography to choroidal neovascularization.

In order to evaluate the clinical usefulness of indocyanine green video-angiography (IA), the angiographic features of choroidal neovascular membranes (CNM) were investigated in 27 eyes with choroidal neovascular diseases by means of standard fluorescein angiography (FA) and IA. FA showed the existence of CNM in 21 eyes and IA demonstrated evidence of CNM in 19 eyes, as "fan, comb or spotty hyperfluorescence" in the early stage and "leakage" in the late stage. In 6 out of 19 eyes the existence of CNM was shown by IA, while FA failed to identify the precise location and size of CNM due to the masking effect of overlying turbid fluid, massive hemorrhage or a large amount of serous fluid. The results imply that IA has an advantage over FA in cases where FA shows only the sign of occult choroidal neovascularization, and that IA can be applied to neovascular maculopathy as a routine examination.

Choroid↗

[Placoid epitheliopathy and serpiginous choroidopathy].

Both acute posterior multifocal placoid pigment epitheliopathy (APMPPE) and geographic or serpiginous choroiditis are probably the result of a primarily inflammatory involvement of the choroid. In the acute phase both diseases may present a similar appearance. The evolution is however quite different. APMPPE usually affects younger individuals and is almost always bilateral; both eyes are often affected simultaneously. In geographic choroiditis the second eye is sometimes involved weeks up to years after the first eye. APMPPE may be considered as the ocular manifestation of a systemic disease possibly induced by a viral infection. The etiology of geographic choroiditis is still unknown.

Adult↗

The ocular ischemic syndrome.

A series of 8 patients (12 eyes) with ocular ischemic syndrome (ocular signs and symptoms due to severe carotid obstructive disease) is presented. Anterior segment signs include rubeosis iridis, neovascular glaucoma and uveitis. Posterior segment manifestations include mid-peripheral intraretinal haemorrhages, narrowed arteries, dilated veins and cotton-wool spots. Fluorescein angiography demonstrates delayed choroidal filling and a prolonged arteriovenous transit time. Pathophysiology, diagnosis, differential diagnosis, treatment and prognosis are briefly discussed.

Aged↗

Posterior microphthalmos.

Posterior microphthalmos is a congenital anomaly of the posterior segment of the eye, caused by an abnormally thickened sclera. The thickened sclera does not impede the growth of the neuro-retina but seems to influence the development of the choroid and of the retinal pigment epithelium. This may explain the common occurrence of a papillomacular fold in such cases. As such eyes are at risk of developing uveal effusion or angle-closure glaucoma, it is important to consider the diagnosis of posterior microphthalmos in high hypermetropic eyes.

Adult↗

High field resolution magnetic resonance imaging of malignant choroidal melanoma.

High resolution surface receiver coil nuclear magnetic resonance imaging (MRI) of the eye and paraorbital areas was performed in a patient with a malignant choroidal melanoma before and after local radiotherapy using ruthenium application. The resulting improvement in signal-to-noise ratio allows for a reduction in the imaging voxel size to 0.31 X 0.31 X 3 mm3 which provided useful morphological information with respect to delineation of tumoral mass. In the same MRI session using a standard head coil imaging method, T1 and T2 relaxation time values were calculated in regions of interest of 3 X 3 mm by means of transversal scan images of orbital and cranial tissues performed in scan times of 7 to 9 minutes. The procedure presented here combines in one single session high resolution imaging performance, previously unobservable in MRI and in other noninvasive imaging techniques, with fast and reliable measurement of T1 and T2 relaxation times within small regions of interest. MRI, a non ionizing technique, offers within reasonable acquisition times not only a good multiplanar description of the site, size and volume of normal and pathologic orbital structures, but, in addition, the prospect of soft tissue differentiation and of accurately documenting the response to and side effects of the therapy of ocular tumors.

Choroid Neoplasms↗

Indocyanine green angiography of submacular choroidal vessels in the human eye.

Indocyanine green angiograms of the macular region in 40 human eyes were evaluated in order to demonstrate the characteristics of the circulatory patterns of the submacular choroid. During both the early and the late phases of choroidal fluorescence nonuniform fluorescence was found. This implies the existence of watershed zones between choroidal arteries and between choroidal veins. A horizontal line running through the fovea was found to form a boundary between arterial systems, and also, in the majority of cases, between venous system.

Adolescent↗

Indocyanine green angiography of choroidal neovascular membranes.

The choroidal circulation was studied in 27 eyes with choroidal neovascular diseases by means of fluorescein and indocyanine green (ICG) angiography. In 10 of the cases the disciform response was seen to be associated with either watershed zones of the choroidal circulation or with areas of choroidal circulatory disturbance. This is consistent with the theory that hypoxic regions of the choroid are the underlying cause of macular disciform response.

Adult↗

Melanocytoma of the optic disc.

On the occasion of the observation of 4 cases of melanocytoma of the optic disc, the authors stress the relative rarity of this pigmented tumor, its benignity and its frequent association with a choroidalnevus. The melanocytoma is mostly stationary and produces no functional symptoms. It is generally diagnosed after the age of 30, and its pathogenesis is unknown.

Adult↗

[Bietti's crystalline fundus dystrophy (author's transl)].

Two cases of Bietti's crystalline fundus dystrophy are presented. The crystals in the posterior pole are associated with a diffuse tapeto-retinal degeneration. The functional symptoms are less severe than in pigmentary retinopathy.

Adult↗

[Irvine-Gass-syndrome (author's transl)].

Cystic edema or the macula of Irvine-Gass syndrome, accompanied by a diminution of the central vision, is observed in 5% of the patients who have been recently operated for cataract. Only the fluorescin angiography can confirm the diagnosis with certainty. The inflammatory and vitreous theories explain most satisfactorily the pathogenesis of the condition.

Cataract Extraction↗