Optometric Management

therapeutic insights
Plugging the Problem
How-to guides for the leading punctum plugs
By Stuart A. Gindoff, O.D., M.B.A., F.A.A.O., Sarasota, Fla.

In the field of punctal occlusion, the introduction of the Herrick plug was a sterling achievement and innovation. Although we still had to consider punctum size and therefore stock various inventory sizes, the plug was easy to insert.

In this article, I'll cover the basics when it comes to inserting the Herrick plug, as well as a later innovation, the SmartPlug.


	Fig. 1: Place the Herrick plug's stylet near the superior punctum in a vertical position.

	Fig. 2: Rotate the top of the Herrick plug's stylet laterally

You can insert Herrick plugs using your slit lamp or a loupe, which I think is easier. Based on the punctum size, select the appropriate Herrick silicone plug shaft size (0.3 mm, 0.5 mm, and 0.7 mm). Each plug has what's referred to as a collapsible bell that stabilizes the silicone plug in the canaliculus.

Herrick plugs are packaged two to a sterile pack that contains the medical-grade silicone plug atop a flexible metal stylet, which is attached to a sliding foam holder. Carefully pull the two foam holders apart to separate them. The foam holder can slide down the stylet for ease of use. Lay the patient back in the chair and anesthetize the cornea with proparacaine. The proparacaine reduces the blink reflex, making plug installation easier.

Hold the foam holder like a pencil and have the patient gaze away from the punctum. With the fingers of your nondominant hand, gently tug the lid to slightly straighten the canaliculus and evert the lid margin. Lacrimedics recommends placing the stylet near the superior punctum in a vertical position and guiding the plug into the vertical canaliculus until the collapsible bell rests at the lid margin (Fig. 1). Although not usually required, you may find punctal dilation necessary to get the point of the Herrick plug started into the punctum.

Rotate the top of the stylet laterally until it's nearly parallel with the lid margin (Fig. 2). This straightens the angle between the vertical and horizontal canaliculus and prepares the pathway for insertion. Advance the plug (toward the nose) 2 mm to 3 mm into the horizontal canaliculus.

As the large end passes the punctum, the collapsible bell will fold inward. Considerable pressure is sometimes needed to push the bell through the punctal orifice. Once beyond the punctum, the bell will reopen and regain its original shape. Withdraw the stylet slowly from the punctum, being careful that the metal stylet does not hit the surface of the eye. If you note that the plug is pulling out with the stylet, gently push the plug back in and pull the stylet to the horizontal position and slowly remove again until the plug releases from the stylet.

Inspect the stylet to confirm that the plug has been released. The force of the blink and the direction of tear flow can cause the plug to migrate further into the horizontal canaliculus, where it lodges lateral to the common canaliculus.

Medennium Inc.'s SmartPlug is designed to soften with body heat from a 0.3-mm diameter by 9-mm length shaft of polymer into a 1 by 2-mm gelatinous cavity filling mass. Made of an innovative thermosensitive, hydrophobic acrylic polymer, SmartPlug morphs upon insertion into the punctum conforming to the shape and size of the canaliculus for a precise, comfortable fit.

If you need to remove the SmartPlug, irrigate the canaliculus with warm water. Medennium reports that in a randomized, three-month open label study of 120 patients (240 eyes) who had a traditional silicone plug properly inserted into one punctum and a SmartPlug in the other, 35% of the silicone plugs had extruded, requiring replacement, while no patient lost a SmartPlug.

► Put your loupe on and adjust your light to sufficiently illuminate the punctum.

► The plugs are packaged in a plastic case containing a plug holder made of a soft plastic. Gently pull the triangular piece of plastic off, leaving the plugs exposed in a narrow channel.


	Fig. 3: Using a few drops of cool BSS or rinsing will ease insertion of the SmartPlug.

	Fig. 4: The SmartPlug softens in about 20 seconds.

We've noticed that patients in their 70s and 80s don't seem to have enough lid temperature to allow the plug to melt in the canaliculus. With older patients having flaccid lids, consider applying a warm wash cloth or a warmed cotton swab over the eye and punctal opening for 60-90 seconds.

With the special grooved forceps supplied by Medennium, gently but firmly grasp the end of the exposed plug. When you first start, you'll likely break a few plugs; they're a bit brittle, especially when cold. Put a few drops of cool BSS or saline on the plug so that the thermodynamic properties of the SmartPlug will work when it gets into the "warmer" patient's punctum. Rinsing also serves as a mild lubricant, allowing for a smoother insertion.

An anesthetic may not be necessary unless you have a squeamish or highly sensitive patient. You might, however, instill a broad spectrum antibiotic immediately before and again after the procedure.

Have your patient look in the direction of the eye you are occluding. (e.g., For the right eye, have the patient look to the right). You'll want to insert, gently angle the 9 mm shaft from vertical towards the horizontal and then slide the SmartPlug about 6 mm or 7 mm into the punctum and proximal canaliculus. As the plug softens (usually within 20 seconds), it slowly slides into the punctal opening.

If, after about 30 seconds, the end of the plug has not disappeared, it's okay to gently tap or further advance the SmartPlug into the punctum. Once it's gone from your view, again instill the broad spectrum antibiotic and repeat the process for the other eye.

Now for billing. Here are some suggested ways to charge for your services regarding punctal occlusion:

► Comprehensive Eye Exam provides the diagnosis of keratoconjunctivitis sicca (KCS) and usually superficial punctuate keratitis. You might also bill for Schirmer's Test or other dry eye related tests. Don't forget that KCS can cause fluctuating sight-related complaints!

► You might decide to perform a collagen trial test before performing a more permanent procedure. If you do, depending on the complexity of the case, consider charging for a Level 2 or Level 3 established patient visit to re-evaluate and confirm the necessity of performing the procedure. Make sure that you review, and annotate your record that you reviewed the patient's current systemic health and medication usage.

Charge for the insertion of the collagen plugs. You can only bill for the procedure of occluding the punctum, not for the plugs themselves. The upper or lower is billed at full price and the other is billed at 50%.

► After 10 days, charge another Level 2 or Level 3, established patient visit because you're spending time reviewing the progress that the patient had with the collagen trials by history. You might also again instill sodium fluorescein, Rose Bengal, or lissamine green to note the presence again of KCS.

If the patient had a positive collagen test, that is, they felt better for a day to perhaps five days and then the dry eye symptoms returned, you'll now charge for the insertion of the permanent plugs. It is suggested that you place one plug in each lower punctum at this visit. Again, charge full price for one punctum and 50% for the second eye treatment.

► After at least 10 days but not more than three weeks, schedule the patient to review symptoms and eye surface health. Evaluate the tear meniscus, inquire as to whether or not the patient's vision fluctuates, and stain with fluorescein and lissamine green. If the patient still has symptoms of dryness, insert a collagen plug in the upper puncta and again charge for plug insertion. Schedule the patient for two weeks to evaluate health and symptoms.

► If the patient returns with improved symptoms the first week and then dryness the second week, proceed with insertion of permanent plugs in the upper puncta and charge for the insertion of two plugs.

Dr. Christensen has a partnership practice in Midwest City, Okla. He's a diplomate in the Cornea and Contact Lens Section of the American Academy of Optometry. He's also a member of National Academies of Practice.

Dr. Gindoff is an adjunct associate clinical professor of optometry at Nova Southeastern University College of Optometry and an adjunct assistant professor of ophthalmology at the University of South Florida College of Medicine. He is also in clinical practice at the Center for Sight in Sarasota, Fla. He earned an M.B.A. with highest honors in 1998 from the University of Sarasota.