2020–2021 BCSC Basic and Clinical Science Course™
11 Lens and Cataract
Chapter 12: Preparing for Cataract Surgery in Special Situations
Compromised Visualization of the Lens
Operating through a small pupil may increase the risk of intraoperative complications. It is important to note the maximum pharmacologic pupil dilation in the preoperative evaluation. A small pupil that is minimally responsive to dilating agents may be widened intraoperatively. The pupil can be bimanually stretched with Kuglen or Lester hooks, the iris can be tethered with hooks (Fig 12-4), or pupil-expansion devices can be employed (Fig 12-5). Viscodilation with a high-viscosity OVD is another method for pupil enlargement. These maneuvers break posterior synechiae and release the pupillary sphincter. However, with excessive manipulation of the iris, the risk of postoperative inflammation increases. Also, because the iris tends to be flaccid and floppy after manual stretching and release, it is more likely to be damaged by the phaco tip.
Figure 12-4 A pupil that dilates insufficiently to allow access to the lens may be widened with iris hooks. In this case, 4 hooks are placed to expose the lens for surgery.
(Courtesy of Lisa Rosenberg, MD.)
Figure 12-5 A Malyugin ring is positioned at the pupillary margin circumferentially.
(Courtesy of Steven Vold, MD.)
To enlarge a small pupil resulting from IFIS, most surgeons prefer to use pupilexpansion devices because unless the pupil is held open mechanically, progressive miosis of the floppy iris tends to occur as the surgery proceeds (Video 12-1). IFIS is a common cause of small pupils; as discussed in detail in Chapter 10, planned adjustments can be considered.
Malyugin ring insertion. Courtesy of Boris Malyugin, MD, PhD.
Go to www.aao.org/bcscvideo_section11
to access all videos in Section 11.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.