Current and Potential Therapies for Ocular Neovascular Diseases

Abstract

therapy approved to treat neovascular AMD. It is a two step procedure involving the intravenous administration of the drug, and subsequent activation by a non-thermal laser beam. This “cool” laser treatment produces a chemical reaction that selectively destroys abnormal blood vessels. However it is only for those patients who have new blood vessel growth under the retina in a well defined, distinctive pattern known as “predominantly classic.” Visudyne was developed by Novartis. Laser photocoagulation is another classic treatment for choroidal NV. The procedure uses laser light to destroy or seal off new blood vessels to prevent leakage. A major drawback of PDT and laser photocoagulation is that recurrent NV post-treatment is extremely common, since that these therapies don’t eliminate the angiogenic stumili. Laser photocoagulation produces many small retinal scars, which cause blind spots in the patient’s visual field. Multiple treatments are always needed. FDA approved the Implantable Miniature Telescope (IMT) in 2010, developed by VisionCare Ophthalmic Technologies. The intraocular implant magnifies images onto the retina to improve central vision damaged by advanced AMD or Stargardt’s maculat dystrophy. This device is only for patients at least 75 years old with severe to profound vision impairment. Among these treatments, VEGF antagonisms have provided major benefits to patients. Recent progress unveiling the molecular pathogenesis of the diseases has lead to potential new drug therapy. Other key angiogenesis mediators, such as Platelet Derived Growth Factor B (PDGF-B) and NF-κB-responsive mediator Vascular Cell Adhesion Molecule-1 (VCAM-1) [9], can provide potential therapy to combat worsening of NV diseases. Nonetheless, monthly injections of VEGF inhibitors into the eyes can cause harmful side effects, and some patients didn’t have an optimal response. A promising potential new treatment is gene-transfer of antiangiogenic factors through viral vectors, which has the potential to provide long-term suppression of NV and excessive vascular leakage [10].