# EvidenceDigest: Anti-VEGF Dosing Regimens in Neovascular Age-Related Macular Degeneration
Clinical bottom line
Anti-VEGF (vascular endothelial growth factor) therapy is the cornerstone of treatment for neovascular age-related macular degeneration (nAMD). Various dosing regimens, including fixed, pro re nata (PRN), and treat-and-extend (T&E) strategies, have been developed to optimize visual outcomes while minimizing treatment burden. The choice of regimen should be tailored to individual patient needs, balancing efficacy, safety, and convenience.
What the evidence shows
Recent studies have evaluated the efficacy of different anti-VEGF dosing regimens in nAMD. The CATT trial (2011) remains a landmark study that compared monthly and PRN dosing of ranibizumab and bevacizumab, demonstrating that both regimens provided similar visual acuity outcomes, although monthly dosing resulted in slightly better anatomical outcomes (PMID: 21526923). This trial established the foundation for flexible dosing strategies.
A more recent study, the TREX-AMD trial (2016), assessed the T&E regimen, showing that it achieved comparable visual outcomes to monthly dosing with fewer injections (PMID: 26780336). This approach allows for individualized treatment intervals based on disease activity, potentially reducing the treatment burden for patients.
The VIEW trials (2012) evaluated aflibercept, confirming its efficacy in both fixed and PRN regimens, with the added benefit of less frequent dosing compared to other anti-VEGF agents (PMID: 22084193). These findings support the use of aflibercept in flexible dosing schedules.
Caveats and uncertainty
While anti-VEGF therapy is highly effective, there are challenges associated with its long-term use. The need for frequent monitoring and injections can be burdensome for patients and healthcare systems. Additionally, the risk of adverse events, such as endophthalmitis and increased intraocular pressure, although low, must be considered.
The choice of dosing regimen should be guided by patient-specific factors, including disease severity, response to treatment, and ability to adhere to follow-up schedules. Further research is needed to refine dosing strategies and explore the potential of emerging therapies that may offer longer-lasting effects.
How this may change practice
The evidence supporting various anti-VEGF dosing regimens provides clinicians with flexibility in managing nAMD. The T&E approach, in particular, offers a balance between maintaining visual outcomes and reducing treatment burden, making it an attractive option for many patients.
Clinicians should engage in shared decision-making with patients, discussing the potential benefits and limitations of each regimen. Regular monitoring and individualized treatment plans are essential to achieving optimal outcomes and minimizing adverse effects.