Mechanical Pupil Dilatation Using Oasis Ring versus Non-mechanical Device Pupil Dilatation for Phacoemulsification in Eyes with Narrow Pupil

Purpose: to compare using Oasis ring for mechanical dilatation of the pupil during phacoemulsification in cases of narrow pupil with non-mechanical dilatation.

Methods: this study included 80 eyes of 67 patients of cataract with narrow pupil divided into 2 groups each of them included 40 eyes. In one group, Oasis ring was used to achieve adequate pupillary dilatation while in the other group, non-mechanical methods as bi-manual stretching, visco-mydriasis and partial sphincrotomies were used. Both groups were compared regarding achieved pupil size, additional time for dilatation, intra-operative difficulties and post-operative pupil characters after one month. This study was conducted at Tanta University Hospital in Egypt.

Results: We found that the mean pupil size was 6.00±0.00 mm Oasis ring group while was 4.26±0.48 mm in the other group. Dilatation needed longer time with Oasis ring where it ranged from 83- 117 seconds. There was more liability for intra-operative difficulties as iris prolapse, minimal bleeding and iris trauma in the non-mechanical group. Post-operative pupil characters were rounded, central and reactive in the first group while oval pupil was found in 17.5% and minute tears in 12.5% of cases of non-mechanical group.

Conclusion: Oasis ring offered more pupil dilatation with less liability for intra-operative complications and preservation of pupil characters. It added more cost and time to achieve adequate pupil dilatation.