Purpose:
A framework for sub-classification of Exudative ARMD has been previously described (Nelson, ARVO 2010)(Table 1) and requires multimodality imaging including spectral-domain OCT, IVFA and ICG videoangiography for evaluation. In addition, it is clear that many patients with Exudative ARMD have persistent leakage after non-selective anti-VEGF monotherapy due to resistant lesions ( polypoidal vasculopathy and arteriolarized neovascularization ) which can only be identified on ICG imaging. These lesions create a dependence on anti-VEGF monotherapy in up to 50% of treated patients. It is important to understand the typical response to non-selective anti-VEGF monotherapy for each subtype of Exudative ARMD so that deviations can be identified and that imaging can be repeated to determine whether the neovascular process has changed.
Methods:
Retrospective study of Treatment-Naive Exudative ARMD patients
Results:
Classic and occult membranes respond differently to anti-VEGF monotherapy. Classic membranes regress, with various degrees of leakage resolution and damage/restoration to the IS/OS junction. This is often related to the degree of arteriolarization or the presence of concurrent polyp formation. Recurrent leakage is not uncommon - careful examination frequently reveals a new area of classic neovascularization. Occult membranes respond with intraretinal and subretinal leakage resolution, however the neovascular complex posterior to the RPE is often unaffected by the therapy. In addition, stable occult membrane may be associated with RPE breach and progression into a classic membrane formation. RPEDs may respond by collapse or rip and often can be seen as a fibrovascular RPED where the previous serous fluid is replaced by more permanent solid fibrovascular core.
Conclusions:
Treating patients with Exudative ARMD with non-selective anti-VEGF monotherapy requires monitoring by multi-modality imaging to determine if the neovascular process is responsive (regressing), nonresponsive, or recurring.
Keywords: age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)