AIM: To retrospectively analyze the prevalence of retinopathy of prematurity(ROP)in 3471 neonates in Suzhou Municipal Hospital.

METHODS: A total of 3471 children(1947 males, 1524 females)were screened for ROP in Suzhou Municipal Hospital from January 2010 to September 2016 using binocular ophthalmoscope or(and)RetCamII. First examination was performed from 4-6wk after birth. The ocular findings were recorded according to the International Classification of ROP and The Early Treatment for ROP. Only the more aggressive eye of bilateral asymmetrical cases was counted for statistical purpose. Children with ROP in both binocular or single eye were counted in 1 case, and the cases required surgeries were defined as severe cases. The prevalence of ROP and severe ROP in recent 6a were analyzed retrospectively.

RESULTS: The overall relevance ratio of ROP and severe ROP was 17.03% and 1.15%. The relevance ratio of ROP and severe ROP of the males were 16.38% and 1.08%, and of the females were 17.85% and 1.25%, the results were not statistically different(χ²=1.296, P=0.255). The relevance ratio of ROP and severe ROP of the single birth infants were 17.61% and 1.13%, and of the multiple birth infants were 15.13% and 1.23%, the results were not statistically different(χ²=2.706, P=0.100). The children were divided into 5 groups according to the birth weight. The relevance ratio of ROP with birth weight <1000g, 1000-1499g,1500-1999g, 2000-2499g and ≥2500g were 75.00%, 36.17%, 10.75%, 6.86% and 3.77% respectively with significant differences(There were significant differences between the three groups which the birth weight <2000g, P<0.005). The relevance ratio of severe ROP were 36.54%, 1.68%, 0.31%, 0.19% and 0 respectively in these birth weight groups(There were significant differences between the three groups which the birth weight <2000g, P<0.005). The children were divided into 4 groups according to gestational weeks, the relevance ratio of severe ROP of gestational age <28wk, 28-31wk, 32-36wk and ≥37wk were 69.12%, 29.91%, 8.28% and 3.33% respectively with significant differences(There were significant differences between the three groups which the gestational age <37wk, P<0.005). The relevance ratio of severe ROP were 25%, 1.52%, 0.24% and 0 in these gestational age groups respectively(There were significant differences between the three groups which the gestational age <37wk, P<0.005).

CONCLUSION: The detection rate of ROP in 3471 premature infants was 17.03%, the severe ROP was 1.15%. There was no evidence that sex and birth were related to ROP, but lower birth weight and smaller gestational age increased the detection rate of ROP.