**2. Advances in nAMD treatment**

Preservation of visual function is the main goal for nAMD treatment. This is achieved by inhibition of the new blood vessel growth and reduction of the fluid leakage [13]. Vascular endothelial growth factor is a major molecule which contributes to development of CNV [14]. Choroidal neovascularization can be slowed by inhibiting VEGF binding to its receptor, VEGF receptor-2, on blood vessels, which is the major proangiogenic pathway [15]. Anti-VEGF agents are antibodies which neutralize VEGF binding to its receptor and they have different mechanisms of action. They reduce fluid leakage from the CNV, stop growth, and lead to regression of CNV [16]. The introduction of the anti-VEGF drugs into clinical practice has immensely improved the prognosis for patients with nAMD, in such a way that nAMD is no longer considered an incurable disease [17]. The first anti-VEGF agent approved in 2004 by Food and Drug Administration (FDA) was pegaptanib sodium, an aptamer that binds VEGF₁₆₅ [18]. Ranibizumab, an antibody fragment that binds all VEGF-A isoforms was FDA approved in 2006 after the ANCHOR and MARINA studies [19, 20]. In the following years, from 2006 till 2013, there were 2 other anti-VEGF therapies available for nAMD treatment: aflibercept and conbercept, approved based on the results of the VIEW 1 and VIEW 2 studies, and PHOENIX study, respectively [21, 22]. Both of them are antibody fusion proteins [23].

*Anti-VEGF Treatment and Optical Coherence Tomography Biomarkers in Wet Age-Related… DOI: http://dx.doi.org/10.5772/intechopen.97689*

Two other anti-VEGF agents approved for therapy in oncology are used "off-label" for nAMD: ziv-aflibercept and bevacizumab [7]. Current care standards for nAMD include regular intravitreal (IVT) injections of anti-VEGF therapy [24]. This poses a substantial burden on patients, as well as health systems worldwide [3]. For some patients, anti-VEGF treatment involves monthly injections over a long period of time, making patient adherence and monitoring difficult, which in turn has consequences for visual and anatomic outcomes [25]. Also, the cost associated with managing nAMD is substantial [26]. In an attempt to lessen the load of frequent therapy and costs associated with anti-VEGF medications, some clinicians proposed alternative dosing strategies which are different from those in the registered clinical trials (q4- or q8-weeks). These include pro re nata (PRN) and treatand-extend (TAE) regimens [27]. They attempt to provide the same efficacy and at the same time more convenient regimen that is easier to adhere to and is taking into account individual OCT features of the patient.

Brolucizumab, a newly developed anti-VEGF drug for nAMD treatment, has demonstrated longer durability and improvement in visual and anatomic outcomes in clinical studies in a q12-week regimen, indicating its potential to reduce treatment burden as an important therapeutic tool in nAMD management [28].
