Changes of choroidal structure after intravitreal aflibercept therapy for polypoidal choroidal vasculopathy.

AIMS: To quantify the changes of the choroidal structure in the enhanced depth imaging optical coherence tomographic (EDI-OCT) images after intravitreal aflibercept (IVA) injections for polypoidal choroidal vasculopathy (PCV).

METHODS: Retrospective, observational case series. Forty eyes of 40 treatment-naive patients who underwent IVA for PCV were examined by EDI-OCT before, and 3 months and 12 months after IVA. The EDI-OCT images were binarised by ImageJ software. The cross-sectional luminal and stromal areas of the inner and outer subfoveal choroid of 1500 µm width were quantified.

RESULTS: The stromal but not the luminal area of the inner choroid was significantly decreased at 3 months and 12 months after the IVA (stromal area, both p<0.001; luminal area, both p>0.050). On the other hand, the luminal but not the stromal area of the outer choroid was significantly decreased at 3 months and 12 months (luminal area, both p<0.001; stromal area, both p>0.050). The Pachychoroid Index, ratio of luminal/stromal area (L/S ratio) of the outer choroid divided by the L/S ratio of the inner choroid, was significantly decreased at 3 months and 12 months (both p<0.050). The Pachychoroid Index was increased and returned almost to the baseline level after recurrences and decreased again after successful re-treatment. The baseline Pachychoroid Index was significantly correlated with the presence of a dry macula, thinner fovea and better visual acuity at 12 months (all p<0.050).

CONCLUSION: The binarisation of the EDI-OCT images can be used to quantify the activity of PCV and to predict the prognosis after IVA.