Evaluation of both native and pathological vascular changes occurring during the Aflibercept intravitreal injections' loading phase in treatment-naïve wet AMD patients.

Abstract

Purpose : To investigate vessel changes occurring after Aflibercept injections in treatment-naïve exudative age-related macular degeneration (AMD) patients.

Methods : Fifteen eyes of 15 patients affected by wet AMD were enrolled in the study. All the patients had a diagnosis of type 1 choroidal neovascularization (CNV) and were treated with three monthly Aflibercept intravitreal injections (IVI). Subjects were evaluated by means of Optical Coherence Tomography Angiography (OCTA) at baseline, the day after the first injection and one month after both the first and the second IVI. At last, all the patients were followed up to 2 months after the 3^rd IVI. Main outcomes were: (i) superficial plexus vessel density; (ii) choroidal thickness; (iii) CNV lesion area; and (iv) CNV flow area.

Results : Foveal superficial vessel density was 29,01% (21,13 to 37,32%) at baseline and was significantly reduced as soon as 1 month after the 1^st IVI (median: 20,78%; IQR: 14,75 to 23,13%; p=0,017). Parafoveal superficial vessel density was 47,09% (44,91 to 51,72%) at baseline and significantly decreased as soon as 1 month after the 2^nd IVI (median: 44,40%; IQR: 41,59 to 49,29%; p=0,034). Choroidal sub-foveal thickness was 185,50 μm (140,25 to 254,25 μm) at baseline and was significantly thinned as soon as 1 month after the 1^st IVI (median: 147,50 μm; IQR: 125,50 to 192,75 μm; p=0,036). CNV lesion area remained stable throughout the follow-up. Nevertheless, interestingly, CNV flow area was significantly reduced as soon as the next day the 1^st IVI (median: 0,37 mm² and IQR: 0,27 to 0,72 mm² at baseline; median: 0,30 mm² and IQR: 0,24 to 0,64 mm² at 1 day after the 1^st IVI; p=0,047).

Conclusions : Intravitreal Aflibercept injections caused a significant change in native retinal and choroidal vasculature. Moreover, the treatment did not cause a reduction in lesion area, but rather reduced the flow in the CNV. Our results give credit to the theory that, in most cases, the treatment does not lead to a reduction in the size of CNV, but rather reduces the number and the perfusion of the smallest pathological vessels.

This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.