Abstract
Purpose :
To investigate the neonatal choroidal circulation in type I retinopathy of prematurity using indocyanine green (ICG) angiography.
Methods :
Eligible infants were identified following routine National Health Service (NHS) retinopathy of prematurity (ROP) screening service operating at the Oxford University Hospitals NHS Foundation Trust Neonatal Intensive Care Unit or referred following treatment at other units. This on-going study is an open label, non-randomised, prospective observational case series (Research Ethics Committee ref. 16/LO/1315) sponsored by the Trust. A single bolus dose of intravenous 0.1 mg/kg ICG-PULSION (Medical Systems SE, Germany) and 0.1 ml/kg 10% sodium fluorescein were administered to five infants with active type I ROP. The infant was positioned for image capture using a ‘flying baby’ technique and serial images were taken of both eyes using a mobile ultra-widefield (UWF) scanning laser imaging device (Optos California, Optos plc, Scotland). Vital signs were recorded.
Results :
Intravenous ICG was well tolerated in all cases with no early adverse side effects. The Protocol doses were sufficient for the UWF imaging device to clearly visualize both the retinal vasculature and choroidal circulation in all cases. Retinal neovascularization did not exhibit leakage of ICG fluorescence. In raw images the retinal capillary circulation did not appear to be imaged as well as with fluorescein angiography. The peripheral extent of choroidal perfusion tended to match the area of retinal perfusion. In those babies who had received partial prior laser therapy, choroidal signal was abolished in the regions that had been treated.
Conclusions :
ICG angiography is well tolerated by premature infants with active type I ROP. The choroidal circulation in ROP exhibits peripheral attenuation that corresponds to the regions of avascularity seen on clinical examination and fluorescein angiography. ICG angiography has theoretical advantages over FFA e.g. imaging might be better in the presence of vitreous hemorrhage, leakage from new vessels does not occur so that laser treatment can be given following angiography without significant flashback.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.