Evaluating Significance of Neovascular Tufts (Popcorn) in Retinopathy of Prematurity Using Ultra-Widefield Optical Coherence Tomography

Abstract

Purpose : Neovascular tufts along the ridge, often referred to as popcorn neovascularization (NV), are a common finding in patients with stage 2 and 3 retinopathy of prematurity (ROP). This retrospective case series aims to further classify the clinical course and significance of popcorn NV in patients with ROP as visualized with ultra-widefield optical coherence tomography (UWF-OCT).

Methods : A prototype UWF-OCT device captured en face scans (>140 degrees) from 136 babies in the neonatal intensive care unit at Oregon Health and Science University starting in December 2020 from all babies of parents who consented to study participation (without respect to demographic risk or other clinical confounders). Images and clinical records of all patients were reviewed retrospectively. Mann-Whitney U tests, proportion tests, and multivariable logistic regression (MLR) were used for statistical analysis.

Results : Of the 64 patients with stage 2 ROP during their disease course, 22 (34%) developed popcorn NV concurrently. On average, patients with popcorn had lower birth weights (660.1g vs 884.7g, P = 0.001), gestational age (GA) (25.3 vs 26.6 weeks, P = 0.01), and were more likely to present with zone I ROP (63.4% vs 16.7%, P = 0.004). In terms of prognosis, they were more likely to progress to stage 3 (68.2% vs 14.3%, P < 0.001) and receive treatment (54.5% vs 16.7%, P = 0.002). Of the 26 patients with stage 3, 18 had popcorn at some point. In the 13 of these babies who had images preceding onset of stage 3, popcorn developed significantly earlier on average than stage 3 (35 vs 37 weeks, P = 0.04). 16/27 (59.3%) patients presenting with zone 1 ROP developed popcorn during their disease course, compared to 9/70 patients (12.9%) who presented with zone 2 disease. On MLR, popcorn was independently associated with progression to stage 3, controlling for GA and initial zone.

Conclusions : Popcorn NV occurs in higher risk babies and may be an independent risk factor for ROP progression. UWF-OCT was useful to visualize the progression of these lesions and may help identify high risk patients in the future and longitudinal monitoring of these lesions may be useful to better understand the pathophysiology of NV in ROP (See Figure 1).

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Figure 1: Enface images taken by UWF-OCT. Images 1A and 1B demonstrate popcorn in the presence of stage 2 disease, which progressed to stage 3 in Image 1C.