Treatments for choroidal and retinal neovascularization: a focus on oligonucleotide therapy and delivery for the regulation of gene function.

Blinding eye diseases caused by neovascularization of the retinal tissue are the leading cause of blindness in Western societies. Current treatments, such as laser photocoagulation, are limited in their effectiveness at halting the progression of angiogenesis and are unable to reduce the number of vessels once they have developed. In addition, although complete blindness is often avoided, vision is often permanently impaired by the treatment itself. Several less invasive treatments are being developed and one of these is oligonucleotide gene therapy in which short stretches of nucleotides are being used as inhibitors of key, metabolic processes involved in angiogenesis. Combined with this is the development of new and improved nucleotide chemistries aimed at overcoming many of the problems associated with oligonucleotide gene therapy, such as poor longevity because of endonuclease activity. In addition, advancements in delivery systems have further enhanced the efficacy of oligonucleotide gene therapy by increasing cellular penetration and localizing delivery to specific cell types and organs.