Biomedical subjects
P Le Hoang
Publications and source records attributed to P Le Hoang.
[Diagnostic vitrectomy in uveitis: possibilities of molecular biology].
Recent developments in molecular biology allow novel diagnostic approaches in intraocular inflammation. Genetic markers as well as species-specific sequences are used for the diagnostics of infection or masquerade syndromes. This article provides state-of-the art information about diagnostic vitrectomy.
Complete bilateral horizontal gaze paralysis disclosing multiple sclerosis.
Two women presented with bilateral internuclear ophthalmoplegia evolving in a few days to complete bilateral horizontal gaze paralysis. Convergence and vertical eye movements were normal. Cerebral MRI showed a few small white matter lesions in the lateral ventricle regions, and, at the brainstem level, a single, small, bilateral lesion affecting the posterior part of the medial pontine tegmentum and responsible for the clinical syndrome. The condition gradually improved in both patients, following a similar progression as at the onset: improvement first involved the adduction movements in both eyes, whereas bilateral abduction paresis still persisted for a few weeks, before complete recovery of eye movements. Bilateral damage to the medial longitudinal fasciculus and subsequent lateral extent of damage to the region of the two abducens emerging fibres may explain the clinical findings. In both cases, the cause was probably multiple sclerosis.
[Endogenous infectious endophthalmitis].
INTRODUCTION: Endogenous endophthtalmitis is an intraocular infection of hematogenous origin. EXEGESIS: It is generally a panuveitis that may be mixed-up with a non-infectious inflammatory disease, promoting delayed treatment and compromising the visual prognosis, as the visual loss rate reaches up to 37.5%. Antibiotherapy should be started immediately after bacteriological examinations and without waiting for vitrectomy. Identification of the causative microorganism is absolutely necessary. It may require aqueous or vitreous culture if cultures from other body fluids are negative and infection progresses. The most common infections are endocarditis and digestive and renal diseases. Virectomy is indicated for first line treatment of ocular abcess and improvement of antibiotic absorption. However, it may lead to retinal detachment. Vitrectomy is also indicated in case of unsuccessful therapy. To decrease the inflammatory reaction and risks of vitreous organization, local or systemic corticotherapy is prescribed after control of the infection. CONCLUSION: Although rare, endogenous endophthalmitis should be diagnosed as it may be mixed-up with inflammatory uveitis, leading to inappropriate corticotherapy. Furthermore, antibiotherapy with good intraocular penetration should be started immediately, but it should be kept in mind that the functional prognosis is poor.
[Abnormalities of the ocular surface in patients with AIDS].
PURPOSE: AIDS patients more and more complain from conjunctival symptoms related to dry eyes and conjunctivitis, but little is known about ocular surface abnormalities in these patients. We used impression cytology (IC) and tear IgE to assess inflammatory status of the ocular surface in AIDS. METHODS: IC were taken in 30 patients infected by HIV (including 28 AIDS patients). After collecting general clinical information, and CD4 rate, we made a complete ophthalmological examination (Schirmer test, BUT, Lissamine green and tear IgE). IC were processed by an immunofluorescence technique with antibodies to HLA DR: an inflammatory marker normally restricted to conjunctival dendritic cells; and to APO 2.7 an apoptotic cell marker. RESULTS: Seventy per cent suffered from subjective and/or objective signs, and BUT was abnormal in 70% of patients. Tear IgE was increased in 36% of the eyes, even without known allergy. A decrease in density of dendritic cells and an abnormal expression of HLA DR antigens by epithelial cells were common features in both groups (respectively 90% and 80% of the eyes). An increase of the APO 2.7 marker was significantly found in 70% of eyes. We found no correlation between clinical abnormalities and laboratory findings. However there was a correlation between the blood CD4 decrease and the HLA DR antigen overexpression. Tear IgE were related to HLA DR expression. CONCLUSION: This work shows that even when AIDS patients are asymptomatic they may present significant alterations of the ocular surface probably due to their immunological disorders.
Detection of human herpes virus 6 in AIDS-associated retinitis by means of in situ hybridization, polymerase chain reaction and immunohistochemistry.
The ubiquitous nature of HHV-6 and its genomic relationship with cytomegalovirus led us to evaluate an etiological link between HHV-6 and AIDS-associated retinitis in a prospective study. HHV-6 infection was studied in patients with AIDS-associated retinitis and in two control populations. Eye pairs were obtained at necropsy from nine patients with AIDS-associated retinitis, four human immunodeficiency virus (HIV)-sero-positive patients with normal fundus examination and three HIV-seronegative patients. HHV-6 infection was detected by polymerase chain reaction (PCR), in situ hybridization and immunohistochemistry. Human cytomegalovirus (CMV) and HIV-1 infections were detected in parallel by the same methods. HHV-6 infection was detected in three cases of AIDS-associated retinitis. In two of these patients, HHV-6 infection was detected both by immunohistochemistry and PCR while in the third case it was detected by in situ hybridization and PCR. In the three patients, fundus examination showed bilateral retinitis in two of them and unilateral retinitis in one of them. HHV-6 infection was not detected in the retina of the two control groups. CMV was also detected in the three cases positive for HHV-6 by all three methods. HIV DNA was detected by PCR in two of three cases and was confirmed in one of these cases by in situ hybridization. These results confirm that HHV-6 infects the retina but suggests that HHV-6 does not have an exclusive causative role in AIDS-associated retinitis, since CMV coinfection of the retina was detected in all three of the patients positive for HHV-6.
