ABSTRACT
Retinal vein occlusion (RVO) is the most common retinal vascular disorder second to diabetic retinopathy. The main risk factors in patients with RVO are hypertension, diabetes, hyperlipidemia, increased blood viscosity and glaucoma. The pathogenesis of RVO has not yet been clarified. In these events platelets could play a very important role. In the present study the platelet response to collagen was deeply investigated. Experiments were carried out on a selected group of RVO patients, which were compared to a group of healthy subjects matched for age, sex, clinical and metabolic characteristics. In resting and activated platelets of both groups of subjects p72syk phosphorylation, phospholipase Cgamma2 phosphorylation, protein kinase C activation, intra-cellular calcium levels and nitric oxide formation were measured. Results show that platelets of patients were more responsive to collagen or ADP than healthy subjects and that the response was significantly different (p < 0.0005) at low concentrations of these agonists. In platelets of patients stimulated with collagen increased phosphorylation of p72syk and phospholipase Cgamma2 was found. Also protein kinase C was more activated in patients. In addition intracellular calcium rise induced by collagen was significantly higher in patients than in healthy subjects. RVO patients showed a lower basal level of nitric oxide both in resting and stimulated platelets compared to healthy subjects. Altogether these results suggest that the platelet hyperaggregability described in patients might be an important factor in the development of RVO contributing to the thrombogenic effects.
Subject(s)
Blood Platelets/drug effects , Collagen/pharmacology , Platelet Activation/drug effects , Retinal Vein Occlusion/blood , Adenosine Diphosphate , Aged , Blood Platelets/metabolism , Calcium/metabolism , Case-Control Studies , Dose-Response Relationship, Drug , Enzyme Activation/drug effects , Female , Humans , Intracellular Signaling Peptides and Proteins/metabolism , Male , Middle Aged , Nitric Oxide/metabolism , Phospholipase C gamma/metabolism , Phosphorylation , Platelet Aggregation/drug effects , Platelet Aggregation Inhibitors/therapeutic use , Platelet Function Tests , Protein Kinase C/metabolism , Protein-Tyrosine Kinases/metabolism , Retinal Vein Occlusion/drug therapy , Retinal Vein Occlusion/metabolism , Syk Kinase , Time FactorsABSTRACT
PURPOSE: To examine combined treatment of intravitreal triamcinolone acetonide (IVT) and photodynamic therapy (PDT) for retinal angiomatous proliferation (RAP). METHODS: Ten eyes of eight consecutive patients with RAP underwent a single injection (about 20 mg) of IVT followed 1 month later by PDT. Best-corrected visual acuity (BCVA) was measured by standardized protocol refraction. RESULTS: Median BCVA was 20/160, 20/64, 20/98, 20/89, 20/89, 20/125 at baseline and 1, 3, 6, 9 and 12 months, respectively. Of ten eyes, six (60%) improved BCVA of at least 3 lines at 1, 3, 6 and 9 months. Four (40%) eyes improved BCVA of at least 3 lines at 12 months. Three eyes (30%) lost >3 lines at 12 months. In all patients intraocular pressure was well controlled. No endophthalmitis, retinal detachment or vitreous haemorrhage developed. CONCLUSIONS: Improvement of BCVA suggests that combination treatment with IVT and PDT for RAP merits further investigation.
Subject(s)
Angiomatosis/drug therapy , Glucocorticoids/therapeutic use , Photochemotherapy , Photosensitizing Agents/therapeutic use , Porphyrins/therapeutic use , Retinal Neovascularization/drug therapy , Triamcinolone/therapeutic use , Drug Therapy, Combination , Fluorescein Angiography , Humans , Injections , Tomography, Optical Coherence , Treatment Outcome , Verteporfin , Visual Acuity , Vitreous BodyABSTRACT
PURPOSE: To examine combined treatment with intravitreal triamcinolone acetonide (IVT) and photodynamic therapy (PDT) for occult with no classic choroidal neovascularization (CNV) secondary to age-related macular degeneration. METHODS: In this prospective, interventional case series, 11 eyes of 10 consecutive patients with occult with no classic CNV underwent a single injection (25 mg) of IVT followed 1 month later by PDT. Best-corrected visual acuity was measured by Early Treatment Diabetic Retinopathy Study (ETDRS) protocol refraction. RESULTS: Median best-corrected visual acuity was 20/160, 20/80, 20/80, 20/50, and 20/80 at baseline and 1, 3, 6, and 12 months, respectively. Best-corrected visual acuity at baseline was statistically different (P < 0.05) than best-corrected visual acuity at 1, 3, and 6 months. Of 11 eyes, 5 (45.5%), 7 (63.6%), 7 (63.6%), and 4 (36.3%) had improved best-corrected visual acuity of at least 3 ETDRS lines at 1, 3, 6, and 12 months, respectively, while 6 (54.5%), 9 (81.8%), 10 (91%), and 8 (73%) had improved best-corrected visual acuity of at least 2 ETDRS lines at 1, 3, 6, and 12 months, respectively. Two eyes (18%) lost >3 lines at 12 months. One eye had intraocular hypertension at 3 months and was treated with a combination of topical antiglaucomatous drugs. One eye developed a dense cataract at the last follow-up visit. No endophthalmitis, retinal detachment, or vitreous hemorrhage developed. Fluorescein leakage and retinal thickness reduced significantly after treatment. CONCLUSIONS: Improvement of best-corrected visual acuity and lack of fluorescein leakage suggest combination treatment with IVT and PDT for occult with no classic CNV merits further investigation.
