[Histological findings in an irradiated choroidal melanoma]. / Histologische Diagnostik eines bestrahlten Aderhautmelanoms.

BACKGROUND: Histological findings of choroidal melanomas after proton beam irradiation have been reported for complicated cases after enucleation. We present specimens of a tumor after transretinal probe excision. PATIENT AND METHODS: One year after irradiation, the biopsy was examined histologically. RESULTS: The specimens showed pigmented, spindle-shaped cells staining positively for Melan-A and HMB-45. Ki-67 showed low proliferation. Caspase-3 staining was normal. CONCLUSIONS: The melanoma still contained vital and even single proliferating cells, but regressed afterwards without additional therapy.

[Retrospective case analysis of ophthalmological and systemic risk factors in patients with retinal vascular occlusion]. / Retrospektive Fallanalyse zum ophthalmologischen und internistischen Risikoprofil von retinalen Gefässverschlüssen.

OBJECTIVE: The aim was to determine systemic risk factors for acute central retinal artery occlusion (CRAO) and central retinal vein occlusion (CRVO) and to evaluate the usefulness of systemic diagnostics in CRAO and CRVO. METHODS: The study consisted of a retrospective chart review including 80 patients (CRAO 38, CRVO 42). All patients underwent systemic diagnostics including blood pressure measurement, blood cholesterol level, carotid Doppler imaging, transthoracic echocardiography (TTE), intraocular pressure measurement, glaucoma history and presence of thrombophilic factors. A systemic medical history was obtained. RESULTS: Systemic hypertension was found in 76.3% CRAO and 75.6% CRVO patients. Abnormal cardiac findings were detected in 61% (CRAO) and 22% (CRVO). Abnormal carotid findings were detected in 44.1% for CRAO and 9.5% for CRVO. Pathological thrombophilic factors were found in both groups for approximately 15%. CONCLUSIONS: TTE and carotid Doppler are important tools in the diagnosis of sources of emboli in patients with CRAO, while for CRVO abnormal findings are revealed by TTE and carotid Doppler less often. Thrombophilia should be ruled out in the absence of common risk factors, especially in younger patients and systemic hypertension should be adequately controlled.

Ultrastructural analysis of the lamina cribrosa after radial optic neurotomy.

Radial optic neurotomy (RON) has been proposed for alleviation of the "scleral outlet compartment syndrome" at the level of the lamina cribrosa, which is thought to play a pathoetiologic role in central retinal vein occlusion (CRVO). The aim of this study has been to analyze the ultrastructural alterations of the lamina cribrosa after RON to gain new insights in the underlying pathomechanical factors. Fifteen donor eyes underwent a standardized open-sky-vitrectomy and RON after removal of the anterior eye segment for keratoplasty. Using a microvitreoretinal blade, a radial incision was performed on the nasal hemisphere of the optic nerve head radial to the optic disc and parallel to the nerve fibre layer. The lamina cribrosa and the surrounding scleral ring were then prepared for light microscopy, scanning (SEM) and transmission electron microscopy (TEM). Ultrastructural analysis demonstrated that in 60% (n=9) of the evaluated cases the scleral ring was dissected completely and in 40% (n=6) only partially. The adjacent neuronal tissue to the dissection area showed only minimal injury. The central retinal vessels were not injured in all cases. Only complete incision of the circular ring of collagen fibrils surrounding the lamina cribrosa via RON resulted in effective relaxation of the scleral outlet and was achieved in 60% of all eyes under standardized conditions. In all cases the adjacent tissue showed only minimal injury. The high rate of incomplete dissection of the scleral outlet may be an explanation for the variable outcome seen in different studies on RON.

[Atypical ocular toxoplasmosis with concomitant ocular reactivation of varicella-zoster virus and cytomegalovirus in an immunocompromised host]. / Atypische Toxoplasmose-Chorioretinitis mit begleitender Varizella-Zoster-Virus und Zytomegalovirus-Reaktivierung bei einem immunsupprimierten Patienten.