Ocular manifestations in patients with HTLV-I associated infection--a clinical study of 93 cases.
The purpose of this study was to confirm that ophthalmological features seen in patients in Martinique, French West Indies, could be linked to infection by HTLV-I. The authors studied 93 HTLV-I infected patients divided into 70 patients with HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP) and 23 asymptomatic HTLV-I carriers. They did a complete ophthalmological examination with an assessment of lacrymal secretion by means of three tests: Shirmer 1, break-up time and rose Bengal. Some patients had a biopsy of secondary salivary glands. When possible, detection of HTLV-I antibodies was carried out in the aqueous humor. In 45 of the 93 patients (48.4%) the presence of dry keratoconjunctivitis was recorded. In 22 of these 45 cases, a biopsy of the secondary salivary glands showed the presence of lymphoplasmocytoid infiltrations comparable to the glandular changes that occur with Gougerot-Sjögren syndrome. Among the 93 patients, 15 cases of uveitis were noted (16.1%) with 13 cases of anterior uveitis and 11 cases of vitritis. The inflammation was bilateral in 9 cases (9/15 = 60%). Two cases of cotton wool spots, 3 cases of abnormalities in the distribution of the retinal pigment and 7 cases of corneal lesions were also noted. Higher levels of anti-HTLV-I antibodies were detected in the aqueous humor of 3 patients with uveitis. The coexistence of dry eye (keratoconjunctivitis), uveitis and retinal microangiopathy in patients who are suffering from HAM/TSP could suggest the involvement of an autoimmune or immunological mechanism in the physiopathology of the illness.
Unusual association of juvenile macular dystrophy with congenital hypotrichosis: occurrence in two siblings suggesting autosomal recessive inheritance.
A familial association between juvenile macular dystrophy and congenital hypotrichosis is described in two siblings aged 25 and 23 years. We put forward arguments for locating the retinal alteration at the level of the retinal pigment epithelium and suggest that the hair disorder could be a Marie-Unna type hypotrichosis. This association is transmitted as an autosomal recessive condition.
[Medium-term tolerance of anterior chamber implants in surgical treatment of severe myopia].
PURPOSE: To determine the tolerance of the corneal endothelium and of the haemato-ocular barrier of phakic highly myopic eyes implanted with an anterior chamber I.O.L.ses. METHODS: Twenty-one phakic highly myopic were operated on with a Z.B.A.C.I.O.L. (manufactured by Domilens) by the same surgeon from May 1989 to June 1990. Complete examination including specular microscopy have been performed before surgery and each 6 months and a Laser Flare Cell Meter at 3 years was performed on 14 eyes. RESULTS: Two eyes of the same patient had to be explanted after surgery for important endothelial cell loss. The 19 others had no complication: no cataract, no loss of endothelial cells, no retinal detachment. 14 eyes examined with a Laser Cell Flare Meter had results within normal limits. So, 19 out of 21 eyes implanted for high myopia with Z.B.A.C.I.O.L. have excellent results 4 years after surgery. CONCLUSION: Regarding these results, it seems possible to use this technique again with the new designed Anterior Chamber I.O.L.. Rigorous follow-up of all the implanted eyes is however required.
[Hemorrhagic macular choroidopathy in young adults. Apropos of a case].
We report a case of haemorrhagic macular choroidopathy in young adult occurring in a 24-year-old woman. The aetiology of the affection remains unknown in Europe, but many authors suggest arterial dissemination of an infectious agent may be involved, as in the American form. In the case described here, it could be Chlamydia Psittaci.
[Diagnostic and predictive importance of the blast transformation test and basophil activation test in retinal vasculitis].
22 patients suffering from Birdshot retinochoroidopathy (10), idiopathic vasculitis (6) and Behcet disease (6) and treated by cyclosporine were tested at regular intervals during 11 to 38 months by the lymphocyte stimulation test (LST) and basophil degranulation test (HBDT) with S retinal antigen. These two tests were found frequently positive especially during acute inflammation for the LST. However HBDT was positive in all the patients before relapse of acute inflammation which is in favor of its predictive value and its involvement in the triggering of inflammation at the basophiles or at the local mast cell level.
Renal function and blood pressure in patients receiving long-term, low-dose cyclosporine therapy for idiopathic autoimmune uveitis.
