Objective To investigate the degree of retinal development in preterm infants.MethodsFlash electroretinography (ERG) was performed on 25 healthy preterm infants and 25 full-term ones, and the response of rod cells and cone cells and maximal mixed responses were recorded. The delitescence and amplitudes of a-and b-waves and the ratio of amplitudes of b-/a-wave of maximal responses were analyzed. ResultsCompared with the full-term infants, The delitescence of responses of rod cells in preterm infants was statistically longer(t=11.007,P=0.000)but without any significant changes of amplitudes (t=1.836,P=0.069); statistically longer delitescence (t=2.44, P=0.010; t=10.800, P=0.000) and lower amplitude (t=5804,P=0.000; t=5.809,P=0.000) of a-and b-wave of maximal response were found in preterm infants group. In the response of cone cells, there were significant differences of the delitescence (t=4.444,P=0.000)and amplitude (t=3.819,P=0.000)of a-wave and delitescence of b-wave(t=2.850,P=0.005) between the two groups, and no statistical difference of amplitude of b-wave (t=0.486,P=0.628) between the two groups. The ratio of amplitudes of b-/a-wave of the maximal mixed response was not significantly different between the two groups (t=1.142,P=0.256).ConclusionsThe development of retinal function is slower in preterm infants than that in full-term ones.(Chin J Ocul Fundus Dis, 2005,21:285-287)
Objective To explore the changes of multifocal electroret inogram (mERG) before and after retinal detachment surgery and its clinical significance. Methods Eighteen patients suffered from rhegmatogen ous retinal detachment underwent mERG before and after surgery using VERIS ScienceTM 4.0. The mERG at different area was compared between preoperative and postope rative surgery. Results Preoperatively, the latencies of a wave and b wave in detached area were statistically longer than in attached area (t=4.541 and 6.784, Plt;0.01). The amplitude densities of a wave and b wave were statistically smaller in detached area than in attached area (t=3.680 and 4.257, Plt;0.01). Postoperatively, the amplitude densities of a wave and b wave at fovea, macula, perimacular area and whole tested area significantly improved. Statistical difference was found before and after surgery, but no statistical difference was found in the latencies of a wave and b wave. The amplitude densities of a wave and b wave in the preoperative detached area were statistically larger after surgery than before surgery (Plt;0.05). Conclusions After retinal detachment surgery, the responses of mERG improve to some degree. mERG was a promising tool to evaluate the recovery of retinal function after surgery . The amplitude densities are more sensitive than the latencies to evaluation of retinal function. (Chin J Ocul Fundus Dis, 2001,17:264-267)