Nailfold Capillaroscopy: A Promising, Noninvasive Approach to Predict Retinopathy of Prematurity

Objective To test the hypothesis that nailfold capillaroscopy can noninvasively detect dysregulated retinal angio-genesis and predict retinopathy of prematurity (ROP) in infants born premature before its development. Methods In a cohort of 32 infants born <33 weeks of gestation, 1386 nailfold capillary network images of the 3 middle fingers of each hand were taken during the first month of life. From these, 25 infants had paired data taken 2 weeks apart during the first month of life. Images were analyzed for metrics of peripheral microvascular density using a machine learning-based segmentation approach and a previously validated microvascular quantification platform (REAVER vascular analysis). Results were correlated with subsequent development of ROP based on a published consensus ROP severity scale. Results In total, 18 of 32 (56%) (entire cohort) and 13 of 25 (52%) (2-time point subgroup) developed ROP. Periph-eral vascular density decreased significantly during the first month of life. In the paired time point analysis, vessel length density, a key metric of peripheral vascular density, was significantly greater at both time points among in-fants who later developed ROP (15 563 and 11 996 mm/mm2, respectively) compared with infants who did not (12 252 and 8845 mm/mm2, respectively) (P < .001, both time points). A vessel length density cutoff of >15100 at T1 or at T2 correctly detected 3 of 3 infants requiring ROP therapy. In a mixed-effects linear regression model, pe-ripheral vascular density metrics were significantly correlated with ROP severity. Conclusions Nailfold microvascular density assessed during the first month of life is a promising, noninvasive biomarker to identify premature infants at highest risk for ROP before detection on eye exam. (J Pediatr 2023;259:113478).