[Ocular toxoplasmosis]

Toxoplasmosis is a parasitic zoonosis which occurs worldwide and is an important cause of blindness. The infection is naturally acquired by the ingestion of oocysts excreted by infected cats or by ingestion of tissue cysts in undercooked or raw meat. Primary infection during pregnancy may result in a congenital infection. Toxoplasmic retinochoroiditis is the most common cause of posterior uveitis in immunocompetent patients. Depending on the patient's age, ocular symptoms vary presenting with reduced visual acuity, strabismus, and nystagmus in young children - in adults decreased vision and floaters are most frequently reported. Active toxoplasmic retinochoroiditis typically presents as grey-white retinal necrosis with choroiditis, vasculitis and vitritis. However, atypical presentations including neuroretinitis, papillitis, Fuchs-like anterior uveitis, scleritis and acute retinal necrosis have been described. The diagnosis is based on clinical findings and can be supported by the detection of antibodies and Toxoplasma gondii DNA. Toxoplasmosis therapy includes antimicrobial drugs and corticosteroids. There are several regimens with different drug combinations including, among others, pyrimethamine, sulfadiazine, clindamycin, and trimethoprim-sulfamethoxazol. The prognosis for ocular toxoplasmosis is favorable in immunocompetent individuals, as long as the central macula is not directly involved. The present article reviews the epidemiology, pathogenesis, clinical presentation and management of toxoplasmic retinochoroiditis.

[Infectious uveitis in infancy: borreliosis, tuberculosis, lues]

Infectious uveitis caused by Borrelia, tuberculosis or syphilis is a rare condition, even in childhood. Because these diseases can be treated successfully, knowledge of their diagnosis and therapy is highly important. The clinical aspects vary from simple conjunctivitis to endophthalmitis or neuro-ophthalmological diseases. The diagnosis of and therapy for borreliosis depend on the stage of the disease. The involvement of different organ systems or positive indirect tests (tuberculin skin test, interferon gamma assays) are important factors in the diagnosis of tuberculosis as the cause of a uveitis. Serology is essential for the diagnosis and monitoring of syphilis.

[Diagnostics in childhood uveitis: what tests for which uveitis?]

BACKGROUND

Intraocular inflammation in children differs considerably from that found in adults. Therefore the diagnostic work-up has to be adapted to the age and specific diseases.

MATERIALS AND METHODS

The published literature was reviewed for results of clinical trials and consensus meetings. In addition, the authors have incorporated their own experience.

RESULTS

Recommendations for a systematic and complete diagnostic work-up are given using tables where possible.

CONCLUSIONS

A close cooperation between ophthalmologists and paediatricians is very important.

Successful infliximab treatment of posterior scleritis in a 13-year-old child refractory to other immunosuppressive therapy

BACKGROUND

Posterior scleritis is a potentially blinding inflammatory disorder rarely seen in children. Standard care consists of systemic administration of steroids and immunosuppressants such as methotrexate or ciclosporin A. We describe the case of a young girl suffering from therapy refractory posterior scleritis successfully treated with the tumor necrosis factor (TNF) inhibitor infliximab.

METHODS

This study was an interventional case report. The medical chart of a 13-year-old child treated with infliximab (5 mg/kg, 10 applications at a 4-8 week interval) was reviewed for changes of visual acuity, fundoscopy, optic choherence tomography, ultrasound imaging, and adverse events.

RESULTS

Infliximab therapy (5 mg/kg, 10 applications at a 4-8 week interval) led to a long-term remission of posterior scleritis after unsuccessful therapy with high dose prednisolone, methotrexate, and ciclosporin A. To date no side effects have been reported.

CONCLUSIONS

Administration of infliximab may be considered under appropriate circumstances to treat children with posterior scleritis.

