Proliferative diabetic retinopathy in long-term diabetic patients with and without clinical osteoarthritis.

OBJECTIVE: To determine whether some long-term diabetic patients with coexisting clinical osteoarthritis (OA) are less likely to develop diabetic retinopathy (DR) than other diabetic patients and whether there is a relation between the timing of the clinical OA onset and DR. DESIGN, SETTING, AND PARTICIPANTS: Retrospective case-control study of 85 osteoarthritic patients with 20 years or more diabetes (A/DM) control group and of 85 non-osteoarthritic diabetic patients (NoA/DM) matched for age, race, duration, and type of diabetes. Digital fundus photographs were graded for retinopathy in masked manner. RESULTS: Glycosylated hemoglobin, hypertension, and smoking showed no significant difference. Twelve out of 85 patients (12.9%) in A/DM group developed proliferative diabetic retinopathy (PDR) whereas 79/85 (92.9%) NoA/DM patients developed PDR (P<0.001). The onset of OA symptoms was known in 80/85 of the A/D patients, including 47 patients with onset before or at the same year as DM and 33 patients with relative onset after the year of DM. All the 10 patients with PDR (10/33) developed OA subsequent to their initiation for diabetic treatment while 0/47 A/DM patients with the onset of osteoarthritic symptoms present before or the same year as their onset of diabetes developed PDR (P<0.001). CONCLUSION: Our study suggests that in long-term DM, PDR was significantly associated with the absence of concomitant clinical OA. This observation was highly significant if the onset of the arthritis was the same year or before the onset of the diabetes.

[The ZEBET database on alternative methods to animal experiments in the Internet--a concrete contribution to the protection of animals]. / Die ZEBET-Datenbank über Alternativen zu Tierversuchen im Internet - ein konkreter Beitrag zum Schutz von Versuchstieren.

Up from February of the year 2000 ZEBET (German Centre for the Documentation and Validation of Alternative Methods) at the Federal Institute for Consumer Health Protection and Veterinary Medicine (BgVV) put the ZEBET-database on alternative methods to animal experiments on the Internet in English via DIMDI, the German Institute for Medical Documentation and Information (http://gripsdb.dimdi.de/engl/guieng.html). The access is free, moreover DIMDI's complete service is available to visitors of the ZEBET-database. The ZEBET database contains documents on alternatives to testing in animals, which have been carefully evaluated by ZEBET's staff according to the "3Rs"-concept established by Russel and Burch in 1959. Therefore, methods documented in the ZEBET database must meet at least one of the following criteria: "replacement" of an animal experiment by a non-animal method, "reduction" of the number of animals used, "refinement" of an experiment by minimising pain and suffering of animals. In addition, the ZEBET-database provides information on the current stage of development and validation of a method and on the acceptance for either scientific or regulatory purposes. Each document is characterised by the following criteria: the title of a method, keywords, assessment, summary and bibliographic references. To search DIMDI<

Experimental preretinal neovascularization by laser-induced venous thrombosis in rats.

PURPOSE: Retinal ischemia and neovascularization (NV) are important components of many retinal disorders. To facilitate further investigation of retinal ischemia and neovascularization, we sought to develop a reproducible in vivo experimental model of venous occlusion by photodynamic thrombosis in rats. METHODS: After anesthesia, 27 eyes of pigmented rats received an intraperitoneal injection of 0.2 ml of, 10% sodium fluorescein 15 minutes prior to laser treatment. With a blue-green argon laser, selected venous sites next to the optic nerve head were photocoagulated indirectly with a 78 diopter lens. Venous occlusion was accomplished using laser parameters of 1.0 second, 50 microns, and 50-100 mW. For a control group, 10 eyes were coagulated on the retina between major vessels using the same parameters after fluorescein injection. For a second control group, 1% sodium hyaluronate was injected into the subretinal space to make a long-standing retinal detachment in 5 eyes. RESULTS: With 1-8 laser impulses, each venous occlusion was obtained and was associated with extreme venous constriction and tortuousity. Retinal edema became evident 10-30 minutes after treatment in the sectors associated with the occluded veins. This edema became a bullous retinal detachment (RD) within 12 hours and intra-retinal hemorrhage was observed. The retinal edema continued for 3-10 days and the retinas reattached spontaneously. Prior to or after retinal reattachment 70% (19/27) of eyes developed retinal NV and tractional RD. Of these, 11 developed NV of the optic disc (NVD), 6 developed NV elsewhere (NVE), and 2 developed NVD and NVE. In 30% (8/27) of the eyes, retinal edema resolved without evidence of NV. In control groups no eyes showed either circulatory disorders or evidence of NV. CONCLUSIONS: This is a new model of retinal ischemia and associated neovascularization established by venous thrombosis that is easily reproducible. Many aspects of rat retinal physiology are known and this model has promise as an avenue for further investigation.

