Retinopathy of Prematurity: A Study of Incidence and Risk Factors in NICU of Al-Minya University Hospital in Egypt

Abstract

Background:

Retinopathy of prematurity (ROP) is a serious complication of prematurity treatment and can lead to blindness unless recognized and treated early.

Objective:

To estimate the incidence of ROP in preterm infants in our NICU, to identify the risk factors which predispose to ROP, and to assess the outcome of these cases.

Materials and Methods:

ROP prospective screening survey was performed enrolling all prematures admitted to the NICU from January 2009 to December 2010, with a gestational age of 32 weeks or less at birth and a birth weight of 1500 g or less. Infants whom gestational age was >32 weeks or birth weight was >1500 g were included if they exposed to oxygen therapy for more than 7 days. Also infants who were born between 32 and 34 weeks gestational age were examined if they had a course of instability (like sepsis, asphyxia or ventilation). A total of 172 infants (88 females) had retinal evaluation by indirect ophthalmoscopy from the 4 ^th postnatal week and followed up periodically. Perinatal risk factors for ROP were assessed using univariate and multivariate analysis. Infants who progressed to stage 3 ROP with plus disease were given laser therapy.

Results:

Out of the studied 172 infants, 33 infants (19.2%) developed ROP in one or both eyes; 18 (54.5%) cases stage 1, 9 (27.3%) cases stage 2 and 6 (18.2%) cases stage 3 with plus disease. None of the studied neonates presented ROP at stages 4 or 5. The six cases diagnosed as ROP stage 3 with plus disease underwent laser ablative therapy. Laser was effective in treatment and decreasing the progression of ROP. Univariate analysis showed that there was a significant relationship between the occurrence of ROP and gestational age ( P=0.000), sepsis ( P=0.004), oxygen therapy ( P=0.018), and frequency of blood transfusions ( P=0.030). However, nonsignificant relationship was found between the occurrence of ROP and sex, mode of delivery, birth weight, respiratory distress syndrome, patent ductus arteriosus, intraventricular hemorrhage, hypotension, phototherapy, duration of oxygen therapy, mechanical ventilation, and CPAP (all P>0.05). Gestational age, sepsis, oxygen therapy and frequency of blood transfusions remained significant variables after logistic regression analysis.

Conclusion:

The incidence of ROP in this study was 19.2%; low gestational age, sepsis, oxygen therapy and frequent blood transfusions were significant risk factors for ROP. Laser was effective in treatment and decreasing the progression of ROP. As this is a unit-based study, a comprehensive countrywide survey on ROP in Egypt is recommended to determine any regional differences in disease incidence.