Effect of Pro Re Nata regimen with anti-VEGF on Type 3 Macular Neovascularization - Long term outcomes.

(348 words) Introduction: The purpose of this study is to investigate long-term outcomes of intravitreal injections (IVI) of anti-vascular endothelial growth factor (VEGF) in neovascular age-related macular degeneration (nAMD) with type 3 macular neovascularization (MNV). METHODS This retrospective study included 19 eyes of 17 patients with nAMD and type 3 MNV treated with anti-VEGF IVI with a loading dose and PRN regimen. Best corrected visual acuity (BCVA), central macular thickness (CMT), presence of macular intraretinal fluid (IRF) and subretinal fluid (SRF), flow area (FA), subfoveal choroidal thickness (CT) and macular atrophy (MA) were assessed at baseline (T0) and during follow up (T1, post loading phase; T2, one year; T3, two years, T4>2 years). The correlations between MA at the last follow-up and standard deviation (SD) values of CMT and CT during follow-up were assessed. The influence of the number of injections on the change in MA over time was also analysed. MA differences at T4 were assessed for pseudodrusen presence. RESULTS BCVA improved significantly during follow-up (p=0.013) particularly increasing from baseline to post loading phase and then did not modify significantly thereafter. CMT significantly reduced from T0 to T1 and remained stable during follow-up (p = <0.001). MNV flow area showed a trend toward increase in the post loading phase that was not statistically significant (p=0.082) and CT decreased significantly during follow-up (p<0.001). MA changed significantly during follow-up (p<0.001) with significant increase from T0 to T3 and from T0 to T4 (p < 0.010). Cochrane Armitage test for trend showed a significant reduction (p=0.001) of macular IRF and SRF during follow-up. MA at T4 showed a significant positive correlation with SD (standard deviation) values of CMT (p=0.040) and CT (p=0.020). Indeed, the number of injections did not influence the change over time of MA (p=0.709). MA at T4 was not statistically significantly different between patients with pseudodrusen at baseline (p=0.497). CONCLUSIONS Intravitreal anti-VEGF injections with PRN regimen in MNV type 3 showed functional and anatomical benefits. Variations of retinal thickness and choroidal thickness during treatment were related to MA modification over time.