A Proinflammatory Function of Toll-Like Receptor 2 in the Retinal Pigment Epithelium as a Novel Target for Reducing Choroidal Neovascularization in Age-Related Macular Degeneration.

Current treatments for choroidal neovascularization, a major cause of blindness for patients with age-related macular degeneration, treat symptoms but not the underlying causes of the disease. Inflammation has been strongly implicated in the pathogenesis of choroidal neovascularization. We examined the inflammatory role of Toll-like receptor 2 (TLR2) in age-related macular degeneration. TLR2 was robustly expressed by the retinal pigment epithelium in mouse and human eyes, both normal and with macular degeneration/choroidal neovascularization. Nuclear localization of NF-κB, a major downstream target of TLR2 signaling, was detected in the retinal pigment epithelium of human eyes, particularly in eyes with advanced stages of age-related macular degeneration. TLR2 antagonism effectively suppressed initiation and growth of spontaneous choroidal neovascularization in a mouse model, and the combination of anti-TLR2 and antivascular endothelial growth factor receptor 2 yielded an additive therapeutic effect on both area and number of spontaneous choroidal neovascularization lesions. Finally, in primary human fetal retinal pigment epithelium cells, ligand binding to TLR2 induced robust expression of proinflammatory cytokines, and end products of lipid oxidation had a synergistic effect on TLR2 activation. Our data illustrate a functional role for TLR2 in the pathogenesis of choroidal neovascularization, likely by promoting inflammation of the retinal pigment epithelium, and validate TLR2 as a novel therapeutic target for reducing choroidal neovascularization.

Iatrogenic dry eye disease: an eledoisin/carnitine and osmolyte drops study.

BACKGROUND: To evaluate the effects of an eye drop containing eledoisin and carnitine in patients suffering from primary open-angle glaucoma (POAG) and ocular discomfort syndrome secondary to a chronically treated with eye drops containing benzalkonium chloride (BAK) as preservative. The dry eye disease was defined as a multifactorial drop disease concerning tears and ocular surface, which brings to discomfort symptoms and visual disorders with potential damage to the ocular surface. Several studies underlined the beneficial effects of secretagogues drugs, such as eledoisin. It is a neuro-peptide extracted from the salivary glands of some shellfishes. Recently, it has been also showed the protective role of carnitine in respect of the ocular surface exposed to the tear film hyperosmolarity. MATERIALS AND METHODS: This randomized double-blind pilot study has been evaluated by lubricant eye drop solutions containing eledoisin and carnitine in 40 patients with ocular discomfort syndrome secondary to POAG, since that the patients were chronically treated with eye drops which decrease eye pressure and contain BAK as preservative. The subjects filled out a questions form concerning the severity of the symptoms and their impact on daily activities. Subsequently Fluorescein Breakup Time (FBUT), Schirmer Test 1 (ST), and Ocular Protection Index (OPI) were measured at baseline and after 15days of treatment. RESULTS: At the end of therapy it was possible to match the beneficial effects of eye drops with carnitin, taurine, sodium hyaluronate and eledoisin. In fact, after 15days of treatment, patients of group 1 showed a decrease of approximately 50% concerning the severity of symptoms and a significant improvement of the tests valued. CONCLUSION: In summary, lubricant eye drops that restore physiological hosmolarity and stimulate tear production represent a promising strategy for dry eye syndrome.

Fixed topical combinations in glaucomatous patients and ocular discomfort.

OBJECTIVE: The purpose of this study was to verify the ocular comfort of a fixed topical combination of brinzolamide 1% plus timolol 0.5% suspension vs. dorzolamide 2% plus timolol 0.5% solution, both preserved with benzalkonium chloride (BAK), in patients with primary open-angle glaucoma (POAG) through subjective and objective methods. BAK is the most commonly used preservative in topical glaucoma medications. METHODS: 62 subjects were examined and included in the analysis. Each patient was asked to complete a questionnaire on symptoms (Ocular Surface Disease Index) and then underwent a series of examinations. The Ocular Protection Index evaluated the risk of damage to the ocular surface, and was expressed as the ratio between fluorescein breakup time and blinking interval. These and other analyses were repeated 30 days after instillation of the new eye drop treatment. RESULTS: The results demonstrated that patients enrolled with the preserved fixed combination of dorzolamide or brinzolamide represented a subgroup of patients in which the discomfort symptoms were supposedly justified by the presence of BAK used chronically in antihypertensive drops. Ocular discomfort scores were significantly higher with dorzolamide/timolol than brinzolamide/timolol (p < 0.0001). CONCLUSIONS: This work shows the better tolerability of brinzolamide 1% plus timolol 0.5% suspension, compared with dorzolamide 2% plus timolol 0.5% solution. Fortunately, some of the adverse reactions induced by preserved eye drop glaucoma medication are reversible after removing the preservatives. Both the potential for added benefit and patient compliance should be considered when selecting ocular hypotensive therapy.

Oxidative stress in preretinopathic diabetes subjects and antioxidants.

BACKGROUND: This study assessed the effect of a systemic oral treatment with antioxidants (AOs) in preretinopathic diabetes (PRD) patients, through the evaluation of oxidative stress in plasma and changes in the full-field electroretinogram (ERG). METHODS: Thirty-two PRD subjects with good metabolic control were recruited. Patients were randomized in two groups, one of which received oral AO treatment with α-lipoic acid at 400 mg/day in association with genistein and vitamins, whereas the other group received a placebo. Free radicals and the AO barrier were evaluated in plasma with the Free Radical Analytical System 4 instrument (H&D srl, Parma, Italy), and the same day the electrophysiological response was measured by ERG. These analyses were performed at enrollment and after 30 days of treatment. RESULTS: Statistically significant increases of plasma AO levels and ERG oscillatory potential values were observed in the group treated with AO, but not in the control group. CONCLUSIONS: Results of this preliminary study suggest that an oral treatment with AOs in PRD subjects may have a protective effect on retinal cells, as detected by ERG analysis, through the strengthening of the plasma AO barrier.