. Author manuscript; available in PMC: 2015 Sep 1.

Published in final edited form as: Ophthalmology. 2014 May 6;121(9):1818–1826. doi: 10.1016/j.ophtha.2014.03.020

Table 5.

Optic nerve parameters in 26 preterm infants when aged 31–36 weeks vs. 37–42 weeks PMA^*

Parameters	31–36 weeks PMA Mean (SD)	37–42 weeks PMA Mean (SD)	Mean Difference Overall (SE)^*	% Change Overall	Estimated Mean Difference per Week (μm)	Estimated % Change per Week	P-Value^**
vDiscDiam (μm)	1254 (193)	1328 (137)	74 (28)	5.9%	16	1.3%	0.008^***
vCupDiam (μm)	918 (219)	915 (267)	−4 (21)	−0.4%	−1	−0.1%	0.431
vC:D	0.74 (0.16)	0.69 (0.17)	−0.05 (0.02)	−6.8%	−0.01	−1.4%	0.015^***
Cup Depth (μm)	432 (148)	461 (170)	28 (26)	6.5%	6	1.4%	0.858

Average weeks between imaging sessions = 4.7

^**

Wilcoxon Rank Sums test, 1-tailed

^***

Repeat analysis with cup offset 150 μm above the disc plane; p-values for vDiscDiam and vC:D changed to p=0.012 and p=0.053, respectively

vDiscDiam, vertical disc diameter; vCupDiam, vertical cup diameter; vC:D, vertical cup-to-disc ratio

SD, standard deviation; SE, standard error