Short-time effect of intravitreal injections on retinal vascular oxygenation and vessel diameter in patients with diabetic macular oedema or neovascular age-related macular degeneration.

Christoph Mitsch,Ursula Schmidt‐Erfurth,Andreas Pollreisz,Sonja Karst,Stefan Sacu,Andreas Gleiss,Christoph Scholda,Berthold Pemp

doi:10.1111/aos.14276

Christoph Mitsch, Ursula Schmidt‐Erfurth + Show 6 more

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https://doi.org/10.1111/aos.14276

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Abstract

PurposeTo investigate the short‐time effect of intravitreal injections (IVI) of the vascular endothelial growth factor inhibitors ranibizumab and aflibercept on retinal arterial and venous oxygen saturation (SO2a and SO2v), arteriovenous oxygen saturation difference (AVD) and vessel diameter (VDa and VDv) in patients with diabetic macular oedema (DME) and patients with choroidal neovascularization (CNV) due to age‐related macular degeneration.MethodsUncontrolled prospective observational study in 100 eyes. Retinal vessel oxygen saturation and diameters were assessed using a retinal oximeter before and minutes after IVI of ranibizumab or aflibercept.Results40 eyes with CNV and 34 eyes with DME were included in the analysis. At baseline, SO2a and SO2v were significantly higher in DME (p = 0.043 and p = 0.009, respectively). After IVI, SO2a significantly decreased in CNV and DME eyes by 2.6% (p = 0.016) and 4.6% (p = 0.002) and SO2v decreased by 14.0% (p = 0.004) and 12.4% (p = 0.017), respectively. However, a significant increase in AVD was only found in CNV (15.7%, p = 0.001). VDa decreased significantly only in DME by 5.7% (p = 0.010). No medication‐specific disease effect was found and vice versa.ConclusionsThe observed changes can be interpreted as signs of increased metabolic demand during the physiological stress after an IVI. The abnormal arterial constriction and the abolished increase in AVD seen only in eyes with DME indicate an impairment of vascular autoregulation and oxygen distribution and a reduced neuroretinal metabolism in the diabetic retina with a significant impact on inner retinal oxygen consumption shortly after IVI.

Highlights

Neovascular age-related macular degeneration (AMD) and diabetic retinopathy (DR) are the most common causes of severe vision loss in the western world (Ambati et al 2003; Yau et al 2012)
The inhibition of vascular endothelial growth factor (VEGF), an angiogenesis and vasopermeability factor prominently involved in the pathogenesis of Diabetic macular oedema (DME) and choroidal neovascularization (CNV), has proven to be an effective therapeutic approach and is widely used for treating both neovascular AMD and DME (Ambati et al 2003; Nicholson & Schachat 2010; Schmidt-Erfurth et al 2014; Wells et al 2016)
2016) and an increase in oxygen saturation of retinal arteries only in a subgroup of CNV patients not responding to treatment (Jakobsen et al 2019)

Summary

Introduction

Neovascular age-related macular degeneration (AMD) and diabetic retinopathy (DR) are the most common causes of severe vision loss in the western world (Ambati et al 2003; Yau et al 2012). The inhibition of vascular endothelial growth factor (VEGF), an angiogenesis and vasopermeability factor prominently involved in the pathogenesis of DME and CNV, has proven to be an effective therapeutic approach and is widely used for treating both neovascular AMD and DME (Ambati et al 2003; Nicholson & Schachat 2010; Schmidt-Erfurth et al 2014; Wells et al 2016). Retinal oximetry has been developed to enable in vivo, non-invasive oxygen saturation measurement in human retinal vessels and has provided new insights into disease mechanisms of different common eye diseases e301 associated with vascular alterations. A reduction in retinal venous oxygen saturation was shown in patients with central retinal vein occlusion (CRVO) which stayed lower during monthly anti-VEGF treatment (Traustason et al 2014)

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