Abstract
Purpose :
There is no published evidence on the retinal vascular maturation process in preterm infants and the factors affecting it. This gap in the evidence causes ambiguity about duration of follow up and potentially increases burden of follow up visits on retinopathy of prematurity (ROP) screening programs. This historic cohort study was planned to establish natural history of retinal vascular maturation in preterm infants and to study whether delayed maturation is associated with presence of ROP or other risk factors.
Methods :
Preterm low birth weight infants enrolled in study hospital’s ROP screening program were the study subjects. Those who had completed follow up until retinal vascular maturation was established were included. Those with- unknown gestational age (GA), requiring treatment for ROP, incomplete medical records were excluded. Data on birth weight (BW), GA and all risk factors for ROP were collected. Delayed maturation was defined as vascular maturation beyond 44 weeks of postmenstrual age (PMA). Statistical tool (Stata 14, StataCorp, Tx) was used to generate descriptive statistics. Statistical tests of association were carried out to establish association between delayed maturation and ROP status as well as other risk factors. Multiple logistic regression analysis was carried out to account for effect of confounders.
Results :
Of the 388 infants recruited, 86 (22.6%) had ROP. Mean GA and BW of the cohort were 32.2 (±2.3) wks and 1576 (±425) gm respectively. Those with ROP had significantly delayed vascular maturation compared to those without ROP (52.4% Vs 22.8%, p< 0.001). Vast majority (96%) of infants showed vascular maturation by 50 weeks of PMA. Among the infants with ROP, most (76.8%) developed it by 38 weeks of PMA, none beyond 44 weeks. In uni-variate analysis lower GA (<30 wks) ) and history of supplemental oxygen were associated with delayed retinal vessel maturation (p <0.001). Multiple logistic regression analysis showed that- presence of ROP, lower GA and history of supplemental O2 were all independent risk factors (p <0.001) for delayed retinal vessel maturation.
Conclusions :
Preterm infants who do not develop ROP by 44 weeks of PMA can be safely discharged from screening follow up even if retina is not mature. However infants with- ROP, lower GA or history of supplemental oxygen might need prolonged follow up until 50 weeks of PMA.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.