Evaluation of the method of DNA amplification (PCR, polymerase chain reaction) for diagnosis of superficial ocular herpes]

We evaluated the polymerase chain reaction (PCR) as a diagnostic method in superficial corneoconjunctival herpes and compared it to viral culture. A total of 38 patients were included and divided into 3 groups according to the clinical aspect. Fourteen patients that had a typical clinical aspect for herpes served as reference to evaluate the method. Nine patients had atypical lesions (herpes-suspects) and 15 patients (13 foreign corneal bodies and 2 adenovirus keratoconjunctivitis) made up the control group. All culture positive cases were also positive with the PCR method (in total 10 cases). In the group of herpes-suspects, one case had both a positive viral culture and a positive PCR; four patients that responded well to antiviral therapy had a negative culture and a positive PCR and four patients were negative with both methods. In the control group two cases of foreign bodies were false-positive. As culture was not performed for these cases it is impossible to known if it was a contamination during the PCR procedure or if concomittant viral shedding occurred. Compared to viral culture, a sensitivity of 100% and a specificity of 87.5% was calculated. PCR seems to be a very sensitive diagnostic method having an acceptable specificity for the diagnosis of superficial ocular herpes simplex disease that proved useful in atypical cases.     

Study of the blood-aqueous barrier in choroidal melanoma.

AIMS--Aqueous flare was used to determine the frequency and amount of blood-aqueous barrier breakdown and correlate it with tumour variables. METHODS--Aqueous flare was analysed prospectively by laser flare photometry in 139 consecutive patients seen in the oncology unit for choroidal melanoma. Both eyes of patients were examined with a laser flare cell meter in a standard fashion. RESULTS--Mean flare difference between healthy and tumour eyes was 3.01 (SD 2.5) photons per millisecond (ph/ms) in 32 cases of small melanomas (p < 0.0001), 10.74 (13.9) ph/ms in 92 cases of medium and large melanomas (p < 0.0001), and 19.23 (11.8) ph/ms in 15 cases of very large melanomas (p < 0.0001). This mean differential flare was significantly higher in medium and large than in small melanomas (p < 0.002) and in very large melanomas than in medium and large melanomas (p < 0.028). A difference of > or = 7 ph/ms between affected and healthy eyes was noted in 70 of 139 melanomas (50.4%). It was found in 3/32 small melanomas (9.4%), in 53/92 medium and large melanomas (57.6%), and in 14/15 very large melanomas (93.3%). CONCLUSION--Multiple linear regression analysis showed that flare was most strongly correlated with tumour volume (r = 0.43; p < 0.0001) and tumour height (r = 0.41; p < 0.0008).     

Acute anterior uveitis: para-infectious hypothesis in predisposed individuals]

The etiology and the physiopathology of acute anterior uveitis (AAU) is not well understood yet. However, two major predisposing factors have been identified: a bacterial infection especially with gram negative organisms (functioning as a trigger) and a genetic background, in particular the expression of HLA B-27 tissue antigen. We report the case of a young woman returning from travel to the Far East with her partner. Both presented simultaneously a gastrointestinal infection with fever and diarrhea. Despite extensive investigations, the infectious agent was never identified because of early empirical antibiotic therapy. A few days later, the patient developed AAU of a moderate grade in both eyes. HLA B-27 testing was positive for her, but not for her partner. Experimental research, based on a animal model such as endotoxin-induced uveitis (EIU), gives us some insight into the possible pathogenic mechanisms of AAU. Footpad injection of endotoxin (lipopolysaccharide component of the wall of gram negative), produce an acute anterior uveitis in rats. Extensive histologic analysis of other organs shows that the anterior segment of the eye is the only structure involved. Intensity of inflammation varies in different rat strains, stressing the importance of the genetic background. The similarity of the animal model to AAU will contribute to orient clinical research towards identifying more thoroughly the possible infectious agent at the origin of AAU and possibly to develop a prophylactic therapy.     

Immunopharmacological analysis of endotoxin-induced uveitis in the rat

Footpad injection of endotoxin causes exclusive ocular inflammation in the rat. In order to clarify its physiopathologic mechanism, we studied the effect of different treatments on endotoxin-induced uveitis (EIU). Salmonella endotoxin was injected into the footpads of Lewis rats. 18 hr later, inflammation was assessed by evaluating proteins and cells in the anterior chamber; arachidonic acid (AA) metabolites, prostaglandin E2 and leukotriene B4, as well as substance P were measured by radioimmunoassay, and Ia-(MHC class II)-antigen expression in ciliary body was assessed by immunohistochemistry. The effect of inhibitors of phospholipase A2 (EPC), of lipoxygenase (azelastine) and of cyclo-oxygenase (diclofenac), as well as dexamethasone, cyclosporine (CsA) and anti-Ia antibody, were evaluated on these parameters. Phospholipase A2 inhibitor EPC and dexamethasone were most effective on inflammation: they also reduced AA metabolites very effectively and prevented Ia-expression. Lipoxygenase and cyclo-oxygenase inhibitors were partially effective on inflammation and on AA metabolites but failed to prevent Ia-expression. Immunosuppressive treatments (CsA and anti-Ia-antibody) also reduced inflammation. Our findings suggest that inflammation mediators initiate inflammation in EIU. Ia-Ag-expression is secondarily produced by mediators leading to additional inflammation due to immune mediated mechanisms.     

