Purpose
To evaluate retinal perfusion in diabetic retinopathy before and after treatment with monthly IVB injections over a medium term follow up, using UWF retinal imaging.
Methods
A retrospective, interventional, non comparative case series. Diabetic patients with newly diagnosed proliferative diabetic retinopathy (PDR) and/or macular edema (ME) were included. All were treated with IVB injections every 4-6 weeks, if pan retinal photocoagulation (PRP) could be deferred for at least four weeks at physician discretion. Patients with previous treatment with laser or angiogenic therapy, media opacity or PDR complications were excluded. Follow up included fluorescein angiography (FA) using UWF laser scanning ophthalmoscope technology (Optomap 200Tx, Optos®) that allowed for high resolution visualization of the retina up to 200 degree in one frame. The main outcome measure was the extent of retinal perfusion . Secondary outcomes were regression of neovascularization (NV), macular ischemia, BCVA and need for PRP or vitrectomy.
Results
Twelve eyes of six patients were enrolled in the study. Mean age was 54.8± 8.1 years. Eleven eyes were diagnosed with PDR and eight eyes with ME. Patients received on average 3 injections and followed for an average of 16.5 ± 3.2 weeks. IVB allowed for regression of NV in 11 eyes, demonstrated on FA a month after first injection. The average ischemic area decreased significantly from 86.2%± 4.9% to 77.2%± 10.7% and the average perfused area increased significantly by 66.5% (P=0.0024) during the follow up period. Two eyes showed minimal reduction in ischemic area after treatment and one of them developed mild persistent vitreous hemorrhage without evidence of active NV. Macular ischemia didn't evolve in any of the study eyes . None of the eyes developed DR complications that required rescue with PRP or vitrectomy. Average BCVA improved significantly from 0.48 log MAR before to 0.26 log MAR after treatment (p=0.0036).
Conclusions
IVB injections improved retinal perfusion in a small series of patients with DR over a medium term follow up. Further prospective large scale studies are needed to determine the role of IVB in PDR.
Keywords: 499 diabetic retinopathy •
748 vascular endothelial growth factor •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)