Comparison of various pupil dilatation methods for phacoemulsification in eyes with a small pupil secondary to pseudoexfoliation

Purpose: To compare 4 methods for intraoperative pupil dilatation in eyes with pseudoexfoliation syndrome and insufficient pupil size during phacoemulsification. Design: Prospective, randomized, comparative, interventional case series. Participants: Forty eyes of 40 patients with pseudoexfoliation and maximally dilated pupil size smaller than 3.5 mm. Intervention: Mechanical pupil dilatation with iris-retractor hooks (group I), polymethyl methacrylate (PMMA) pupil dilator-ring (Morcher, Stuttgart, Germany) (group II), Beehler pupil dilator (group III), and bimanual stretching (group IV). Main Outcome Measures: Performance (pupil size achieved), complications, and added surgical time. Results: The mean pupil sizes achieved with the PMMA pupil-dilator ring, Beehler pupil dilator, and bimanual stretching were 5.9+/-0.6 mm, 5.5+/-0.8 mm, and 4.9+/-0.7 mm, respectively. A square-shaped pupil was achieved with iris-retractor hooks, and the mean size of the largest circle that can fit in this square was 5.6+/-0.6 mm. There were no statistically significant differences in the postdilatation pupil sizes between the 4 study groups (P>0.05). Apart from self-limited intraoperative hemorrhage from pupil margin, iris sphincter rupture was the only observed complication related to mechanical pupil dilatation. This occurred in 4 eyes in groups I and III, 3 eyes in group IV, and 1 eye in group II (P>0.05). The mean added surgical time for placement of iris-retractor hooks and for implantation of a PMMA pupil-dilator ring was 297+/-51 and 176+/-54 seconds, respectively. The additional time required for pupil dilatation with the Beehler pupil dilator and bimanual stretching was 65+/-8 and 55+/-10 seconds, respectively. The time needed for pupil dilatation in groups I and II is significantly longer than that in groups III and IV (P<0.001). Conclusions: All 4 methods used in this study were effective procedures for the mechanical dilatation of small pupils secondary to pseudoexfoliation syndrome. Iris-retractor hooks and the PMMA pupil-dilator ring are the most time-consuming techniques but have the advantage of a stable pupil size throughout the surgery. The PMMA pupil-dilator ring causes the least iris trauma. The Beehler pupil dilator and bimanual stretching technique were the least time-consuming methods for mechanical pupil dilatation. (C) 2004 by the American Academy of Ophthalmology.