Pupil Size and Postoperative Visual Function

Abstract

It is known that pupil size also plays an important role in the visual outcomes of the surgical procedure. The smaller pupil size may have some advantages in its superiority for image formation, such as an increasing depth of focus, a decrease in higher-order aberrations, and a decrease in light scatter, all of which may partly offset the deleterious effects of reduced luminance and diffraction. Modern cataract surgery using newer phacoemulsification techniques has shown no significant adverse effect on postoperative pupil size, which allows us to predict the postoperative pupil size and visual performance. However, a greater variability in pupil size even in elderly patients indicates the clinical significance of the individual assessment of pupil size in cataract surgery. The postoperative visual function is significantly affected by the preoperative pupil size, and thus we can predict, to some extent, the postoperative visual performance of cataract patients in a clinical setting, if we can accurately measure the preoperative pupil size. Pupil diameter should be assessed dynamically with the open-view type of binocular infrared pupillometer, offering high reproducibility, under natural-viewing conditions. Pupil size plays an essential role in postoperative visual performance, not only in monofocal IOL-implanted eyes but also premium IOL (multifocal IOL, toric IOL, and aspheric IOL)-implanted eyes. Accordingly, we should pay much attention to the preoperative pupil size in order to acquire excellent visual outcomes and subsequent patient satisfaction after cataract surgery.