Ocular pulse amplitude and retinal vessel caliber changes after intravitreal ranibizumab

Abstract

The purpose of the present study was to examine the effects of intravitreal ranibizumab on ocular pulse amplitude (OPA) and retinal vessel caliber (RVC) in wet age-related macular degeneration (AMD). Thirty-two eyes of 32 wet AMD patients were included in this case series. Three consecutive monthly injections of ranibizumab were performed. The OPA was measured with the Pascal dynamic contour tonometer. RVC measurements were taken with spectral-domain optical coherence tomography. Pre-injection mean OPA value was 2.55 ± 0.76 mmHg and post-injections mean OPA value was 2.79 ± 0.88 mmHg at the last visit (p = 0.10). Pre-injection mean arteriole and venule RVC were 96.7 ± 9.4 and 125.9 ± 8.4 µm; while post-injections arteriole and venule RVC were 96.0 ± 8.7 and 125.6 ± 8.9 µm, respectively (p > 0.05). OPA and RVC are unchanged after triple intravitreal ranibizumab injections, indicating that this treatment does not significantly alter gross retina-choroidal vasculature and hemodynamics.

Comparative Retinal Vessel Size Study of Intravitreal Ranibizumab and Bevacizumab in Eyes with Neovascular Age-Related Macular Degeneration

“…Overall, 12 patients with nonneovascular AMD were also included as the control group. Pekel et al [21] reported no significant change in retinal vessel diameters (measured with spectral-domain OCT) after triple doses of intravitreal RAN injections were administered to 32 patients with wet AMD. There was no control group included in the study.…”

“…There are even some reports on a fellow-eye treatment effect for intravitreal RAN and BEV [31,32] . None of the prior vessel diameter studies [19][20][21]23] , except 1 [22] , presented any results pertaining to noninjected fellow eyes following anti-VEGF delivery. Intravitreal RAN did not induce any alterations in vessel caliber in the noninjected eyes [22] .…”

Ocular Blood Flow Autoregulation Mechanisms and Methods

“…As large methods have been described in previous research, no single vascular indicator can completely evaluate ocular blood flow [ 15 , 16 ]. Every technique measures its specific aspects of ocular circulation, each with different limitations but providing a view of ocular hemodynamics [ 14 ]: pulsatile ocular blood flow, a possible indication of choroidal blood flow [ 17 , 18 ]; color Doppler imaging (CDI), a widely used assessment to evaluate retrobulbar vascular circulation [ 19 ]; scanning laser Doppler flowmeter, for quantifying superficial layers of ONH and retinal vascular circulation [ 19 , 20 ]; and optical coherence tomography (OCT), for detecting noninvasive vascular mapping at the microcirculation level.…”

Ocular pulse amplitude and retinal vessel caliber changes after intravitreal dexamethasone implant

“…Ocular pulse amplitude (OPA) signifies the difference between systolic and diastolic values of pulsatile intraocular pressure (IOP) and thus indirectly reflects choroidal blood flow. 2 Studies have also shown that intravitreal anti-vascular endothelial growth factor (VEGF) agents affect ocular blood flow. 3 …”

“…Reflective of retinal blood flow, 4 retinal arteriole caliber (RAC), and retinal venule caliber (RVC) can be measured using color fundus photography, 5 retinal angiography photographs, 6 and optical coherence tomography (OCT) scans. 2 Earlier research found that intravitreal anti-VEGF agents significantly dilate retinal venules and constrict retinal arterioles although the underlying mechanisms remain unclear. 7 Further, it has been shown that anti-VEGF agent may induce a reduction in choroidal thickness.…”