METHODS: Totally 44 cataract patients with small pupil were treated in our hospital from January 2016 to October 2017 were randomly divided into the control group(22 cases, 31 eyes)and the observation group(22 cases, 30 eyes). The patients in control group was treated by conventional phacoemulsification surgery, within surgery the small pupils were dilated by cleavage and lens position hook; the patients in observation group use OASIS iris expander within surgery. The best corrected visual acuity(BCVA), corneal endothelial cell counts, pupil size, intraocular pressure(IOP)of two groups before and after surgery were compared and analyzed, and the application effect of built-in type OASIS iris expander was evaluated.

RESULTS: At 1mo after operation, the BCVA of the two groups were significantly improved, and the BCVA of the observation group(0.09±0.04)was significantly better than that of the control group(0.20±0.03), the difference was statistically significant(P<0.05). At 1mo after operation, the corneal endothelial cell counts of the two groups were significantly decreased, but the corneal endothelial cell counts of the observation group(2455.77±52.98/mm²)were significantly higher than those of the control group(2298.94±49.12/mm²), the difference was statistically significant(P<0.05). At 1mo after operation, the pupil diameter of the two groups was enlarged(P<0.05), and the pupil diameter of the observation group(3.52±1.14mm)was larger than that of the control group(3.15±1.02mm, P>0.05). At 6mo after operation, the pupil diameter of the two groups was significantly enlarged(P<0.05), but there was no significant difference in the pupil diameter between the two groups(P>0.05). At 1mo after operation, intraocular pressure in both groups was lower than that before operation(P<0.05), and the intraocular pressure in observation group(13.40±1.73mmHg)was lower than that in control group(13.93±1.98mmHg, P>0.05). At 6mo after operation, intraocular pressure in both groups was lower than that before operation and 1mo after operation(P<0.05), but there was no significant difference in intraocular pressure between the two groups at 6mo after operation(P>0.05).

CONCLUSION: The OASIS built-in iris dilator can improve the best corrected visual acuity, reduce intraocular pressure and expand pupil diameter in small pupil phacoemulsification.