Cone function in children with a history of preterm birth.

Color vision was examined by psychophysical tests and photopic color full-field electroretinography (ERG) in formerly preterm children, and compared with those of full-term children. In a prospective case-control study, 25 patients with a history of preterm birth 7-14 years of age were divided into three groups: group I, laser-treated retinopathy of prematurity [ROP] (n = 7); group II, spontaneously regressed ROP (n = 8); group III, no ROP (n = 10). Age-matched full-term born children comprised the control group (n = 8). Color vision was assessed by Fansworth D15 and Lanthony desaturated D15 tests. The cone function was tested using photopic full-field ERG. Besides the ISCEV standard stimuli, blue light on amber background was also used (S-cone ERG). The correlation between ERG parameters and prematurity or ROP was determined. We found no significant differences between any patient group and the control group in the results of the psychophysical tests, and implicit times of the ERG responses. The ERG b-wave amplitudes were significantly lower in group I (laser-treated ROP) compared to controls, for 2 of 4 stimulus conditions i.e. the standard (P = 0.028) and S-cone (P = 0.017) single flash ERGs. The general estimating equation model statistics found a significant effect of prematurity on the b-wave amplitudes (P = 0.025, standard, P = 0.014, S-cone ERG). A slightly reduced photopic ERG b-wave amplitude may be associated with prematurity.