The macula is the central portion of the retina. At the centre of the macula is the fovea. Although the fovea is only 0.5 mm in diameter, it is responsible for the ability to read, drive, and recognize fine detail, including facial features. order cialis professional
Age-related macular degeneration (AMD) is now the leading cause in North America of visual loss in patients older than 50 years. Although there are no population-based studies conducted in Canada, the Beaver Dam study conducted in the United States revealed that nearly 2% of all patients evaluated had evidence of “late” AMD, as did 7.8% of patients older than 75. Five-year incidence of late AMD in that study was 1%. From data provided by this and other studies, we can estimate that more than 700000 Canadians have some form of AMD and more than 100000 have “wet” AMD. levitra canadian pharmacy
Patients with AMD have seriously reduced quality of life. In fact, we were recently able to demonstrate that blind patients with macular degeneration had a 60% reduction in the quality of their lives. Age-related maculopathy is a degenerative disease of the deep retinal layers, including the retinal pigment epithelium. The disease can be classified as either dry or wet. Patients with the wet type of the disease have either choroidal neovascularization (CNV) (where new blood vessels grow under the retina or retinal pigment epithelium) or detachment of the pigment epithelium caused by serous fluid or blood. Patients with wet AMD should have retinal angiography to determine whether a new blood vessel is causing leakage and whether it is treatable by either thermal laser photocoagulation or photodynamic therapy. Viagra Professional 100 mg
The Macular Photocoagulation Study, a multicentre, randomized clinical trial, was able to demonstrate the benefit of thermal laser photocoagulation for treatment of “classic” CNV located under (subfoveal), near (juxtafoveal), or away from (extrafoveal) the centre of the macula. (In classic CNV, the new blood vessel is well delineated on early angiographs and leaks in the late phases.) Although treatment conferred long-term benefits on patients with subfoveal CNV, the immediate visual loss associated with this treatment has limited its clinical usefulness. viagra from canadian pharmacy
The Treatment of Age-Related Macular Degeneration with Photo-dynamic Therapy (TAP) study recently evaluated photodynamic therapy for treatment of subfoveal CNV secondary to AMD. Photodynamic therapy is a two-step procedure that involves injection of a photosensitizing dye, verteporfin (Visudyne from CIBA Vision), followed by laser light energy (689 nm). This therapy reduces the potentially damaging effects of the laser on healthy tissue, because the energy is preferentially absorbed by the neovascular tissue. The TAP study was able to demonstrate that photodynamic therapy lowered the chances of losing essential vision by 28% (absolute risk reduction, 28%); that three eyes with predominantly classic CNV need to be treated to prevent one from losing essential vision (number needed to treat, 3); and that 13% of treated patients had improvements in vision while only 6% of those who received placebo had improvement. Viagra 400 mg
Average patients in this study needed between five and six treatments with photodynamic therapy to entirely eliminate leakage from their new blood vessels.
Although the drug was generally well tolerated, photosensitizing reactions did occur. Patients who undergo this treatment should stay away from sunlight and strong lights for 48 hours after treatment. cymbalta online
Figure 1. Wet age-related macular degeneration: A) Choroidalneovas-cular membrane; B) Predominantly classic choroidal neovascular membrane on angiography.
The patient was referred to a retinal specialist on an urgent basis. Clinical examination revealed presence of wet AMD (Figure 1A). An angiogram demonstrated presence of predominantly classic CNV (Figure 1B). The patient underwent photodynamic therapy with verteporfin, and his vision stabilized. On a follow-up visit, persistent leakage was noted on angiography, and additional treatment was given. On the most recent examination, the patient’s vision had improved to 6/12, and leakage had stopped. canadian pharmacy topamax