Stellenwert der Uveitis im Rahmen demyelinisierender Erkrankungen des Zentralnervensystems

An involvement of the visual system can be found in many neurologic diseases. Especially demyelinating processes of the central nervous system (CNS) and multiple sclerosis (MS) in particular present with a variety of ophthalmological abnormalities. While optic neuritis (ON) is known to be a positive predictor for the development of MS and can be considered a symptom of the disease, the high frequency of uveitis observed in MS patients seems to occur rather in the context of a general predisposition for autoimmune disorders. However, MS-associated uveitis can precede the onset of neurological symptoms by many years and shows response to treatment with steroids and interferons, suggesting the presence of similar underlying pathogenic mechanisms. Therefore, further studies are warranted in order to reveal whether administration of early immunomodulatory therapy can delay or even prevent the clinical manifestation of MS in a distinct subgroup of patients presenting with uveitis.

Okuläre Toxoplasmose und Toxocariasis im Kindesalter

Toxoplasmosis and toxocariasis are parasitic infections that are transmitted by cats and dogs, respectively, to humans, and which may induce posterior uveitis already in childhood. Toxoplasmosis presents as a congenitally or postnatally contracted infection whereas toxocariasis is always an acquired disease. The typical ocular sign of toxoplasmosis is retinochoroiditis, occurring as an active lesion, in most instances, associated with an inactive pigmented scar. In contrast, toxocariasis leads to a choroidal granuloma secondarily involving the retina or an endophthalmitis-like picture. Although toxoplasmosis represents the most common cause of posterior uveitis, there are uncertainties regarding the timing and specificity of the diagnosis, namely in atypical cases and those at risk of permanent severe loss of function. Antiparasitic treatment should be tailored to the severity of the inflammation and the risk of visual function loss. Concomitant steroids may be used to control the sequelae of unspecific inflammation, but should be used with caution and must be combined with an antimicrobial regimen. Because it is a rare disorder, one may not be familiar with the clinical presentation and suggested therapy for ocular toxocariasis. With this survey we, therefore, wish to provide a current, practice-oriented overview on the infection, ocular manifestations, diagnosis and treatment of ocular toxoplasmosis and toxocariasis in childhood.

The Ets-1 transcription factor is involved in pterygial angiogenesis

Pterygial pathology is characterized by abnormal corneal epithelial proliferation, stromal modulation, matrix degradation and a strong tendency for otherwise absent corneal vascularization. As the proto-oncogene Ets-1 is known to play a key role in angiogenesis and matrix degradation in other tissues, its involvement in corneal vascularization was investigated. Fifteen pterygia representing two groups were studied. Group 1 consisted of five clinically active pterygia, and group 2 consisted of 10 samples of clinically non-active pterygia. (35)S-labelled ets-1 antisense and sense riboprobes were used for in-situ hybridization of Ets-1 transcription factor in all pterygia. The cytoplasm of blood vessel endothelial cells showed strong expression of ets-1 mRNA in all group 1 pterygia. In contrast, no expression of ets-1 was found in group 2 pterygia. Proto-oncogene ets-1 expression has been shown for the first time in the metaplastic pterygium, an eye tissue of unknown pathogenesis.

[Ocular toxocariasis. From biology to therapy]

Ocular toxocariasis represents an organ manifestation of the systemic infection with the Nematode larva Toxocara canis. The infection can provoke very different changes in the eye. Especially posterior uveitis, vitreous body infiltrates, epiretinal membranes and suberetinal granulomas can occur. The diagnosis of these changes can be difficult due to the variety of the symptoms and on the other side by the absence of characteristic specific changes. Moreover unclear findings can occur when only serological examinations are performed. In unclear cases the antibody-detection by means of ELISA from the vitreous body fluid can be useful. The examination of vitreous body material can prove toxocara infection when no systemic signs of infection are present and no antibodies are detectable in the serum. Besides the systemic anti-helminthic therapy with Albendazol the pars plana vitrectomy is a substantial therapeutic option in ocular toxocariasis when vitreo-retinal complications are present. A well timed adequate therapy can stabilize the visual acuity in many cases.

