The statistical analysis of the incidence and risk factors of the pupillary membrane formation was made on a series of patients with extracapsular cataract extraction (ECCE) or phacoemusification (Phaco) with domestic posterior chamber intraocular lens (PC IOL) implantation and domestic viscoelastic material application from 1992 to 1997.The results indicated that the total incidence of pupillary membrane was 11.8% (81/684 eyes) in the senile cataract group. The incidence of pupillary membrane was respectively 21.7%

19% and 31.8% in the groups of patients with hypertension

diabetes and combined; it was 7% and 15.1% in the mature and immature cataract groups; and it was 11.8% and 12% in the ECCE and Phaco groups. In addition

the incidence of pupillary membrane was 28.3%

43.8% and 33.3% in the groups with traumatic cataract

congenital cataract

and cataract due to uveitis

respectively. The results of statistical analysis suggest that the incidence of pupillary membrane formation following cataract surgery with PC IOL implantation shows a significant increase in the patients with hypertension

diabetes with hypertension

immature cataract

traumatic

congenital compact and cataract due to uveitis.