AIM: To study the changes of pupil diameter and its effects during phacoemulsification.

METHODS:Block design, prospective study. 60 cataract patients(60 eyes)were selected, which divided into two groups according to the age, young age group(group A, 20 eyes of 20 patients)and older age group(group B, 40 eyes of 40 patients). Two groups were all given compound tropicamide eye drops for fully mydriasis before operation, computer software to process images during operation, and according to the cornea amplification ratio measure pupil diameter during the operation phase: before the corneal tunnel incision(t1), after injection of sodium hyalurantae(t2), before artificial lens implantation(t3), at the end of the surgery(t4). Statistical analysis of data using SPSS18.0 software.

RESULTS: The pupil diameter measurements of t1-t4 were followed respectively: group A were 8.36±0.65, 8.97±0.50, 8.67±0.63, 8.72±0.96mm; group B were 7.73±0.58, 8.23±0.59, 7.89±0.16, 7.70±0.63mm. Overall comparisons between the two groups, the pupil diameter measurements had differences during the operation phase(F=26.696,P< 0.05). Comparisons between the two groups at different time points: the pupil diameter of t1-t4 in group A was larger than that in group B, with statistically differences(P<0.05). The pupil diameter of each groups had a tendency to change in different operation phrases, with no statistically differences(F=2.617,P>0.05). Comparisons in a group at different time points: the pupil diameter of t2 was larger than that in t1, with statistically differences(P>0.05), the pupil diameter of t3 and t4 were decreased in group B, with statistically differences(P<0.05).

CONCLUSION: Compound tropicamide eye drops are given for mydriasis before operation, young patients with cataract and senile patients with cataract can achieve the effect of surgery for mydriasis, the pupil stability of phacoemulsification in senile patients with cataract are lower than that in young patients with cataract.