AIM:To observe the clinical effect of phacoemul-sification and intraocular lens on patients with angle-closure glaucoma at preclinical or presymptomatic stage.·METHODS:Sixty-six patients (66 eyes) with acute angle-closure glaucoma at preclinical or presymptomatic stage were chosen and randomly divided into three groups,with 22 eyes in each group.Group A received laser peripheral iridotomy.Group B received phacoemulsifi-cation and intraocular lens.Group C received phacoe-mulsification and intraocular lens combined with peripheral iridotomy.The changes of intraocular pressure,anterior chamber angle,corrected vision and anterior chamber depth were examined during the 11.72±0.96 months follow-up.·RESULTS:The results in the final follow-up after operation were as follows:the anterior chamber angle in group A,group B and group C widened significantly(P<0.05),the difference in the gonioscopy grading of the anterior chamber angle among the three groups was not statistically significant.The anterior chamber depth in Group A did not change significantly,the anterior chamber depth significantly increased in group B and group C(P<0.05),the anterior chamber depth in group A was lower than that in group B and group C,and the difference was statistically significant(P<0.05),the difference between group B and group C was not statistically significant.The intraocular pressure in the three groups did not change significantly,the variance in the intraocular pressure among the three groups was not statistically significant.The sensitivity of dark room provocative test in group A did not change significantly,the sensitivity of dark room provocative test in group B and group C significantly decreased(P<0.05),the difference among the three groups was not statistically significant.The corrected vision in group A did not change significantly,the corrected vision in group B and group C improved significantly(P<0.05).·CONCLUSION:Phacoemulsification and intraocular lens is superior to laser peripheral iridotomy on the aspects of widening the anterior chamber angle,reducing potentialy the sensitivity of dark room provocative test and improving the corrected vision.It is not necessary to combine peripheral iridotomy with phacoemulsification and intraocular lens.