Endotoxin-induced uveitis (EIU) in the rat: A study of inflammatory and immunological mechanisms

Endotoxin-induced uveitis (EIU) can be produced by systemic injection of endotoxin (ET). It is not clear yet why exclusive ocular involvement occurs in this model. To clarify this question and to establish the sequence of inflammatory events, EIU was induced in Lewis rats by footpad injection of Salmonella ET. Ocular inflammatory response (anterior chamber cells and proteins), aqueous inflammation mediators (thromboxane B₂, prostaglandin E₂, leukotriene B₄ and substance P) and MHC class 2 (Ia) antigen expression in the ciliary body were monitored for 72 hours. Thromboxane B₂ was detected early in the aqueous humor, peaking already 1 hour after ET injection. Prostaglandin E₂ & leukotriene B₄ peaks and a second peak of thromboxane B₂ were recorded 18 hours after ET-injection, at the time of maximal ocular inflammation. MHC-class 2 expression was first detected in the ciliary body stroma at the vascular level 6 hours after ET injection and was massively expressed in the ciliary body epithelium at 18 and 72 hours. It is hypothetized that ciliary body endothelium is particularly sensitive to the effect of ET and is the site of thrombocyte adherence. Vascular damage leads in succession to cellular infiltration, release of inflammation mediators and disruption of blood-ocular barrier. MHC-class 2 expression is a secondary phenomenon and is probably at the origin of additional tissue damage from immune effector mechanisms.     

Epidemiological characteristics of uveitis in Switzerland

Since January 1990, data from uveitis patients have been systematically stored in a computer data bank. During the period from January 1990 to March 1993, 435 new patients (185 female and 250 male, mean age 43 years; range 6–92) were seen at the Uveitis Clinic of the Hopital Jules Gonin. These 435 patients (630 eyes) were subdivided into anterior uveitis (268 patients — 62%), intermediate uveitis (47 patients — 11%), posterior uveitis (89 patients — 20%) and panuveitis (31 patients — 7%). The incidence of uveitis for the referral area considered was calculated to be 17 per 100,000 inhabitants per year. A specifie diagnosis was found in 312 cases (72%). The most frequently diagnosed entities were HLA-B27-associated acute anterior uveitis (67 cases — 15.4%), uveitis associated with acute herpes zoster ophthalmicus (40 cases — 9.2%), toxoplasmosis (39 cases — 9%), typical pars planitis (29 cases — 6.7%), sarcoidosis (29 cases — 6.7%), Fuchs' heterochromic cyclitis (27 cases — 6.2%), herpetic anterior uveitis (21 cases — 4.8%) and acute retinal necrosis (11 cases — 2.5%). Incidence and distribution of most disease entities correspond to those of other European series.     

Indocyanine green angiography features in toxoplasmic retinochoroiditis

BACKGROUND: Indocyanine green (ICG) angiography detects the infrared fluorescence of ICG through the retinal pigment epithelium, providing visualization of the choroidal vascular network. The aim of this study was to analyze ICG angiographic features in toxoplasmic retinochoroiditis. METHODS: Indocyanine green angiography was performed according to a standard uveitis angiographic protocol in 28 consecutive patients diagnosed with acute toxoplasmic retinochoroiditis. Indocyanine green angiographic data were compared with fundus color photographs and fluorescein angiography (FA). Evolution of ICG angiographic signs after therapy (pyrimethamine and sulfadiazine with or without a tapering course of oral corticosteroids) was further analyzed. RESULTS: The main focus of retinochoroiditis was hypofluorescent at all phases of the ICG angiogram in 25/28 cases (89%), but late phase (35-45 minutes) ICG hyperfluorescence was seen in three cases, all of which had very superficial retinal involvement. The most striking features, however, were multiple hypofluorescent satellite dark dots (SDD), present in 21/28 cases (75%). In 17 of these 21 patients, hypofluorescent areas were silent on FA and fundus examination. After therapy, SDD disappeared from most of the cases. Furthermore, the hypofluorescence under the main lesion was markedly reduced or disappeared in some cases. CONCLUSIONS: Indocyanine green angiography showed that toxoplasmic retinochoroiditis is a more widespread process than is clinically suspected because it extends beyond the visible lesions. Indocyanine green angiography appears useful in assessing the extent of choroidal involvement and the evolution of lesions. It might become an important follow-up parameter and also may give new insights into the pathophysiology of this disease. Based on the findings gathered so far, ICG angiography appears indicated in the workup and management of toxoplasmic retinochoroiditis.     

Corneal transplantation

Corneal transplantation is the most widely practiced form of clinical transplantation. This was made possible by the development of donor handling and preservation techniques, such as cooled culture media and organ-culture systems, that guarantee a sufficient supply of donor tissue. Corneal grafting is performed to improve visual function, to preserve the integrity of the eye, or to reduce pain. Patients with visual disability who present with keratoconus or dystrophy have a good prognosis for retaining a thin, transparent graft on a long-term basis. In this patient group the limiting factor for a gratifying visual outcome is high residual postkeratoplasty astigmatism, a still-too-frequent occurrence. Refinement in trephination techniques should help overcome this pitfall. Patients with vascularization or regrafting who are in the high-risk category may benefit from HLA matching or the use of cyclosporine and other immunosuppressive agents that are currently being tested in experimental models for reducing the impact of allograft rejection.     

Dynamische intraligamentäre Stabilisierung frischer Rupturen des vorderen Kreuzbandes (Ligamys)

Trauma und Berufskrankheit - Die Ersatzplastik des vorderen Kreuzbandes (VKB) mittels körpereigener Sehne hat sich als Standardverfahren in der Behandlung der VKB-Ruptur etabliert. Dennoch...