CAPOS Award: Choroidal hypoperfusion defects in retinopathy of prematurity: a new fluoresceine angiographic finding

Authors: Tianwei E. Zhou, Nasrin Tehrani, Peter Kertes, Kamiar Mireskandari. University of Toronto.

Author Disclosures: T.E. Zhou: None. N. Tehrani: None. P. Kertes: None. K. Mireskandari: None.


Abstract Body: 

Purpose: Retinopathy of prematurity (ROP) remains the major ocular disorder of the neonates in the world. Its retinal pathology is well studied. Recently, choroidal involution has been described as a key feature in ROP and its animal model. Choroid is the exclusive blood supply to the photoreceptors. Therefore, choroidal involution could lead to insufficient energy to the outer retina.Intravenous fluoresceine angiography (IVFA) allows dynamic assessment of the choroidal vasculature. In premature children, IVFA is not commonly performed and available at few centers only. Therefore, imaging studies based on choroidal IVFA remain scarce in the literature. In this project, we systematically analyzed IVFA data in ROP patients who needed treatment, and described key imaging features in this population. 

Study Design: In this retrospective study, ROP patients who received intravitreal bevacizumab from 2011-2020 were identified at the Hospital for Sick Children. Only one eye per patient was used. 

Methods: Clinical information, including birth weight (BW), gestational age (GA) and ROP staging, was collected. Three (3) experts were asked to categorize each image based on the following: 1) image quality (adequate or inadequate for diagnosis), 2) the presence or absence of choroidal hypoperfusion at the arteriovenous phase, and 3) the location of choroidal hypoperfusion (peripheral [outside the arcades], central [inside the arcades], and multifocal [both outside and inside the arcades]). Inter-rater agreement was assessed by Fleiss’ κ. 

Results: One-hundred-and-eighteen (118) ROP patients were identified for review; among them, 79 had IVFA. Three (3) IVFAs were excluded due to poor image quality, and 2 due to severe phenotypes that precluded proper visualization of choroid. Seventy-four (74) had high quality images that enabled further analyses. The 74 infants had an average BW of 600.4 grams, and an average GA of 23.9 weeks. The majority (69.4%) had zone I, stage 3+ ROP. The average age at receiving IVFA was 9.7 months (range: 2.0 to 24 months). In terms of choroidal IVFA patterns, 64 eyes (86.5%) demonstrated multifocal areas of choroidal hypoperfusion; 4 eyes showed central hypoperfusion; and 4 eyes showed peripheral hypoperfusion. Only 2 eyes were deemed to have a normal choroidal pattern. Fleiss’ κ for interrater agreement was 0.85 (almost perfect). 

Conclusions: To our knowledge, this study represents the largest series that systematically describes choroidal vascular abnormalities in ROP patients. It highlights the notion that ROP affects both the retina and the choroid. Long-term ophthalmic follow-ups with angiography are needed to further study ROP patients.

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