Investigative ophthalmology & visual science
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Invest. Ophthalmol. Vis. Sci. · Jun 1998
Light history and age-related changes in retinal light damage.
To determine the effects of age and long-term light- or dark-rearing environments on acute, intense-light-mediated retinal degeneration. ⋯ The age-related increase in susceptibility to retinal light damage in rats is influenced by their long-term daily light history. Decreasing retinal irradiance by dark-rearing eliminates the age-related increase in light damage, suggesting a correlation between light environment and retinal gene expression associated with damage. In all rats, retinal light damage resulted in a pattern of DNA fragmentation consistent with apoptotic cell death and in an increased expression of HO-1 mRNA. Antioxidant treatment greatly reduced apoptosis and HO-1 expression. This indicates that light damage involves an oxidative process that may also trigger apoptosis in the retina. The rat aging model may provide useful insights into the role of light environment associated with retinal degeneration in an aging human population.
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Invest. Ophthalmol. Vis. Sci. · May 1998
Increased frequencies of interleukin-2- and interferon-gamma-producing T cells in patients with active Behçet's disease.
To elucidate the profile of cytokine-producing T cells in patients with active or inactive Behçet's disease (BD), the frequencies of type 1 (Interleukin- [IL] 2, interferon-gamma [IFN-gamma]) and type 2 (IL-4) cytokine-producing CD4+ and CD8+ cells in peripheral blood were investigated, and the effect of immunosuppressive drugs on the profile of cytokine-producing cells was evaluated. ⋯ The frequencies of type 1 cytokine-producing CD4+ and CD8+ cells increased in patients with active BD. Effective immunosuppressive treatments decreased the population of type 1 cytokine-producing CD4+ and CD8+ cells. These results suggest that type 1 cytokine-producing cells play an important role in the immunopathogenesis of the inflammation in BD.
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Invest. Ophthalmol. Vis. Sci. · Feb 1998
Randomized Controlled Trial Clinical TrialRisk factors for high-risk proliferative diabetic retinopathy and severe visual loss: Early Treatment Diabetic Retinopathy Study Report #18.
To identify risk factors for the development of high-risk proliferative diabetic retinopathy (PDR) and for the development of severe visual loss or vitrectomy (SVLV) in eyes assigned to deferral of photocoagulation in the Early Treatment Diabetic Retinopathy Study (ETDRS). ⋯ These analyses supported the view that the retinopathy-inhibiting effect of better glycemic control extends across all ages, both diabetes types, and all stages of retinopathy up to and including the severe nonproliferative and early proliferative stages and the possibility that reducing elevated blood lipids and treating anemia slow the progression of retinopathy.
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Invest. Ophthalmol. Vis. Sci. · Nov 1997
A new method for studying the selective adherence of blood lymphocytes to the microvasculature of human retina.
To develop a sensitive and reproducible technique for measuring the adherence of blood lymphocytes to vessel walls exposed in sections of human retina and for examining the role of lymphocyte and vascular adhesion molecules in these events. ⋯ This technique allows measurements to be made of lymphocyte adherence to vascular and nonvascular structures of retina ex vivo. Extension of this approach to the study of leukocyte adherence to sections of pathologic retina may be of clinical and experimental applicability in understanding mechanisms of retinal inflammation.
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Invest. Ophthalmol. Vis. Sci. · Sep 1997
Reduction by antiinflammatory drugs of the response of corneal sensory nerve fibers to chemical irritation.
Nonsteroidal antiinflammatory drugs (NSAIDs) have been applied topically to reduce ocular pain caused by corneal injury or anterior segment surgery. The authors investigated whether the analgesic effects of the NSAIDs diclofenac, indomethacin, and flurbiprofen and of the calcium channel antagonist diltiazem on corneal pain are mediated by a reduction of nerve activity in corneal polymodal nociceptive fibers. ⋯ Indomethacin, diclofenac, and flurbiprofen, as well as the calcium antagonist diltiazem, diminish the responsiveness of corneal polymodal nociceptors to chemical stimuli. This appears to be caused, in part, by a direct effect of these drugs on the excitability of polymodal nerve endings, but also by an inhibition by NSAIDs of the formation of cyclooxygenase products such as prostaglandins, thus reducing the enhanced responsiveness of nociceptors caused by local release of arachidonic acid metabolites from injured cells.