Purpose: To determine the correlation between blood flow metrics measured by intravenous fluorescein angiography (IVFA) and the blood flow velocity index (BFVi) obtained by laser speckle contrast imaging (LSCI) in infants with retinopathy of prematurity (ROP).
Design: Prospective comparative pilot study.
Subjects: Seven eyes from 7 subjects with ROP.
Methods: Unilateral LSCI and IVFA data were obtained from each subject in the neonatal intensive care unit. Five LSCI-based metrics and 5 IVFA-based metrics were extracted from images to quantify blood flow patterns in the same region of interest. Correlation between LSCI-based and IVFA-based blood flow metrics was compared between 2 subgroups of ROP severity: moderate ROP (defined as stage ≤ 2 without Plus disease) and severe ROP (defined as stage ≥3 or Plus disease).
Main outcome measures: Pearson and Kendall rank correlation coefficients between IVFA and LSCI metrics; Student t test P values comparing LSCI metrics between "severe" and "moderate" ROP groups.
Results: Pearson correlations between IVFA and LSCI included arterial-venous transit time (AVTT) and peak BFVi (pBFVi; r = -0.917; P = 0.004), AVTT and dip BFVi (dBFVi; r = -0.920; P = 0.003), AVTT and mean BFVi (r = -0.927- P = 0.003), and AVTT and volumetric rise index (r = -0.779; P = 0.039). Kendall rank correlation between AVTT and dBFVi was r = -0.619 (P = 0.051). pBFVi was higher in severe ROP than in moderate ROP (8.4 ± 0.6 and 4.4 ± 1.8, respectively; P = 0.0045 using the 2-sample t test with pooled variance and P = 0.0952 using the Wilcoxon rank-sum test).
Conclusions: Correlation was found between blood flow metrics obtained by IVFA and noninvasive LSCI techniques. We demonstrate the feasibility of obtaining quantitative metrics using LSCI in infants with ROP in this pilot study; however, further investigation is needed to evaluate its potential use in clinical assessment of ROP severity.
Financial disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
Keywords: Blood flow; Intravenous fluorescein angiography; Laser speckle contrast imaging; Laser speckle flowgraphy; Retinopathy of prematurity.
© 2024 by the American Academy of Ophthalmology.