Objective: To investigate the descriptive epidemiological characteristics of cases with anophthalmos and microphthalmos in China.
Method: According to the hospital-bases monitoring method, the birth defects monitoring program was undertaken in 443 - 588 hospitals from 30 provinces, cities and autonomous regions in China. Data of the new born babies including intra-uterine death and stillbirth from 28 weeks of gestation to a period of 7 days after birth were collected between 1988 and 1992.
Results: There were 3,246,408 babies monitored, among which 382 cases of anophthalmos and microphthalmos were found. The average prevalence rate was 1.18/10,000 in China. The decreasing tendency of prevalence rate was shown during the period (chi(2) = 7.381, P < 0.01). The average prevalence rate in the rural area was significantly higher than that in the urban area, and the female cases were higher than that of male cases. The prevalence rates among various regions varied from 0.21 to 2.29/10,000 with the highest in Gansu province and lowest in Tianjin city. 87.7% of the cases with anophthalmos and microphthalmos were associated with other congenital malformations (multiple malformations). The associated malformations were mostly facial (including ear, neck, etc.) followed by skeletomuscular system and central nervous system. 8.1% of cases were diagnosed as syndromes, among which trisomy 21 was the most common condition.
Conclusions: There were large variations in the prevalence rates of anophthalmos and microphthalmos in different parts in China. Careful analysis, particularly the chromosome analysis, should be performed to correctly diagnose the cases, especially for those with multiple malformations.