Pupil dynamics after in-the-bag versus anterior and retropupillary iris-fixated intraocular lens implantation

An Intraocular Lens (IOL) fixated on the iris either anteriorly, as a phakic IOL, or posteriorly, as an aphakic IOL, can influence pupil motility. In this interventional case series study, we evaluated pupil size under different levels of illumination (scotopic = 0.04 lx, low-mesopic = 0.4 lx and high-mesopic = 4 lx) for anterior iris-claw IOL fixation for correcting myopia or hyperopia (IFPH), retropupillary iris-claw IOL fixation to correct aphakia or as treatment for late in-the-bag IOL dislocation/subluxation (IFRP), and capsular-fixation IOL in-the-bag implantation (IB). Pupil size was measured preoperatively for the IFPH- and IB-group as well as 6 months after surgery for all groups. We analyzed a total of 70 eyes: 22 eyes of 11 patients with phakic IOLs, 22 eyes of 20 patients in the IFRP group and 26 eyes of 13 patients in the IB group. Both IFPH and IB showed a smaller postoperative scotopic pupil size, compared with the preoperative values. When compared to postoperative values of IB and IFPH, IFRP showed a significantly smaller postoperative scotopic pupil size (IFPH: 5.89 ± 0.83 mm, IFRP: 4.37 ± 0.83 mm, IB: 5.34 ± 0.98 mm, p < 0.001) while no differences were seen at high-mesopic lighting. Neither of the surgical techniques seems to impair the constriction of the pupil.

Efficiency of Pupillary Stretching in Cataract Surgery

Purpose To assess the efficiency of pupillary stretching with iris hooks in poorly dilatable pupils during phacoemulsification. Methods Forty eyes with maximal preoperative mydriasis less than 4.5 mm (mean 3.9 mm S.D. 1.0) received bimanual pupillary stretching according to the technique of Miller and Keener (1994). Results Small pupils were mainly caused by long-term pilocarpine therapy (n=21), posterior synechia (n=11) or diabetic iridopathy (n=7). With multidirectional stretching, the pupil could be enlarged to mean 6.6 mm (S.D. 0.66), lasting throughout phacoemulsification. The effect of stretching was significantly greater in eyes with synechias, but no significant differences in post-operative pupil motility was observed between the three subgroups. Six eyes with pronounced postoperative inflammation responded well to antiinflammatory treatment. Conclusions Done with routine surgical instruments, bimanual pupillary stretching seems to be an easy, safe and effective procedure for enlarging small pupils by an average of 2.7 mm during phacoemulsification, especially in eyes with posterior synechias.