[Screening analysis of retinopathy of prematurity and treatment of threshold retinopathy of prematurity].

OBJECTIVE

To investigate the incidence and the risk factors associated with the development of retinopathy of prematurity (ROP) by ROP screening in the premature infants and to evaluate the treatment effect of threshold ROP.

METHODS

From March 2000 to December 2004, 108 premature infants with birth weight less than 2.0 kg or gestational age less than 37 weeks admitted to the Neonatal Intensive Care Unit at Guangdong Provincial People's Hospital were enrolled in the present study. They were examined with binocular indirect ophthalmoscope. The perinatal variables of the premature infants were analyzed to evaluate their correlation with the development of ROP. The infants with threshold ROP were treated with retinal photocoagulation or cryotherapy.

RESULTS

The overall incidence of ROP was 21.3% (23 of 108). Among 23 premature infants with ROP, 56.5% (13 of 23) were in stage 1, 13.0% (3 of 23) in stage 2 and 30.4% (7 of 23) in stage 3. All infants with ROP stage 3 fulfilled the criteria of threshold ROP. As compared with non-ROP group, ROP infants had lower birth weight [(1.43 +/- 0.25) kg; t = 4.059, P < 0.001], shorter gestation age [(31.0 +/- 2.3) W; t = 2.637, P = 0.013], longer median time of oxygen supplementation (17 d; Z = -3.630, P < 0.001) and more demand of mechanical ventilation (chi(2) = 12.009, P = 0.001). Cases with multiple gestational births in ROP group were not significantly different from that in non-ROP group (chi(2) = 1.013, P = 0.314). Multivariate logistic regression analysis showed that low birth weight (beta = -2.542, OR = 0.079, P = 0.032) and mechanical ventilation (beta = 1.341, OR = 3.823, P = 0.025) were significantly associated with the development of ROP. In a total of seven cases with threshold ROP, six cases were treated with retinal laser photocoagulation or transscleral cryotherapy timely. After followed up for two months to two years, all treated eyes had normal pupil response to the light. The optic disk, macula and posterior retina appeared normal. No abnormal retinal vessels and proliferative vitreoretinopathy were found. One premature infant with threshold ROP, not treated by laser photocoagulation or transscleral cryotherapy, developed retinal detachment in both eyes.

CONCLUSIONS

Premature infants with low birth weigh, shorter gestational age, longer history of oxygen supplemental and the using of mechanical ventilation have more chance of developing ROP. The analysis of risk factors will be helpful in understanding and prediction of development of ROP. ROP screening and timely treatment for threshold ROP are very important for preventing the development of advanced ROP in premature infants.