Objective To observe the characteristics of morphological development of premature retina at 33-46 weeks of gestational corrected age (GCA). Methods A total of 268 premature infants were divided into 7 groups according to the GCA (33-34，35-36，37-38，39-40，41-42，43-44 and 45-46 weeks). The ocular fundus of those infants were recorded and analyzed by an indirect ophthalmoscopelinked imaging system. Results As GCA increases, noticeable macular morphological changes occurred and recorded in 96% of infant at 45-46 weeks of GCA. Retinas were gradually vascularized at 41-42 weeks (nasal retina) or 43-44 weeks (area Ⅲ,temporal retina), and pigmented in 84% of infant at 45-46 weeks of GCA. Conclusion Macular morphological patterns, retinal blood vessels and pigments continue to develop in postnatal premature infants.
Objective To observe the development of cone/rod functions in children with retinopathy of prematurity (ROP) after laser photocoagulation. Methods 30 ROP patients (60 eyes) treated with laser photocoagulation (case group) and 30 preterm infants (60 eyes) without ROP (control group) were enrolled in this study. Flash Electroretinogram (F-ERG) was performed on all the children, and the response of rod cells and cone cells, maximal mixed responses and oscillatory potentials were recorded. Results Compared with the control group, the amplitude of response of rod cells was obviously decreased (t=-2.385, P＜0.05), while the latency phase of rod cells was obviously prolonged (t=-2.799,P＜0.05); the amplitudes of a-and b-wave of maximal response were significantly decreased in the case group (t=-2.967, -4.037; P＜0.05). But there was no significant difference of amplitudes(t=-1.402) and latency phase (t=-1.637,0.465)of b-/a-wave of the maximal mixed response between two groups(P＞0.05). In the response of cone cells, there was no significant difference of the latency phase (t=1.222) and amplitude (t=-0.636)of a-wave as well as amplitude (t=-1.927) of b-wave between two groups (P＞0.05). The latency phase of b-wave of cone cells in the case group was longer than that in the control group (t=-2.466,P＜0.05). Conclusions Compared to no-ROP preterm infant retina, laser-treated ROP retina has normal cone function development and delayed rod function development.