Objective: To determine the incidence and risk factors of retinopathy of prematurity (ROP) among premature infants.
Methods: The fundus examination data of 2185 cases of premature infants [birth body weight ≤ 2000 g or gestational age (GA) ≤ 34 weeks] in neonatal intensive care unit of Bayi Children's Hospitals in Beijing between January 2009 and December 2010 were collected and retrospectively analyzed.
Results: Of 2185 cases of premature infants (1571 had used supplemental oxygen) received RetCam-II ophthalmoscopy screening, 287 cases developed ROP with the incidence of 13.1% according to the international classification of ROP (ICROP), including 34 cases (11.9%) suffering from zone I, 147 cases (51.2%) from zone II, and 106 cases (36.9%) from zone III. Stage 1, 2 and 3 lesions were 117 cases, 142 cases and 28 cases, accounting for 40.8%, 49.5% and 9.7%, respectively, while stage 4 and stage 5 lesions were not found. Thirty-six cases developed plus disease, accounting for 12.5%. Between ROP and Non-ROP groups, there were significant differences in birth weight (1269.9 ± 380.0) g vs (1479.7 ± 359.3) g vs (1633.9 ± 352.3) g, gestational age (30.6 ± 2.0) g vs (32.4 ± 1.8) W and time of supplemental oxygen [Median 10 d (0 to 71 d) vs 2 d (0 to 36 d)]. Among zone I, II and III groups, there were significant differences in birth weight (1269.9 ± 380.0) g vs (1479.7 ± 359.3) g vs (1633.9 ± 352.3) g, gestational age (29.3 ± 2.2) W vs (30.5 ± 1.9) W vs (31.2 ± 1.8) W and time of supplemental oxygen[Median 14 d (0 to 52 d)vs 10 d (0 to 71 d) vs 8 d (0 to 52 d)] (χ(2) = 257.5, 371.7, 6.695; P < 0.05), while among stage 1, 2 and 3 groups, there were also significant differences in birth weight (1593.3 ± 413.7) g vs (1481.3 ± 336.7) g vs (1325.3 ± 313.7) g, gestational age (30.9 ± 2.0) W vs (30.6 ± 1.9) W vs (29.5 ± 1.7) W and time of supplemental oxygen [Median 8 d (0 to 52 d) vs 11 d (0 to 65 d) vs 12 d (0 to 71 d)] (χ(2) = 230.8, 273.5, 6.695; P < 0.05). In 1004 cases admitted in 2009, 150 developed ROP with the incidence of 14.9%; while in 1181 cases admitted in 2010, 137 developed ROP with the incidence of 11.6%. There was significant differences in the incidence of ROP between these two years (χ(2) = 5.305, P < 0.05). Thirty-eight infants (1.7%) received laser therapy and only 3 infants progressed to stage 4 after laser therapy. Three infants with laser failed stopped progress after vasectomy. Finally, all patients were cured without blindness.
Conclusions: Less birth weight, shorter GA and time of supplemental oxygen are close related to the development of ROP. It is necessary to pay high attention to the screen on premature infants with smaller gestation age, lower birth weight or using oxygen for the reduction or even avoid of blindness.