OBJECTIVE: To determine the renal side effects of long-term, low-dose cyclosporine therapy (initial dose, 5 mg/kg body weight per day) in patients with autoimmune idiopathic uvetis. DESIGN: Cohort study with at least 2 years of follow-up. SETTING: A teaching hospital in Paris, France (Hôpital Pitié-Salpétrière). PATIENTS: Sixteen patients with idiopathic autoimmune uveitis who were normotensive and had normal renal function before treatment. Cyclosporine was administered orally for at least 2 years at an initial dosage of 5 mg/kg body weight per day. RESULTS: After 2 years of treatment, the serum creatinine level increased by 35 +/- 5 mumol/L (0.40 +/- 0.06 mg/dL) (95% CI, 25 to 46 mumol/L, [73 +/- 4 to 108 +/- 4 mumol/L]). Creatinine clearance decreased significantly from 120 +/- 5 mL/min to 75 +/- 4 mL/min. Glomerular filtration rate decreased from 116 +/- 8 mL/min to 75 +/- 3 mL/min, and effective renal plasma flow decreased from 455 +/- 24 mL/min to 338 +/- 30 mL/min (P less than 0.05). Cyclosporine induced a significant increase in serum uric acid, total cholesterol, and serum potassium levels. Blood pressure was normal in all patients before treatment; 81% (95% CI, 64% to 98%) of these patients developed hypertension after 24 months of treatment. Blood pressure was controlled with a single drug in all but two patients. CONCLUSIONS: In patients with healthy native kidneys, long-term cyclosporine therapy, even at a low dose (5 mg/kg per day), is nephrotoxic and is associated with a high incidence of hypertension.
Effects of cyclosporine on tubular acidification function in patients with idiopathic uveitis.
Renal tubular acidification function was studied in 12 patients treated with cyclosporine (Cy) for idiopathic uveitis (IU) and in 5 patients with IU not treated with Cy. After intravenous bicarbonate loading fractional bicarbonate excretion was similar in both groups indicating normal proximal tubular acidification function. Plasma renin activity, plasma aldosterone and transtubular potassium gradient were similar in both groups. Distal hydrogen ion secretion evaluated by the ability to increase urine-blood (U-B) pCO2 in a highly alkaline urine was impaired in Cy-treated patients (31.8 +/- 3.2 mm Hg) as compared to controls (47.9 +/- 0.5 mm Hg) (p < 0.005). We conclude that Cy therapy is associated with a distal acidification defect with a low U-B pCO2 gradient during sodium bicarbonate loading. Because none of our Cy-treated patients spontaneously developed over metabolic acidosis one could classify them as having an incomplete form of distal tubular acidosis.
[Cerebral infarction, placoid epitheliopathy and sarcoidosis].
We report a case of cerebral infarction in the basal territory of the left middle cerebral artery, associated with acute posterior multifocal placoid pigment epitheliopathy, most probably due to sarcoidosis. Neurological symptoms resolved spontaneously without sequelae. We discuss the relationship between acute posterior multifocal placoid pigment epitheliopathy, sarcoidosis and cerebral granulomatous angiitis.
[Ocular prognosis in Behçet's disease].
The ocular prognosis of Behçet's disease was assessed in 31 French native patients with ocular involvement. The mean follow-up time was 6 years. Ophthalmologic manifestations revealed the disease in 61% of patients, and it was the first symptom in 29%. Two groups of patients could be identified: the minor forms (23%) which remained stable with colchicine alone and the severe forms (77%) which required steroid (32%) and/or immunosuppressive (45%) therapy. In the severe forms, 32 eyes were unchanged, 4 eyes showed improvement, and 12 eyes showed deterioration in visual acuity. Positivity of HLA B5, sex and complete form of the disease were not predictive factors of ocular involvement, or of its seriousness. At 6 years, 16% of the eyes (versus 14% at the beginning) had a visual acuity less than 1/10, and 71% (versus 74% at the beginning) had a visual acuity greater than 8/10. A close collaboration between ophthalmologists and internists allows a good visual prognosis in Behçet's disease.
[Preparation of the patient for ophthalmologic surgery].
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Increased endothelin level after cyclosporine therapy.
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[Syphilitic uveitis and human immunodeficiency virus infection].
Ocular syphilis is rare in human immunodeficiency virus infected individuals. We think that syphilis should be considered in evaluating such patients presenting with uveitis. Most often, ocular syphilis includes retinitis associated with anterior or posterior uveitis, sometimes with optic neuritis. Concurrent neurosyphilis is frequent and may be more aggressive; it may progress more rapidly and cause more atypical signs than in patients without human immunodeficiency virus infection. This suggests the need for lumbar puncture in the evaluation of coinfected patients. The standard serological tests for syphilis (in blood and cerebrospinal fluid) may be nonreactive in human immunodeficiency virus seropositive patients. It may be because of the alteration of immunologic response of such patients. All coinfected patients with human immunodeficiency virus and syphilis should be treated with high-dose intravenous penicillin G sodium as recommended for neurosyphilis. We describe two human immunodeficiency virus infected patients with ocular syphilis and neurosyphilis.