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Background: Retinopathy of prematurity (ROP) can lead to retinal detachment and severe vision loss and is a common cause of childhood blindness. Optical coherence tomography angiography (OCTA) is a noninvasive imaging modality that can be used to detect potential abnormalities in the microvasculature in this population. The objective of this study is to assess the feasibility of a newly developed handheld swept source OCT (SS-OCT) device to successfully acquire structural vitreoretinal and retinal microvascular images in awake premature infants.Methods: OCT and OCTA images were acquired at the time of routine ROP examinations from awake, unsedated preterm infants in the Neonatal Intensive Care Unit using a clinical research prototype handheld probe integrated with an SS-OCT system working at 1,060 nm wavelength and an imaging speed of 200,000 A-scans per second (200 kHz), enabling volume OCT and OCTA scans. Each volume was acquired with approximately 36˚ field of view (~6.3×6.3 mm in infants) in 4.8 s. Quality of acquired OCT and OCTA volume images, microvascular information, and vitreoretinal features were determined by 3-masked grader consensus.Results: Twelve infants (5 females, mean gestational age 28.3 weeks, median birth weight 901 g, stages 0 to 3 ROP) underwent a total of 73 individual eye imaging sessions. High-quality OCT images of the fovea and the optic nerve were present in 69/73 (94.5%) and 56/73 (76.7%) scans, respectively. Vitreous bands were observed in 10/73 (13.7%); punctate hyperreflective vitreous opacities in 47/73 (64.4%); epiretinal membrane (ERM) in 6/73 (8.2%); and cystoid macular edema (CME) in 12/73 (16.4%) scans. Mild vessel elevation was noted in 3/73 (4.1%) images, and severe vessel elevation in 4/73 (5.5%) scans. OCTA images obtained in 8 awake infants revealed good quality images of the foveal microvasculature in 11/19 (58%) eye imaging sessions for 6/8 (75%) infants; and peripapillary microvasculature in 14/19 (74%) eye imaging sessions for 5/8 (63%) infants. Conclusions:The SS-OCTA handheld device can capture important vitreoretinal characteristics such as peripapillary and foveal microvasculature, as well as hyperreflective punctate vitreous opacities and tractional vitreous bands, which may predict ROP severity. These images were captured in awake, premature infants without the use of direct ocular contact, an eyelid speculum, or sedation.

Objective: To evaluate the association between retinopathy of prematurity and vitreous findings in premature infants detected by handheld spectral-domain optical coherence tomography.Design: Prospective, observational cohort study.Participants: Consecutive sample of 92 premature infants requiring retinopathy of prematurity screening at two academic neonatal intensive care units, between July 2015 and March 2018. Methods:Infants underwent handheld spectral domain optical coherence tomography at the time of routine retinopathy of prematurity examinations. Two masked, trained graders analyzed right eye vitreoretinal findings including semi-automated quantification of punctate hyperreflective vitreous opacities within 5 foveal/parafoveal B-scans (Vitreous Opacity Ratio). Main Outcome Measures:Excluding post-treatment data, vitreous findings were compared to clinical retinopathy of prematurity diagnoses.Results: Agreement between image graders for all vitreoretinal findings was 91% (kappa=0.86 [95% confidence interval, 0.82-0.90], P<0.001). Among 92 infants undergoing 280 imaging sessions (52% male, mean gestational age 28.3±2.8 weeks, mean birthweight 1014.5±285.0 grams), 36/92 (39%) developed retinopathy of prematurity. Punctate hyperreflective vitreous opacities were identified in 61/92 (66%) infants. The presence of punctate hyperreflective vitreous opacities at least once was associated with a diagnosis of retinopathy of prematurity (62% vs. 29% without opacities, P=0.003), maximum retinopathy of prematurity stage (P=0.001), pre-plus or plus disease (24% vs. 5%, P=0.005), and type 1 disease (14% vs. 2%, P=0.03).

Purpose To compare retinal vascular parameters acquired by handheld swept-source optical coherence tomography angiography (SS-OCTA) between nonsedated preterm and full-term infants. Methods Preterm and full-term infants at the University of Washington Medical Center were enrolled. Retinal angiograms (nominal size ∼7 × 7 mm 2 ) were obtained at each routine retinopathy of prematurity (ROP) screening session for preterms and once during the first 72 hours of life for full-terms. Macular vessel area density and nonperfusion area were evaluated on the binarized vasculature map in both small (1.5 × 1.5 mm) and large (3 × 3 mm) quadrants. Average vessel diameter and tortuosity values were obtained from each large vessel branch (length >200 µm). All vascular analyses used previously published algorithms. Results Handheld SS-OCTA captured 31 of 55 (56%) high-quality volumes on 8 awake preterm infants (gestational age 28 ± 4 weeks, birth weight 891 ± 314 g, postmenstrual age at first imaging session 37 ± 2 weeks) and 48 of 54 (89%) volumes on 12 awake full-term infants (gestational age 39 ± 1 weeks, birth weight 3405 ± 329 g). Signal-to-noise ratio was 5.08 ± 1.52 dB in preterm and 4.90 ± 1.12 dB in full-term infants. Preterm infants had higher mean large vessel tortuosity compared to full-term infants ( P = 0.004). The large nasal quadrant vessel area density of infants with stage 3 and/or pre-plus or worse ROP was higher than other preterm infants ( P = 0.007). Conclusions Although inadequate image quality limited usable imaging sessions, handheld SS-OCTA achieved adequate signal-to-noise ratio in nonsedated infants for quantitative retinal vascular parameter analysis. Translational Relevance Large- and small-vessel parameters were associated with prematurity and ROP severity, respectively.

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