Thrombus and branch retinal vein occlusion

Branch retinal vein occlusion (BRVO) is often associated with arteriosclerosis. Typically the occlusion occurs at an arteriovenous crossing. We report a case of a previously healthy patient who developed a BRVO. Funduscopy and fluorescein angiography suggested an intravascular thrombus as the cause of the occlusion. The investigations performed were positive for systemic hypertension and hyperlipidaemia. After 2 months, fundus examination revealed disappearance of the intravascular thrombus, resolution of the macular edema and improvement of the — visual acuity. Certain physiological characteristics of the retinal circulation associated with hyperlipidaemia and systemic hypertension appear to favour thrombus formatio

VZV retinal vasculitis without systemic infection: diagnosis and monitoring with quantitative polymerase chain reaction

To report a case of unilateral varicella zoster virus (VZV) retinal vasculitis aspect in an immunocompetent child without systemic infection. Clinically, no signs of retinal necrosis or frosted branch vasculitis were present. This is an observational case report. Quantitative PCR was performed on the aqueous humor (AH) using primers specific for herpes virus (cytomegalovirus, Epstein-Barr virus, herpes simplex virus 1-2, and VZV). The patient was treated with intravenous acyclovir, intravitreous ganciclovir, and oral valacyclovir. A positive quantitative PCR result was found for VZV DNA (1.72×106 viral copies/ml) in the AH. After 6months, PCR of the AH was negative. Herpes viruses are involved in the pathogenesis of isolated retinal vasculitis. This case demonstrates that quantitative PCR is useful to detect viral DNA in AH and to monitor the viral activity and the therapeutic respons

A shared HLA-DRB1 epitope in the DR beta first domain is associated with Vogt-Koyanagi-Harada syndrome in Indian patients

PURPOSE: Vogt-Koyanagi-Harada (VKH) disease and sympathetic ophthalmia (SO) are two distinct entities that share common clinical and histopathological features; however, it remains unknown whether they have a common genetic susceptibility. Several studies have shown an association of human leukocyte antigen (HLA)-DR4 with VKH disease in patients of different ethnic backgrounds. We present in this paper the HLA-DRB1 genotyping analysis of a large cohort of VKH patients from southern India and compare these patients to patients with SO and to healthy individuals from the same geographic area. METHODS: VKH patients were diagnosed according to the revised criteria of the International Committee on VKH disease. Patients with granulomatous uveitis after ocular trauma or multiple eye surgeries were diagnosed as having SO. Genomic DNA was extracted from all patients and controls. Samples were analyzed for HLA-DRB1 alleles by reverse polymerase chain reaction (PCR) sequence-specific oligonucleotide (SSO) hybridization on microbeads, using the Luminex technology, and by PCR sequence-specific primers (SSP) typing for DRB1*04 allele determination. Strength of associations was estimated by odds ratios (OR) and 95% confidence intervals (CI) and frequencies were compared using the Fisher's exact test. RESULTS: HLA-DRB1 alleles were determined in 94 VKH patients, 39 SO patients, and 112 healthy controls. HLA-DRB1*04 frequency was higher in VKH patients (20.2% versus 10.3% in controls; OR=2.2, p=0.005, pc=0.067). This association was lower than the association of HLA-DRB1*04 frequency in cohorts of patients from different origins. No significant DR4 association with SO was detected. HLA-DRB1*0405 and HLA-DRB1*0410 alleles were significantly increased in VKH patients (8.5% versus 0.9% in controls; OR=10.3, 95% CI=2.34-45.5, p<0.001). These two alleles share the epitope S57-LLEQRRAA (67-74) in the third hypervariable region of the HLA-DR molecule. None of the DRB1 alleles was significantly associated with SO. CONCLUSIONS: Based on the association of HLA-DRB1*0405 and HLA-DRB1*0410 alleles with VKH disease, we propose that the epitope S57-LLEQRRAA (67-74) in the third hypervariable region of the HLA-DRbeta1 molecule is the relevant susceptibility epitope. This genetic component seems specific to VKH disease since no correlation could be identified in SO patients. The weaker association with HLA-DR4 in this VKH patient cohort compared to VKH patients from northern India is probably related to the lower frequency of HLA-DRB1*0405 in our study group. The HLA-DRB1 association with susceptibility to VKH syndrome seems weaker in Indian patients compared to Japanese or Hispanic patients, suggesting a different non-HLA immunogenetic background in Indian VKH patients

