Dry Eye Dx and Tx
Choosing Punctal Plugs
One common question practitioners ask when I lecture on dry eye management is, Which punctal occluder should I use on my dry eye patients? I usually weigh three primary factors when selecting punctal plugs for any given patient: lid configuration, ease of removal and cost.
My answer assumes that the patient has undergone a thorough dry eye workup revealing some tear production, but not enough to adequately protect the ocular surface. It also assumes that the patient has reported a definite benefit from temporary occlusion with dissolvable implants.
Choosing the Right Plug
Lid or punctal configuration is probably the most important factor. I often find it helpful to evaluate the profile of the eyelids from the lateral aspect, using low magnification and swinging the observation system to the side. If the lid/puncta are relatively vertical (not rolled in) so that the puncta are in apposition to the conjunctival surface, I opt for EagleVision plugs such as the Super Eagle. A number of different variants of this design are available.
I personally prefer Odyssey Medical's Parasol. As the name suggests, the nose is configured like an umbrella, so it collapses during insertion but then expands back to its original shape after it's within the ampulla of the puncta. This design seems to have fewer issues with falling out spontaneously, and Odyssey replaces any plug that falls out within 30 days of implantation at no charge. The company has redesigned the plugs with a flat dome; even if they rub slightly on the conjunctiva, they're better tolerated than plugs with a higher profile dome.
One benefit of all domed designs is ease of removal if, for some reason, it becomes necessary to explant the plug.
When patients present with puncta that are in frank apposition to the globe, I prefer an intracanalicular plug. Three choices are available. The Herrick plugs (Lacrimedics, Inc.) are now fabricated in an opaque material, so it's very easy to transilluminate the lid and see if they're still in place. I find Herrick plugs easy to insert, and there's very little problem with them falling out. But if you need to remove a Herrick plug, the procedure can be difficult for doctor and patient alike. In some cases, we've simply been unable to irrigate them out of the lacrimal drainage system.
The SmartPlug (Medennium, Inc.) is a 9mm acrylic rod before placement into the undilated punctum. Once you insert a portion of the rod inside the punctum, body temperature causes the rod to shrink in length and expand in width to form a soft, gel-like plug. SmartPlugs aren't difficult to insert, but they are fragile and easily broken, and some practitioners find that the packaging system isn't very doctor friendly. SmartPlugs require a certain amount of body heat to make the polymer shrink, and in older individuals it may be necessary to hold a warm compress on the eyelid to encourage shrinkage. I find them easier to remove than the Herrick plug; simply irrigate with warm saline. Unfortunately, the literature reports increased incidence of canaliculitis with the SmartPlug.
The Oasis Medical Form Fit plug has a more user-friendlier, pre-loaded inserter packaging system. When dry, the plug is 3mm long and 0.3mm wide, but its volume expands nearly 20 times when hydrated by the tears. Similar to the SmartPlug, the Form Fit is rather easy to remove with saline irrigation.
Using Punctal Plugs Profitably
Cost is unfortunately a real factor in punctal plug implantation. For instance, Medicare pays providers for the procedure, but not for the plug itself; we are reimbursed the same amount whether the plug costs us $15 or $50. Plugs are available in bulk at significantly reduced prices; you may want to keep this in mind when deciding which plugs to incorporate into your practice.
Dr. Townsend is in private practice in Canyon, Texas, and is a consultant at the Amarillo VA Medical Center. E-mail him at email@example.com.
For references, please visit www.clspectrum.com/references.asp and click on document #136.