[Bacterial keratitis. Current diagnostic aspects]

Keratitis remains the third most common etiology for blindness worldwide. Whereas bacteria still predominate as causative organisms in temperate climates, fungal and mixed infections are more common in tropical and semitropical areas. In recent years, a shift in the causative organisms, as well as predisposing factors, has been reported. Risk factors that may have gained in importance, such as wearing contact lenses and corneal surgery, have been identified. Microorganisms, especially Pseudomonas spp. and mycobacteria have been frequently isolated in these patients. A changing pattern in microorganism infection has been observed that might be caused by inappropriate use of potent antimicrobial agents. Because of the sight threatening nature of bacterial keratitis, proper diagnosis and antibiotic selection are required. Management should be guided by the appropriate diagnosis, severity of clinical symptoms and underlying risk factors. Molecular techniques, such as polymerase chain reaction, have increased our diagnostic options, even when they cannot replace established procedures. This article reviews the current data and procedures available for the diagnosis of bacterial keratitis.

Therapie und Prognose der bakteriellen Keratitis

This review discusses the current therapy for bacterial keratitis, especially that using quinolones of the fourth generation. In addition, the importance of additive steroids is discussed. Steroids should be administered at a low dose and tapered off slowly, whereas antibiotics should be applied at a high dosage and discontinued abruptly.

[Confocal microscopy in corneal dystrophies: a comparison between confocal slit scanning (ConfoScan P2) and laser scanning microscopy (Rostock Cornea Modul-HRT II)]

BACKGROUND

The object of this work was a comparison of confocal images of corneal dystrophies made by a slit scanning microscope versus a laser scanning microscope.

MATERIAL AND METHODS

Using the Rostock Cornea Modul-HRT II as a confocal laser scanning microscope the images of five patients with some epithelial, stromal and endothelial corneal dystrophies were acquired. The pictures were compared qualitatively with those taken by the slit scanning microscope "ConfoScan P2" from corresponding pathologies. Also, the images of normal corneas of ten healthy persons were acquired for a qualitative comparison.

RESULTS

Confocal images from both devices were able to provide significant helpful diagnostic findings about the corneal microstructure. Essential qualitative differences between the images of both devices used were not observed. Due to the additional hardware components and the software module for image acquisition, analysis and archiving, the RCM-HRT II is favoured over the "ConfoScan P2". Nevertheless, the evaluation in favour of the RCM-HRT II has to be confined because an optimised, user-friendly enhancement, the "ConfoScan 4" is currently available.

CONCLUSION

Evaluating corneal dystrophies in vivo, an equivalent utility of both technical approaches has been observed.

Effects of local and systemic viral interleukin-10 gene transfer on corneal allograft survival

In this study, we explored the immunomodulatory effects of viral interleukin (IL) IL-10 after ex vivo and in vivo gene transfer in experimental corneal transplantation. Wistar-Furth rats were used as donors and major histocompatibility complex class I/II-disparate Lewis rats served as recipients. For ex vivo gene therapy donor corneas were either transfected with liposome/vIL-10 plasmid DNA mixtures or transduced with a vIL-10 expressing adenovirus vector (AdvIL-10). For in vivo studies, recipients were treated with AdvIL-10 intraperitoneally 1 day before transplantation. Graft survival was analysed using the Kaplan-Meier survival method. To monitor the efficacy of the therapy messenger RNA (mRNA) cytokine expression profiles in grafts and draining lymph nodes were analysed by quantitative real-time reverse transcription-polymerase chain reaction. Moreover, anti-adenovirus immunity was also investigated. Neither ex vivo liposome-mediated vIL-10 gene transfer nor ex vivo AdvIL-10 gene transfer led to prolonged corneal allograft survival. In contrast, corneal allograft survival was significantly prolonged in animals receiving systemic AdvIL-10 gene transfer. Moreover, only systemic vIL-10 gene therapy modulated the cytokine mRNA expression profile in draining lymph nodes. Interestingly, systemic AdvIL-10 gene transfer could not inhibit the generation of anti-adenovirus antibodies. Our data indicate systemic expression of the vIL-10 gene is required to modulate the cytokine expression profile in the draining lymph nodes, which might be a pre-requisite for the success of cytokine gene therapy.