Purpose: This study aimed to
evaluate risk factors associated with threshold retinopathy of prematurity (ROP)
in premature infants referred to Farabi Eye Hospital during 2008-2009. Since
blindness and sever visual impairments will occur in a high percentage of
infants stricken with threshold retinopathy, we intended to examine relationship
between demographic factors and threshold retinopathy in Farabi Eye Hospital,
which, as a tertiary center, represents an appropriate sample of Iran’s population.
Methods: In this retrospective
case-control study, infants less than 37 weeks and/or birth weight less than
2,500 grams referred to Farabi Eye Hospital were included. The eyes were examined
and a questionnaire was filled out for each infant. Based on the recording
data, the relation between risk factors and threshold ROP was assessed.
Results: Out of 1,718 eyes
participated in this study, 791 eyes had retinopathy. The incidence of
threshold retinopathy in this study was 7.4 percent. We could figure out
significant relationships between gestational age, birth weight, oxygen
supplementation, duration of ventilation, blood transfusion, respiratory
distress syndrome (RDS), postconceptual age and chronic respiratory disease
with threshold ROP using independent sample t-test between two groups
(infants with threshold retinopathy and infants without it). Cross-tab test
revealed a significant relation between threshold retinopathy and risk factors
such as sepsis (p=0.006), oxygen supplementation (p=0.000), blood transfusion (p=0.004),
RDS (p=0.000), weight (p=0.000) age at first examination (p=0.000), and
duration of ventilation. Logistic regression showed that the age (postmenstrual)
more than 40 weeks at the time of first examination could be the predicting
factors of threshold retinopathy.
Conclusion: The most important
risk factors of threshold ROP are low gestational age, low birth weight, delayed
in initial examination and the duration of oxygen therapy.
Iranian Journal of Ophthalmology 201426(1):48-52 © 2014 by the Iranian Society of Ophthalmology