Branch retinal artery occlusion associated with directional coronary atherectomy after percutaneous transluminal coronary angioplasty.

PURPOSE: To report a case of branch retinal artery occlusion after atherectomy. METHODS: A 51-year-old man complained of visual loss in the right eye after directional coronary atherectomy, performed secondary to a complicated percutaneous transluminal coronary angioplasty. He underwent a full ophthalmologic examination, including fluorescein angiography and Doppler ultrasound. RESULTS: Visual Acuity was 20/30 with an inferior scotoma present in the right eye. There were three Hollenhorst plaques present inside the superotemporal vascular arcade. CONCLUSIONS: There is a small but definite risk of retinal microinfarctions after atherectomy.

Treatment of retinal breaks with autologous serum in an experimental model.

PURPOSE: The standard treatment for retinal breaks is thermal adhesion. Breaks in the posterior pole (i.e., macular holes) recently have been treated using vitrectomy and the recombinant cytokine transforming growth factor-beta. This has been shown to achieve closure of the retinal breaks by stimulating localized fibrocellular proliferation. Serum has been shown to contain chemoattractants and mitogens for many types of cells. The authors studied the clinical and histologic effect of autologous serum application to retinal breaks in an experimental model. METHOD: Twenty-four rabbits underwent pars plana lensectomy, vitrectomy, retinectomy, fluid-air exchange, application of test solution (12 with Hank's buffered salt solution and 12 with autologous serum), and air-gas exchange. Clinical examination with indirect ophthalmoscopy was performed, and animals were killed 5, 14, and 28 days after treatment. Tissue sections through the retinectomy were studied by light microscopy, electron microscopy, and immunocytochemistry. RESULTS: None of the serum-treated eyes showed retinal detachment at the site of the retinectomy by evaluation with indirect ophthalmoscopy at each of the time points. In contrast, in control eyes retinal detachment developed at the retinectomy site from 0% at day 5 to 50% at day 14 and 75% at day 28. By light microscopy, serum-treated eyes contained multilayers of fibroblast-like cells adhering the retinectomy edges to the underlying retinal pigment epithelium and choroid. The control eyes had nonadherent retinal edges at the retinectomy site with little sign of fibrocellular response. Results were confirmed by electron microscopy. The fibroblast-like cells by immunocytochemistry contained vimentin, cytokeratin 18, and/or glial fibrillary acidic protein. CONCLUSION: This study suggests that serum induces a localized fibrocellular response at the retinectomy edges compared with control eyes. This response, characterized by light microscopy, electron microscopy, and immunocytochemistry, appears to involve a mixed population of glial, retinal pigment epithelial, and/or fibroblastic cells. These cells seem to enhance adhesion and subsequent reattachment of the edges of the retinectomies at the time points studied when compared with controls.

Treatment of experimental autoimmune uveitis in the rat with systemic succinylacetone.

The effects of succinylacetone (SA) on the development of S-antigen-induced experimental autoimmune uveitis (EAU) in the rat were studied. SA totally suppressed EAU at Day 14 when animals were treated with a constant infusion of 1.80 mg/hr by an osmotic minipump. Three intervals of treatment with this dose rate were used (Day 0-7, Day 7-14, or Day 0-14) and, regardless of dosage interval, suppression of the disease was complete. There was a significant inhibition of S-antigen-induced lymphocyte proliferative responses in cells from popliteal lymph nodes (P less than 0.009) as well as a significant decrease of S-antigen antibody production. Animals treated with SA at a rate of 0.90 or 0.45 mg/hr developed EAU in a dose-related fashion. Animals treated with 1.8 mg/hr from Day 7-14 but killed at Day 30 had 100% breakthrough of the disease. Succinylacetone inhibits the expression of EAU and significantly suppresses the immune response to S-antigen. However, once therapy is discontinued the high incidence of breakthrough suggests a reversible noncytotoxic mechanism of immune modulation.

Transient postictal cortical blindness.

An 8-year-old boy with insulin-dependent diabetes mellitus and a seizure disorder demonstrated transient visual loss after severe seizure activity. The role of hypoglycemia in relation to his transient cortical blindness remains indeterminate. The nature of the cortical involvement, the rate of visual recovery, and prior reports of postictal phenomena emphasize the relatively benign nature of this condition in children.