. Author manuscript; available in PMC: 2014 Sep 15.

Published in final edited form as: Ophthalmology. 2013 Oct 15;120(12):2706–2713. doi: 10.1016/j.ophtha.2013.07.051

Table 1. Baseline Characteristics of Infants.

Characteristics	Results
No. of infants/eyes	343/684
BW (g)	928±192
GA (wks)	27.2±2.1
Born in the study hospital (%)	96.8
Singleton births (%)	74.9
Non-black race (%)	60.1
Male (%)	48.4
Per capita income ($, thousands)	20.4±8.0
Threshold ROP (infants/eyes)	33/63
ROP warranting surgery (infants/eyes)	36/68
SROP (infants/eyes)	40/76

BW = birth weight; GA = gestational age; ROP = retinopathy of prematurity; SROP = severe retinopathy of prematurity.

Plus-minus values are means ± standard deviations. Eyes with ROP warranting surgery included those with classic threshold ROP in zone I or II and a few eyes with type 1 prethreshold ROP in zone I or posterior zone II that examiners chose to treat because of high risk of poor outcome. SROP was defined as ROP warranting surgery or type 1 prethreshold ROP in zone I because some eyes with type 1 prethreshold ROP in zone I were not treated at that level of disease and spontaneously regressed or progressed to threshold ROP and were then treated.