Retinal vascular development in an immature retina at 33-34 weeks postmenstrual age predicts retinopathy of prematurity

Abstract

In preterm birth, the immature retina can develop a potentially blinding disorder of the eye known as retinopathy of prematurity (ROP). The vaso-proliferative phase of ROP begins at an approximate postmenstrual age (PMA) of 32 weeks. There is little or no evidence of an association between ROP development and retinal status in the early vaso-proliferative phase. We aimed to evaluate the retinal vascular findings of infants at 33-34 weeks PMA to determine their risk of ROP. We reviewed 130 serial wide-field retinal images from 65 preterm infants born before the gestational age of 31 weeks. ROP occurred more frequently in infants having a leading vascular edge within posterior Zone II. This was in contrast to normal infants, who are characterized by complete retinal vascularization up to Zone II at 34 weeks PMA. The probability of ROP development in preterm infants with retinal edge hemorrhage was 24.58 times higher than in preterm infants without retinal edge hemorrhage. Eyes with ROP that required treatment showed significantly delayed retinal vascularization accompanied by pre-plus disease. In conclusion, retinal status in the early vaso-proliferation phase might determine the risk of ROP.

Figure 1

Schematic representation of the data selection procedure followed in this study.

Figure 2

A preterm infant born at 27 + 3 weeks gestational age, with a birth weight of 1190 g. (a,b) RetCam fundus images of the right eye at 33 + 3 weeks postmenstrual age (PMA), demonstrating a retinal edge hemorrhage (red arrow) at posterior Zone II area. (c,d) RetCam fundus images at 34 + 3 weeks PMA, demonstrating a demarcation without a line (blue arrows) between stage 0 and stage 1 at the vascular-avascular junction that showed signs of retinal hemorrhage the week before.

Figure 3

Definition of Zone I area and posterior Zone II area in retinopathy of prematurity. A disc-fovea (DF) unit corresponds to the distance between the center of the optic disc and the fovea center. The Zone I area is defined as the area within a circle of a radius that is twice the DF distance (area inside the red dotted line). The posterior Zone II area is defined as the area inside a circle of a radius that is three times the DF distance (area inside the blue dotted line), excluding the Zone I area.

Figure 4

A preterm infant born at 27 + 6 weeks gestational age, with a birth weight of 760 g, progressing into aggressive posterior retinopathy of prematurity. RetCam fundus images of left eye at 34 + 5 weeks postmenstrual age showed the (a) pre-plus disease, (b) circumferential peripheral vessels (white arrow), (c) the leading vascular edge at posterior Zone II (outside the red dotted line) area, and (d) a retinal edge hemorrhage (red arrow). The blue line indicates the two disc-fovea (DF) unit.