Small pupils can increase the risk of complications during and after any surgical procedure, and should be documented on the referral notes. A pupil that fails to dilate can yield a poor capsulotomy, which makes cataract removal more difficult and might result in iris trauma, anterior capsular tear, posterior capsular rupture, vitreous loss, increased inflammation, irregular pupil shape and photophobia.

Inadequate dilation often is seen in patients with intraoperative floppy iris syndrome (IFIS), pseudoexfoliation syndrome, uveitis, posterior synechiae, trauma or previous intraocular surgery.¹ Take note that certain medications, such as Flomax (tamsulosin, Boehringer Ingelheim), increase the risk of IFIS. Hallmark signs of IFIS include limited preoperative pupil dilation, iris stromal billowing, iris prolapse and pupillary constriction during cataract surgery.

Multimedia

Using the Malyugin Ring to maintain good pupil dilation helps the surgeon avoid iris trauma, capsular tear/rupture and vitreous loss. Click here to view a video of how this procedure is performed.  Photo/video: John Sheppard, M.D.

There are several steps that can help minimize the risk of IFIS and ensure adequate dilation:

• Pharmaceuticals. Therapeutic agents with strong anti-cholinergic drops (atropine 1%), non-steriodal anti-inflammatory drops and preservative-free lidocaine with epinephrine used intracamerally can maximize dilation.
  
• Intraoperative techniques. Manual separation and stretching of the iris breaks the adhesions between the iris, the lens capsule and the cornea (synechiolysis).² Also, high-viscosity ophthalmic viscosurgical devices can help enlarge the pupil. Adjustments can be made to the flow settings during phaco to lower the risk of iris incarceration.
  
• Surgical devices. Pupil expansion devices, including iris hooks and the Malyugin Ring (MicroSurgical Technology), permit adequate views of intraocular structures. Currently, there are several pupil-expanding devices on the market. This month’s Surgical Minute video will illustrate the use of the Malyugin Ring.
  

The Malyugin Ring is a useful tool for phacoemulsification surgery. It’s a one-piece design that exhibits a square shape and four equidistantly located circular loops, which include a gap to accommodate the iris tissue. The device catches and holds the pupillary margin steady, maximizes pupil dilation with eight touch points, is easy to insert and remove, protects the iris sphincter during surgery and allows the pupil to return to its normal shape, size and function after the operation.³

In both of our practices, surgeons prefer the Malyugin Ring to iris hooks because of easier insertion and removal, maximal pupil dilation (up to 7mm), fewer incisions (iris hooks require four additional paracenteses spaced 90° apart) and a lower risk of capsular tear. 

1. Loden JC, Gayton JL, Snyder ME, et al. Cataract surgery in an eye with a small pupil. Cataract Refract Surg Today. May 2012. Available at: http://bmctoday.net/crstoday/pdfs/crst0512_phacopearls.pdf. Accessed November 9, 2012.
2. Malyugin B. Pupil issues in cataract surgery. Cataract Refract Surg Today. March 2012. Available at: http://bmctoday.net/crstodayeurope/pdfs/0312CRSTEuro_Malyugin_Fundamentals.pdf. Accessed November 9, 2012.
3. MicroSurgical Technology. Products: Malyugin Ring. Available at: www.microsurgical.com/our-products/malyugin-ring. Accessed November 9, 2012.