Intraocular penetration of penciclovir after oral administration of famciclovir: a population pharmacokinetic model

Objectives We developed a population model that describes the ocular penetration and pharmacokinetics of penciclovir in human aqueous humour and plasma after oral administration of famciclovir. Methods Fifty-three patients undergoing cataract surgery received a single oral dose of 500 mg of famciclovir prior to surgery. Concentrations of penciclovir in both plasma and aqueous humour were measured by HPLC with fluorescence detection. Concentrations in plasma and aqueous humour were fitted using a two-compartment model (NONMEM software). Inter-individual and intra-individual variabilities were quantified and the influence of demographics and physiopathological and environmental variables on penciclovir pharmacokinetics was explored. Results Drug concentrations were fitted using a two-compartment, open model with first-order transfer rates between plasma and aqueous humour compartments. Among tested covariates, creatinine clearance, co-intake of angiotensin-converting enzyme inhibitors and body weight significantly influenced penciclovir pharmacokinetics. Plasma clearance was 22.8 ± 9.1 L/h and clearance from the aqueous humour was 8.2 × 10−5 L/h. AUCs were 25.4 ± 10.2 and 6.6 ± 1.8 μg · h/mL in plasma and aqueous humour, respectively, yielding a penetration ratio of 0.28 ± 0.06. Simulated concentrations in the aqueous humour after administration of 500 mg of famciclovir three times daily were in the range of values required for 50% growth inhibition of non-resistant strains of the herpes zoster virus family. Conclusions Plasma and aqueous penciclovir concentrations showed significant variability that could only be partially explained by renal function, body weight and comedication. Concentrations in the aqueous humour were much lower than in plasma, suggesting that factors in the blood-aqueous humour barrier might prevent its ocular penetration or that redistribution occurs in other ocular compartment

L'iridocyclite hétérochromique de Fuchs

L'uvée est la tunique vasculaire se trouvant entre la sclère et la rétine neurosensorielle. Elle se compose de la choroïde, du corps ciliaire et de l'iris. Ces tissus sont isolés par une barrière anatomique appelé barrière hémato-oculaire, créant l'homéostasie nécessaire à une fonction visuelle optimale. Cette barrière se situe au niveau de l'épithélium pigmentaire de la rétine, du corps ciliaire et autour de la lumière des vaisseaux rétiniens et iriens (jonctions serrées de l'endothélium vasculaire). La majorité des inflammations intraoculaire trouve son origine dans l'uvée avec pour conséquence une rupture de la barrière hémato-oculaire. Le terme d'uvéite recouvre toutes les inflammations intraoculaires quelles soient d'origine infectieuse ou immunologique. On classifie les uvéites en fonction de la localisation anatomique de l'inflammation (antérieure, intermédiaire, postérieure), la présentation clinique (granulomateuse, non-granulomateuse), la durée d'évolution (aigue, chronique) et le diagnostique spécifique. L'Hétérochromie de Fuchs est une uvéite dont l'étiologie reste encore incertaine

VZV retinal vasculitis without systemic infection: diagnosis and monitoring with quantitative Polymerase Chain Reaction

To report a case of unilateral varicella zoster virus (VZV) retinal vasculitis aspect in an immunocompetent child without systemic infection. Clinically, no signs of retinal necrosis or frosted branch vasculitis were present. This is an observational case report. Quantitative PCR was performed on the aqueous humor (AH) using primers specific for herpes virus (cytomegalovirus, Epstein-Barr virus, herpes simplex virus 1-2, and VZV). The patient was treated with intravenous acyclovir, intravitreous ganciclovir, and oral valacyclovir. A positive quantitative PCR result was found for VZV DNA (1.72 x 10(6) viral copies/ml) in the AH. After 6 months, PCR of the AH was negative. Herpes viruses are involved in the pathogenesis of isolated retinal vasculitis. This case demonstrates that quantitative PCR is useful to detect viral DNA in AH and to monitor the viral activity and the therapeutic response

Bacterial keratitis after nonpenetrating glaucoma surgery

A 68-year-old woman had uneventful deep sclerectomy with a collagen implant in the left eye that was complicated by infectious keratitis 2 weeks later. Corneal scraping revealed the presence of Staphylococcus aureus. The patient responded to topical antibiotic treatment, and the corneal infiltration resolved, leaving a corneal scar. Bacterial keratitis may occur after nonpenetrating glaucoma surgery and should be included in the list of early postoperative complications