Purpose:
To assess the rate of change of retinal vessel diameter over time in infants at risk for the development of retinopathy of prematurity (ROP).
Methods:
28 infants at risk for the development of ROP were included in this longitudinal study. Patients with at least three image sessions were selected from a larger study of 148 patients at risk for the development of ROP (birth weight ≤1250 grams & gestational age (GA) ≤ 32 weeks). Digital fundus images were obtained using a NIDEK NM200D non-contact camera, at 32-34 weeks gestational age, 2-4 weeks before the maximal stage of ROP or treatment for ROP occurred. Subjects were photographed every 1-2 weeks until retinal vasculature matured, regressed or the baby was treated. The three highest quality images of the right eye from each date were masked and analyzed using VesselMap semi-automated software. Vessel diameter was measured for the superior and inferior temporal arteries & veins using arbitrary units. The same segment of each vessel was measured across study dates. The rate of change of vessel diameter in one week was calculated for each eye based on the linear regression slope, & compared between eyes that developed severe ROP requiring treatment (n=10) & controls that developed no ROP or less severe ROP not requiring treatment (n=18). A multivariate comparison of slope was performed to adjust for the effects of GA and postconceptional age.
Results:
Mean GA was 25.7 weeks in the control group and 25.4 weeks in the treated group. An average of 5.6 ± 0.41 (± 1 SE) and 3.5 ± 0.37 visits, were analyzed for the control and treated group, respectively (p=0.002). Eyes that developed ROP requiring treatment showed a significantly greater increase in venous diameter over time than controls (Table 1). Retinal arteries showed a trend for increased rate of change but the difference did not achieve statistical significance.
Conclusions:
On average, the rate of retinal vein diameter increases early in the course of ROP and may help to identify patients at risk for severe ROP requiring treatment.
Keywords: retinopathy of prematurity • infant vision