BACKGROUND: Necrotising retinopathy in immunocompromised hosts is characterised by an unfavourable course often with unspecific clinical features. Therefore, differential diagnosis can be critical. HISTORY AND SIGNS: A case of an initially therapy-resistant, necrotizing retinopathy is presented in a 65-year-old immunocompromised male patient suffering from chronic B-cell leukemia. THERAPY AND OUTCOME: Despite demonstration of cytomegalovirus and Varicella-Zoster-Virus DNA by polymerase chain reaction in vitreous, aqueous humour samples and from retinal biopsy with specific antiviral therapy, a progression of retinal necrosis was noted. Finally Toxoplasma gondii DNA was detected and retinal necrosis resolved after specific treatment. However, visual acuity remains poor because of optic nerve atrophy. CONCLUSIONS: The polymerase chain reaction is an important diagnostic tool for differential diagnosis in immunocompromised patients suffering from necrotising retinopathy. If resistance to therapy is noted atypical ocular toxoplasmosis should be considered. The presented case report shows that even multiple infections are possible in the same host.

Treatment of central retinal vein occlusion by radial optic neurotomy in 107 cases.

BACKGROUND: To evaluate the potential role of radial optic neurotomy (RON), a new surgical technique has been recently proposed for treating central retinal vein occlusion (CRVO). It is hypothesized that CRVO constitutes a neurovascular compartment syndrome at the site of the lamina cribrosa, which can be alleviated by performing a radial incision at the nasal part of the optic nerve head, relaxing the cribriform plate and the adjacent sclera. METHODS: One hundred and seven patients were treated with RON for CRVO at five collaborating ophthalmologic centers. All patients were evaluated by a standardized protocol. For analysis of the angiographic and fundus findings, reference images were used. Intraoperative and postoperative complications were reviewed. RESULTS: On 55 right and 52 left eyes of 107 patients (55.6% male, 44.4% female) with a median age of 68 years (range 21-91 years), RON was performed. The median follow-up time was 6 months (range 1-24 months). The median preoperative visual acuity (VA) was 0.05 (logMAR 1.3), increasing to a median postoperative VA of 0.08 (logMAR 1.1). Patients with an interval of more than 90 days between RON and onset of CRVO showed no significant change in VA at the 6-month follow-up. Severe peripapillary swelling of the optic nerve head prior to RON resulted in an average increase of 4.2 lines in VA at the 6-month follow-up. Angiographic findings of shunt vessels were seen in 18/30 cases after 12 months and were accompanied by an average improvement of VA of six lines. Visual field tests showed various defects in 86.8% of all cases. In one patient an iatrogenic injury of the central retinal artery occurred (0.9%). CONCLUSION: Despite the potential risk of visual field defects, RON seems to be a quite safe procedure. The majority of patients showed rapid normalization of the morphologic fundus findings, with an improvement in VA uncommon for the natural history of CRVO. No significant change in VA was seen in patients with an interval of more than 90 days between the onset of CRVO and RON. A prospective study is warranted for further investigation.

Rapid transmembrane movement of phosphatidylcholine in small unilamellar lipid vesicles formed by detergent removal.

Small unilamellar phosphatidylcholine vesicles, formed by solubilizing phosphatidylcholine with sodium cholate and removing the detergent by gel filtration, have been studied in their interaction with phospholipid exchange protein. The exchange of phosphatidylcholine between the vesicles and erythrocyte ghosts was greatly stimulated by the phosphatidylcholine-specific exchange protein from bovine liver. It was found that 95% of the phosphatidylcholine was readily available for exchange within 3 h at 37 degrees C. In similar vesicles prepared by sonication only 70% of the phosphatidylcholine was rapidly exchangeable. Our results indicate that the transmembrane movement of phosphatidylcholine across the bilayer of vesicles prepared by the cholate technique is a relatively fast process. The results are discussed with respect to the presence of trace amounts of lipid-associated cholate which may facilitate the transbilayer exchange of phosphatidylcholine.