By Robert M. Kershner, MD, MS, FACS
Eye Laser Consulting
Boston, MA 02111
It has been less than three decades since cataract surgery was performed under a balanced salt solution infusion, or even worse, under a bolus of air. The introduction of Ophthalmic ViscoSurgical Devices (OVDs), formally known as the viscoelastics, have unquestionably made our surgery more predictable, quicker and less traumatic to the eye and the patient. What has been the single greatest advance in this technology is that it has allowed us as eye surgeons to tackle surgical cases today that we would have never attempted a few short years ago. There are literally dozens of OVDs on the market today, most of them grandchildren of the original 1% hyaluronate solution (Pfizer Ophthalmics, Inc., NY, formally Pharmacia Corp.) But today's products are much more dynamic and the selection is broader, there are dispersives , cohesives (such as Healon and Healon GV) and the newest entry into our armamentarium in the fight against the challenging cataract case-2.3% hyaluronate or the viscoadaptive , Healon5 (Pfizer Ophthalmics, Inc. NY).
With this variety of surgical tools at our disposal, cataract surgeons should fear no case, right? Well that is almost true, with a single exception-if the surgeon uses the tool and fails to remove it at the end of the case, the postoperative pressure surprise may be haunting him in follow-up.
The following case illustrates how best to prevent the postoperative pressure surprise when using the new OVDs.
A 78 year-old woman with longstanding uveitis due to previous Chron's disease, in remission, presents with a dense cataract and a scarred irregular pupil (Figure1). This pupil (less than 3.0mm) can impede visualization and make capsulorrhexis, phacoemulsification and instrumentation into the eye more difficult with its attendant risk of iris sphincter tear, bleeding, iris emulsification, ruptured posterior capsule and loss of the nucleus into the vitreous. Using eye drops preoperatively is fruitless in dilating the bound-down and scarred pupil. Surgeons can attempt mechanical methods with devices to enlarge the pupil such as a blade, needle or scissors to make multiple iris sphincter tears, retractors, mechanical stretching devices or pupillary retainers 1 . I have found that the use of the viscoadaptive Healon5, can effectively dilate the pupil and allow the procedure to be performed without compromise.
At the start of the case, following clear corneal incision placement, a small bolus of Healon5 was placed into the center of the pupil. Using directed injection the synechiae were lysed and the pupil margin pushed out of the way. An uneventful capsulorrhexis, phaco and implantation of the new anterior modified prolate intraocular lens, Tecnis Z-9000 Pfizer Ophthalmics, Inc NY) were completed without difficulty.
Many surgeons would be fearful of using a dense OVD in a compromised eye with the high risk of a postoperative pressure rise. But it didn't happen. As with all good surgeons, what I put into the eye, I made sure to remove. The secret in this case is to never place a device where you can't get at it to get it out. By taking advantage of a characteristic of a viscoadaptive, namely, it will stay put where you place it, careful placement of the OVD only onto the center of the pupil , allowed me to directly visualize its removal following lens implantation.
Less is more, if used sparingly, and only where it is needed, the OVD can be effectively and completely removed at the end of the case. If you take the visco out of the OVD, the postoperative pressure surprise doesn't have to be there to remind you that you didn't.
1. Kershner, RM Management of the Small Pupil in Clear Corneal Cataract Surgery Journal of Cataract and Refractive Surger y , 2002; 28:1826-1831.
Dr. Kershner is Clinical Professor of Ophthalmology and Neuroscience and Director of Eye Laser Consulting in Boston, Massachussetts.
Small, scarred and irregular pupil prior to cataract surgery-Kershner