Indocyanine green angiographic features in tuberculous chorioretinitis

PURPOSE: To determine choroidal involvement in presumed tuberculous posterior uveitis by examining indocyanine green angiographic features. METHODS: Indocyanine green angiography was performed according to a standard uveitis angiographic protocol in eight consecutive patients (15 eyes) with presumed posterior tuberculous uveitis. RESULTS: In 100% of the 15 examined eyes, indocyanine green angiography disclosed choroidal lesions that were subclinical, not detected by fundus examination or fluorescein angiography, in six (40%) of 15 eyes. Findings were classified into four main angiographic signs: (1) irregularly distributed, hypofluorescent areas in the early and intermediate phases of angiography that either became isofluorescent (type 1 hypofluorescence) or remained hypofluorescent (type 2 hypofluorescence) in the late phase; (2) numerous, small, focal, hyperfluorescent spots; (3) choroidal vessels that appeared fuzzy in the intermediate phase because of leakage, leading in the late phase to (4) diffuse choroidal hyperfluorescence. Type 1 hypofluorescent lesions, fuzzy choroidal vessels, and diffuse choroidal hyperfluorescence tended to regress after the initiation of antituberculous and corticosteroid treatment. Focal hyperfluorescence tended to be associated with longstanding disease. CONCLUSIONS: Indocyanine green angiography was useful in assessing and quantifying the as yet unknown extent of choroidal involvement in tuberculous posterior uveitis. Its characteristic appearance may be a valuable contribution to the diagnosis and monitoring of treatment response.     

Ultrasound biomicroscopy in peripheral retinovitreal toxocariasis.

PURPOSE: To report ultrasound biomicroscopic features in peripheral retinovitreal Toxocara uveitis. METHODS: Three patients with unilateral vitreitis suspected to be caused by peripheral toxocariasis were referred for ultrasound biomicroscopic examination of the peripheral retina, pars plana, and adjacent vitreous. RESULTS: In two of the three patients, characteristic pseudocystic transformation of the peripheral vitreous was seen. In both patients, Toxocara serology was positive and eosinophilia was present. In the third patient, no pseudocystic transformation of the peripheral vitreous was seen; however, there was the dense thickening adjacent to the pars plana usually seen by ultrasound biomicroscopy in pars planitis and corresponding to clinically visible snowbanks. The third patient had a negative Toxocara serology and later developed bilateral intermediate uveitis of the pars planitis type. In none of 48 patients with diverse inflammatory conditions of the retroiridal space that were examined by ultrasound biomicroscopy were the characteristic Toxocara-associated pseudocystic images seen. CONCLUSIONS: Pseudocystic transformation of the peripheral vitreous appears to be a rather specific and sensitive ultrasound biomicroscopic sign in patients with presumed peripheral toxocariasis that will likely aid diagnosis in difficult cases.     

Dynamische intraligamentäre Stabilisierung frischer Rupturen des vorderen Kreuzbandes (Ligamys)

Anterior cruciate ligament (ACL) reconstruction with the use of autologous tendon grafts is the gold standard in the treatment of ACL instability; however, many different techniques have been proposed to suture freshly ruptured ACLs. Unfortunately, the rate of recurrent instability is high. A new technique, dynamic intraligamentary stabilization (DIS), was developed to restore biomechanical stability after primary ACL repair and therefore to allow stable healing. In order to compensate for the anisometry of the ACL, in contrast to simple augmentation a spring mechanism is used in DIS that helps to maintain the tibia in a posterior drawer position during all degrees of flexion. Initial results of biomechanical and clinical studies are promising, indicating that reconstruction of knee joint kinematics after ACL repair with DIS is possible; however, further clinical studies are required to determine its usefulness in the clinical setting.     

Immunological profiles in patients with acute retinal necrosis

Purpose: Acute retinal necrosis (ARN) is a newly recognized disease caused by human commensal viruses of the herpes family (herpes simplex virus, varicella-zoster virus and cytomegalovirus) occurring in apparently immunocompetent patients. As at least three viruses can cause ARN, the modification in the host-virus interaction at the origin of the disease most probably comes from the host. A review of 216 reported cases of ARN showed that there were signs of impaired cellular immunity in 16% of these cases. The purpose of this study was to investigate immune parameters in ARN. Methods: In nine HIV-negative ARN patients who were not under steroid or immunosuppressive therapy, the following prospective immunological investigations were performed: (1) skin testing for delayed-type hypersensitivity to seven common antigens (Candida, diphtheria, purified protein derivative tuberculin Proteus, Streptococcus, tetanus, Trichophyton); (2) lymphocytic proliferative responses in vitro to these antigens and to three mitogens; (3) determination of blood lymphocyte sub-populations by flow cytometry. Results: Cutaneous anergy was found in five of seven tested cases. The lymphocyte proliferative index was less than 20% of the index of a control group for all antigens in three of nine cases, and for three or more antigens in eight of nine cases. In eight of nine cases there was a relative increase of B-lymphocytes, and in seven of nine cases 13-lymphocytes were also increased in absolute numbers. In all nine cases one or more of these parameters were abnormal. Conclusion: Our findings suggest that ARN may develop in association with an imbalance of the immune system characterized by an impaired cellular response and/or a maintained or increased Immoral response.     

Retinal Vasculitis

Retinal vasculitis is a sight-threatening intraocular inflammation affecting the retinal vessels. It may occur as an isolated ocular condition, as a manifestation of infectious or neoplastic disorders, or in association with a systemic inflammatory disease. The search for an underlying etiology should be approached in a multidisciplinary fashion based on a thorough history, review of systems, physical examination, and laboratory evaluation. Discrimination between infectious and noninfectious etiologies of retinal vasculitis is important because their treatment is different. This review is based on recently published articles on retinal vasculitis and deals with its clinical diagnosis, its link with systemic diseases, and its laboratory investigation.