Quinn GE, et al. - Authors ascertained the incidence, onset, and early course of retinopathy of prematurity (ROP) in the largest cohort to date that is representative of infants who are undergoing ROP screening. The knowledge of ROP screening is added by the findings as they include all eligible infants, not just high-risk infants as in previous studies. Some stage of ROP was developed in more than 40% of at-risk premature infants, and most retinopathy regresses without treatment. Nonetheless, severe ROP was developed in approximately 12.5%, which occurs almost exclusively among infants with a birth weight (BW) of less than 1251 g.

• Experts conducted a secondary analysis of data from the Postnatal Growth and Retinopathy of Prematurity (G-ROP) retrospective cohort study in 29 hospitals in the United States and Canada between January 2006 and December 2011 and included 7,483 infants who underwent serial ROP examinations.
• In either eye, most severe ROP classified as no ROP, mild ROP, type 2 ROP, or type 1 ROP (per Early Treatment for ROP Study criteria).
• They noted that the onset at postmenstrual age for zone I disease and stage of ROP, plus disease, and treatment.

• As per data, this study included 7,483 infants with a mean (SD) BW of 1,099 (259) g and a mean (SD) gestational age of 28 (3) weeks who underwent ROP examinations.
• Findings suggested that out of these, ROP developed in 3,224 infants (43.1%), 459 (6.1%) developed type 1 and 472 (6.3%) type 2 ROP, 514 (6.9%) underwent treatment in 1 or both eyes, and 147 (2%) had zone I disease.
• Moreover, in infants with a BW of less than 1,251 g, they noted occurrence of 98.1% of type 1 or 2 ROP cases.
• Results demonstrated that only about half of the eyes (49.4%) were vascularized into zone III by 37 weeks postmenstrual age.