Retinopathy of prematurity: Revisiting incidence and risk factors from Oman compared to other countries

Abstract

Purpose:The purpose of this study is to determine the incidence of retinopathy of prematurity (ROP) and the maternal/neonatal risk factors at a tertiary care hospital in Oman, compared to other countries.Patients and Methods:A retrospective analysis of premature neonates born with gestational age (GA) 24–32 weeks at Sultan Qaboos University Hospital, Oman, from January 2007 to December 2010. Maternal and neonatal in-hospital course was retrieved. The incidence of ROP was reported. Risk factors analyses were performed using univariate and multivariate statistics.Results:A total of 171 neonates (57% males, 43% females) were included for analysis. The incidence of ROP (any stage) was 69/171 (40.4%). Infants with ROP had significantly lower GA (27.7±2 weeks) compared to non-ROP group (30.2±1.7 weeks), P < 0.001),P < 0.001) and significantly lower birth weight (BW) (948 ± 242 g in ROP group vs. 1348 ± 283 g in non-ROP group;P < 0.001). Other significant risk factors associated with ROP were: small for GA, respiratory distress syndrome, requirement for ventilation, duration of ventilation or oxygen therapy, bronchopulmonary dysplasia, hyperglycemia, late onset sepsis (clinical or proven), necrotizing enterocolitis, patent ductus arteriosus, seizures, and number of blood transfusions. There was no significant difference in maternal characteristics between the ROP and non-ROP groups except that mothers of infants with ROP were found to be significantly younger. Logistic regression analysis revealed early GA, low BW, duration of Oxygen therapy, and late-onset clinical or proven sepsis as independent risk factors.Conclusion:ROP is still commonly encountered in neonatal practice in Oman and other countries. Early GA, low BW, and prolonged oxygen therapy continue to be the main risk factors associated with the occurrence of ROP in our setting. In addition, an important preventable risk factor identified in our cohort includes clinical or proven late-onset sepsis.

Association between sepsis and retinopathy of prematurity: a systematic review and meta-analysis

“…As mentioned above, sepsis can be classified as early or late and as bacterial or fungal. Since most of the original studies performed fundus examinations for ROP screening 4~6 weeks after birth, only two studies27 28 provided findings that might include late-onset sepsis. It is difficult for us to distinguish whether these patients had early-onset or late-onset sepsis.…”

Cumulative evidence for association of sepsis and retinopathy of prematurity

“…[58,60] Thus, it is important to adjust for the influence of oxygen and mechanical ventilation on the relationship of sepsis and ROP. However, of the 34 studies included, only 7 studies [22,26,33,35,36,40,44] had concurrently adjusted for this 2 factors. In addition, although there are 14 studies which adjusted the confounder of oxygen use, the bias may still exist because it is difficult to adjust appropriately for oxygenation to normalizing the oxygenation among studies.…”

Retinopathy of prematurity: a review of risk factors and their clinical significance

“…328 These results have been replicated in multiple subsequent studies, both for the risk of incident ROP and of treatment-requiring ROP. 6,10,11,13,14,17,18,21,47,57,65,75,77,94,102,109,114,122,125,135,138,143,147,152,157,174,202,204,216,228,231,233,236,240,246,255,263,266,271,276,282,283,285,308,311,312,315,335,337,348,362,367,371,373,378,391,398,405,406,410,412,418…”

“…88,419 A number of subsequent studies found the duration of oxygen therapy to be a significant risk factor for severe ROP. 10,13,39,57,71,74,109,114,131,149,152,167,231,236,257,264,276,283,312,313,315,364,401,412,428 Similarly, many studies identified prolonged mechanical ventilation as a risk factor for any or severe ROP. 11,12,36,39,53,57,106,120,157,167,187,211,232,263,266,274,275,286,335,337,345,348,368,370,405,406,412,417…”