EyeWorld Asia-Pacific September 2013 Issue

9 September 2013 EWAP FEAturE Big lessons for small pupil cataract surgery by Maxine Lipner EyeWorld Senior Contributing Writer AT A GLANCE • Use of the more tissue-friendly Malyugin ring is one mechanical way surgeons can contend with small pupils in traditional and IFIS cases. • New study results show that use of intracameral phenylephrine 1.5% is effective for both preventing and reversing IFIS and accompanying pupil constriction. • Off-label use of the femtosecond laser is gaining ground in small pupil cataract cases, together with the Malyugin ring and dilating solutions. Getting educated on the latest approaches F or patients who have small pupils or who develop them during cataract removal, current innovations are making the surgery as uneventful as possible. Solutions range from use of Malyugin rings (Microsurgical Technology, MST, Redmond, Wash., USA) and other pupil-expansion devices to pharmacological phenylephrine dilation to femtosecond laser use and more. Having a small pupil to contend with during cataract surgery is no minor issue, according to Boris E. Malyugin, MD , deputy director general, S.N. Fyodorov Eye Microsurgery Complex, Moscow, Russia. “The small pupil, apart from the obviously increased chances of iris damage, gives poor visualization and restricts surgeon’s access to the lens,” Dr. Malyugin said. “And there is a tendency to create a smaller capsulorhexis.” This can cause greater propensity toward the risk of anterior capsule damage with the ultrasonic needle, the chopper, or another instrument used during the phacoemulsification process. It can result in more difficult evacuation of the cortical material because of visualization issues, he explained, adding that it can also lead to difficulty in ensuring the lens is correctly implanted and potentially enhances the chance of capsular phimosis postoperatively. The Malyugin ring sounds the first bell To make visualization easier, Dr. Malyugin pioneered his now oft-used ring several years ago. He felt that the need was unfulfilled at that point. “It was a demand (from) some unmet expectations because even though using pharmacological agents is very effective, in many cases this approach is not sufficient,” Dr. Malyugin said. Likewise, prior mechanical approaches were less than optimal. “Cutting the iris is quite a well- known and well-established technique,” Dr. Malyugin said. “I was concerned with bleeding because there is a high chance of this when you are cutting the highly vascularized iris tissue.” He wanted an option that was potentially more forgiving to tissue than traditional stretching methods. With the Malyugin ring, the expanded pupil is round— despite the fact that the device has a square edge. “In spite of the device being square, the pupil is round because the corners of the device are connected with the thread that supports the iris and catches it in the middle of the side portion of the ring,” Dr. Malyugin said. This method of expansion is less traumatizing to the tissue than iris hooks, which result in a square stretched pupil, with a perimeter that is longer in places than with the Malyugin ring. “With the Malyugin ring the iris tissue is not overstretched,” Dr. Malyugin said. The ring comes in two diameters—6.25 and 7 mm. The larger ring was created especially for intraoperative floppy iris (IFIS) cases, he noted. “The pupil can actually be bigger at the beginning of an IFIS case, then during the procedure it starts to constrict,” Dr. Malyugin said. If the physician suspects the patient may develop IFIS and attempts to prophylactically insert the ring before pupil constriction begins, the bigger ring is needed, he explained. William W. Culbertson, MD , professor of ophthalmology; director of cornea and refractive surgery services; and the Lou Higgins Chair of Ophthalmology, Bascom Palmer Eye Institute, Miami, Fla., USA, finds the Reversion of IFIS. Patient under treatment with tamsulosin who forgot to mention the intake of the drug. IFIS developed during phacoemulsification. Note the miosis and prolapsed through the paracentesis and main incision. Intracameral mydriatic dilation. Pupil size at the beginning of surgery. No dilating drops were instilled. A decision was made to inject 0.6 cc of intracameral phenylephrine 1.5%, which caused the pupil to dilate back to its preoperative level, restored iris rigidity, and stopped the tendency of the iris to prolapse. This is a view of the pupil diameter at the end of the case, which reached its preoperative level. Pupil size after intracameral injection of 0.3 ml of lidocaine 2%; it remained stable throughout surgery. This is an image of the pupil size at the end of the case. Source (all): Ramon Lorente, MD continued on page 10