Choroidal Neovascularization: Pathogenesis, Diagnosis, and Current Management Strategies

Choroidal neovascularization (CNV) is characterized by the growth of new blood vessels from the choroid to the subretinal pigment epithelium, subretinal space, or both. Newer diagnostic and treatment methods, such as, Optical Coherence Tomography Angiography and anti-vascular Endothelial Growth Factors, are becoming increasingly effective for CNV diagnosis and management, respectively. Anti-VEGF (Ranibizumab, Bevacizumab, and Aflibercept) treatment has become the first-line treatment for CNV and has replaced other methods, such as laser photocoagulation and photodynamic therapy. The current literature has established similar safety and efficacy of the three drugs (Ranibizumab, Bevacizumab, and Aflibercept) in the treatment of CNV, especially when the visual loss is mild. However, Aflibercept has been reported to result in slightly better long-term visual outcomes. Newer molecules such as Brolucizumab and Faricimab show the potential to decrease the treatment frequency and increase efficacy due to better penetration and by increasing drug concentration in the retina, addressing the limitations of the currently available drug options.
However, their investigation was in the early stages and may have taken some time before being seen in the clinic. Innovative methods for continuous drug delivery to the vitreous through the use of dedicated ocular implants filled with anti-VEGF drugs for controlled release (port delivery systems) have also shown promising results in clinical trials. The development of this technique is expected to reduce the total number of injections and maintain stable vision. Different clinical trial protocols across studies remain an issue in addressing research questions related to dosing frequency and gaps.